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Adrogué HJ, Madias NE. Acute sodium bicarbonate administration improves ventilatory efficiency in experimental respiratory acidosis: clinical implications. Pflugers Arch 2024; 476:901-909. [PMID: 38532117 DOI: 10.1007/s00424-024-02949-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/10/2024] [Accepted: 03/20/2024] [Indexed: 03/28/2024]
Abstract
Administering sodium bicarbonate (NaHCO3) to patients with respiratory acidosis breathing spontaneously is contraindicated because it increases carbon dioxide load and depresses pulmonary ventilation. Nonetheless, several studies have reported salutary effects of NaHCO3 in patients with respiratory acidosis but the underlying mechanism remains uncertain. Considering that such reports have been ignored, we examined the ventilatory response of unanesthetized dogs with respiratory acidosis to hypertonic NaHCO3 infusion (1 N, 5 mmol/kg) and compared it with that of animals with normal acid-base status or one of the remaining acid-base disorders. Ventilatory response to NaHCO3 infusion was evaluated by examining the ensuing change in PaCO2 and the linear regression of the PaCO2 vs. pH relationship. Strikingly, PaCO2 failed to increase and the ΔPaCO2 vs. ΔpH slope was negative in respiratory acidosis, whereas PaCO2 increased consistently and the ΔPaCO2 vs. ΔpH slope was positive in the remaining study groups. These results cannot be explained by differences in buffering-induced decomposition of infused bicarbonate or baseline levels of blood pH, PaCO2, and pulmonary ventilation. We propose that NaHCO3 infusion improved the ventilatory efficiency of animals with respiratory acidosis, i.e., it decreased their ratio of total pulmonary ventilation to carbon dioxide excretion (VE/VCO2). Such exclusive effect of NaHCO3 infusion in animals with respiratory acidosis might emanate from baseline increased VD/VT (dead space/tidal volume) caused by bronchoconstriction and likely reduced pulmonary blood flow, defects that are reversed by alkali infusion. Our observations might explain the beneficial effects of NaHCO3 reported in patients with acute respiratory acidosis.
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Affiliation(s)
- Horacio J Adrogué
- Department of Medicine, Baylor College of Medicine, Houston, TX, USA
- Department of Medicine, Division of Nephrology, Houston Methodist Hospital, Houston, TX, USA
| | - Nicolaos E Madias
- Department of Medicine, Tufts University School of Medicine, Boston, MA, USA.
- Department of Medicine, Division of Nephrology, St. Elizabeth's Medical Center, Boston, MA, USA.
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Joe YE, Lee CY, Kim N, Lee K, Kang SJ, Oh YJ. Effect of permissive hypercarbia on lung oxygenation during one-lung ventilation and postoperative pulmonary complications in patients undergoing thoracic surgery: A prospective randomised controlled trial. Eur J Anaesthesiol 2023; 40:691-698. [PMID: 37455644 DOI: 10.1097/eja.0000000000001873] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
BACKGROUND The effect of hypercarbia on lung oxygenation during thoracic surgery remains unclear. OBJECTIVE To investigate the effect of hypercarbia on lung oxygenation during one-lung ventilation in patients undergoing thoracic surgery and evaluate the incidence of postoperative pulmonary complications. DESIGN Prospective randomised controlled trial. SETTING A tertiary university hospital in the Republic of Korea from November 2019 to December 2020. PATIENTS Two hundred and ninety-seven patients with American Society of Anaesthesiologists physical status II to III, scheduled to undergo elective lung resection surgery. INTERVENTION Patients were randomly assigned to Group 40, 50, or 60. An autoflow ventilation mode with a lung protective ventilation strategy was applied to all patients. Respiratory rate was adjusted to maintain a partial pressure of arterial carbon dioxide of 40 ± 5 mmHg in Group 40, 50 ± 5 mmHg in Group 50 and 60 ± 5 mmHg in Group 60 during one-lung ventilation and at the end of surgery. MAIN OUTCOME MEASURES The primary outcome was the arterial oxygen partial pressure/fractional inspired oxygen ratio after 60 min of one-lung ventilation. RESULTS Data from 262 patients were analysed. The partial pressure/fractional inspired oxygen ratio was significantly higher in Group 50 and Group 60 than in Group 40 (269.4 vs. 262.9 vs. 214.4; P < 0.001) but was not significantly different between Group 50 and Group 60. The incidence of postoperative pulmonary complications was comparable among the three groups. CONCLUSION Permissive hypercarbia improved lung oxygenation during one-lung ventilation without increasing the risk of postoperative pulmonary complications or the length of hospital stay. TRIAL REGISTRATION NCT04175379.
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Affiliation(s)
- Young-Eun Joe
- From the Department of Anaesthesiology and Pain Medicine, and Anaesthesia and Pain Research Institute (Y-EJ, NK, KL, SJK, YJO) and Department of Thoracic and Cardiovascular Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea (CYL)
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Hof S, Truse R, Weber L, Herminghaus A, Schulz J, Weber APM, Maleckova E, Bauer I, Picker O, Vollmer C. Local Mucosal CO 2 but Not O 2 Insufflation Improves Gastric and Oral Microcirculatory Oxygenation in a Canine Model of Mild Hemorrhagic Shock. Front Med (Lausanne) 2022; 9:867298. [PMID: 35573010 PMCID: PMC9096873 DOI: 10.3389/fmed.2022.867298] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Acute hemorrhage results in perfusion deficit and regional hypoxia. Since failure of intestinal integrity seem to be the linking element between hemorrhage, delayed multi organ failure, and mortality, it is crucial to maintain intestinal microcirculation in acute hemorrhage. During critical bleeding physicians increase FiO2 to raise total blood oxygen content. Likewise, a systemic hypercapnia was reported to maintain microvascular oxygenation (μHbO2). Both, O2 and CO2, may have adverse effects when applied systemically that might be prevented by local application. Therefore, we investigated the effects of local hyperoxia and hypercapnia on the gastric and oral microcirculation. Methods Six female foxhounds were anaesthetized, randomized into eight groups and tested in a cross-over design. The dogs received a local CO2-, O2-, or N2-administration to their oral and gastric mucosa. Hemorrhagic shock was induced through a withdrawal of 20% of estimated blood volume followed by retransfusion 60 min later. In control groups no shock was induced. Reflectance spectrophotometry and laser Doppler were performed at the gastric and oral surface. Oral microcirculation was visualized by incident dark field imaging. Systemic hemodynamic parameters were recorded continuously. Statistics were performed using a two-way-ANOVA for repeated measurements and post hoc analysis was conducted by Bonferroni testing (p < 0.05). Results The gastric μHbO2 decreased from 76 ± 3% to 38 ± 4% during hemorrhage in normocapnic animals. Local hypercapnia ameliorated the decrease of μHbO2 from 78 ± 4% to 51 ± 8%. Similarly, the oral μHbO2 decreased from 81 ± 1% to 36 ± 4% under hemorrhagic conditions and was diminished by local hypercapnia (54 ± 4%). The oral microvascular flow quality but not the total microvascular blood flow was significantly improved by local hypercapnia. Local O2-application failed to change microvascular oxygenation, perfusion or flow quality. Neither CO2 nor O2 changed microcirculatory parameters and macrocirculatory hemodynamics under physiological conditions. Discussion Local hypercapnia improved microvascular oxygenation and was associated with a continuous blood flow in hypercapnic individuals undergoing hemorrhagic shock. Local O2 application did not change microvascular oxygenation, perfusion and blood flow profiles in hemorrhage. Local gas application and change of microcirculation has no side effects on macrocirculatory parameters.
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Affiliation(s)
- Stefan Hof
- Department of Anesthesiology, Duesseldorf University Hospital, Duesseldorf, Germany
| | - Richard Truse
- Department of Anesthesiology, Duesseldorf University Hospital, Duesseldorf, Germany
| | - Lea Weber
- Department of Anesthesiology, Duesseldorf University Hospital, Duesseldorf, Germany
| | - Anna Herminghaus
- Department of Anesthesiology, Duesseldorf University Hospital, Duesseldorf, Germany
| | - Jan Schulz
- Department of Anesthesiology, Duesseldorf University Hospital, Duesseldorf, Germany
| | - Andreas P M Weber
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Eva Maleckova
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Inge Bauer
- Department of Anesthesiology, Duesseldorf University Hospital, Duesseldorf, Germany
| | - Olaf Picker
- Department of Anesthesiology, Duesseldorf University Hospital, Duesseldorf, Germany
| | - Christian Vollmer
- Department of Anesthesiology, Duesseldorf University Hospital, Duesseldorf, Germany
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Tiruvoipati R, Serpa Neto A, Young M, Marhoon N, Wilson J, Gupta S, Pilcher D, Bailey M, Bellomo R. An Exploratory Analysis of the Association between Hypercapnia and Hospital Mortality in Critically Ill Patients with Sepsis. Ann Am Thorac Soc 2022; 19:245-254. [PMID: 34380007 DOI: 10.1513/annalsats.202102-104oc] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Rationale: Hypercapnia may affect the outcome of sepsis. Very few clinical studies conducted in noncritically ill patients have investigated the effects of hypercapnia and hypercapnic acidemia in the context of sepsis. The effect of hypercapnia in critically ill patients with sepsis remains inadequately studied. Objectives: To investigate the association of hypercapnia with hospital mortality in critically ill patients with sepsis. Methods: This is a retrospective study conducted in three tertiary public hospitals. Critically ill patients with sepsis from three intensive care units between January 2011 and May 2019 were included. Five cohorts (exposure of at least 24, 48, 72, 120, and 168 hours) were created to account for immortal time bias and informative censoring. The association between hypercapnia exposure and hospital mortality was assessed with multivariable models. Subgroup analyses compared ventilated versus nonventilated and pulmonary versus nonpulmonary sepsis patients. Results: We analyzed 84,819 arterial carbon dioxide pressure measurements in 3,153 patients (57.6% male; median age was 62.5 years). After adjustment for key confounders, both in mechanically ventilated and nonventilated patients and in patients with pulmonary or nonpulmonary sepsis, there was no independent association of hypercapnia with hospital mortality. In contrast, in ventilated patients, the presence of prolonged exposure to both hypercapnia and acidemia was associated with increased mortality (highest odds ratio of 16.5 for ⩾120 hours of potential exposure; P = 0.007). Conclusions: After adjustment, isolated hypercapnia was not associated with increased mortality in patients with sepsis, whereas prolonged hypercapnic acidemia was associated with increased risk of mortality. These hypothesis-generating observations suggest that as hypercapnia is not an independent risk factor for mortality, trials of permissive hypercapnia avoiding or minimizing acidemia in sepsis may be safe.
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Affiliation(s)
- Ravindranath Tiruvoipati
- Department of Intensive Care Medicine, Peninsula Health, Melbourne, Victoria, Australia
- Australian and New Zealand Intensive Care Research Centre, Peninsula Clinical School, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Ary Serpa Neto
- Australian and New Zealand Intensive Care Research Centre, Peninsula Clinical School, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Marcus Young
- Department of Intensive Care, Austin Health, Heidelberg, Victoria, Australia
| | - Nada Marhoon
- Department of Intensive Care, Austin Health, Heidelberg, Victoria, Australia
| | - John Wilson
- Peninsula Health Informatics, Frankston Hospital, Melbourne, Victoria, Australia
| | - Sachin Gupta
- Department of Intensive Care Medicine, Peninsula Health, Melbourne, Victoria, Australia
- Australian and New Zealand Intensive Care Research Centre, Peninsula Clinical School, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - David Pilcher
- Australian and New Zealand Intensive Care Research Centre, Peninsula Clinical School, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
- Department of Intensive Care Medicine, The Alfred Hospital, Melbourne, Victoria, Australia; and
| | - Michael Bailey
- Australian and New Zealand Intensive Care Research Centre, Peninsula Clinical School, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
- Data Analytics Research and Evaluation, the University of Melbourne and Austin Hospital, Melbourne, Victoria, Australia
| | - Rinaldo Bellomo
- Australian and New Zealand Intensive Care Research Centre, Peninsula Clinical School, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
- Department of Intensive Care, Austin Health, Heidelberg, Victoria, Australia
- Data Analytics Research and Evaluation, the University of Melbourne and Austin Hospital, Melbourne, Victoria, Australia
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Masterson C, Horie S, McCarthy SD, Gonzalez H, Byrnes D, Brady J, Fandiño J, Laffey JG, O'Toole D. Hypercapnia in the critically ill: insights from the bench to the bedside. Interface Focus 2021; 11:20200032. [PMID: 33628425 PMCID: PMC7898152 DOI: 10.1098/rsfs.2020.0032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 01/16/2023] Open
Abstract
Carbon dioxide (CO2) has long been considered, at best, a waste by-product of metabolism, and at worst, a toxic molecule with serious health consequences if physiological concentration is dysregulated. However, clinical observations have revealed that 'permissive' hypercapnia, the deliberate allowance of respiratory produced CO2 to remain in the patient, can have anti-inflammatory effects that may be beneficial in certain circumstances. In parallel, studies at the cell level have demonstrated the profound effect of CO2 on multiple diverse signalling pathways, be it the effect from CO2 itself specifically or from the associated acidosis it generates. At the whole organism level, it now appears likely that there are many biological sensing systems designed to respond to CO2 concentration and tailor respiratory and other responses to atmospheric or local levels. Animal models have been widely employed to study the changes in CO2 levels in various disease states and also to what extent permissive or even directly delivered CO2 can affect patient outcome. These findings have been advanced to the bedside at the same time that further clinical observations have been elucidated at the cell and animal level. Here we present a synopsis of the current understanding of how CO2 affects mammalian biological systems, with a particular emphasis on inflammatory pathways and diseases such as lung specific or systemic sepsis. We also explore some future directions and possibilities, such as direct control of blood CO2 levels, that could lead to improved clinical care in the future.
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Clyde TP, Coletta M, Jones CW, Kilgannon H, Fuller BM, Trzeciak S, Roberts BW. Effects of hypercapnia in sepsis: A scoping review of clinical and pre-clinical data. Acta Anaesthesiol Scand 2021; 65:430-437. [PMID: 33315238 DOI: 10.1111/aas.13763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/23/2020] [Accepted: 11/29/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND Perform a scoping review of (1) pre-clinical studies testing the physiological effects of higher PaCO2 levels in the setting of sepsis models and (2) clinical investigations testing the effects of hypercapnia on clinical outcomes in mechanically ventilated patients with sepsis. METHODS We performed a search of CENTRAL, PUBMED, CINAHL, and EMBASE. Study inclusion criteria for pre-clinical studies were: (1) bacterial sepsis model (2) measurement of PaCO2 , and (3) comparison of outcome measure between different PaCO2 levels. Inclusion criteria for clinical studies were: (1) diagnosis of sepsis, (2) receiving invasive mechanical ventilation, (3) measurement of PaCO2 , and (4) comparison of outcomes between different PaCO2 levels. We performed a qualitative analysis to collate and summarize the physiological and clinical effects of hypercapnia according to the recommended methodology from the Cochrane Handbook. RESULTS Fifteen pre-clinical and nine clinical studies were included. Among pre-clinical studies, the individual studies found higher PaCO2 augments tissue blood flow and oxygenation, and attenuates inflammation and lung injury; however, all pre-clinical studies were found to have some degree of risk of bias. Six of the nine clinical studies were deemed to be good quality. Among clinical studies hypercapnia was associated with increased cerebral perfusion and oxygenation; however, there were conflicting results testing the association between hypercapnia and mortality. CONCLUSION While individual pre-clinical studies identified potential mechanisms by which changes in PaCO2 levels could affect pathophysiology in sepsis, there is a paucity of clinical data as to the optimal PaCO2 range, demonstrating a need for future research. REGISTRATION PROSPERO number CRD42018086703.
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Affiliation(s)
- Thomas P Clyde
- The Department of Medicine, Cooper University Hospital, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Michael Coletta
- The Department of Emergency Medicine, Cooper University Hospital, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Christopher W Jones
- The Department of Emergency Medicine, Cooper University Hospital, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Hope Kilgannon
- The Department of Emergency Medicine, Cooper University Hospital, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Brian M Fuller
- Departments of Emergency Medicine and Anesthesiology, Division of Critical Care Medicine, Washington University School of Medicine, St. Louis, MI, USA
| | - Stephen Trzeciak
- The Department of Medicine, Cooper University Hospital, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Brian W Roberts
- The Department of Emergency Medicine, Cooper University Hospital, Cooper Medical School of Rowan University, Camden, NJ, USA
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Chand R, Swenson ER, Goldfarb DS. Sodium bicarbonate therapy for acute respiratory acidosis. Curr Opin Nephrol Hypertens 2021; 30:223-230. [PMID: 33395037 DOI: 10.1097/mnh.0000000000000687] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Respiratory acidosis is commonly present in patients with respiratory failure. The usual treatment of hypercapnia is to increase ventilation. During the recent surge of COVID-19, respiratory acidosis unresponsive to increased mechanical ventilatory support was common. Increasing mechanical ventilation comes at the expense of barotrauma and hemodynamic compromise from increasing positive end-expiratory pressures or minute ventilation. Treating acute respiratory acidemia with sodium bicarbonate remains controversial. RECENT FINDINGS There are no randomized controlled trials of administration of sodium bicarbonate for respiratory acidemia. A recent review concluded that alkali therapy for mixed respiratory and metabolic acidosis might be useful but was based on the conflicting and not conclusive literature regarding metabolic acidosis. This strategy should not be extrapolated to treatment of respiratory acidemia. Low tidal volume ventilation in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) has beneficial effects associated with permissive hypercapnia. Whether the putative benefits will be negated by administration of alkali is not known. Hypercapnic acidosis is well tolerated, with few adverse effects as long as tissue perfusion and oxygenation are maintained. SUMMARY There is a lack of clinical evidence that administration of sodium bicarbonate for respiratory acidosis has a net benefit; in fact, there are potential risks associated with it.
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Affiliation(s)
- Ranjeeta Chand
- Nephrology Division, New York University Langone Health and Nephrology Section, NY Harbor VA Healthcare System
| | - Erik R Swenson
- Pulmonary, Critical Care and Sleep Medicine Division, University of Washington, and VA Puget Sound Healthcare System, Seattle, Washington, USA
| | - David S Goldfarb
- Nephrology Division, New York University Langone Health and Nephrology Section, NY Harbor VA Healthcare System
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Efficacy and Safety of Carbon Dioxide Versus Air Insufflation for Colonoscopy in Deeply Sedated Pediatric Patients. J Pediatr Gastroenterol Nutr 2020; 71:34-39. [PMID: 32044831 DOI: 10.1097/mpg.0000000000002650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Studies have shown the advantages of carbon dioxide (CO2) over air insufflation in the adult population during colonoscopies. This study was designed to investigate the efficacy and safety of CO2 insufflation in deeply sedated children undergoing colonoscopy. METHODS This was a prospective, randomized, double-blind clinical trial. We recruited 100 consecutive pediatric patients who had colonoscopy under deep sedation for various indications. Patients were first randomized by history of abdominal pain and then randomly assigned to either CO2 or air insufflation. Postprocedural abdominal pain scores were registered on a 10-point visual analog rating scale and significant pain was defined as a score of 3 or higher. Abdominal circumferences and end tidal CO2 (ETCO2) levels were measured. Complications during and after the procedure were recorded. RESULTS We did not find statistically significant difference between CO2 and air insufflation on univariate analysis because of low number of children experiencing significant pain after colonoscopy. After adjusting for baseline pain, we found that pain was significantly lower in patients after CO2 versus air insufflation on multivariable analysis (P = 0.03). The significant factors related to pain were duration of the procedure (P = 0.006), history of abdominal pain (P = 0.002) and previous abdominal surgery (P = 0.02). CO2 insufflation was associated with decreased abdominal circumference after colonoscopy (P = 0.002). Girls were more likely to have pain regardless of intervention (P = .04). CONCLUSIONS Most children tolerate endoscopic procedures without significant pain. Our study was underpowered to show significant difference between air and CO2 on univariate analysis. CO2 insufflation during colonoscopy, however, may reduce postprocedural abdominal pain. Significant factors for increased pain on multivariate analysis included colonoscopy length over 30 minutes, history of abdominal pain, and previous abdominal surgery.
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Pre-Treatment with Ten-Minute Carbon Dioxide Inhalation Prevents Lipopolysaccharide-Induced Lung Injury in Mice via Down-Regulation of Toll-Like Receptor 4 Expression. Int J Mol Sci 2019; 20:ijms20246293. [PMID: 31847115 PMCID: PMC6940754 DOI: 10.3390/ijms20246293] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/07/2019] [Accepted: 12/11/2019] [Indexed: 12/29/2022] Open
Abstract
Various animal studies have shown beneficial effects of hypercapnia in lung injury. However, in patients with acute respiratory distress syndrome (ARDS), there is controversial information regarding the effect of hypercapnia on outcomes. The duration of carbon dioxide inhalation may be the key to the protective effect of hypercapnia. We investigated the effect of pre-treatment with inhaled carbon dioxide on lipopolysaccharide (LPS)-induced lung injury in mice. C57BL/6 mice were randomly divided into a control group or an LPS group. Each LPS group received intratracheal LPS (2 mg/kg); the LPS groups were exposed to hypercapnia (5% carbon dioxide) for 10 min or 60 min before LPS. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected to evaluate the degree of lung injury. LPS significantly increased the ratio of lung weight to body weight; concentrations of BALF protein, tumor necrosis factor-α, and CXCL2; protein carbonyls; neutrophil infiltration; and lung injury score. LPS induced the degradation of the inhibitor of nuclear factor-κB-α (IκB-α) and nuclear translocation of NF-κB. LPS increased the surface protein expression of toll-like receptor 4 (TLR4). Pre-treatment with inhaled carbon dioxide for 10 min, but not for 60 min, inhibited LPS-induced pulmonary edema, inflammation, oxidative stress, lung injury, and TLR4 surface expression, and, accordingly, reduced NF-κB signaling. In summary, our data demonstrated that pre-treatment with 10-min carbon dioxide inhalation can ameliorate LPS-induced lung injury. The protective effect may be associated with down-regulation of the surface expression of TLR4 in the lungs.
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Radermacher P, Maggiore SM, Mercat A. FiftyYears ofResearch inARDS.Gas Exchange in Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med 2017; 196:964-984. [DOI: 10.1164/rccm.201610-2156so] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Peter Radermacher
- Institute of Anaesthesiological Pathophysiology and Process Engineering, University Medical School, Ulm, Germany
| | - Salvatore Maurizio Maggiore
- Section of Anesthesia, Analgesia, Perioperative, and Intensive Care, Department of Medical, Oral, and Biotechnological Sciences, School of Medicine and Health Sciences, “SS. Annunziata” Hospital, “Gabriele d’Annunzio” University of Chieti-Pescara, Chieti, Italy; and
| | - Alain Mercat
- Department of Medical Intensive Care and Hyperbaric Medicine, Angers University Hospital, Angers, France
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Effects of Different Crystalloid Solutions on Hemodynamics, Peripheral Perfusion, and the Microcirculation in Experimental Abdominal Sepsis. Anesthesiology 2016; 125:744-754. [PMID: 27655180 DOI: 10.1097/aln.0000000000001273] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Crystalloid solutions are used to restore intravascular volume in septic patients, but each solution has limitations. The authors compared the effects of three crystalloid solutions on hemodynamics, organ function, microcirculation, and survival in a sepsis model. METHODS Peritonitis was induced by injection of autologous feces in 21 anesthetized, mechanically ventilated adult sheep. After baseline measurements, animals were randomized to lactated Ringer's (LR), normal saline (NS), or PlasmaLyte as resuscitation fluid. The sublingual microcirculation was assessed using sidestream dark field videomicroscopy and muscle tissue oxygen saturation with near-infrared spectroscopy. RESULTS NS administration was associated with hyperchloremic acidosis. NS-treated animals had lower cardiac index and left ventricular stroke work index than LR-treated animals from 8 h and lower mean arterial pressure than LR-treated animals from 12 h. NS-treated animals had a lower proportion of perfused vessels than LR-treated animals after 12 h (median, 82 [71 to 83] vs. 85 [82 to 89], P = 0.04) and greater heterogeneity of proportion of perfused vessels than PlasmaLyte or LR groups at 18 h. Muscle tissue oxygen saturation was lower at 16 h in the NS group than in the other groups. The survival time of NS-treated animals was shorter than that of the LR group (17 [14 to 20] vs. 26 [23 to 29] h, P < 0.01) but similar to that of the PlasmaLyte group (20 [12 to 28] h, P = 0.74). CONCLUSIONS In this abdominal sepsis model, resuscitation with NS was associated with hyperchloremic acidosis, greater hemodynamic instability, a more altered microcirculation, and more severe organ dysfunction than with balanced fluids. Survival time was shorter than in the LR group.
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Vasopressin V1A receptors mediate the stabilization of intestinal mucosal oxygenation during hypercapnia in septic rats. Microvasc Res 2016; 106:24-30. [DOI: 10.1016/j.mvr.2016.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 02/28/2016] [Accepted: 03/05/2016] [Indexed: 12/27/2022]
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Chung KK, Rhie RY, Lundy JB, Cartotto R, Henderson E, Pressman MA, Joe VC, Aden JK, Driscoll IR, Faucher LD, McDermid RC, Mlcak RP, Hickerson WL, Jeng JC. A Survey of Mechanical Ventilator Practices Across Burn Centers in North America. J Burn Care Res 2016; 37:e131-9. [PMID: 26135527 PMCID: PMC5312724 DOI: 10.1097/bcr.0000000000000270] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Burn injury introduces unique clinical challenges that make it difficult to extrapolate mechanical ventilator (MV) practices designed for the management of general critical care patients to the burn population. We hypothesize that no consensus exists among North American burn centers with regard to optimal ventilator practices. The purpose of this study is to examine various MV practice patterns in the burn population and to identify potential opportunities for future research. A researcher designed, 24-item survey was sent electronically to 129 burn centers. The χ, Fisher's exact, and Cochran-Mantel-Haenszel tests were used to determine if there were significant differences in practice patterns. We analyzed 46 questionnaires for a 36% response rate. More than 95% of the burn centers reported greater than 100 annual admissions. Pressure support and volume assist control were the most common initial MV modes used with or without inhalation injury. In the setting of Berlin defined mild acute respiratory distress syndrome (ARDS), ARDSNet protocol and optimal positive end-expiratory pressure were the top ventilator choices, along with fluid restriction/diuresis as a nonventilator adjunct. For severe ARDS, airway pressure release ventilation and neuromuscular blockade were the most popular. The most frequently reported time frame for mechanical ventilation before tracheostomy was 2 weeks (25 of 45, 55%); however, all respondents reported in the affirmative that there are certain clinical situations where early tracheostomy is warranted. Wide variations in clinical practice exist among North American burn centers. No single ventilator mode or adjunct prevails in the management of burn patients regardless of pulmonary insult. Movement toward American Burn Association-supported, multicenter studies to determine best practices and guidelines for ventilator management in burn patients is prudent in light of these findings.
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Affiliation(s)
- Kevin K. Chung
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Ryan Y. Rhie
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Jonathan B. Lundy
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Robert Cartotto
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Elizabeth Henderson
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Melissa A. Pressman
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Victor C. Joe
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - James K. Aden
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Ian R. Driscoll
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Lee D. Faucher
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Robert C. McDermid
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - Ronald P. Mlcak
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - William L. Hickerson
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
| | - James C. Jeng
- From the United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Uniformed Services University of the Health Sciences, Bethesda, Maryland; Sunnybrook Health Sciences Centre, Toronto, Canada; Massachusetts General Hospital, Boston; Arizona Burn Center, Phoenix; University of California Irvine Regional Burn Center, Orange; University of Wisconsin Hospital, Madison; University of Alberta, Edmonton, Canada; Shriners Hospital for Children, Galveston, Texas; Memphis Burn Center, Memphis, Tennessee; and Mount Sinai Beth Israel Medical Center, New York, New York
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15
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Swenson ER. Hypoxia and Its Acid-Base Consequences: From Mountains to Malignancy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 903:301-23. [PMID: 27343105 DOI: 10.1007/978-1-4899-7678-9_21] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hypoxia, depending upon its magnitude and circumstances, evokes a spectrum of mild to severe acid-base changes ranging from alkalosis to acidosis, which can alter many responses to hypoxia at both non-genomic and genomic levels, in part via altered hypoxia-inducible factor (HIF) metabolism. Healthy people at high altitude and persons hyperventilating to non-hypoxic stimuli can become alkalotic and alkalemic with arterial pH acutely rising as high as 7.7. Hypoxia-mediated respiratory alkalosis reduces sympathetic tone, blunts hypoxic pulmonary vasoconstriction and hypoxic cerebral vasodilation, and increases hemoglobin oxygen affinity. These effects and others can be salutary or counterproductive to tissue oxygen delivery and utilization, based upon magnitude of each effect and summation. With severe hypoxia either in the setting of profound arterial hemoglobin desaturation and reduced O2 content or poor perfusion (ischemia) at the global or local level, metabolic and hypercapnic acidosis develop along with considerable lactate formation and pH falling to below 6.8. Although conventionally considered to be injurious and deleterious to cell function and survival, both acidoses may be cytoprotective by various anti-inflammatory, antioxidant, and anti-apoptotic mechanisms which limit total hypoxic or ischemic-reperfusion injury. Attempts to correct acidosis by giving bicarbonate or other alkaline agents under these circumstances ahead of or concurrent with reoxygenation efforts may be ill advised. Better understanding of this so-called "pH paradox" or permissive acidosis may offer therapeutic possibilities. Rapidly growing cancers often outstrip their vascular supply compromising both oxygen and nutrient delivery and metabolic waste disposal, thus limiting their growth and metastatic potential. However, their excessive glycolysis and lactate formation may not necessarily represent oxygen insufficiency, but rather the Warburg effect-an attempt to provide a large amount of small carbon intermediates to supply the many synthetic pathways of proliferative cell growth. In either case, there is expression and upregulation of many genes involved in acid-base homeostasis, in part by HIF-1 signaling. These include a unique isoform of carbonic anhydrase (CA-IX) and numerous membrane acid-base transporters engaged to maintain an optimal intracellular and extracellular pH for maximal growth. Inhibition of these proteins or gene suppression may have important therapeutic application in cancer chemotherapy.
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Affiliation(s)
- Erik R Swenson
- Pulmonary and Critical Care Medicine, Department of Medicine, University of Washington, Seattle, WA, USA. .,Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA. .,VA Puget Sound Health Care System, University of Washington, Seattle, WA, USA.
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16
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Kaynar O, Karapinar T, Hayirli A, Baydar E. Reliability of the Lactate Scout point-of-care instrument for the determination of bloodl-lactate concentration in sheep. Vet Clin Pathol 2015; 44:559-63. [DOI: 10.1111/vcp.12288] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Ozgur Kaynar
- Department of Biochemistry; Faculty of Veterinary Medicine; Ataturk University; Erzurum Turkey
| | - Tolga Karapinar
- Department of Internal Medicine; Faculty of Veterinary Medicine; Firat University; Elazig Turkey
| | - Armagan Hayirli
- Department of Animal Nutrition and Nutritional Disorders; Faculty of Veterinary Medicine; Ataturk University; Erzurum Turkey
| | - Ersoy Baydar
- Department of Internal Medicine; Faculty of Veterinary Medicine; Firat University; Elazig Turkey
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17
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18
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Curley GF, Laffey JG, Kavanagh BP. Rebuttal from Gerard F. Curley, John G. Laffey and Brian P. Kavanagh. J Physiol 2013; 591:2771-2. [PMID: 23729792 DOI: 10.1113/jphysiol.2013.255638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Gerard F Curley
- Department of Anesthesia, Keenan Research Centre in the Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada
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19
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Curley GF, Laffey JG, Kavanagh BP. CrossTalk proposal: there is added benefit to providing permissive hypercapnia in the treatment of ARDS. J Physiol 2013; 591:2763-5. [PMID: 23729790 DOI: 10.1113/jphysiol.2013.252601] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Gerard F Curley
- Department of Anesthesia, Keenan Research Centre in the Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada
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20
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Beitler JR, Hubmayr RD, Malhotra A. CrossTalk opposing view: there is not added benefit to providing permissive hypercapnia in the treatment of ARDS. J Physiol 2013; 591:2767-9. [PMID: 23729791 DOI: 10.1113/jphysiol.2013.252619] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Jeremy R Beitler
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, MA, USA.
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21
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Bautista AF, Akca O. Hypercapnia: is it protective in lung injury? Med Gas Res 2013; 3:23. [PMID: 24209944 PMCID: PMC3833649 DOI: 10.1186/2045-9912-3-23] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 11/05/2013] [Indexed: 11/10/2022] Open
Abstract
Hypercapnic acidosis has been regarded as a tolerated side effect of protective lung ventilation strategies. Various in vivo and ex vivo animal studies have shown beneficial effects in acute lung injury setting, but some recent work raised concerns about its anti-inflammatory properties. This mini-review article aims to expand the potential clinical spectrum of hypercapnic acidosis in critically ill patients with lung injury. Despite the proven benefits of hypercapnic acidosis, further safety studies including dose-effect, level-and-onset of anti-inflammatory effect, and safe applicability period need to be performed in various models of lung injury in animals and humans to further elucidate its protective role.
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Affiliation(s)
| | - Ozan Akca
- Department of Anesthesiology & Perioperative Medicine, University of Louisville, Louisville, KY 40202, USA.
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22
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Dries DJ, Endorf FW. Inhalation injury: epidemiology, pathology, treatment strategies. Scand J Trauma Resusc Emerg Med 2013; 21:31. [PMID: 23597126 PMCID: PMC3653783 DOI: 10.1186/1757-7241-21-31] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 04/11/2013] [Indexed: 01/19/2023] Open
Abstract
Lung injury resulting from inhalation of smoke or chemical products of combustion continues to be associated with significant morbidity and mortality. Combined with cutaneous burns, inhalation injury increases fluid resuscitation requirements, incidence of pulmonary complications and overall mortality of thermal injury. While many products and techniques have been developed to manage cutaneous thermal trauma, relatively few diagnosis-specific therapeutic options have been identified for patients with inhalation injury. Several factors explain slower progress for improvement in management of patients with inhalation injury. Inhalation injury is a more complex clinical problem. Burned cutaneous tissue may be excised and replaced with skin grafts. Injured pulmonary tissue must be protected from secondary injury due to resuscitation, mechanical ventilation and infection while host repair mechanisms receive appropriate support. Many of the consequences of smoke inhalation result from an inflammatory response involving mediators whose number and role remain incompletely understood despite improved tools for processing of clinical material. Improvements in mortality from inhalation injury are mostly due to widespread improvements in critical care rather than focused interventions for smoke inhalation. Morbidity associated with inhalation injury is produced by heat exposure and inhaled toxins. Management of toxin exposure in smoke inhalation remains controversial, particularly as related to carbon monoxide and cyanide. Hyperbaric oxygen treatment has been evaluated in multiple trials to manage neurologic sequelae of carbon monoxide exposure. Unfortunately, data to date do not support application of hyperbaric oxygen in this population outside the context of clinical trials. Cyanide is another toxin produced by combustion of natural or synthetic materials. A number of antidote strategies have been evaluated to address tissue hypoxia associated with cyanide exposure. Data from European centers supports application of specific antidotes for cyanide toxicity. Consistent international support for this therapy is lacking. Even diagnostic criteria are not consistently applied though bronchoscopy is one diagnostic and therapeutic tool. Medical strategies under investigation for specific treatment of smoke inhalation include beta-agonists, pulmonary blood flow modifiers, anticoagulants and antiinflammatory strategies. Until the value of these and other approaches is confirmed, however, the clinical approach to inhalation injury is supportive.
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Affiliation(s)
- David J Dries
- Department of Surgery, Regions Hospital, St. Paul, MN 55101, USA.
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23
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Moderate and prolonged hypercapnic acidosis may protect against ventilator-induced diaphragmatic dysfunction in healthy piglet: an in vivo study. Crit Care 2013; 17:R15. [PMID: 23347872 PMCID: PMC4056755 DOI: 10.1186/cc12486] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 01/07/2013] [Indexed: 11/10/2022] Open
Abstract
Introduction Protective ventilation by using limited airway pressures and ventilation may result in moderate and prolonged hypercapnic acidosis, as often observed in critically ill patients. Because allowing moderate and prolonged hypercapnia may be considered protective measure for the lungs, we hypothesized that moderate and prolonged hypercapnic acidosis may protect the diaphragm against ventilator-induced diaphragmatic dysfunction (VIDD). The aim of our study was to evaluate the effects of moderate and prolonged (72 hours of mechanical ventilation) hypercapnic acidosis on in vivo diaphragmatic function. Methods Two groups of anesthetized piglets were ventilated during a 72-hour period. Piglets were assigned to the Normocapnia group (n = 6), ventilated in normocapnia, or to the Hypercapnia group (n = 6), ventilated with moderate hypercapnic acidosis (PaCO2 from 55 to 70 mm Hg) during the 72-hour period of the study. Every 12 hours, we measured transdiaphragmatic pressure (Pdi) after bilateral, supramaximal transjugular stimulation of the two phrenic nerves to assess in vivo diaphragmatic contractile force. Pressure/frequency curves were drawn after stimulation from 20 to 120 Hz of the phrenic nerves. The protocol was approved by our institutional animal-care committee. Results Moderate and prolonged hypercapnic acidosis was well tolerated during the study period. The baseline pressure/frequency curves of the two groups were not significantly different (Pdi at 20 Hz, 32.7 ± 8.7 cm H2O, versus 34.4 ± 8.4 cm H2O; and at 120 Hz, 56.8 ± 8.7 cm H2O versus 60.8 ± 5.7 cm H2O, for Normocapnia and Hypercapnia groups, respectively). After 72 hours of ventilation, Pdi decreased by 25% of its baseline value in the Normocapnia group, whereas Pdi did not decrease in the Hypercapnia group. Conclusions Moderate and prolonged hypercapnic acidosis limited the occurrence of VIDD during controlled mechanical ventilation in a healthy piglet model. Consequences of moderate and prolonged hypercapnic acidosis should be better explored with further studies before being tested on patients.
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24
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Tsuji T, Aoshiba K, Itoh M, Nakamura H, Yamaguchi K. Hypercapnia accelerates wound healing in endothelial cell monolayers exposed to hypoxia. Open Respir Med J 2013; 7:6-12. [PMID: 23524473 PMCID: PMC3601342 DOI: 10.2174/1874306401307010006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 02/01/2013] [Accepted: 02/03/2013] [Indexed: 02/07/2023] Open
Abstract
INTRODUCTION While tissue hypoxia is known to play a critical role in the process of vascular injury and repair, the effect of hypercapnia on this process remains uncertain. We investigated whether hypercapnia might influence endothelial cell wound healing under the influence of hypoxia. MATERIALS AND METHODOLOGY Monolayers of human umbilical venous endothelial cells (HUVECs) were scratch-wounded and incubated under different levels of O2, CO2, and pH in the environment. RESULTS Inhibition of wound healing was observed in the HUVEC monolayers under the hypoxic condition as compared to the normoxic condition. Both hypercapnic acidosis and buffered hypercapnia, but not normocapnic acidosis improved the rate of wound healing under the influence of hypoxia. The beneficial effect of hypercapnia was associated with stimulation of cell proliferation, without effects on cell adhesion, migration or apoptosis. On the other hand, the stimulatory effect of hypercapnia on wound healing and cell proliferation was not noted under normoxic conditions. CONCLUSION These results suggest that hypercapnia, rather than acidosis per se, accelerated the wound healing in HUVEC monolayers cultured under hypoxic conditions. The effect of hypercapnia on wound healing was due, at least in part, to the stimulation of cell proliferation by hypercapnia.
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Affiliation(s)
- Takao Tsuji
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami, Inashiki, Ibaraki 300-0395, Japan
| | - Kazutetsu Aoshiba
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami, Inashiki, Ibaraki 300-0395, Japan
- Address correspondence to this author at the Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center3-20-1, Chuou, Ami, Inashiki, Ibaraki 300-0395, Japan; Tel: 81-29-887-1161;
Fax 81-29-888-3463; E-mail:
| | - Masayuki Itoh
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami, Inashiki, Ibaraki 300-0395, Japan
| | - Hiroyuki Nakamura
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami, Inashiki, Ibaraki 300-0395, Japan
| | - Kazuhiro Yamaguchi
- Comprehensive and Internal Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10 nishi-ogu, Arakawa-ku, Tokyo 116-8567, Japan
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25
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Nilsson MCA, Fredén F, Larsson A, Wiklund P, Bergquist M, Hambraeus-Jonzon K. Hypercapnic acidosis transiently weakens hypoxic pulmonary vasoconstriction without affecting endogenous pulmonary nitric oxide production. Intensive Care Med 2012; 38:509-17. [PMID: 22270473 DOI: 10.1007/s00134-012-2482-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 12/06/2011] [Indexed: 11/29/2022]
Abstract
PURPOSE Hypercapnic acidosis often occurs in critically ill patients and during protective mechanical ventilation; however, the effect of hypercapnic acidosis on endogenous nitric oxide (NO) production and hypoxic pulmonary vasoconstriction (HPV) presents conflicting results. The aim of this study is to test the hypothesis that hypercapnic acidosis augments HPV without changing endogenous NO production in both hyperoxic and hypoxic lung regions in pigs. METHODS Sixteen healthy anesthetized pigs were separately ventilated with hypoxic gas to the left lower lobe (LLL) and hyperoxic gas to the rest of the lung. Eight pigs received 10% carbon dioxide (CO(2)) inhalation to both lung regions (hypercapnia group), and eight pigs formed the control group. NO concentration in exhaled air (ENO), nitric oxide synthase (NOS) activity, cyclic guanosine monophosphate (cGMP) in lung tissue, and regional pulmonary blood flow were measured. RESULTS There were no differences between the groups for ENO, Ca(2+)-independent or Ca(2+)-dependent NOS activity, or cGMP in hypoxic or hyperoxic lung regions. Relative perfusion to LLL (Q (LLL)/Q (T)) was reduced similarly in both groups when LLL hypoxia was induced. During the first 90 min of hypercapnia, Q (LLL)/Q (T) increased from 6% (1%) [mean (standard deviation, SD)] to 9% (2%) (p < 0.01), and then decreased to the same level as the control group, where Q (LLL)/Q (T) remained unchanged. Cardiac output increased during hypercapnia (p < 0.01), resulting in increased oxygen delivery (p < 0.01), despite decreased PaO(2) (p < 0.01)(.) CONCLUSIONS Hypercapnic acidosis does not potentiate HPV, but rather transiently weakens HPV, and does not affect endogenous NO production in either hypoxic or hyperoxic lung regions.
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Affiliation(s)
- Manja C A Nilsson
- Department of Anesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden.
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26
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Fuchs H, Mendler MR, Scharnbeck D, Ebsen M, Hummler HD. Very low tidal volume ventilation with associated hypercapnia--effects on lung injury in a model for acute respiratory distress syndrome. PLoS One 2011; 6:e23816. [PMID: 21886825 PMCID: PMC3158784 DOI: 10.1371/journal.pone.0023816] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 07/27/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Ventilation using low tidal volumes with permission of hypercapnia is recommended to protect the lung in acute respiratory distress syndrome. However, the most lung protective tidal volume in association with hypercapnia is unknown. The aim of this study was to assess the effects of different tidal volumes with associated hypercapnia on lung injury and gas exchange in a model for acute respiratory distress syndrome. METHODOLOGY/PRINCIPAL FINDINGS In this randomized controlled experiment sixty-four surfactant-depleted rabbits were exposed to 6 hours of mechanical ventilation with the following targets: Group 1: tidal volume = 8-10 ml/kg/PaCO(2) = 40 mm Hg; Group 2: tidal volume = 4-5 ml/kg/PaCO(2) = 80 mm Hg; Group 3: tidal volume = 3-4 ml/kg/PaCO(2) = 120 mm Hg; Group 4: tidal volume = 2-3 ml/kg/PaCO(2) = 160 mm Hg. Decreased wet-dry weight ratios of the lungs, lower histological lung injury scores and higher PaO(2) were found in all low tidal volume/hypercapnia groups (group 2, 3, 4) as compared to the group with conventional tidal volume/normocapnia (group 1). The reduction of the tidal volume below 4-5 ml/kg did not enhance lung protection. However, oxygenation and lung protection were maintained at extremely low tidal volumes in association with very severe hypercapnia and no adverse hemodynamic effects were observed with this strategy. CONCLUSION Ventilation with low tidal volumes and associated hypercapnia was lung protective. A tidal volume below 4-5 ml/kg/PaCO(2) 80 mm Hg with concomitant more severe hypercapnic acidosis did not increase lung protection in this surfactant deficiency model. However, even at extremely low tidal volumes in association with severe hypercapnia lung protection and oxygenation were maintained.
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Affiliation(s)
- Hans Fuchs
- Division of Neonatology and Pediatric Critical Care, Department of Pediatrics and Adolescent Medicine, Ulm University, Ulm, Germany.
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27
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Curley G, Hayes M, Laffey JG. Can 'permissive' hypercapnia modulate the severity of sepsis-induced ALI/ARDS? CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2011; 15:212. [PMID: 21457509 PMCID: PMC3219408 DOI: 10.1186/cc9994] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Gerard Curley
- Department of Anestheisa, Clinical Sciences Institute, National University, Galway, Ireland
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Hypercapnic Acidosis Preserves Gastric Mucosal Microvascular Oxygen Saturation in a Canine Model of Hemorrhage. Shock 2010; 34:636-42. [DOI: 10.1097/shk.0b013e3181e68422] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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29
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Bench-to-bedside review: hypercapnic acidosis in lung injury--from 'permissive' to 'therapeutic'. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:237. [PMID: 21067531 PMCID: PMC3220022 DOI: 10.1186/cc9238] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Modern ventilation strategies for patients with acute lung injury and acute respiratory distress syndrome frequently result in hypercapnic acidosis (HCA), which is regarded as an acceptable side effect ('permissive hypercapnia'). Multiple experimental studies have demonstrated advantageous effects of HCA in several lung injury models. To date, however, human trials studying the effect of carbon dioxide per se on outcome in patients with lung injury have not been performed. While significant concerns regarding HCA remain, in particular the possible unfavorable effects on bacterial killing and the inhibition of pulmonary epithelial wound repair, the potential for HCA in attenuating lung injury is promising. The underlying mechanisms by which HCA exerts its protective effects are complex, but dampening of the inflammatory response seems to play a pivotal role. After briefly summarizing the physiological effects of HCA, a critical analysis of the available evidence on the potential beneficial effects of therapeutic HCA from in vitro, ex vivo and in vivo lung injury models and from human studies will be reviewed. In addition, the potential concerns in the clinical setting will be outlined.
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Abstract
Carbon dioxide is a waste product of aerobic cellular respiration in all aerobic life forms. PaCO2 represents the balance between the carbon dioxide produced and that eliminated. Hypocapnia remains a common - and generally underappreciated - component of many disease states, including early asthma, high-altitude pulmonary edema, and acute lung injury. Induction of hypocapnia remains a common, if controversial, practice in both adults and children with acute brain injury. In contrast, hypercapnia has traditionally been avoided in order to keep parameters normal. More recently, advances in our understanding of the role of excessive tidal volume has prompted clinicians to use ventilation strategies that result in hypercapnia. Consequently, hypercapnia has become increasingly prevalent in the critically ill patient. Hypercapnia may play a beneficial role in the pathogenesis of inflammation and tissue injury, but may hinder the host response to sepsis and reduce repair. In contrast, hypocapnia may be a pathogenic entity in the setting of critical illness. The present paper reviews the current clinical status of low and high PaCO2 in the critically ill patient, discusses the insights gained to date from studies of carbon dioxide, identifies key concerns regarding hypocapnia and hypercapnia, and considers the potential clinical implications for the management of patients with acute lung injury.
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Affiliation(s)
- Gerard Curley
- Department of Anaesthesia, Clinical Sciences Institute, National University of Ireland, Galway, Ireland
- Lung Biology Group, National Centre of Biomedical Engineering Sciences, National University of Ireland, Galway, Ireland
| | - John G Laffey
- Department of Anaesthesia, Clinical Sciences Institute, National University of Ireland, Galway, Ireland
- Lung Biology Group, National Centre of Biomedical Engineering Sciences, National University of Ireland, Galway, Ireland
| | - Brian P Kavanagh
- Departments of Critical Care Medicine and Anesthesia and the Program in Physiology and Experimental Medicine, The Hospital for Sick Children, University of Toronto, 555 university Avenue, Toronto, ON M5G 1X8, Canada
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[Microcirculatory alterations in critically ill patients: pathophysiology, monitoring and treatments]. ACTA ACUST UNITED AC 2010; 29:135-44. [PMID: 20116198 DOI: 10.1016/j.annfar.2009.10.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Accepted: 10/28/2009] [Indexed: 01/18/2023]
Abstract
Microcirculation represents a complex system devoted to provide optimal tissue substrates and oxygen. Therefore, pathophysiological and technological knowledge developments tailored for capillary circulation analysis should generate major advances for critically ill patients' management. In the future, microcirculatory monitoring in several critical care situations will allow recognition of macro-microcirculatory decoupling, and, hopefully, it will promote the use of treatments aimed at preserving tissue oxygenation and substrate delivery.
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A LARGE-BOLUS INJECTION, BUT NOT CONTINUOUS INFUSION OF SODIUM SELENITE IMPROVES OUTCOME IN PERITONITIS. Shock 2009; 32:140-6. [DOI: 10.1097/shk.0b013e318193c35d] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Hypercapnic acidosis attenuates shock and lung injury in early and prolonged systemic sepsis. Crit Care Med 2009; 37:2412-20. [DOI: 10.1097/ccm.0b013e3181a385d3] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Fowler RA, Adhikari NKJ, Scales DC, Lee WL, Rubenfeld GD. Update in critical care 2008. Am J Respir Crit Care Med 2009; 179:743-58. [PMID: 19383928 DOI: 10.1164/rccm.200902-0207up] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Robert A Fowler
- University of Toronto, Department of Medicine, Sunnybrook Health Sciences Centre, Chief, Program in Trauma, Emergency, and Critical Care, Toronto, ON, M4V 1E5 Canada
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Gnaegi A, Feihl F, Boulat O, Waeber B, Liaudet L. Moderate hypercapnia exerts beneficial effects on splanchnic energy metabolism during endotoxemia. Intensive Care Med 2009; 35:1297-304. [PMID: 19373455 DOI: 10.1007/s00134-009-1488-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Accepted: 03/22/2009] [Indexed: 02/07/2023]
Abstract
PURPOSE Low tidal volume ventilation and permissive hypercapnia are required in patients with sepsis complicated by ARDS. The effects of hypercapnia on tissue oxidative metabolism in this setting are unknown. We therefore determined the effects of moderate hypercapnia on markers of systemic and splanchnic oxidative metabolism in an animal model of endotoxemia. METHODS Anesthetized rats maintained at a PaCO(2) of 30, 40 or 60 mmHg were challenged with endotoxin. A control group (PaCO(2) 40 mmHg) received isotonic saline. Hemodynamic variables, arterial lactate, pyruvate, and ketone bodies were measured at baseline and after 4 h. Tissue adenosine triphosphate (ATP) and lactate were measured in the small intestine and the liver after 4 h. RESULTS Endotoxin resulted in low cardiac output, increased lactate/pyruvate ratio and decreased ketone body ratio. These changes were not influenced by hypercapnia, but were more severe with hypocapnia. In the liver, ATP decreased and lactate increased independently from PaCO(2) after endotoxin. In contrast, the drop of ATP and the rise in lactate triggered by endotoxin in the intestine were prevented by hypercapnia. CONCLUSIONS During endotoxemia in rats, moderate hypercapnia prevents the deterioration of tissue energetics in the intestine.
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Affiliation(s)
- Alex Gnaegi
- Division of Clinical Pathophysiology and Medical Teaching, Faculty of Biology and Medicine, University Hospital Center, CHUV-BH 08-621, 1011, Lausanne, Switzerland
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Das S, Du Z, Bassly S, Singer L, Vicencio AG. Effects of chronic hypercapnia in the neonatal mouse lung and brain. Pediatr Pulmonol 2009; 44:176-82. [PMID: 19142892 DOI: 10.1002/ppul.20971] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Permissive hypercapnia is increasingly utilized in the care of premature infants to prevent bronchopulmonary dysplasia. In a previous investigation, we described gene expression changes in the neonatal mouse lung exposed to chronic hypercapnia that might contribute to lung protection and accelerated maturation. However, it is unknown whether chronic hypercapnia increases alveolar formation, nor if it has detrimental effects in other developing organs such as the brain. OBJECTIVE To determine whether chronic hypercapnia accelerates early alveolar formation and increases neuronal cell injury in the developing mouse lung and brain, respectively. DESIGN Mouse pups were exposed to 8% CO(2) + 21% O(2) starting at postnatal day (P) 2 until P7. Control animals were maintained in room air. Animals were sacrificed at P4 or P7, and lungs and brains were excised and analyzed. RESULTS Exposure to 8% CO(2) resulted in an increased expression of alpha-smooth muscle actin (alpha-sma) which localized to the tips of developing alveolar buds, and also an increased number of alveolar buds at P7. Importantly, hypercapnic animals also demonstrated evidence of increased TUNEL-positive cells in the brain. CONCLUSIONS Exposure to chronic hypercapnia may lead to early initiation of alveolar budding in the neonatal mouse, but may also lead to increased TUNEL-positive cells in the developing brain.
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Affiliation(s)
- Sumon Das
- Department of Pediatrics, Division of Critical Care Medicine, Albert Einstein College of Medicine and Children's Hospital at Montefiore, Bronx, New York 10467, USA
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Key Questions in Ventilator Management of the Burn-Injured Patient (First of Two Parts). J Burn Care Res 2009; 30:128-38. [DOI: 10.1097/bcr.0b013e318191fe44] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Akça O. Carbon dioxide and tissue oxygenation: is there sufficient evidence to support application of hypercapnia for hemodynamic stability and better tissue perfusion in sepsis? Intensive Care Med 2008; 34:1752-4. [DOI: 10.1007/s00134-008-1184-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Accepted: 05/27/2008] [Indexed: 10/21/2022]
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Lactate and base deficit become worse immediately after reperfusion following hemorrhagic shock and are improved with hypoventilation. Resuscitation 2008. [DOI: 10.1016/j.resuscitation.2008.03.222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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