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Patel N, Lin P, Stack M, Conrad JM, Fakioglu H, Abomoelak B, Horvath K, Mehta DI. Oral Care Associated With Less Microaspiration in Ventilated Cardiac Patients. JPGN REPORTS 2023; 4:e290. [PMID: 37181916 PMCID: PMC10174743 DOI: 10.1097/pg9.0000000000000290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 09/08/2022] [Indexed: 05/16/2023]
Abstract
Aspiration is common in mechanically ventilated patients and may predispose patients to aspiration pneumonia, chemical pneumonitis, and chronic lung damage. Pepsin A is a specific marker of gastric fluid aspiration and is often detected in ventilated pediatric patients. We investigated the effect of oral care and throat suctioning in the detection of pepsin A in tracheal aspirates (TAs) up to 4 hours after these procedures. Methods Twelve pediatric patients between age 2 weeks to 14 years who underwent intubation for cardiac surgery were enrolled in this study. Six of the 12 patients were consented before their surgery with initial specimen collected at the time of intubation and last one shortly before extubation (intubation duration < 24 hours). The remaining 6 patients were consented after cardiac surgery. All specimens were collected per routine care per respiratory therapy protocol and shortly before extubation (intubation duration > 24 hours). Tracheal fluid aspirates were collected every 4 to 12 hours in the ventilated patients. Enzymatic assay for gastric pepsin A and protein determination were performed. The time of oral care and throat suctioning within 4 hours prior was recorded prospectively. Results A total of 342 TA specimens were obtained from the 12 intubated pediatric patients during their course of hospitalization; 287 (83.9%) showed detectable total pepsin (pepsin A and C) enzyme activity (> 6 ng/mL) and 176 (51.5%) samples had detectable pepsin A enzyme levels (>6 ng/mL of pepsin A). Only 29 samples of 76 samples (38.2%) had evidence of microaspiration after receiving oral care, while 147 of 266 (55.3%) samples were pepsin A positive when no oral care was provided. Odds ratio is 0.50 (Cl 0.30-0.84), and the number needed to treat is 5.8 (Confidence interval 3.4-22.3). Testing air filters for pepsin was not beneficial. Conclusion Oral care is a highly effective measure to prevent microaspiration of gastric fluid in ventilated pediatric patients. The number needed to treat (5.8) suggests this is a very effective prevention strategy. Our study suggests that pepsin A is a useful and sensitive biomarker that allows identification of gastric aspiration.
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Affiliation(s)
- Nishant Patel
- From the Center for Digestive Health and Nutrition, Arnold Palmer Hospital for Children, Orlando, FL
| | - Philip Lin
- From the Center for Digestive Health and Nutrition, Arnold Palmer Hospital for Children, Orlando, FL
| | - Michael Stack
- Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - Janet M. Conrad
- Pediatric Gastroenterology and Translational Research Laboratory, Cardiology Arnold Palmer Hospital for Children, Orlando, FL
| | - Harun Fakioglu
- Department of Pediatric Cardiology Arnold Palmer Hospital for Children, Orlando, FL
| | - Bassam Abomoelak
- Pediatric Gastroenterology and Translational Research Laboratory, Cardiology Arnold Palmer Hospital for Children, Orlando, FL
| | - Karoly Horvath
- From the Center for Digestive Health and Nutrition, Arnold Palmer Hospital for Children, Orlando, FL
| | - Devendra I. Mehta
- From the Center for Digestive Health and Nutrition, Arnold Palmer Hospital for Children, Orlando, FL
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2
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Pepsin and the Lung—Exploring the Relationship between Micro-Aspiration and Respiratory Manifestations of Gastroesophageal Reflux Disease. J Pers Med 2022; 12:jpm12081296. [PMID: 36013245 PMCID: PMC9410290 DOI: 10.3390/jpm12081296] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 11/16/2022] Open
Abstract
Gastroesophageal reflux disease (GERD) is one of the most commonly encountered disorders in clinical practice nowadays, with an increasing burden on healthcare systems worldwide. GERD-related respiratory symptoms such as unexplained chronic cough, bronchial asthma or chronic obstructive pulmonary disease (COPD) with frequent exacerbations often pose diagnostic and therapeutic challenges and may require a multidisciplinary approach. Moreover, a potential role of GERD as a risk factor has been proposed for chronic rejection in patients who underwent lung transplantation. Pepsin has gained considerable attention from the scientific community in the last few years as a possible surrogate biomarker for GERD. The aim of this narrative review was to provide an overview of the potential utility of pepsin detection as a marker of micro-aspiration in various biological fluids retrieved from patients with suspected GERD-induced respiratory manifestations and in lung transplant patients with allograft dysfunction. Data on the subject remains highly contradictory, and while certain studies support its applicability in investigating atypical GERD manifestations, at the moment, it would be realistic to accept a modest utility at best. A major lack of consensus persists regarding topics such as the optimal timeframe for fluid collection and cut-off values. Further research is warranted in order to address these issues.
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3
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Kosutova P, Mikolka P. Aspiration syndromes and associated lung injury: incidence, pathophysiology and management. Physiol Res 2021. [DOI: 10.33549//physiolres.934767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Aspiration is a common condition affecting healthy or sick patients which could create an acute or chronic inflammatory reaction in the lungs. Aspiration syndromes could be categorized according to a content entering the respiratory system into bacterial aspiration pneumonia with the gastric or oropharyngeal bacteria entering, aspiration chemical pneumonitis with bacteria-freegastric acid aspiration, or aspiration of a foreign body which causes an acute pulmonary emergency. There are differences in the clinical presentation of volume-dependent aspirations (microaspiration and macroaspiration): the higher is the volume of aspiration, the greater is the injury to the patient and more serious are the health consequences (with 70 % mortality rate for hospitalized patients). Aspiration syndromes can affect both the airways and pulmonary parenchyma, leading to acute lung injury, increased hospitalization rate and worse outcomes in critically ill patients. Impaired alveolar-capillary permeability, oedema formation, neutrophilic inflammatory response and pulmonary surfactant inactivation lead to reduced lung compliance and loss of aerated lung tissue and give rise to hypoxemia and respiratory failure. This review discusses the effect of aspiration events on the pulmonary tissue. The main focus is to distinguish the differences between bacterial and chemical pneumonia, their clinical presentation and symptoms, risk factors of developing the changes, possibilities of diagnostics and management as well as prevention of aspirations. Because of a risk of serious lung damage after the aspiration, pathophysiology and processes leading to lung tissue injury are discussed in detail. Data sources represent a systematic literature search using relevant medical subject headings.
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4
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Cui Y, Cui Y. [Intraoperative Aspiration]. ZHONGGUO FEI AI ZA ZHI = CHINESE JOURNAL OF LUNG CANCER 2021; 23:393-401. [PMID: 32429641 PMCID: PMC7260386 DOI: 10.3779/j.issn.1009-3419.2020.101.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
术中误吸是外科手术中常见的肺部并发症,麻醉和体位是导致术中误吸的主要因素。近年来,围手术期肺保护已受到外科和麻醉医师的广泛关注,如何加速术后康复进程,减少相关并发症发生,显著改善患者预后已成为当前外科治疗的主要目标。本文将以术中误吸为重点,从解剖、病理生理、表现、诊断、处理和预防等方面展开综述。
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Affiliation(s)
- Yiyao Cui
- Department of Thoracic Surgery, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing 100050, China
| | - Yong Cui
- Department of Thoracic Surgery, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing 100050, China
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Kim SY, Mongey R, Wang P, Rothery S, Gaboriau DCA, Hind M, Griffiths M, Dean CH. The acid injury and repair (AIR) model: A novel ex-vivo tool to understand lung repair. Biomaterials 2020; 267:120480. [PMID: 33157373 DOI: 10.1016/j.biomaterials.2020.120480] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/11/2020] [Accepted: 10/18/2020] [Indexed: 12/22/2022]
Abstract
Research into mechanisms underlying lung injury and subsequent repair responses is currently of paramount importance. There is a paucity of models that bridge the gap between in vitro and in vivo research. Such intermediate models are critical for researchers to decipher the mechanisms that drive repair and to test potential new treatments for lung repair and regeneration. Here we report the establishment of a new tool, the Acid Injury and Repair (AIR) model, that will facilitate studies of lung tissue repair. In this model, injury is applied to a restricted area of a precision-cut lung slice using hydrochloric acid, a clinically relevant driver. The surrounding area remains uninjured, thus mimicking the heterogeneous pattern of injury frequently observed in lung diseases. We show that in response to injury, the percentage of progenitor cells (pro surfactant protein C, proSP-C and TM4SF1 positive) significantly increases in the injured region. Whereas in the uninjured area, the percentage of proSP-C/TM4SF1 cells remains unchanged but proliferating cells (Ki67 positive) increase. These effects are modified in the presence of inhibitors of proliferation (Cytochalasin D) and Wnt secretion (C59) demonstrating that the AIR model is an important new tool for research into lung disease pathogenesis and potential regenerative medicine strategies.
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Affiliation(s)
- Sally Yunsun Kim
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Róisín Mongey
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Peizhu Wang
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Stephen Rothery
- Facility for Imaging by Light Microscopy, NHLI, Faculty of Medicine, Imperial College London, London, UK
| | - David C A Gaboriau
- Facility for Imaging by Light Microscopy, NHLI, Faculty of Medicine, Imperial College London, London, UK
| | - Matthew Hind
- National Heart and Lung Institute, Imperial College London, London, UK; National Institute for Health Research (NIHR) Respiratory Biomedical Research Unit at the Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK
| | - Mark Griffiths
- National Heart and Lung Institute, Imperial College London, London, UK; Peri-Operative Medicine Department, St Bartholomew's Hospital, London, UK
| | - Charlotte H Dean
- National Heart and Lung Institute, Imperial College London, London, UK; MRC Harwell Institute, Harwell Campus, Oxfordshire, UK.
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Xiao Q, Wang Y, Sun L, Lu S, Li J, Chen Y, Wu Y. Immediate Prone Positioning After Massive Gastric Aspiration Reduces Lung Injury Possibly by Attenuating Interleukin-6-Mediated Lung-Tissue Inflammation in Pigs. Biol Res Nurs 2019; 22:64-74. [PMID: 31529988 DOI: 10.1177/1099800419875521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Gastric aspiration, which can cause acute, diffuse, inflammatory lung injury, is of particular concern in critically ill patients. This study aimed to determine the effects of immediate prone positioning on the degree of lung injury and inflammatory response induced by gastric aspiration. Following induction of gastric aspiration by injection of gastric fluid, 16 healthy pigs were randomized to one of two groups: supine position (SP) or prone position (PP). After ventilation and monitoring for 6 hr, all pigs were euthanized. The ratio of the partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FIO2) and the partial pressure of arterial carbon dioxide (PaCO2) were recorded during the 6-hr study period. Serum levels of interleukin (IL)-6 were measured every 2 hr, and the mean optical density (MOD) of IL-6 in lung tissues and lung-injury scores were measured at the end of the experiment. The PP group showed a significantly higher PaO2/FIO2 ratio, lower serum IL-6 concentration (p = .015), lower lung-injury scores (p = .012), and lower IL-6 concentration and MOD of IL-6 in lung tissue, especially in dorsal (p = .001, p = .021, respectively) and nondependent regions (p = .005, p = .035, respectively) than the SP group. There were no statistically significant differences in PaCO2 between the groups. Lung-injury severity was positively correlated with the IL-6 concentration and MOD of IL-6 in lung tissues (p < .05). These results suggest that immediate prone positioning alleviated the degree of aspiration-induced lung injury, possibly through mitigating IL-6-mediated lung inflammation.
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Affiliation(s)
- Qian Xiao
- School of Nursing, Capital Medical University, Beijing, China
| | - Yanling Wang
- School of Nursing, Capital Medical University, Beijing, China
| | - Liu Sun
- School of Nursing, Capital Medical University, Beijing, China
| | - Sai Lu
- College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Jia Li
- School of Nursing, Capital Medical University, Beijing, China
| | - Yun Chen
- School of Nursing, Capital Medical University, Beijing, China
| | - Ying Wu
- School of Nursing, Capital Medical University, Beijing, China
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7
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Presta MV, Bhavani SS, Abdelmalak BB. Nil per os guidelines: what is changing, what is not, and what should? Minerva Anestesiol 2018; 84:1413-1419. [DOI: 10.23736/s0375-9393.18.13042-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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8
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Ayala P, Vivar R, Montalva R, Olmos P, Meneses M, Borzone GR. Elastin degradation products in acute lung injury induced by gastric contents aspiration. Respir Res 2018; 19:165. [PMID: 30170599 PMCID: PMC6119254 DOI: 10.1186/s12931-018-0873-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/23/2018] [Indexed: 12/19/2022] Open
Abstract
Background Gastric contents aspiration is a high-risk condition for acute lung injury (ALI). Consequences range from subclinical pneumonitis to respiratory failure, depending on the volume of aspirate. A large increment in inflammatory cells, an important source of elastase, potentially capable of damaging lung tissue, has been described in experimental models of aspiration. We hypothesized that in early stages of aspiration-induced ALI, there is proteolytic degradation of elastin, preceding collagen deposition. Our aim was to evaluate whether after a single orotracheal instillation of gastric fluid, there is evidence of elastin degradation. Methods Anesthesized Sprague-Dawley rats received a single orotracheal instillation of gastric fluid and were euthanized 4, 12 and 24 h and at day 4 after instillation (n = 6/group). We used immunodetection of soluble elastin in lung tissue and BALF and correlated BALF levels of elastin degradation products with markers of ALI. We investigated possible factors involved in elastin degradation and evaluated whether a similar pattern of elastin degradation can be found in BALF samples of patients with interstitial lung diseases known to have aspirated. Non-parametric ANOVA (Kruskall-Wallis) and linear regression analysis were used. Results We found evidence of early proteolytic degradation of lung elastin. Elastin degradation products are detected both in lung tissue and BALF in the first 24 h and are significantly reduced at day 4. They correlate significantly with ALI markers, particularly PMN cell count, are independent of acidity and have a similar molecular weight as those obtained using pancreatic elastase. Evaluation of BALF from patients revealed the presence of elastin degradation products not present in controls that are similar to those found in BALF of rats treated with gastric fluid. Conclusions A single instillation of gastric fluid into the lungs induces early proteolytic degradation of elastin, in relation to the magnitude of alveolar-capillary barrier derangement. PMN-derived proteases released during ALI are mostly responsible for this damage. BALF from patients showed elastin degradation products similar to those found in rats treated with gastric fluid. Long-lasting effects on lung elastic properties could be expected under conditions of repeated instillations of gastric fluid in experimental animals or repeated aspiration events in humans.
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Affiliation(s)
- Pedro Ayala
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | - Raúl Vivar
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | - Rebeca Montalva
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | - Pablo Olmos
- Department of Diabetes and Nutrition, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Manuel Meneses
- Pathology Unit, Instituto Nacional del Tórax, Santiago, Chile
| | - Gisella R Borzone
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile.
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9
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Diep JK, Russo TA, Rao GG. Mechanism-Based Disease Progression Model Describing Host-Pathogen Interactions During the Pathogenesis of Acinetobacter baumannii Pneumonia. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2018; 7:507-516. [PMID: 29761668 PMCID: PMC6118322 DOI: 10.1002/psp4.12312] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/09/2018] [Indexed: 01/01/2023]
Abstract
The emergence of highly resistant bacteria is a serious threat to global public health. The host immune response is vital for clearing bacteria from the infected host; however, the current drug development paradigm does not take host‐pathogen interactions into consideration. Here, we used a systems‐based approach to develop a quantitative, mechanism‐based disease progression model to describe bacterial dynamics, host immune response, and lung injury in an immunocompetent rat pneumonia model. Previously, Long‐Evans rats were infected with Acinetobacter baumannii (A. baumannii) strain 307‐0294 at five different inocula and total lung bacteria, interleukin‐1beta (IL‐1β), tumor necrosis factor‐α (TNF‐α), cytokine‐induced neutrophil chemoattractant 1 (CINC‐1), neutrophil counts, and albumin were quantified. Model development was conducted in ADAPT5 version 5.0.54 using a pooled approach with maximum likelihood estimation; all data were co‐modeled. The final model characterized host‐pathogen interactions during the natural time course of bacterial pneumonia. Parameters were estimated with good precision. Our expandable model will integrate drug effects to aid in the design of optimized antibiotic regimens.
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Affiliation(s)
- John K Diep
- UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA.,University at Buffalo, State University of New York, Buffalo, New York, USA
| | - Thomas A Russo
- University at Buffalo, State University of New York, Buffalo, New York, USA.,Veterans Administration Western New York Healthcare System, Buffalo, New York, USA
| | - Gauri G Rao
- UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA.,University at Buffalo, State University of New York, Buffalo, New York, USA
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10
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Ayala P, Torres J, Vivar R, Meneses M, Olmos P, San Martin T, Borzone GR. Acute lung injury by gastric fluid instillation: activation of myofibroblast apoptosis during injury resolution. Respir Res 2018; 19:57. [PMID: 29631627 PMCID: PMC5891902 DOI: 10.1186/s12931-018-0763-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/23/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Gastric contents aspiration in humans has variable consequences depending on the volume of aspirate, ranging from subclinical pneumonitis to respiratory failure with up to 70% mortality. Several experimental approaches have been used to study this condition. In a model of single orotracheal instillation of gastric fluid we have shown that severe acute lung injury evolves from a pattern of diffuse alveolar damage to one of organizing pneumonia (OP), that later resolves leaving normal lung architecture. Little is known about mechanisms of injury resolution after a single aspiration that could be dysregulated with repetitive aspirations. We hypothesized that, in a similar way to cutaneous wound healing, apoptosis may participate in lung injury resolution by reducing the number of myofibroblasts and by affecting the balance between proteases and antiproteases. Our aim was to study activation of apoptosis as well as MMP-2/TIMP-2 balance in the sub-acute phase (4-14 days) of gastric fluid-induced lung injury. METHODS Anesthesized Sprague-Dawley rats received a single orotracheal instillation of gastric fluid and were euthanized 4, 7 and 14 days later (n = 6/group). In lung tissue we studied caspase-3 activation and its location by double immunofluorescence for cleaved caspase-3 or TUNEL and alpha-SMA. MMP-2/TIMP-2 balance was studied by zymography and Western blot. BALF levels of TGF-β1 were measured by ELISA. RESULTS An OP pattern with Masson bodies and granulomas was seen at days 4 and 7 that was no longer present at day 14. Cleaved caspase-3 increased at day 7 and was detected by immunofluorescence in Masson body-alpha-SMA-positive and -negative cells. TUNEL-positive cells at days 4 and 7 were located mainly in Masson bodies. Distribution of cleaved caspase-3 and TUNEL-positive cells at day 14 was similar to that in controls. At the peak of apoptosis (day 7), an imbalance between MMP-2 activity and TIMP-2 expression was produced by reduction in TIMP-2 expression. CONCLUSIONS Apoptosis is activated in Masson body-alpha-SMA-positive and -negative cells during the sub-acute phase of gastric fluid-induced lung injury. This mechanism likely contributes to OP resolution, by reducing myofibroblast number and new collagen production. In addition, pre-formed collagen degradation is favored by an associated MMP-2/TIMP-2 imbalance.
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Affiliation(s)
- Pedro Ayala
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | - Jorge Torres
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | - Raúl Vivar
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | - Manuel Meneses
- Pathology Unit, Instituto Nacional del Tórax, Santiago, Chile
| | - Pablo Olmos
- Department of Diabetes and Nutrition, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Tamara San Martin
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | - Gisella R Borzone
- Department of Respiratory Diseases and Medical Research Center, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile.
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11
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Hunt EB, Sullivan A, Galvin J, MacSharry J, Murphy DM. Gastric Aspiration and Its Role in Airway Inflammation. Open Respir Med J 2018; 12:1-10. [PMID: 29456774 PMCID: PMC5806178 DOI: 10.2174/1874306401812010001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/22/2017] [Accepted: 01/01/2018] [Indexed: 12/15/2022] Open
Abstract
Gastro-Oesophageal Reflux (GOR) has been associated with chronic airway diseases while the passage of foreign matter into airways and lungs through aspiration has the potential to initiate a wide spectrum of pulmonary disorders. The clinical syndrome resulting from such aspiration will depend both on the quantity and nature of the aspirate as well as the individual host response. Aspiration of gastric fluids may cause damage to airway epithelium, not only because acidity is toxic to bronchial epithelial cells but also due to the effect of digestive enzymes such as pepsin and bile salts. Experimental models have shown that direct instillation of these factors to airways epithelia cause damage with a consequential inflammatory response. The pathophysiology of these responses is gradually being dissected, with better understanding of acute gastric aspiration injury, a major cause of acute lung injury, providing opportunities for therapeutic intervention and potentially, ultimately, improved understanding of the chronic airway response to aspiration. Ultimately, clarification of the inflammatory pathways which are related to micro-aspiration via pepsin and bile acid salts may eventually progress to pharmacological intervention and surgical studies to assess the clinical benefits of such therapies in driving symptom improvement or reducing disease progression.
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Affiliation(s)
- E B Hunt
- The Department of Respiratory Medicine, Cork University Hospital, Cork, Ireland.,The Health Research Board Clinical Research Facility, University College Cork, Cork, Ireland
| | - A Sullivan
- The APC Microbiome Institute, Schools of Medicine and Microbiology, University College Cork, Ireland
| | - J Galvin
- The APC Microbiome Institute, Schools of Medicine and Microbiology, University College Cork, Ireland
| | - J MacSharry
- The APC Microbiome Institute, Schools of Medicine and Microbiology, University College Cork, Ireland
| | - D M Murphy
- The Department of Respiratory Medicine, Cork University Hospital, Cork, Ireland.,The Health Research Board Clinical Research Facility, University College Cork, Cork, Ireland
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Toba H, Tomankova T, Wang Y, Bai X, Cho HR, Guan Z, Adeyi OA, Tian F, Keshavjee S, Liu M. XB130 deficiency enhances lipopolysaccharide-induced septic response and acute lung injury. Oncotarget 2018; 7:25420-31. [PMID: 27029000 PMCID: PMC5041914 DOI: 10.18632/oncotarget.8326] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 03/08/2016] [Indexed: 01/03/2023] Open
Abstract
XB130 is a novel oncoprotein that promotes cancer cell survival, proliferation and migration. Its physiological function in vivo is largely unknown. The objective of this study was to determine the role of XB130 in lipopolysaccharide (LPS)-induced septic responses and acute lung injury. LPS was intraperitoneally administrated to Xb130 knockout (KO) and wild type (WT) mice. There was a significant weight loss in KO mice at Day 2 and significantly higher disease scores during the 7 days of observation. The levels of tumor necrosis factor-alpha, monocyte chemoattractant protein-1, interleukin-6 and interleukin-10 in the serum were significantly higher in KO mice at Day 2. In KO mice there were a significantly higher lung injury score, higher wet/dry lung weight ratio, more apoptotic cells and less proliferative cells in the lung. Macrophage infiltration was significantly elevated in the lung of KO mice. There was significantly increased number of p-GSK-3β positive cells in KO mice, which were mainly neutrophils and macrophages. XB130 is expressed in alveolar type I and type II cells in the lung. The expression in these cells was significantly reduced after LPS challenge. XB130 deficiency delayed the recovery from systemic septic responses, and the presence of XB130 in the alveolar epithelial cells may provide protective mechanisms by reducing cell death and promoting cell proliferation, and reducing pulmonary permeability.
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Affiliation(s)
- Hiroaki Toba
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Tereza Tomankova
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Yingchun Wang
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Xiaohui Bai
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Hae-Ra Cho
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Zhehong Guan
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Oyedele A Adeyi
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Feng Tian
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Shaf Keshavjee
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Mingyao Liu
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, Universal Health Network, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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13
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14
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Son YG, Shin J, Ryu HG. Pneumonitis and pneumonia after aspiration. J Dent Anesth Pain Med 2017; 17:1-12. [PMID: 28879323 PMCID: PMC5564131 DOI: 10.17245/jdapm.2017.17.1.1] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 02/19/2017] [Accepted: 02/20/2017] [Indexed: 12/25/2022] Open
Abstract
Aspiration pneumonitis and aspiration pneumonia are clinical syndromes caused by aspiration. These conditions are clinically significant due to their high morbidity and mortality. However, aspiration as a preceding event are often unwitnessed, particularly in cases of asymptomatic or silent aspiration. Furthermore, despite the difference in treatment approaches for managing aspiration pneumonitis and aspiration pneumonia, these two disease entities are often difficult to discriminate from one another, resulting in inappropriate treatment. The use of unclear terminologies hinders the comparability among different studies, making it difficult to produce evidence-based conclusions and practical guidelines. We reviewed the most recent studies to define aspiration, aspiration pneumonitis, and aspiration pneumonia, and to further assess these conditions in terms of incidence and epidemiology, pathophysiology, risk factors, diagnosis, management and treatment, and prevention.
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Affiliation(s)
- Young Gon Son
- Department of Anesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Jungho Shin
- Department of Anesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Ho Geol Ryu
- Department of Anesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
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15
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Hackett AP, Trinick RE, Rose K, Flanagan BF, McNamara PS. Weakly acidic pH reduces inflammatory cytokine expression in airway epithelial cells. Respir Res 2016; 17:82. [PMID: 27422381 PMCID: PMC4947271 DOI: 10.1186/s12931-016-0399-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/06/2016] [Indexed: 02/08/2023] Open
Abstract
Background Aspiration lung disease (ALD) is a common cause of respiratory morbidity in children and adults with severe neurodisability (sND). Recent studies suggest that chronic microaspiration of gastric contents is associated with mild rather than low, airway acidification. We investigated inflammatory responses to infection by airway epithelial cells (AECs) exposed to weakly acidic media. Methods Using pH measurements from children with sND at high risk of ALD as a guide, we incubated AECs in weakly acidic (pH5.5–7.4) media alone; in combination with lipopolysaccharide (LPS); or prior to LPS stimulation at normal pH. Interleukin (IL) -6 and IL-8 expression were measured. Results IL-6/8 expression in AECs simultaneously exposed to weakly acidic media and LPS for 4 h was reduced with no effect on cell viability. Pre-incubation of AECs at weakly acidic pH also reduced subsequent LPS-induced cytokine expression. Suppression of inflammation was greatest at lower pHs (pH 5.5–6.0) for prolonged periods (16/24 h), but this also adversely affected cell viability. Conclusion AEC inflammatory responses to bacterial stimuli is markedly reduced in a mildly acidic environment.
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Affiliation(s)
- A P Hackett
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - R E Trinick
- Alder Hey Children's Hospital NHS Foundation Trust, Eaton Rd, Liverpool, UK
| | - K Rose
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - B F Flanagan
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - P S McNamara
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK. .,Alder Hey Children's Hospital NHS Foundation Trust, Eaton Rd, Liverpool, UK.
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Puig F, Herrero R, Guillamat-Prats R, Gómez MN, Tijero J, Chimenti L, Stelmakh O, Blanch L, Serrano-Mollar A, Matthay MA, Artigas A. A new experimental model of acid- and endotoxin-induced acute lung injury in rats. Am J Physiol Lung Cell Mol Physiol 2016; 311:L229-37. [PMID: 27317688 DOI: 10.1152/ajplung.00390.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 06/08/2016] [Indexed: 01/11/2023] Open
Abstract
The majority of the animal models of acute lung injury (ALI) are focused on the acute phase. This limits the studies of the mechanisms involved in later phases and the effects of long-term treatments. Thus the goal of this study was to develop an experimental ALI model of aspiration pneumonia, in which diffuse alveolar damage continues for 72 h. Rats were intratracheally instilled with one dose of HCl (0.1 mol/l) followed by another instillation of one dose of LPS (0, 10, 20, 30, or 40 μg/g body weight) 2 h later, which models aspiration of gastric contents that progresses to secondary lung injury from bacteria or bacterial products. The rats were euthanized at 24, 48, and 72 h after the last instillation. The results showed that HCl and LPS at all doses caused activation of inflammatory responses, increased protein permeability and apoptosis, and induced mild hypoxemia in rat lungs at 24 h postinstillation. However, this lung damage was present at 72 h only in rats receiving HCl and LPS at the doses of 30 and 40 μg/g body wt. Mortality (∼50%) occurred in the first 48 h and only in the rats treated with HCl and LPS at the highest dose (40 μg/g body wt). In conclusion, intratracheal instillation of HCl followed by LPS at the dose of 30 μg/g body wt results in severe diffuse alveolar damage that continues at least 72 h. This rat model of aspiration pneumonia-induced ALI will be useful for testing long-term effects of new therapeutic strategies in ALI.
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Affiliation(s)
- F Puig
- CIBER de Enfermedades Respiratorias, Madrid, Spain; Critical Care Center, Corporació Sanitària i Universitària Parc Taulí, Institut d' Investigació i Innovació Parc Taulí, Sabadell, Spain;
| | - R Herrero
- CIBER de Enfermedades Respiratorias, Madrid, Spain; Intensive Care Medicine Service, Hospital Universitario de Getafe, Getafe, Spain
| | - R Guillamat-Prats
- CIBER de Enfermedades Respiratorias, Madrid, Spain; Critical Care Center, Corporació Sanitària i Universitària Parc Taulí, Institut d' Investigació i Innovació Parc Taulí, Sabadell, Spain
| | - M N Gómez
- Critical Care Center, Corporació Sanitària i Universitària Parc Taulí, Institut d' Investigació i Innovació Parc Taulí, Sabadell, Spain
| | - J Tijero
- Critical Care Center, Corporació Sanitària i Universitària Parc Taulí, Institut d' Investigació i Innovació Parc Taulí, Sabadell, Spain
| | - L Chimenti
- Critical Care Center, Corporació Sanitària i Universitària Parc Taulí, Institut d' Investigació i Innovació Parc Taulí, Sabadell, Spain
| | - O Stelmakh
- Laboratorio de Análisis Clínico, Hospital Universitario de Getafe, Getafe, Spain
| | - L Blanch
- CIBER de Enfermedades Respiratorias, Madrid, Spain; Critical Care Center, Corporació Sanitària i Universitària Parc Taulí, Institut d' Investigació i Innovació Parc Taulí, Sabadell, Spain
| | - A Serrano-Mollar
- CIBER de Enfermedades Respiratorias, Madrid, Spain; Instituto de Investigaciones Biomédicas de Barcelona, CSIC, Barcelona, Spain; and
| | - M A Matthay
- Departments of Medicine and Anesthesia and the Cardiovascular Research Institute, University of California, San Francisco, California
| | - A Artigas
- CIBER de Enfermedades Respiratorias, Madrid, Spain; Critical Care Center, Corporació Sanitària i Universitària Parc Taulí, Institut d' Investigació i Innovació Parc Taulí, Sabadell, Spain
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17
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Ayala P, Meneses M, Olmos P, Montalva R, Droguett K, Ríos M, Borzone G. Acute lung injury induced by whole gastric fluid: hepatic acute phase response contributes to increase lung antiprotease protection. Respir Res 2016; 17:71. [PMID: 27301375 PMCID: PMC4907014 DOI: 10.1186/s12931-016-0379-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 05/17/2016] [Indexed: 11/28/2022] Open
Abstract
Background Gastric contents aspiration in humans is a risk factor for severe respiratory failure with elevated mortality. Although aspiration-induced local lung inflammation has been studied in animal models, little is known about extrapulmonary effects of aspiration. We investigated whether a single orotracheal instillation of whole gastric fluid elicits a liver acute phase response and if this response contributes to enrich the alveolar spaces with proteins having antiprotease activity. Methods In anesthetized Sprague-Dawley rats receiving whole gastric fluid, we studied at different times after instillation (4 h −7 days): changes in blood cytokines and acute phase proteins (fibrinogen and the antiproteases alpha1-antitrypsin and alpha2-macroglobulin) as well as liver mRNA expression of the two antiproteases. The impact of the systemic changes on lung antiprotease defense was evaluated by measuring levels and bioactivity of antiproteases in broncho-alveolar lavage fluid (BALF). Markers of alveolar-capillary barrier derangement were also studied. Non-parametric ANOVA (Kruskall-Wallis) and linear regression analysis were used. Results Severe peribronchiolar injury involving edema, intra-alveolar proteinaceous debris, hemorrhage and PMNn cell infiltration was seen in the first 24 h and later resolved. Despite a large increase in several lung cytokines, only IL-6 was found elevated in blood, preceding increased liver expression and blood concentration of both antiproteases. These changes, with an acute phase response profile, were significantly larger for alpha2-macroglobulin (40-fold increment in expression with 12-fold elevation in blood protein concentration) than for alpha1-antitrypsin (2–3 fold increment in expression with 0.5-fold elevation in blood protein concentration). Both the increment in capillary-alveolar antiprotease concentration gradient due to increased antiprotease liver synthesis and a timely-associated derangement of the alveolar-capillary barrier induced by aspiration, contributed a 58-fold and a 190-fold increase in BALF alpha1-antitrypsin and alpha2-macroglobulin levels respectively (p < 0.001). Conclusions Gastric contents-induced acute lung injury elicits a liver acute phase response characterized by increased mRNA expression of antiproteases and elevation of blood antiprotease concentrations. Hepatic changes act in concert with derangement of the alveolar capillary barrier to enrich alveolar spaces with antiproteases. These findings may have significant implications decreasing protease burden, limiting injury in this and other models of acute lung injury and likely, in recurrent aspiration.
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Affiliation(s)
- Pedro Ayala
- Department of Respiratory Diseases and Medical Research Center, Faculty of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | | | - Pablo Olmos
- Department of Nutrition, Diabetes and Metabolism, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rebeca Montalva
- Department of Respiratory Diseases and Medical Research Center, Faculty of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile
| | - Karla Droguett
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mariana Ríos
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gisella Borzone
- Department of Respiratory Diseases and Medical Research Center, Faculty of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 350, piso 1, Santiago, Chile.
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18
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Zhou J, Jiang L, Long X, Fu C, Wang X, Wu X, Liu Z, Zhu F, Shi J, Li S. Bone-marrow-derived mesenchymal stem cells inhibit gastric aspiration lung injury and inflammation in rats. J Cell Mol Med 2016; 20:1706-17. [PMID: 27061967 PMCID: PMC4988291 DOI: 10.1111/jcmm.12866] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 03/03/2016] [Indexed: 12/25/2022] Open
Abstract
Gastric aspiration lung injury is one of the most common clinical events. This study investigated the effects of bone‐marrow‐derived mesenchymal stem cells (BMSCs) on combined acid plus small non‐acidified particle (CASP)‐induced aspiration lung injury. Enhanced green fluorescent protein (EGFP+) or EGFP−BMSCs or 15d‐PGJ2 were injected via the tail vein into rats immediately after CASP‐induced aspiration lung injury. Pathological changes in lung tissues, blood gas analysis, the wet/dry weight ratio (W/D) of the lung, levels of total proteins and number of total cells and neutrophils in bronchoalveolar lavage fluid (BALF) were determined. The cytokine levels were measured using ELISA. Protein expression was determined by Western blot. Bone‐marrow‐derived mesenchymal stem cells treatment significantly reduced alveolar oedema, exudation and lung inflammation; increased the arterial partial pressure of oxygen; and decreased the W/D of the lung, the levels of total proteins and the number of total cells and neutrophils in BALF in the rats with CASP‐induced lung injury. Bone‐marrow‐derived mesenchymal stem cells treatment decreased the levels of tumour necrosis factor‐α and Cytokine‐induced neutrophil chemoattractant (CINC)‐1 and the expression of p‐p65 and increased the levels of interleukin‐10 and 15d‐PGJ2 and the expression of peroxisome proliferator‐activated receptor (PPAR)‐γ in the lung tissue in CASP‐induced rats. Tumour necrosis factor‐α stimulated BMSCs to secrete 15d‐PGJ2. A tracking experiment showed that EGFP+BMSCs were able to migrate to local lung tissues. Treatment with 15d‐PGJ2 also significantly inhibited CASP‐induced lung inflammation and the production of pro‐inflammatory cytokines. Our results show that BMSCs can protect lung tissues from gastric aspiration injury and inhibit lung inflammation in rats. A beneficial effect might be achieved through BMSC‐derived 15d‐PGJ2 activation of the PPAR‐γ receptor, reducing the production of proinflammatory cytokines.
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Affiliation(s)
- Jing Zhou
- Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China.,Department of General Practice, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Liyan Jiang
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Xuan Long
- Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Cuiping Fu
- Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiangdong Wang
- Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaodan Wu
- Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zilong Liu
- Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Fen Zhu
- Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jindong Shi
- Department of Respiratory Medicine, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China
| | - Shanqun Li
- Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
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19
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Araos JD, Ayala PS, Meneses M, Contreras R, Cutiño A, Montalva RM, Tazelaar HD, Borzone GR. Resolution of Lung Injury after a Single Event of Aspiration. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:2698-708. [DOI: 10.1016/j.ajpath.2015.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 05/05/2015] [Accepted: 07/01/2015] [Indexed: 01/21/2023]
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20
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Nemzek JA, Hodges AP, He Y. Bayesian network analysis of multi-compartmentalized immune responses in a murine model of sepsis and direct lung injury. BMC Res Notes 2015; 8:516. [PMID: 26423575 PMCID: PMC4589912 DOI: 10.1186/s13104-015-1488-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 09/21/2015] [Indexed: 12/20/2022] Open
Abstract
Background Inflammatory disease processes involve complex and interrelated systems of mediators. Determining the causal relationships among these mediators becomes more complicated when two, concurrent inflammatory conditions occur. In those cases, the outcome may also be dependent upon the timing, severity and compartmentalization of the insults. Unfortunately, standard methods of experimentation and analysis of data sets may investigate a single scenario without uncovering many potential associations among mediators. However, Bayesian network analysis is able to model linear, nonlinear, combinatorial, and stochastic relationships among variables to explore complex inflammatory disease systems. In these studies, we modeled the development of acute lung injury from an indirect insult (sepsis induced by cecal ligation and puncture) complicated by a direct lung insult (aspiration). To replicate multiple clinical situations, the aspiration injury was delivered at different severities and at different time intervals relative to the septic insult. For each scenario, we measured numerous inflammatory cell types and cytokines in samples from the local compartments (peritoneal and bronchoalveolar lavage fluids) and the systemic compartment (plasma). We then analyzed these data by Bayesian networks and standard methods. Results Standard data analysis demonstrated that the lung injury was actually reduced when two insults were involved as compared to one lung injury alone. Bayesian network analysis determined that both the severity of lung insult and presence of sepsis influenced neutrophil recruitment and the amount of injury to the lung. However, the levels of chemoattractant cytokines responsible for neutrophil recruitment were more strongly linked to the timing and severity of the lung insult compared to the presence of sepsis. This suggests that something other than sepsis-driven exacerbation of chemokine levels was influencing the lung injury, contrary to previous theories. Conclusions To our knowledge, these studies are the first to use Bayesian networks together with experimental studies to examine the pathogenesis of sepsis-associated lung injury. Compared to standard statistical analysis and inference, these analyses elucidated more intricate relationships among the mediators, immune cells and insult-related variables (timing, compartmentalization and severity) that cause lung injury. Bayesian networks are an effective tool for evaluating complex models of inflammation.
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Affiliation(s)
- Jean A Nemzek
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Andrew P Hodges
- Center for Computational Medicine and Biology, University of Michigan Medical School, Ann Arbor, MI, USA. .,Bioinformatics and Systems Biology, Sanford
- Burnham Medical Research Institute, La Jolla, CA, USA.
| | - Yongqun He
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, 48109, USA. .,Center for Computational Medicine and Biology, University of Michigan Medical School, Ann Arbor, MI, USA.
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21
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Abstract
OBJECTIVES Gastroesophageal reflux and aspiration can occur in premature infants who are supported with mechanical ventilation. The relation between physical positioning and gastric aspiration in ventilated infants has not been studied. Pepsin measured in tracheal aspirate (TA) emerged as a specific marker for aspiration. The objective of our study was to assess pepsin in TA of ventilated infants at 2 different positions: supine and right lateral. METHODS We conducted a randomized controlled trial on premature infants who were enterally fed and supported with mechanical ventilation. Patients were randomized into intervention and control groups. In the intervention group, infants were placed supine for 6 hours before a sample of TA was obtained. A second sample was collected 6 hours later while lying in the right lateral position. In the control group, the 2 samples of TA were obtained while infants remained in the supine position during the entire study time. Pepsin in TA was measured while blinded to the group assignment. RESULTS A total of 34 patients were enrolled and randomized to intervention (n = 17) and control (n = 17) groups. Gestational age was 32.7 ± 2.7 weeks, and birth weight was 1617 ± 526 g; both groups had similar demographic and clinical characteristics. Pepsin concentration did not differ between groups at baseline. In the intervention group, pepsin concentration significantly declined from 13 ng/mL (interquartile range [IQR] 11.9-38.7) to 10 ng/mL (IQR 7-12; P < 0.001), whereas it did not change in the control group (P = 0.42). CONCLUSIONS The right lateral positioning is associated with decreased TA pepsin. The implications of the present study on hospital practice and clinical outcomes need further investigations.
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22
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Aspiration during Monitored Anesthesia Care. Anesthesiology 2015; 122:471-2. [DOI: 10.1097/aln.0000000000000535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Lee A, Festic E, Park PK, Raghavendran K, Dabbagh O, Adesanya A, Gajic O, Bartz RR. Characteristics and outcomes of patients hospitalized following pulmonary aspiration. Chest 2014; 146:899-907. [PMID: 24811480 DOI: 10.1378/chest.13-3028] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Pulmonary aspiration is an important recognized cause of ARDS. Better characterization of patients who aspirate may allow identification of potential risks for aspiration that could be used in future studies to mitigate the occurrence of aspiration and its devastating complications. METHODS We conducted a secondary analysis of the Lung Injury Prediction Score cohort to better characterize patients with aspiration, including their potential risk factors and related outcomes. RESULTS Of the 5,584 subjects at risk for ARDS and who required hospitalization, 212 (3.8%) presented with aspiration. Subjects who aspirated were likely to be male (66% vs 56%, P < .007), slightly older (59 years vs 57 years), white (73% vs 61%, P = .0004), admitted from a nursing home (15% vs 5.9%, P < .0001), have a history of alcohol abuse (21% vs 8%, P < .0001), and have lower Glasgow Coma Scale (median, 13 vs 15; P < .0001). Aspiration subjects were sicker (higher APACHE [Acute Physiology and Chronic Health Evaluation] II score), required more mechanical ventilation (54% vs 32%, P < .0001), developed more moderate to severe ARDS (12% vs 3.8%, P < .0001), and were twofold more likely to die in-hospital, even after adjustment for severity of illness (OR = 2.1; 95% CI, 1.2-3.6). Neither obesity nor gastroesophageal reflux was associated with aspiration. CONCLUSIONS Aspiration was more common in men with alcohol abuse history and a lower Glasgow Coma Scale who were admitted from a nursing home. It is independently associated with a significant increase in the risk for ARDS as well as morbidity and mortality. Findings from this study may facilitate the design of future clinical studies of aspiration-induced lung injury.
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Affiliation(s)
- Augustine Lee
- Department of Critical Care Medicine and Division of Pulmonary Medicine, Mayo Clinic Florida, Jacksonville, FL.
| | - Emir Festic
- Department of Critical Care Medicine and Division of Pulmonary Medicine, Mayo Clinic Florida, Jacksonville, FL
| | - Pauline K Park
- Division of Acute Care Surgery, Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Krishnan Raghavendran
- Division of Acute Care Surgery, Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Ousama Dabbagh
- Division of Pulmonary and Critical Care, Department of Internal Medicine, University of Missouri, Columbia, MO
| | - Adebola Adesanya
- Department of Anesthesiology, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Ognjen Gajic
- Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
| | - Raquel R Bartz
- Department of Anesthesiology, Duke University Medical Center, Durham, NC
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Dietary advanced glycation end-products, its pulmonary receptor, and high mobility group box 1 in aspiration lung injury. J Surg Res 2014; 191:214-23. [PMID: 24814199 DOI: 10.1016/j.jss.2014.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 01/15/2014] [Accepted: 04/01/2014] [Indexed: 01/11/2023]
Abstract
BACKGROUND Gastric aspiration is a significant cause of acute lung injury and acute respiratory distress syndrome. Environmental risk factors, such as a diet high in proinflammatory advanced glycation end-products (AGEs), may render some patients more susceptible to lung injury after aspiration. We hypothesized that high dietary AGEs increase its pulmonary receptor, RAGE, producing an amplified pulmonary inflammatory response in the presence of high mobility group box 1 (HMGB1), a RAGE ligand and an endogenous signal of epithelial cell injury after aspiration. MATERIALS AND METHODS CD-1 mice were fed either a low AGE or high AGE diet for 4 wk. After aspiration injury with acidified small gastric particles, bronchoalveolar lavage and whole-lung tissue samples were collected at 5 min, 1 h, 5 h, and 24 h after injury. RAGE, soluble RAGE (sRAGE), HMGB1, cytokine and chemokine concentrations, albumin levels, neutrophil influx, and lung myeloperoxidase activity were measured. RESULTS We observed that high AGE-fed mice exhibited greater pulmonary RAGE levels before aspiration and increased bronchoalveolar lavage sRAGE levels after aspiration compared with low AGE-fed mice. Lavage HMGB1 levels rose immediately after aspiration, peaking at 1 h, and strongly correlated with sRAGE levels in both dietary groups. High AGE-fed mice demonstrated higher cytokine and chemokine levels with increased pulmonary myeloperoxidase activity over 24 h versus low AGE-fed mice. CONCLUSIONS This study indicates that high dietary AGEs can increase pulmonary RAGE, augmenting the inflammatory response to aspiration in the presence of endogenous damage signals such as HMGB1.
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Pulmonary blood flow increases in damaged regions directly after acid aspiration in rats. Anesthesiology 2014; 119:890-900. [PMID: 23846582 DOI: 10.1097/aln.0b013e3182a17e5b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND After gastric aspiration events, patients are at risk of pulmonary dysfunction and the development of severe acute lung injury and acute respiratory distress syndrome, which may contribute to the development of an inflammatory reaction. The authors' aim in the current study was to investigate the role of the spatial distribution of pulmonary blood flow in the pathogenesis of pulmonary dysfunction during the early stages after acid aspiration. METHODS The authors analyzed the pulmonary distribution of radiolabeled microspheres in normal (n = 6) and injured (n = 12) anesthetized rat lungs using positron emission tomography, computed tomography, and histological examination. RESULTS Injured regions demonstrate increased pulmonary blood flow in association with reduced arterial pressure and the deterioration of arterial oxygenation. After acid aspiration, computed tomography scans revealed that lung density had increased in the injured regions and that these regions colocalized with areas of increased blood flow. The acid was instilled into the middle and basal regions of the lungs. The blood flow was significantly increased to these regions compared with the blood flow to uninjured lungs in the control animals (middle region: 1.23 [1.1; 1.4] (median [25%; 75%]) vs. 1.04 [1.0; 1.1] and basal region: 1.25 [1.2; 1.3] vs. 1.02 [1.0; 1.05], respectively). The increase in blood flow did not seem to be due to vascular leakage into these injured areas. CONCLUSIONS The data suggest that 10 min after acid aspiration, damaged areas are characterized by increased pulmonary blood flow. The results may impact further treatment strategies, such as drug targeting.
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26
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Lee JY, Jo YY. Preoperative fasting in emergencies: choice for preventing aspiration pneumonitis. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2014. [DOI: 10.5124/jkma.2014.57.5.429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Ji Yeon Lee
- Department of Anesthesiology and Pain Medicine, Gachon University Gil Medical Center, Incheon, Korea
| | - Youn Yi Jo
- Department of Anesthesiology and Pain Medicine, Gachon University Gil Medical Center, Incheon, Korea
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Low pH environmental stress inhibits LPS and LTA-stimulated proinflammatory cytokine production in rat alveolar macrophages. BIOMED RESEARCH INTERNATIONAL 2013; 2013:742184. [PMID: 24288685 PMCID: PMC3830824 DOI: 10.1155/2013/742184] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/12/2013] [Accepted: 07/17/2013] [Indexed: 02/06/2023]
Abstract
Gastric aspiration increases the risks for developing secondary bacterial pneumonia. Cytokine elaboration through pathogen recognition receptors (PRRs) is an important mechanism in initiating innate immune host response. Effects of low pH stress, a critical component of aspiration pathogenesis, on the PRR pathways were examined, specifically toll-like receptor-2 (TLR2) and TLR4, using isolated rat alveolar macrophages (aMØs). We assessed the ability of aMØs after brief exposure to acidified saline to elaborate proinflammatory cytokines in response to lipopolysaccharide (LPS) and lipoteichoic acid (LTA) stimulation, known ligands of TLR4 and TLR2, respectively. Low pH stress reduced LPS- and LTA-mediated cytokine release (CINC-1, MIP-2, TNF-α, MCP-1, and IFN-β). LPS and LTA increased intracellular Ca2+ concentrations while Ca2+ chelation by BAPTA decreased LPS- and LTA-mediated cytokine responses. BAPTA blocked the effects of low pH stress on most of LPS-stimulated cytokines but not of LTA-stimulated responses. In vivo mouse model demonstrates suppressed E. coli and S. pneumoniae clearance following acid aspiration. In conclusion, low pH stress inhibits antibacterial cytokine response of aMØs due to impaired TLR2 (MyD88 pathway) and TLR4 signaling (MyD88 and TRIF pathways). The role of Ca2+ in low pH stress-induced signaling is complex but appears to be distinct between LPS- and LTA-mediated responses.
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B Moore B, Lawson WE, Oury TD, Sisson TH, Raghavendran K, Hogaboam CM. Animal models of fibrotic lung disease. Am J Respir Cell Mol Biol 2013; 49:167-79. [PMID: 23526222 DOI: 10.1165/rcmb.2013-0094tr] [Citation(s) in RCA: 298] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Interstitial lung fibrosis can develop as a consequence of occupational or medical exposure, as a result of genetic defects, and after trauma or acute lung injury leading to fibroproliferative acute respiratory distress syndrome, or it can develop in an idiopathic manner. The pathogenesis of each form of lung fibrosis remains poorly understood. They each result in a progressive loss of lung function with increasing dyspnea, and most forms ultimately result in mortality. To better understand the pathogenesis of lung fibrotic disorders, multiple animal models have been developed. This review summarizes the common and emerging models of lung fibrosis to highlight their usefulness in understanding the cell-cell and soluble mediator interactions that drive fibrotic responses. Recent advances have allowed for the development of models to study targeted injuries of Type II alveolar epithelial cells, fibroblastic autonomous effects, and targeted genetic defects. Repetitive dosing in some models has more closely mimicked the pathology of human fibrotic lung disease. We also have a much better understanding of the fact that the aged lung has increased susceptibility to fibrosis. Each of the models reviewed in this report offers a powerful tool for studying some aspect of fibrotic lung disease.
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Affiliation(s)
- Bethany B Moore
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109-2200, USA.
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Waybright RA, Coolidge W, Johnson TJ. Treatment of clinical aspiration: A reappraisal. Am J Health Syst Pharm 2013; 70:1291-300. [DOI: 10.2146/ajhp120319] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Ryan A. Waybright
- Avera McKennan Hospital and University Health Center (AMHUHC), Sioux Falls, SD; at the time of writing he was Postgraduate Year 2 (PGY2) Critical Care Pharmacy Resident, AMHUHC
| | - William Coolidge
- AMHUHC; at the time of writing he was PGY2 Critical Care Pharmacy Resident, AMHUHC
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Chiang SR, Tang HJ, Chen CH, Chen CC, Lee WY, Chang PC, Chiu YH, Chuang YC. Acid aspiration provokes the pneumonia caused by multidrug-resistant Acinetobacter baumannii in BALB/c mice. Int J Infect Dis 2013; 17:e454-60. [PMID: 23522637 DOI: 10.1016/j.ijid.2013.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 01/15/2013] [Accepted: 01/28/2013] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To determine whether acid aspiration provokes the development of multidrug-resistant Acinetobacter baumannii (MDRAB) pneumonia in its host. METHODS Groups of mice were inoculated intratracheally (IT) with 50 μl of 0.1N HCl and 1 × 10(8) colony-forming units (CFU) Ab396 (A+Ab group), or 50 μl of 0.1N HCl and 20 μl of 0.9% saline (A+S group), or 20 μl of 0.9% saline and 1 × 10(8) CFU of Ab396 (S+Ab group), or 50 μl of 0.9% saline and 20 μl of 0.9% saline (S+S group). Cytokines, bacterial loads in the bronchoalveolar lavage fluid (BALF), lung permeability, histopathology of the lungs, and survival rates were evaluated. RESULTS Only the A+Ab mice developed extensive Ab396 pneumonia and had significantly elevated bacterial loads, increased lung leakage, and lower levels of tumor necrosis factor alpha (TNF-α) compared with the other three groups (p<0.05, Mann-Whitney U-test). Moreover, a strong synergistic effect (p<0.05, two-way analysis of variance) was observed between the acid induction and Ab396 infection, resulting in lung injury and an unfavorable survival outcome. CONCLUSIONS Lung injury caused by acid aspiration provoked secondary MDRAB pneumonia; also synergistic effects between acid aspiration and Ab396 infection resulted in a detrimental outcome in the infected mice.
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Affiliation(s)
- Shyh-Ren Chiang
- Department of Internal Medicine, Chi Mei Medical Center, 901, Chung-Hwa Road, Yung-Kang Dist., Tainan City, Taiwan
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Davidson BA, Vethanayagam RR, Grimm MJ, Mullan BA, Raghavendran K, Blackwell TS, Freeman ML, Ayyasamy V, Singh KK, Sporn MB, Itagaki K, Hauser CJ, Knight PR, Segal BH. NADPH oxidase and Nrf2 regulate gastric aspiration-induced inflammation and acute lung injury. THE JOURNAL OF IMMUNOLOGY 2013; 190:1714-24. [PMID: 23296708 DOI: 10.4049/jimmunol.1202410] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recruitment of neutrophils and release of reactive oxygen species are considered to be major pathogenic components driving acute lung injury (ALI). However, NADPH oxidase, the major source of reactive oxygen species in activated phagocytes, can paradoxically limit inflammation and injury. We hypothesized that NADPH oxidase protects against ALI by limiting neutrophilic inflammation and activating Nrf2, a transcriptional factor that induces antioxidative and cytoprotective pathways. Our objective was to delineate the roles of NADPH oxidase and Nrf2 in modulating acute lung inflammation and injury in clinically relevant models of acute gastric aspiration injury, a major cause of ALI. Acid aspiration caused increased ALI (as assessed by bronchoalveolar lavage fluid albumin concentration) in both NADPH oxidase-deficient mice and Nrf2(-/-) mice compared with wild-type mice. NADPH oxidase reduced airway neutrophil accumulation, but Nrf2 decreased ALI without affecting neutrophil recovery. Acid injury resulted in a 120-fold increase in mitochondrial DNA, a proinflammatory and injurious product of cellular necrosis, in cell-free bronchoalveolar lavage fluid. Pharmacologic activation of Nrf2 by the triterpenoid 1-[2-cyano-3-,12-dioxooleana-1,9 (11)-dien-28-oyl]imidazole limited aspiration-induced ALI in wild-type mice and reduced endothelial cell injury caused by mitochondrial extract-primed human neutrophils, leading to the conclusion that NADPH oxidase and Nrf2 have coordinated, but distinct, functions in modulating inflammation and injury. These results also point to Nrf2 as a therapeutic target to limit ALI by attenuating neutrophil-induced cellular injury.
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Affiliation(s)
- Bruce A Davidson
- Department of Anesthesiology, University at Buffalo School of Medicine, Buffalo, NY 14214, USA
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Alaçam H, Karlı R, Alıcı Ö, Avcı B, Güzel A, Kozan A, Mertoğlu C, Murat N, Şalış O, Güzel A, Şahin M. The effects of α-tocopherol on oxidative damage and serum levels of Clara cell protein 16 in aspiration pneumonitis induced by bile acids. Hum Exp Toxicol 2012; 32:53-61. [DOI: 10.1177/0960327112459531] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Our aim in this study is to examine the effects of α-tocopherol (AT) on rats with aspiration pneumonitis induced with bile acids (BAs). The animals were divided in to four groups, namely saline group ( n = 7), saline + AT group ( n = 7), BA group ( n = 7), and BA + AT group ( n = 7). Saline and BA groups aspirated intratracheally with 1 ml/kg saline and 1 ml/kg bile acids, respectively. AT was given at 20 mg/kg/day dosage for 7 days to the groups. AT group was given 20 mg/kg/day AT for 7 days. Malondialdehyde (MDA), Clara cell protein 16 (CC-16), catalase (CAT), superoxide dismutase (SOD), as well as peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar histiocytes, and necrosis were evaluated. The CAT activity of the BA group was significantly lower than the saline group. In the BA + AT group, there was a significant increase in SOD and CAT activities when compared with that of the BA group. The CC-16 and MDA contents in the BA group were significantly higher than in the saline group. The CC-16 and MDA levels of the BA + AT group were significantly lower than BA group. Histopathologic changes were seen in BA group, and there was a significant decrease in the BA + AT group. In conclusion, AT might be beneficial in the treatment of aspiration pneumonitis induced by BAs because AT decreased oxidative damage and resulted in a decrease in CC-16 levels.
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Affiliation(s)
- H Alaçam
- Department of Medical Biochemistry, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
| | - R Karlı
- Department of Otorhinolaryngology, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
| | - Ö Alıcı
- Department of Pathology, Samsun Education and Research Hospital, Samsun, Turkey
| | - B Avcı
- Department of Medical Biochemistry, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
| | - A Güzel
- Department of Chest Disease, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
| | - A Kozan
- Department of Medical Biochemistry, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
| | - C Mertoğlu
- Department of Medical Biochemistry, Faculty of Medicine, Gaziosmanpaşa University, Tokat, Turkey
| | - N Murat
- Department of Statistics, Ondokuz Mayıs University, Samsun, Turkey
| | - O Şalış
- Mental Health and Diseases Hospital, Samsun, Turkey
| | - A Güzel
- Department of Pediatrics, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - M Şahin
- Department of Medical Biochemistry, Faculty of Medicine, Gaziosmanpaşa University, Tokat, Turkey
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Chen MG, Atkins CL, Bruce SR, Khan AM, Liu Y, Alcorn JL. Infant formula alters surfactant protein A (SP-A) and SP-B expression in pulmonary epithelial cells. Pediatr Pulmonol 2011; 46:903-12. [PMID: 21520433 PMCID: PMC6671285 DOI: 10.1002/ppul.21455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 01/14/2011] [Accepted: 02/05/2011] [Indexed: 11/08/2022]
Abstract
Surfactant proteins A (SP-A) and SP-B are critical in the ability of pulmonary surfactant to reduce alveolar surface tension and provide innate immunity. Aspiration of infant milk formula can lead to lung dysfunction, but direct effects of aspirated formula on surfactant protein expression in pulmonary cells have not been described. The hypothesis that infant formula alters surfactant protein homeostasis was tested in vitro by assessing surfactant protein gene expression in cultured pulmonary epithelial cell lines expressing SP-A and SP-B that were transiently exposed (6 hr) to infant formula. Steady-state levels of SP-A protein and mRNA and SP-B mRNA in human bronchiolar (NCI-H441) and mouse alveolar (MLE15) epithelial cells were reduced in a dose-dependent manner 18 hr after exposure to infant formula. SP-A mRNA levels remained reduced 42 hr after exposure, but SP-B mRNA levels increased 10-fold. Neither soy formula nor non-fat dry milk affected steady-state SP-A and SP-B mRNA levels; suggesting a role of a component of infant formula derived from cow milk. These results indicate that infant formula has a direct, dose-dependent effect to reduce surfactant protein gene expression. Ultimately, milk aspiration may potentially result in a reduced capacity of the lung to defend against environmental insults.
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Affiliation(s)
- Maurice G Chen
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
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Abstract
OBJECTIVE Aspiration of oropharyngeal or gastric contents into the lower respiratory tract is a common event in critically ill patients and can lead to pneumonia or pneumonitis. Aspiration pneumonia is the leading cause of pneumonia in the intensive care unit and is one of the leading risk factors for acute lung injury and acute respiratory distress syndromes. Despite its frequency, it remains largely a disease of exclusion characterized by ill-defined infiltrates on the chest radiograph and hypoxia. An accurate ability to diagnose aspiration is paramount because different modalities of therapy, if applied early and selectively, could change the course of the disease. This article reviews definitions, diagnosis, epidemiology, pathophysiology, including animal models of aspiration-induced lung injury, and evidence-based clinical management. Additionally, a review of current and potential biomarkers that have been tested clinically in humans is provided. DATA SOURCES Data were obtained from a PubMed search of the medical literature. PubMed "related articles" search strategies were used. SUMMARY AND CONCLUSIONS Aspiration in the intensive care unit is a clinically relevant problem requiring expertise and awareness. A definitive diagnosis of aspiration pneumonitis or pneumonia is challenging to make. Advances in specific biomarker profiles and prediction models may enhance the diagnosis and prognosis of clinical aspiration syndromes. Evidence-based management is supportive, including mechanical ventilation, bronchoscopy for particulate aspiration, consideration of empiric antibiotics for pneumonia treatment, and lower respiratory tract sampling to define pathogenic bacteria that are causative.
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Han B, Haitsma JJ, Zhang Y, Bai X, Rubacha M, Keshavjee S, Zhang H, Liu M. Long pentraxin PTX3 deficiency worsens LPS-induced acute lung injury. Intensive Care Med 2010; 37:334-42. [PMID: 21072499 DOI: 10.1007/s00134-010-2067-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Accepted: 10/04/2010] [Indexed: 01/16/2023]
Abstract
OBJECTIVE Long pentraxin PTX3 is an inflammatory mediator and a component of the humoral arm of innate immunity. PTX3 expression is increased in animals with acute lung injury (ALI) and in patients with sepsis or acute respiratory distress syndrome and is considered to be a potential biomarker for these diseases. However, the role of PTX3 in the pathogenesis of ALI is not fully understood. We hypothesized that PTX3, as an important immune modulator, may determine the severity of ALI. METHODS Lipopolysaccharide (LPS) was intra-tracheally administrated to PTX3 knock-out (PTX3-KO) and wild-type (WT) mice. Lung injury, neutrophil infiltration, cell death, fibrin deposition, and tissue factor expression in the lung were determined. Local and systemic inflammatory responses were assessed by measuring cytokines in the lung and plasma. RESULTS LPS instillation induced ALI in both PTX3-KO and WT mice. Interestingly, PTX3 deficiency significantly increased the magnitude/extent of lung injury compared to that in WT mice. The severe lung injury was accompanied by elevated neutrophil infiltration, cell death, and fibrin deposition in the lung. PTX3 deficiency also enhanced LPS-induced tissue factor expression/activation in the lung and increased tumor necrosis factor-alpha and monocyte chemoattractant protein-1 levels in the plasma. CONCLUSION Our data suggest that the endogenously expressed PTX3 plays a protective role in the pathogenesis of ALI and that a lack of PTX3 may enhance neutrophil recruitment, cell death, activation of coagulation cascades, and inflammatory responses in the lung.
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Affiliation(s)
- Bing Han
- Latner Thoracic Surgery Research Laboratories, Toronto General Research Institute, University Health Network, Toronto, ON, Canada
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Chakravarthy KV, Davidson BA, Helinski JD, Ding H, Law WC, Yong KT, Prasad PN, Knight PR. Doxorubicin-conjugated quantum dots to target alveolar macrophages and inflammation. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2010; 7:88-96. [PMID: 20887813 DOI: 10.1016/j.nano.2010.09.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2009] [Revised: 08/23/2010] [Accepted: 09/02/2010] [Indexed: 10/19/2022]
Abstract
UNLABELLED The ability to provide targeted therapeutic delivery in the lung would be a major advancement in pharmacological treatments for many pulmonary diseases. Critical issues for such successful delivery would require the ability to target specific cell types, minimize toxicity (e.g., inflammatory response), and deliver therapeutic levels of drugs. We report here on the ability of nanoconjugates of CdSe/CdS/ZnS quantum dots (QDs) and doxorubicin (Dox) to target alveolar macrophages (aMØs), cells that play a critical role in the pathogenesis of inflammatory lung injuries. Confocal imaging showed the release of Dox from the QD-Dox nanoconjugate, as was evident by its accumulation in the cell nucleus and induction of apoptosis, implying that the drug retains its bioactivity after coupling to the nanoparticle. Inflammatory injury parameters (albumin leakage, proinflammatory cytokines, and neutrophil infiltration) were recorded after in vivo administration of QD-Dox and Dox, observing no significant effect after QD-Dox treatment compared with Dox. These results demonstrate that nanoparticle platforms can provide targeted macrophage-selective therapy for the treatment of pulmonary disease. FROM THE CLINICAL EDITOR Pulmonary inflammatory diseases still often remain challenging to treat, despite decades of advances and several available agents. In this study, a quantum dot-based alveolar delivery system is presented, targeting macrophages with doxorubicin.
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Affiliation(s)
- Krishnan V Chakravarthy
- Department of Microbiology and Immunology, State University of New York at Buffalo, Buffalo, New York, USA
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Jaoude PA, Knight PR, Ohtake P, El-Solh AA. Biomarkers in the diagnosis of aspiration syndromes. Expert Rev Mol Diagn 2010; 10:309-19. [PMID: 20370588 PMCID: PMC2882092 DOI: 10.1586/erm.10.7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Recognizing and managing the different types of aspiration events remain a challenging task due to the lack of distinguishing clinical or laboratory characteristics. Numerous biomarkers in serum, sputum and bronchoalveolar lavage have been studied, and their role in the recognition of aspiration remains controversial at this time. Recent animal investigations using an array of biomarkers based on distinct pathogenic features of each aspiration event have produced promising results; however, they have not been validated in humans. Newer markers are being introduced as diagnostic and prognostic tools in conditions such as community-acquired pneumonia and sepsis, but they have not been examined in aspiration. The present review summarizes the different biomarkers that have been studied in aspiration and those who might have a potential clinical use in the future.
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Affiliation(s)
- Philippe Abou Jaoude
- The Veterans Affairs Western New York, Healthcare System, Buffalo, NY, USA and Western New York Respiratory Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, NY, USA
| | - Paul R Knight
- The Veterans Affairs Western New York, Healthcare System, Buffalo, NY, USA and Department of Anesthesiology, State University of New York at Buffalo School of Medicine and Biomedical Sciences and School of Public Health and Health Professions, NY, USA
| | - Patricia Ohtake
- Department of Rehabilitation Science, State University of New York at Buffalo School of Medicine and Biomedical Sciences and School of Public Health and Health Professions, NY, USA
| | - Ali A El-Solh
- Medical Research, Bldg 20 (151) VISN02, VA Western New York Healthcare System, 3495 Bailey Avenue, Buffalo, NY, 14215-1199, USA and Western New York Respiratory Research Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, NY, USA and Department of Social and Preventive Medicine State University of New York at Buffalo School of Medicine and Biomedical Sciences and School of Public Health and Health Professions, NY, USA, Tel.: +1 716 862 7366, Fax: +1 425 675 4502
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Predictive modeling and inflammatory biomarkers in rats with lung contusion and gastric aspiration. ACTA ACUST UNITED AC 2010; 67:1182-90. [PMID: 20009665 DOI: 10.1097/ta.0b013e318187a2bf] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND This study uses statistical predictive modeling and hierarchical cluster analyses to examine inflammatory mediators and cells in bronchoalveolar lavage (BAL) as putative biomarkers in rats with blunt trauma lung contusion (LC), gastric aspiration (combined acid and small gastric food particles, CASP), or a combination of the two. METHODS Specific parameters assessed in the innate pulmonary inflammatory response were leukocytes, macrophages, and polymorphonuclear neutrophils (PMNs) in BAL; whole lung myeloperoxidase activity; and a series of cytokines or chemokines present in BAL at 5 or 24 hours after injury: tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, interferon-gamma, IL-10, macrophage inflammatory protein-2, cytokine-induced neutrophil chemoattractant-1, and monocyte chemoattractant protein-1. RESULTS Rats with LC, CASP, LC + CASP all had severe lung injury compared with uninjured controls based on decreased arterial oxygenation or increased BAL albumin at 5 or 24 hours postinsult. However, the injury groups had distinct overall patterns of inflammation that allowed them to be discriminated accurately by hierarchical cluster analysis (29 of 30 and 35 of 37 rats were correctly classified in hierarchical clusters at 5 and 24 hours, respectively). Moreover, predictive analyses based on an extension of standard receiver-operator characteristic methodology discriminated individual animals and groups with similar high accuracy based on a maximum of two inflammatory parameters per group (29 of 30 and 36 of 37 rats were correctly classified at 5 hours and 24 hours, respectively). CONCLUSIONS These results support the possibility that inflammatory biomarker profiles could be developed in the future to improve the diagnosis and management of trauma patients with unwitnessed (occult) gastric aspiration who have an increased risk of clinical acute lung injury or the acute respiratory distress syndrome.
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Nemzek JA, Abatan O, Fry C, Mattar A. Functional contribution of CXCR2 to lung injury after aspiration of acid and gastric particulates. Am J Physiol Lung Cell Mol Physiol 2009; 298:L382-91. [PMID: 20044435 DOI: 10.1152/ajplung.90635.2008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effects of individual ELR+ CXC chemokines have been documented in experimental models of acid aspiration. However, aspiration lung injury would be influenced by the combined effects of these chemokines and other factors related to their function. Therefore, the role of the chemokine receptor CXCR2 was examined in lung injury induced by aspiration of acid and acid with gastric particulates. Anesthetized mice were given intratracheal injections of saline, acid solution, or acid containing gastric particles. Within 6 h, bronchoalveolar lavage fluid neutrophils and albumin increased relative to the severity of the insult. Immunohistochemistry and RT-PCR demonstrated striking increases in pulmonary expression of CXCR2 after aspiration. In CXCR2-deficient mice, neutrophil recruitment to airways was significantly reduced after aspiration of either acid or acid with particles. However, lung injury scores were unaffected in Ccr2-/- mice in the acid + particles group. Esterase-stained lung tissue demonstrated that focal aggregates of inflammatory cells contained neutrophils in the Ccr2-/- mice. These studies suggest CXCR2 and its ligands are dominant mediators of neutrophil recruitment to airways after aspiration. However, CXCR2-independent mechanisms recruit neutrophils into areas of cellular aggregation after aspiration of acidified gastric particulates.
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Affiliation(s)
- Jean A Nemzek
- Unit for Laboratory Animal Medicine, Department of Pathology, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA.
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Zhao X, Town JR, Li F, Li W, Zhang X, Gordon JR. Blockade of neutrophil responses in aspiration pneumonia via ELR-CXC chemokine antagonism does not predispose to airway bacterial outgrowth. Pulm Pharmacol Ther 2009; 23:22-8. [PMID: 19751843 DOI: 10.1016/j.pupt.2009.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2008] [Revised: 08/31/2009] [Accepted: 09/03/2009] [Indexed: 11/26/2022]
Abstract
Pneumonia associated with aspiration of bacterial-laden gastric contents is characterized by Glu-Leu-Arg (ELR)-CXC chemokine (e.g., CXC2L1, CXCL8) expression leading to local neutrophil sequestration. This neutrophil response is designed to be protective, but overly aggressive responses can be pathogenic in themselves. Herein we assessed whether blocking neutrophil responses in a guinea pig model of aspiration pneumonia would foster airway bacterial growth. Guinea pigs (n=5) were challenged intranasally with saline, acidified saline or acidified gastric contents (35mg/kg body weight, pH 2.0) and treated subcutaneously with 250mug/kg of the human ELR-CXC chemokine antagonist CXCL8((3-72))K11R/G31P (G31P) or saline. After 20h the animals' airway inflammatory responses and bacterial burdens were assessed. A loss of vascular integrity was apparent in the lungs of the saline-treated aspiration pneumonia animals (12.07+/-1.3% of the pleural surfaces exhibited hemorrhagic consolidation, 4.6x10(6) RBC/ml bronchoalveolar lavage fluid [BALF]), as was a pulmonary neutrophilia. The BAL fluids contained gram-negative and -positive bacteria (total load, 6.3+/-3.2x10(7) CFU/ml BALF) that are associated with nosocomial infections in humans. The G31P-treatments attenuated the pulmonary vascular complications (2.27+/-0.5% pleural surface hemorrhagic consolidation, 0.46x10(6) RBC/ml BALF), and reduced the pulmonary neutrophilia by >/=86%. The G31P-treatments did not lead to significant changes in the airway bacterial loads (total load, 3.46+/-1.8x10(7) CFU/ml BALF). This data indicates that attenuation of the pulmonary neutrophil response in aspiration pneumonia reduces pathology very significantly but does not reduce the efficiency of pulmonary bacterial clearance.
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Affiliation(s)
- Xixing Zhao
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Canada
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Surfactant dysfunction in lung contusion with and without superimposed gastric aspiration in a rat model. Shock 2009; 30:508-17. [PMID: 18323743 DOI: 10.1097/shk.0b013e3181673fc5] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This study investigates surfactant dysfunction in rats with lung contusion (LC) induced by blunt chest trauma. Rats at 24 h postcontusion had a decreased percent content of large surfactant aggregates in cell-free bronchoalveolar lavage (BAL) and altered large-aggregate composition with decreased phosphatidylcholine (PC), increased lyso-PC, and increased protein compared with uninjured controls. The surface activity of large aggregates on a pulsating bubble surfactometer was also severely impaired at 24 h postcontusion. Decreases in large surfactant aggregate content and surface activity were improved, but still apparent, at 48 and 72 h postcontusion compared with uninjured control rats and returned to normal by 96 h postcontusion. The functional importance of surfactant abnormalities in LC injury was documented in pilot studies showing that exogenous surfactant replacement at 24 h postcontusion improved inflation/deflation lung volumes. Additional experiments investigated a clinically relevant combination of LC plus gastric aspiration (combined acid and small gastric food particles) and found reductions in large surfactant aggregates in BAL similar to those for LC. However, rats given LC + combined acid and small gastric food particles versus LC had more severe surfactant dysfunction based on decreases in surface activity and alterations in large aggregate composition. Combined data for all animal groups had strong statistical correlations between surfactant dysfunction (increased minimum surface tension, decreased large aggregates in BAL, decreased aggregate PC, and increased aggregate lyso-PC) and the severity of inflammatory lung injury (increased total protein, albumin, protein/phospholipid ratio, neutrophils, and erythrocytes in BAL plus increased whole lung myeloperoxidase activity). These results show that surfactant dysfunction is important in the pathophysiology of LC with or without concurrent gastric aspiration and provides a rationale for surfactant replacement therapy in these prevalent clinical conditions.
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Role of proinflammatory activity contained in gastric juice from intensive care unit patients to induce lung injury in a rabbit aspiration model. Crit Care Med 2008; 36:3205-12. [DOI: 10.1097/ccm.0b013e31818f0e20] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Sands MF, Ohtake PJ, Mahajan SD, Takyar SS, Aalinkeel R, Fang YV, Blume JW, Mullan BA, Sykes DE, Lachina S, Knight PR, Schwartz SA. Tissue inhibitor of metalloproteinase-1 modulates allergic lung inflammation in murine asthma. Clin Immunol 2008; 130:186-98. [PMID: 18955015 DOI: 10.1016/j.clim.2008.08.029] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 08/08/2008] [Accepted: 08/30/2008] [Indexed: 10/21/2022]
Abstract
Matrix metalloproteinases (MMPs) modulate development, inflammation, and repair in lungs. Tissue inhibitors of MMPs (TIMPs) interact with MMPs, controlling the intensity and nature of the response to injury. Absence of MMP-9, -2, and -8 activities is associated with altered lung inflammation during allergic sensitization. To test the hypothesis that the absence of TIMP-1 enhances allergic lung inflammation, airway hyperreactivity (AHR), and lung remodeling in asthma, we studied TIMP-1 null (TIMP-1 KO) mice and their WT controls using an ovalbumin (OVA) asthma model. TIMP-1 KO mice, compared to WT controls, developed an asthma phenotype characterized by AHR, pronounced cellular lung infiltrates, greater reduction in lung compliance, enhanced Th2 cytokine mRNA and protein expression, and altered collagen lung content associated with enhanced MMP-9 activity. Our findings support the hypothesis that TIMP-1 plays a protective role by preventing AHR and modulating inflammation, remodeling, and cytokine expression in an animal model of asthma.
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Affiliation(s)
- Mark F Sands
- VA Western New York Healthcare System, Buffalo, NY 14215, USA.
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Raghavendran K, Davidson BA, Huebschmann JC, Helinski JD, Hutson AD, Dayton MT, Notter RH, Knight PR. Superimposed gastric aspiration increases the severity of inflammation and permeability injury in a rat model of lung contusion. J Surg Res 2008; 155:273-82. [PMID: 19515386 DOI: 10.1016/j.jss.2008.08.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 07/18/2008] [Accepted: 08/17/2008] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Lung contusion (LC) from blunt thoracic trauma is a clinically-prevalent condition that can progress to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Patients with LC are at risk for gastric aspiration at the time of trauma, but the combined insults have not been well-studied in animal models. This study tests the hypothesis that concurrent gastric aspiration (combined acid and small gastric particles, CASP) at the time of trauma significantly increases permeability injury and inflammation compared with LC alone, and also modifies the inflammatory response to include distinct features compared with the aspiration component of injury. MATERIALS AND METHODS Four groups of adult male Long-Evans rats were studied (LC, CASP, LC+CASP, uninjured controls). LC was induced in anesthetized rats at a fixed impact energy of 2.0 J, and CASP (1.2 mL/kg body weight, 40 mg particles/mL, pH=1.25) was instilled through an endotracheal tube. Lung injury and inflammation were assessed by arterial blood gases and levels of albumin, cells, and cytokines/chemokines in bronchoalveolar lavage (BAL) at 5 and 24 h. RESULTS Rats with LC+CASP had lower mean PaO(2)/FiO(2) ratios compared with LC alone at 24 h, and higher BAL albumin concentrations compared with either LC or CASP alone. Rats with LC+CASP versus LC had more severe inflammation based on higher levels of PMN in BAL at 5 h, increased whole lung myeloperoxidase (MPO) activity at 5 and 24 h, and increased levels of inflammatory mediators in BAL (TNFalpha, IL-1beta, and MCP-1 at 5 and 24 h; IL-10, MIP-2, and CINC-1 at 5 h). Rats with LC+CASP also had distinct aspects of inflammation compared with CASP alone, i.e., significantly higher levels of IL-10 (5 and 24 h), IL-1beta (24 h), CINC-1 (24 h), and MCP-1 (24 h), and significantly lower levels of MPO (5 h), MIP-2 (5 h), and CINC-1 (5 h). CONCLUSIONS Concurrent gastric aspiration can exacerbate permeability lung injury and inflammation associated with LC, and also generates a modified inflammatory response compared with aspiration alone. Unwitnessed gastric aspiration has the potential to contribute to more severe forms of LC injury associated with progression to ALI/ARDS and pneumonia in patients with thoracic trauma.
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Farhath S, He Z, Nakhla T, Saslow J, Soundar S, Camacho J, Stahl G, Shaffer S, Mehta DI, Aghai ZH. Pepsin, a marker of gastric contents, is increased in tracheal aspirates from preterm infants who develop bronchopulmonary dysplasia. Pediatrics 2008; 121:e253-9. [PMID: 18245400 DOI: 10.1542/peds.2007-0056] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The objective of this study was to study the association between pepsin in tracheal aspirate samples and the development of bronchopulmonary dysplasia in preterm infants. METHODS Serial tracheal aspirate samples were collected during the first 28 days from mechanically ventilated preterm neonates. Bronchopulmonary dysplasia was defined as the need for supplemental oxygen at 36 weeks' postmenstrual age. An enzymatic assay with a fluorescent substrate was used to detect pepsin. Total protein was measured by the Bradford assay to correct for the dilution during lavage. Immunohistochemistry using antibody against human pepsinogen was performed in 10 lung tissue samples from preterm infants. RESULTS A total of 256 tracheal aspirate samples were collected from 59 preterm neonates. Pepsin was detected in 234 (91.4%) of 256 of the tracheal aspirate samples. Twelve infants had no bronchopulmonary dysplasia, 31 infants developed bronchopulmonary dysplasia, and 16 infants died before 36 weeks' postmenstrual age. The mean pepsin concentration was significantly lower in infants with no bronchopulmonary dysplasia compared with those who developed bronchopulmonary dysplasia or developed bronchopulmonary dysplasia/died before 36 weeks' postmenstrual age. Moreover, the mean pepsin level was significantly higher in infants with severe bronchopulmonary dysplasia compared with moderate bronchopulmonary dysplasia. The mean pepsin level in tracheal aspirate samples from the first 7 days was also lower in infants with no bronchopulmonary dysplasia compared with those who developed bronchopulmonary dysplasia or developed bronchopulmonary dysplasia/died before 36 weeks' postmenstrual age. Pepsinogen was not localized in the lung tissues by immunohistochemistry. CONCLUSION The concentration of pepsin was increased in the tracheal aspirate of preterm infants who developed bronchopulmonary dysplasia or died before 36 weeks' postmenstrual age. Recovery of pepsin in tracheal aspirate samples is secondary to gastric aspiration, not by hematogenous spread or local synthesis in the lungs. Chronic aspiration of gastric contents may contribute in the pathogenesis of bronchopulmonary dysplasia.
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Affiliation(s)
- Sabeena Farhath
- Division of Gastroenterology and Nutrition and Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, Delaware, USA
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Nader ND, McQuiller PS, Raghavendran K, Spengler RN, Knight PR. The role of alveolar macrophages in the pathogenesis of aspiration pneumonitis. Immunol Invest 2007; 36:457-71. [PMID: 17691026 DOI: 10.1080/08820130701361053] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
RATIONALE A robust TNFalpha response is seen following aspiration of food particles, while there is only a modest response to acid. OBJECTIVES To examine the direct effects of acid and particulate components of gastric content on local and systemic macrophages. METHODS Pathogen-free Long-Evans rats were injured with intratracheal instillation of normal saline (SHAM), low pH saline (ACID), small non-acidic particles (SNAP) or acidified particles (CASP). The alveolar (local) and the peritoneal (systemic) macrophages were harvested following the injury. MEASUREMENTS We examined the phagocytic activity and TNFalpha release by the alveolar and peritoneal macrophages following in vivo and in vitro exposure to acid and/or food particles. TNFalpha release by macrophages was examined in response to E. coli lipopolysaccharide (LPS) stimulation. MAIN RESULTS In rats injured with gastric particles, the number of the mononuclear cells was higher than those obtained from acid-injured animals. Both in vivo and in vitro exposure of the alveolar macrophages to SNAP resulted in increased production of TNFalpha within 8 hours. Transient exposure of the alveolar macrophages to a low pH environment suppressed LPS-induced production of this cytokine. Additionally, the phagocytic activity of the alveolar macrophages was inhibited by in vitro exposure of the macrophages to acid. CONCLUSIONS We conclude that the two components of gastric aspiration have diverse effects on local and systemic macrophages. Although there is a synergy between acid and gastric particulate in producing an acute lung injury, the modulatory effects of these injuries on the alveolar macrophages are averse.
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Affiliation(s)
- Nader D Nader
- Department of Anesthesiology, University at Buffalo, State University of New York, Buffalo, New York 14215, USA.
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Janda M, Scheeren TWL, Nöldge-Schomburg GFE. Management of pulmonary aspiration. Best Pract Res Clin Anaesthesiol 2007; 20:409-27. [PMID: 17080693 DOI: 10.1016/j.bpa.2006.02.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Pulmonary aspiration of gastric contents in the perioperative phase is associated with increased postoperative morbidity and mortality. For the management of aspiration, differentiation between acid-associated aspiration pneumonitis and aspiration pneumonia as a consequence of a secondary bacterial contamination is of crucial importance. The incidence of aspiration in elective surgery is 1 per 2000-3000 anaesthesias in adults. In children, it is slightly more common with 1 per 1200-2600 anaesthesias. In the context of emergency anaesthesias the incidence of aspiration is three to four times higher. The risk particularly increases with recent ingestion of solid food or fluids, with older patients, with pregnant women, and with consciousness-reduced patients. Besides giving a review of the pathophysiology, incidence, and the risk factors of aspiration, this article places emphasis on the practical management of this anaesthesia-associated complication. Cricoid pressure, as a non-evidence-based but clinically wide-spread method in the context of the prophylaxis of aspiration, is discussed critically. The main part deals with strategies to structure the management of aspiration by use of scientific concepts based on medical crisis management. For this, an algorithm based on current scientific investigations is presented.
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Affiliation(s)
- Matthias Janda
- Department of Anaesthesiology and Intensive Care Medicine, University of Rostock, Schillingallee 35, 18055 Rostock, Germany.
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