Acute respiratory distress syndrome and pneumothorax

Impact of pneumothorax on mortality, morbidity, and hospital resource utilization in COVID-19 patients: a propensity matched analysis of nationwide inpatient sample database

BACKGROUND

Spontaneous pneumothorax (PTX) is more prevalent among COVID-19 patients than other critically ill patients, but studies on this are limited. This study compared clinical characteristics and in-hospital outcomes among COVID-19 patients with concomitant PTX to provide insight into how PTX affects health care utilization and complications, which informs clinical decisions and healthcare resource allocation.

METHODS

The 2020 Nationwide Inpatient Sample was used analyze patient demographics and outcomes, including age, race, sex, insurance status, median income, length of hospital stay, mortality rate, hospitalization costs, comorbidities, mechanical ventilation, and vasopressor support. Propensity score matching was employed for additional analysis.

RESULTS

Among 1,572,815 COVID-19 patients, 1.41% had PTX. These patients incurred significantly higher hospitalization costs ($435,508 vs. $96,668, p < 0.001) and longer stays (23.6 days vs. 8.6 days, p < 0.001). In-hospital mortality was substantially elevated for PTX patients (65.8% vs. 14.4%, p < 0.001), with an adjusted odds ratio of 14.3 (95% CI 12.7-16.2). Additionally, these patients were more likely to require vasopressors (16.6% vs. 3.3%), mechanical circulatory support (3.5% vs. 0.3%), hemodialysis (16.6% vs. 5.6%), invasive mechanical ventilation (76.9% vs. 15.1%), non-invasive mechanical ventilation (19.1% vs. 5.8%), tracheostomy (13.3% vs. 1.1%), and chest tube placement (59.8% vs. 0.8%).

CONCLUSIONS

Our findings highlight the severe impact of PTX on COVID-19 patients, characterized by higher mortality, more complications, and increased resource utilization. Also, being Hispanic, male, or obese increased the risk of developing concomitant PTX with COVID-19.

Clinical characteristics of pneumothorax and pneumomediastinum in mechanical ventilated patients with coronavirus disease 2019: a case series

BACKGROUND

Pneumothorax (PTX) and pneumomediastinum (PM) have been reported as potential complications in patients with coronavirus disease 2019 (COVID-19); however, their risk factors and etiology remain unknown. Herein, we investigated the clinical characteristics of mechanically ventilated patients with COVID-19 with PTX or PM.

METHODS

We examined patients with severe COVID-19 requiring mechanical ventilation who were admitted to the intensive care unit of a tertiary-level emergency medical center in Tokyo, Japan between April 1, 2020. and October 31, 2021. We collected and analyzed the clinical characteristics of the patients who presented with either PTX or PM during mechanical ventilation.

RESULTS

During the study period, a total of 165 patients required mechanical ventilation, and 15 patients with PTX/PM during mechanical ventilation were selected. Three patients with obvious causes were excluded, and the remaining 12 patients were analyzed (7.3%). The mortality rate in these patients was as high as 50%, demonstrating the difficulty of treatment in the presence of PTX/PM. PTX/PM occurred 14.5 days after intubation. A peak pressure of > 30 cmH2O was only apparent in one patient, suggesting that high positive pressure ventilation may be less involved than mentioned in the literature. In addition, the inspiratory effort was not strong in our group of patients. (P0.1 was 2.1 cm H2O [1.0-3.8]).

CONCLUSION

Various factors are associated with the development of PTX/PM in patients on mechanical ventilation for COVID-19. We did not find a strong correlation between PTM/PM and barotrauma or strong inspiratory efforts, which have been identified as potential causes in previous studies.

Pneumomediastinum and pneumothorax in acute respiratory distress syndrome (ARDS) patients: a narrative review

Background and Objective

Acute respiratory distress syndrome (ARDS) is a severe, life-threatening medical condition characterized by poor oxygenation due to non-compliant lungs secondary diffuse alveolar damage. Encouragingly, the incidence of ARDS has declined steadily recently, attributed mainly to implementation of keystone guidelines and continuous research efforts. Mechanical ventilation is the cornerstone of supportive care for ARDS patients. This review aims to consolidate the current knowledge on pneumothorax (PNX) and pneumomediastinum (PMD) and to enhance the understanding of the readers. The objectives are to (I) explore the etiology and risk factors of PNX and PMD, (II) discuss the various diagnostic modalities available, (III) evaluate management options, and (IV) recent advancements.

Methods

A search of the literature was conducted using PubMed, MEDLINE, and Google Scholar for relevant articles pertaining to PNX and PMD in ARDS population. The clinical presentation, diagnostic and management strategies of PNX, PMD, and ARDS were summarized, and all authors reviewed the selection and decide which studies to include.

Key Content and Findings

The adoption of lung-protective ventilation strategies, based on the review of literature from the recent years, shows that it has played a significant role in reducing the occurrence of barotrauma, such as PNX and PMD. However, PNX and PMD remains to be a challenging complication to manage. With a specific focus on PNX and PMD, this review provides valuable insights into effectively managing and understanding these critical complications among ARDS patients.

Conclusions

ARDS, with its evolving definition, continues to pose a life-threatening threat. Despite the widespread adoption of lung-protective ventilation strategies, PNX and PMD present persistent challenges in management. Further research is imperative to enhance the risk assessment of ARDS patients prone to developing PNX and PMD and to institute more effective prevention and treatment measures.

The outcome of high-frequency oscillatory ventilation in pediatric patients with acute respiratory distress syndrome in an intensive care unit

BACKGROUND

In adults with acute respiratory distress syndrome (ARDS), high-frequency oscillatory ventilation (HFOV) has been associated with higher mortality rates. Therefore, its use in children with ARDS is still controversial.

OBJECTIVES

Evaluate the overall mortality of HFOV in children with ARDS and explore mortality-related risk factors; compare the outcome of using HFOV post-endotracheal intubation early (≤24 hours) versus late (≤24 hours).

DESIGN

Retrospective (medical record review) SETTING: Pediatric intensive care unit in a tertiary care center in Saudi Arabia.

PATIENTS AND METHODS

Data were collected from medical records of all pediatric patients with ARDS aged one week to 14 years, who were admitted to the pediatric intensive care unit (PICU) from January 2016-June 2019 and who required HFOV.

MAIN OUTCOME MEASURES

PICU mortality.

SAMPLE SIZE AND CHARACTERISTICS

135 ARDS patients including 74 females (54.8%), and 61 males (45.2%), with a median age (interquar-tile range) of 35 (72) months.

RESULTS

The overall mortality rate was 60.0% (81/135), and most died in the first 28 days in the PICU (91.3%, 74/8). Of non-survivors, 75.3% (61/81) were immunocompromised, and 24.7% (20/81) were immuno-competent patients, 52 (64.2%) received inotropic support, 40 (49.4%) had a bone-marrow transplant (BMT) before HFOV initiation. Although the prone position was used in 20.7% (28/135) to improve the survival rate post-HFOV ventilation, only 28.6% (8/28) survived. In addition, altered code status or chemotherapy reported a significant association with mortality (P<.05). Interestingly, early HFOV initiation (≤24 hours) did not seem to have a high impact on survival compared to late initiation (>24 hours); (57.4% vs. 42.6%, P=.721).

CONCLUSION

Immunocompromised and oncology patients, including post-BMT, reported poorer outcomes, and neither the prone position nor early use of HFOV improved outcomes. However, it is recommended to replicate the study in a larger cohort to generalize the results.

LIMITATIONS

Retrospective single-center study.

Imaging the acute respiratory distress syndrome: past, present and future

In patients with the acute respiratory distress syndrome (ARDS), lung imaging is a fundamental tool in the study of the morphological and mechanistic features of the lungs. Chest computed tomography studies led to major advances in the understanding of ARDS physiology. They allowed the in vivo study of the syndrome's lung features in relation with its impact on respiratory physiology and physiology, but also explored the lungs' response to mechanical ventilation, be it alveolar recruitment or ventilator-induced lung injuries. Coupled with positron emission tomography, morphological findings were put in relation with ventilation, perfusion or acute lung inflammation. Lung imaging has always been central in the care of patients with ARDS, with modern point-of-care tools such as electrical impedance tomography or lung ultrasounds guiding clinical reasoning beyond macro-respiratory mechanics. Finally, artificial intelligence and machine learning now assist imaging post-processing software, which allows real-time analysis of quantitative parameters that describe the syndrome's complexity. This narrative review aims to draw a didactic and comprehensive picture of how modern imaging techniques improved our understanding of the syndrome, and have the potential to help the clinician guide ventilatory treatment and refine patient prognostication.

Pneumothorax and Pneumomediastinum Complicating Organophosphate Poisoning: A Case Series of Complications Less Understood

Organophosphate compounds are used as insecticides in agricultural and domestic settings throughout the world. Acute organophosphorus (OP) poisoning is a major public health issue. Early diagnosis of OP poisoning and prompt atropinization can save lives. Respiratory failure may occur in patients with OP poisoning for many reasons, including aspiration of gastric contents, excessive secretions, pneumonia, and sepsis complicating acute respiratory distress syndrome. Till date, however, spontaneous pneumothorax and pneumomediastinum have not been reported in cases of OP poisoning. This report presents two similar cases of OP poisoning in which spontaneous pneumothorax and pneumomediastinum developed following OP ingestion.

Spontaneous pneumothorax with coronavirus disease 2019 in non-ventilated patients: A single-center retrospective case series

Background

Pneumothorax is a rare complication of coronavirus disease 2019, and many of its associated factors are related to mechanical ventilation. We investigated the incidence and clinical features of patients with pneumothorax and coronavirus disease 2019 at a field hospital for patients who did not require intubation.

Materials and methods

An isolated field hospital for COVID-19 patients who did not require ventilation was constructed. Patients who developed pneumothorax were extracted and reviewed retrospectively.

Results

Between May 2020 and February 2021, 1061 patients were admitted to this field hospital. Among them, eight patients (0.75%, three men and four women) developed pneumothorax. The mean age at incidence was 79.9 (range: 20–96) years; all patients were over the age of 80 years, except one 20-year-old woman. Six of these eight patients (75%) died.

Conclusion

Although pneumothorax is a rare complication of coronavirus disease-2019, it is predictive of a poor prognosis in older-adult patients.

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Incidence of pneumothorax in patients without mechanical ventilation was 0.75%.

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The mean age was 79.9 years and six of eight (75%) died.

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Pneumothorax is rare and predictive of poor prognosis patients with COVID-19.

Case Report: Bullous Lung Disease Following COVID-19

More than 87% of patients report the persistence of at least one symptom after recovery from the Coronavirus disease 2019 (COVID-19). Dyspnea is one of the most frequently reported symptoms following severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) infection with persistent chest radiological abnormalities up to 3 months after symptom onset. These radiological abnormalities are variable and most commonly include ground-glass opacities, reticulations, mosaic attenuation, parenchymal bands, interlobular septal thickening, bronchiectasis, and fibrotic-like changes. However, in this case report, we describe findings of bullous lung disease as a complication of SARS CoV-2 infection. As the pandemic continues, there is a need to understand the multiple respiratory manifestations of post-acute sequelae of COVID-19. We, therefore, present this case to add to the current body of literature describing pulmonary disease as a consequence of SARS CoV-2 infection.

Incidence of Pneumothorax and Pneumomediastinum in 497 COVID-19 Patients with Moderate-Severe ARDS over a Year of the Pandemic: An Observational Study in an Italian Third Level COVID-19 Hospital

(1) Background: COVID-19 is a novel cause of acute respiratory distress syndrome (ARDS). Indeed, with the increase of ARDS cases due to the COVID-19 pandemic, there has also been an increase in the incidence of cases with pneumothorax (PNX) and pneumomediastinum (PNM). However, the incidence and the predictors of PNX/PMN in these patients are currently unclear and even conflicting. (2) Methods: The present observational study analyzed the incidence of barotrauma (PNX/PNM) in COVID-19 patients with moderate-severe ARDS hospitalized in a year of the pandemic, also focusing on the three waves occurring during the year, and treated with positive-pressure ventilation (PPV). We collected demographic and clinical data. (3) Results: During this period, 40 patients developed PNX/PNM. The overall incidence of barotrauma in all COVID-19 patients hospitalized in a year was 1.6%, and in those with moderate-severe ARDS in PPV was 7.2% and 3.8 events per 1000 positive-pressure ventilator days. The incidence of barotrauma in moderate-severe ARDS COVID-19 patients during the three waves was 7.8%, 7.4%, and 8.7%, respectively. Treatment with noninvasive respiratory support alone was associated with an incidence of barotrauma of 9.1% and 2.6 events per 1000 noninvasive ventilator days, of which 95% were admitted to the ICU after the event, due to a worsening of respiratory parameters. The incidence of barotrauma of ICU COVID-19 patients in invasive ventilation over a year was 5.8% and 2.7 events per 1000 invasive ventilator days. There was no significant difference in demographics and clinical features between the barotrauma and non-barotrauma group. The mortality was higher in the barotrauma group (17 patients died, 47.2%) than in the non-barotrauma group (170 patients died, 37%), although this difference was not statistically significant (p = 0.429). (4) Conclusions: The incidence of PNX/PNM in moderate-severe ARDS COVID-19 patients did not differ significantly between the three waves over a year, and does not appear to be very different from that in ARDS patients in the pre-COVID era. The barotrauma does not appear to significantly increase mortality in COVID-19 patients with moderate-severe ARDS if protective ventilation strategies are applied. Attention should be paid to the risk of barotrauma in COVID-19 patients in noninvasive ventilation because the event increases the probability of admission to the intensive care unit (ICU) and intubation.

CXCR7 Antagonism Reduces Acute Lung Injury Pathogenesis

Loss of control in the trafficking of immune cells to the inflamed lung tissue contributes to the pathogenesis of life-threatening acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS). Targeting CXCR7 has been proposed as a potential therapeutic approach to reduce pulmonary inflammation; however, its role and its crosstalk with the two chemokine receptors CXCR3 and CXCR4 via their shared ligands CXCL11 and CXCL12 is not yet completely understood. The present paper aimed to characterize the pathological role of the CXCR3/CXCR4/CXCR7 axis in a murine model of ALI. Lipopolysaccharide (LPS) inhalation in mice resulted in the development of key pathologic features of ALI/ARDS, including breathing dysfunctions, alteration in the alveolar capillary barrier, and lung inflammation. LPS inhalation induced immune cell infiltration into the bronchoalveolar space, including CXCR3⁺ and CXCR4⁺ cells, and enhanced the expression of the ligands of these two chemokine receptors. The first-in-class CXCR7 antagonist, ACT-1004-1239, increased levels of CXCL11 and CXCL12 in the plasma without affecting their levels in inflamed lung tissue, and consequently reduced CXCR3⁺ and CXCR4⁺ immune cell infiltrates into the bronchoalveolar space. In the early phase of lung inflammation, characterized by a massive influx of neutrophils, treatment with ACT-1004-1239 significantly reduced the LPS-induced breathing pattern alteration. Both preventive and therapeutic treatment with ACT-1004-1239 reduced lung vascular permeability and decreased inflammatory cell infiltrates. In conclusion, these results demonstrate a key pathological role of CXCR7 in ALI/ARDS and highlight the clinical potential of ACT-1004-1239 in ALI/ARDS pathogenesis.

Pneumothorax due to COVID-19: Analysis of case reports

Cases of pneumothorax/pneumomediastinum have been reported in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, the time to onset and hospital stay have rarely been studied. Coronavirus disease 2019 (COVID-19) patients with these complications are described to determine the time to onset, associated comorbidities, and location and duration of pneumothorax. A search in PubMed yielded simple frequencies and a bivariate analysis of deaths. There were 113 confirmed cases in 67 articles. The median time from the date of hospital admission to the presence of pneumothorax was 8 days. Right hemithorax was the most frequent form of pneumothorax. Almost half of the patients required intubation for invasive mechanical ventilation. Although the frequency of this phenomenon was not high among hospitalized patients with confirmed SARS-CoV-2, it was high among those who developed acute respiratory distress syndrome (ARDS). This study contributes to the literature because it presents a large number of patients who developed pneumothorax after admission, which was characterized by clinical deterioration (dyspnea, tachypnea, pleuritic chest pain, and subcutaneous emphysema) and low oxygen saturation levels. Pneumothorax/pneumomediastinum is recommended as a differential diagnosis, even without considering the presence of chronic pulmonary comorbidities or invasive mechanical ventilation.

Pleural abnormalities in COVID-19: a narrative review

OBJECTIVE

This narrative review aims to provide a detailed overview of pleural abnormalities in patients with coronavirus disease 19 or COVID-19.

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is a novel beta coronavirus responsible for COVID-19. Although pulmonary parenchymal and vascular changes associated with COVID-19 are well established, pleural space abnormalities have not been the primary focus of investigations.

METHODS

Narrative overview of the medical literature regarding pleural space abnormalities in COVID-19. The appropriate manuscripts were identified by searching electronic medical databases and by hand searching the bibliography of the identified papers. Pleural abnormalities on transverse and ultrasound imaging are discussed. The incidence, clinical features, pathophysiology, and fluid characteristics of pleural effusion are reviewed. Studies reporting pneumothorax and pneumomediastinum are examined to evaluate for pathogenesis and prognosis. A brief comparative analysis of pleural abnormalities among patients with COVID-19, severe acute respiratory syndrome (SARS), and Middle Eastern respiratory syndrome (MERS) has been provided.

CONCLUSIONS

Radiologic pleural abnormalities are common in COVID-19, but the incidence of pleural effusion appears to be low. Pneumothorax is rare and does not independently predispose the patient to worse outcomes. SARS-CoV-2 infects the pleural space; however, whether the pleural fluid can propagate the infection is unclear.

Immediate pneumothorax after neurosurgical procedures

Objective

Pneumothorax after neurosurgical procedures is very rare and incompletely understood. This study was performed to explore the clinical characteristics and pathogenesis of pneumothorax after neurosurgery.

Methods

We retrospectively evaluated patients admitted from December 2016 to April 2019 for treatment of spontaneous intracranial hemorrhage. The inclusion criteria were neurosurgical procedures (open surgeries or endovascular intervention) performed under general anesthesia, no performance of central venous puncture during surgery, and occurrence of pneumothorax immediately after the neurosurgical procedure.

Results

Eight patients developed pneumothorax after neurosurgical procedures for spontaneous intracranial hemorrhage under general anesthesia. Of the eight patients, seven had aneurysmal subarachnoid hemorrhage and one had left temporal–parietal hemorrhage. The lung injury prediction score (LIPS) was 3, 4, 5, 6, and 9.5 in three, one, two, one, and one patient, respectively. During the operation, volume-controlled ventilation (tidal volume, 8–10 mL/kg) was selected for all patients.

Conclusions

Neurogenic pulmonary edema, inappropriate mechanical ventilation, and stimulation by endotracheal intubation might conjointly contribute to postoperative pneumothorax. To avoid this rare entity, mechanical ventilation with a low tidal volume or low pressure during general anesthesia should be adopted for patients with hemorrhagic cerebrovascular diseases involving the temporal lobe and a LIPS of >3.

A Dedicated Veno-Venous Extracorporeal Membrane Oxygenation Unit during a Respiratory Pandemic: Lessons Learned from COVID-19 Part II: Clinical Management

(1) Background: COVID-19 acute respiratory distress syndrome (CARDS) has several distinctions from traditional acute respiratory distress syndrome (ARDS); however, patients with refractory respiratory failure may still benefit from veno-venous extracorporeal membrane oxygenation (VV-ECMO) support. We report our challenges caring for CARDS patients on VV-ECMO and alterations to traditional management strategies. (2) Methods: We conducted a retrospective review of our institutional strategies for managing patients with COVID-19 who required VV-ECMO in a dedicated airlock biocontainment unit (BCU), from March to June 2020. The data collected included the time course of admission, VV-ECMO run, ventilator length, hospital length of stay, and major events related to bleeding, such as pneumothorax and tracheostomy. The dispensation of sedation agents and trial therapies were obtained from institutional pharmacy tracking. A descriptive statistical analysis was performed. (3) Results: Forty COVID-19 patients on VV-ECMO were managed in the BCU during this period, from which 21 survived to discharge and 19 died. The criteria for ECMO initiation was altered for age, body mass index, and neurologic status/cardiac arrest. All cannulations were performed with a bedside ultrasound-guided percutaneous technique. Ventilator and ECMO management were routed in an ultra-lung protective approach, though varied based on clinical setting and provider experience. There was a high incidence of pneumothorax (n = 19). Thirty patients had bedside percutaneous tracheostomy, with more procedural-related bleeding complications than expected. A higher use of sedation was noted. The timing of decannulation was also altered, given the system constraints. A variety of trial therapies were utilized, and their effectiveness is yet to be determined. (4) Conclusions: Even in a high-volume ECMO center, there are challenges in caring for an expanded capacity of patients during a viral respiratory pandemic. Though institutional resources and expertise may vary, it is paramount to proceed with insightful planning, the recognition of challenges, and the dynamic application of lessons learned when facing a surge of critically ill patients.

Case Report: Massive Spontaneous Pneumothorax-A Rare Form of Presentation for Severe COVID-19 Pneumonia

Background and Objectives: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a viral disease that is spreading worldwide and became a pandemic. Although most of the time, the symptoms of the infection are flu like, a percentage of patients develop severe forms, along with severe complications. Many of them are known among front-line health workers, but the number of uncommon presentations and complications has increased. This case report aims to alert healthcare workers on less common forms of presentation, and to introduce this differential diagnosis in the evaluation of patients with COVID-19, given the increasing occurrence of pneumothorax in patients who are not mechanical ventilated. Case presentation: A 57-year-old female patient came to the Emergency Department (ED) by ambulance, with acute respiratory failure. She had SpO₂ (peripheral O₂ saturation ) = 43% on room air at home, and 86% on admission in ED after oxygen delivery (on a reservoir mask). SARS-CoV-2 infection was suspected based on symptoms that started three days ago (fever, dry cough, dyspnea, and fatigability). Blood was taken for lab tests, pharyngeal and nasal swabs for the reverse transcription–PCR (RT-PCR) test, and native computed tomography (CT) was scheduled. The thoracic CT scan showed massive right pneumothorax, partially collapsed lung, multiple bilateral lung infiltrates with a ground glass aspect and the RT-PCR test came back positive for SARS-CoV-2 infection. Despite the prompt diagnosis and treatment of pneumothorax (thoracostomy was performed and the drain tube was placed), the patient died after a long hospitalization in the intensive care unit. Conclusion: Secondary spontaneous pneumothorax (SSP), as a complication in severe forms of COVID-19 pneumonia, especially in female patients without risk factors is rare, and early diagnosis and treatment are essential for increasing the survival chances of these patients.

High incidence and mortality of pneumothorax in critically Ill patients with COVID-19

BACKGROUND

The clinical characteristics of the patients with COVID-19 complicated by pneumothorax have not been clarified.

OBJECTIVES

To determine the epidemiology and risks of pneumothorax in the critically ill patients with COVID-19.

METHODS

Retrospectively collecting and analysing medical records, laboratory findings, chest X-ray and CT images of 5 patients complicated by pneumothorax.

RESULTS

The incidence of pneumothorax was 10% (5/49) in patients with ARDS, 24% (5/21) in patients receiving mechanical ventilation, and 56% (5/9) in patients requiring invasive mechanical ventilation, with 80% (4/5) patients died. All the 5 patients were male and aged ranging from 54 to 79 years old. Pneumothorax was most likely to occur 2 weeks after the beginning of dyspnea and associated with reduction of neuromuscular blockers, recruitment maneuver, severe cough, changes of lung structure and function.

CONCLUSIONS

Pneumothorax is a frequent and fatal complication of critically ill patients with COVID-19.

COVID-19 with bilateral pneumothoraces- case report

To the best of our knowledge, there is no case report or data published regarding COVID pneumonitis presenting initially as pneumothorax.There are 3 case reports published to-date (May 30, 2020) reporting secondary pneumothorax as complication in later stages of Acute respiratory distress syndrome (ARDS) secondary to COVID-19 in non-ventilated patients. We present a case of COVID-19 disease presenting as tension pneumothorax after a week of symptoms and developing a second pneumothorax on the contralateral side post mechanical ventilation.

Lower airways inflammation in patients with ARDS measured using endotracheal aspirates: a pilot study

Introduction

Our knowledge of acute respiratory distress syndrome (ARDS) pathogenesis is incomplete. The goal of this pilot study is to investigate the feasibility of measuring lower airways inflammation in patients with ARDS using repeated endotracheal aspirates (ETAs).

Methods

ETAs were obtained within 24 hours by intensive care unit admission from 25 mechanically ventilated patients with ARDS and 10 of them underwent a second ETA within 96 hours after the first sampling. In each sample, cell viability was assessed using trypan blue exclusion method and the total and differential cell counts were measured using Neubauer-improved cell counting chamber and cytospins stained with Diff-Quik.

Results

The median cell viability was 89 (IQR 80–93)%, with a median total cell count of 305 (IQR 130–1270)×10³/mL and a median macrophage, neutrophil, lymphocyte and eosinophil count, respectively, of 19.8 (IQR 5.4–71.6)×10³/mL; 279 (IQR 109–1213)×10³/mL; 0 (IQR 0–0.188)×10³/mL; 0 (IQR 0–1.050)×10³/mL. Eosinophil count in the ETA correlated with the number of blood eosinophils (r=0.4840, p=0.0142). Cell viability and total and differential cell counts were neither significantly different in the second ETA compared with the first ETA nor were unaffected by the presence or absence of bacteria in the blood and/or ETA, or by the ARDS aetiology, apart from the macrophage count which was significantly increased in patients with ARDS associated with acute pancreatitis compared with those associated with pneumonia (p=0.0143).

Conclusions

ETA can be used to investigate the cellularity of the lower airways in patients with ARDS and it is an easy-to-perform and non-invasive procedure. Eosinophil counts in ETA and blood are significantly correlated. The number of macrophages in ETA may be affected by the aetiology of the ARDS.

Minimally invasive procedures

Minimally invasive procedures, which include laparoscopic surgery, use state-of-the-art technology to reduce the damage to human tissue when performing surgery. Minimally invasive procedures require small "ports" from which the surgeon inserts thin tubes called trocars. Carbon dioxide gas may be used to inflate the area, creating a space between the internal organs and the skin. Then a miniature camera (usually a laparoscope or endoscope) is placed through one of the trocars so the surgical team can view the procedure as a magnified image on video monitors in the operating room. Specialized equipment is inserted through the trocars based on the type of surgery. There are some advanced minimally invasive surgical procedures that can be performed almost exclusively through a single point of entry-meaning only one small incision, like the "uniport" video-assisted thoracoscopic surgery (VATS). Not only do these procedures usually provide equivalent outcomes to traditional "open" surgery (which sometimes require a large incision), but minimally invasive procedures (using small incisions) may offer significant benefits as well: (I) faster recovery; (II) the patient remains for less days hospitalized; (III) less scarring and (IV) less pain. In our current mini review we will present the minimally invasive procedures for thoracic surgery.

Pneumothorax: an up to date "introduction"

The pneumothorax is an abnormal collection of air or gas in the pleural space that separates the lung from the chest wall. Like pleural effusion where a large abnormal concentration of fluid (>100 mL) is liquid buildup in that space, pneumothorax may interfere with normal breathing. A medical term that it is used is the collapsed lung, although that term may also refer to atelectasis. There are two major types of pneumothorax; there is one that occurs without an apparent cause and in the absence of significant lung disease, while the so called; "secondary" pneumothorax occurs in the presence of existing lung pathology. In a minority of cases, the amount of air in the chest increases markedly when a one-way valve is formed by an area of damaged tissue, leading to a third type of pneumothorax, called "tensioned".

Heimlich valve and pneumothorax

The Heimlich valve is a small one-way valve used for chest drainage that empties into a flexible collection device and prevents return of gases or fluids into the pleural space. The Heimlich valve is less than 13 cm (5 inches) long and facilitates patient ambulation. Currently there are several systems in the market. It can be used in many patients instead of a traditional water seal drainage system. The Heimlich chest drainage valve was developed so that the process of draining the pleural cavity could be accomplished in a safe, relatively simple, and efficient manner. This valve system has replaced the cumbersome underwater drainage bottle system. Moreover; the Heimlich valve system connects to chest tubing and allows fluid and air to pass in one direction only. This system functions in any position, and it does not ever need to be clamped, a regulated suction can be attached to it if necessary. The valve drains into a plastic bag that can be held at any level, allowing the patient undergoing chest drainage to be ambulatory simply by carrying the bag. In the current mini review we will present the Heimlich valve system and method of insertion.

Pneumothorax as a complication of central venous catheter insertion

The central venous catheter (CVC) is a catheter placed into a large vein in the neck [internal jugular vein (IJV)], chest (subclavian vein or axillary vein) or groin (femoral vein). There are several situations that require the insertion of a CVC mainly to administer medications or fluids, obtain blood tests (specifically the "central venous oxygen saturation"), and measure central venous pressure. CVC usually remain in place for a longer period of time than other venous access devices. There are situations according to the drug administration or length of stay of the catheter that specific systems are indicated such as; a Hickman line, a peripherally inserted central catheter (PICC) line or a Port-a-Cath may be considered because of their smaller infection risk. Sterile technique is highly important here, as a line may serve as a port of entry for pathogenic organisms, and the line itself may become infected with organisms such as Staphylococcus aureus and coagulase-negative Staphylococci. In the current review we will present the complication of pneumothorax after CVC insertion.

Pacemaker insertion

A pacemaker (PM) (or artificial PM, so as not to be confused with the heart's natural PM) is a medical device that uses electrical impulses, delivered by electrodes contracting the heart muscles, to regulate the beating of the heart. The primary purpose of this device is to maintain an adequate heart rate, either because the heart's natural PM is not fast enough, or there is a block in the heart's electrical conduction system. Modern PMs are externally programmable and allow the cardiologist to select the optimum pacing modes for individual patients. Some combine a PM and defibrillator in a single implantable device. PMs can be temporary or permanent. Temporary PMs are used to treat short-term heart problems, such as a slow heartbeat that's caused by a heart attack, heart surgery, or an overdose of medicine. Permanent PMs are used to control long-term heart rhythm problems. A PM can relieve some arrhythmia symptoms, such as fatigue and fainting. A PM also can help a person who has abnormal HRs resume a more active lifestyle. In the current mini review we will focus on the insertion of a PM and the possible pneumothorax that can be caused.

Pneumothorax from diagnosis to treatment, hands on course: Part II

Pneumothorax is a situation where air is inserted in the pleural space that separates the lung from the chest wall. Pneumothorax can be primary or secondary. There is also a third type called; tensioned. Based on the concentration of air and type of pneumothorax the proper treatment has to be selected. There are cases where the concentration is minimal and observation is enough and more severe cases where surgery is required. Currently there are many techniques used for the biopsy of lung lesions. The bronchoscope (forceps, fine needle aspiration), fine needle aspiration under computed tomography scan and endobronchial ultrasound (EBUS) are commonly used. However, all these techniques have in common a possible side effect; pneumothorax. In our current issue we will focus on the different minimally invasive techniques of pneumothorax management. Moreover, a presentation will be made for several systems that are being used for air or fluid aspiration.

Chest drainage systems in use

A chest tube is a flexible plastic tube that is inserted through the chest wall and into the pleural space or mediastinum. It is used to remove air in the case of pneumothorax or fluid such as in the case of pleural effusion, blood, chyle, or pus when empyema occurs from the intrathoracic space. It is also known as a Bülau drain or an intercostal catheter. Insertion of chest tubes is widely performed by radiologists, pulmonary physicians and thoracic surgeons. Large catheters or small catheters are used based on each situation that the medical doctor encounters. In the current review we will focus on the chest drain systems that are in use.

Video-assisted thoracic surgery and pneumothorax

Video-assisted thoracoscopic surgery (VATS) is a type of thoracic surgery performed using a small video camera that is introduced into the patient's chest via a scope. It is considered a minimally invasive technique where the surgeon is able to view the instruments that are being used along with the anatomy on which the surgeon is operating. The camera and instruments are inserted through separate holes in the chest wall also known as "ports", depending on the patient and problem there are surgeries with one port "uniport", two or three ports. These small ports have the advantage that fewer infections are observed. This allows for a faster recovery. Traditionally, thoracic surgery performed for diagnosis or treatment of chest conditions has required access to the chest through thoracotomy or sternotomy incisions. Vats minimally invasive technique has replaced in many cases thoracotomy or sternotomy. In our current review we will present this technique in detail.

Semi-Fowler vs. lateral decubitus position for thoracoscopic sympathectomy in treatment of primary focal hyperhidrosis

BACKGROUND AND OBJECTIVE

The aim of this study is to compare usefulness of Semi-Fowler position vs. lateral decubitus position for thoracoscopic sympathectomy in treatment of primary focal hyperhidrosis.

MATERIALS AND METHODS

From January 2009 to January 2010, 263 consecutive patients with palmar and axillar hyperhidrosis underwent thoracoscopic sympathectomy Th2-Th4. Patients were divided into two groups: group A (n=133) underwent thoracoscopic sympathectomy through lateral decubitus using double lumen endotracheal intubation, and group B (n=130) underwent thoracoscopic sympathectomy through Semi-Fowler supine position (semi sitting with arm abducted) using single lumen endotracheal intubation without insufflation of CO2, but with short apnea period. All operations were performed through two 5 mm operating ports, videothoracoscopic camera 0° and endoscopic ultrasound activated harmonic scalpel.

RESULTS

There were 107 males and 156 females with median age 30.31±8.35 years. Two groups were comparable in gender, age, severity of sweating. All operations were successfully performed with no complications or perioperative morbidity. For group A average operation time for both sides was 31.2±3.87 min and for group B average time was 14.19±4.98 min. In group B apnea period per one lung lasts 2.86±1.15 min and during that period observed saturation was 92.65%±5.66% without significant cardiorespiratory disturbances. Pleural drains were taken off on operation table after forced manually lung reexpansion. Patients were discharged from hospital for few hours, after the operation and radiologic confirmation of complete lung reexpansion.

CONCLUSIONS

Based on this data (shorter operating time, lack of incomplete lung collapse, insignificant apnea and better reexpansion of lungs) we concluded that thoracoscopic sympathectomy through Semi-Fowler supine position is highly effective and easy to perform for primary hyperhidrosis.

Open thoracotomy for pneumothorax

A thoracotomy is an incision into the pleural space of the chest. It is performed by surgeons (or emergency physicians under certain circumstances) to gain access to the thoracic organs, most commonly the heart, the lungs, or the esophagus, or for access to the thoracic aorta or the anterior spine. This surgical procedure is a major surgical maneuver it is the first step in many thoracic surgeries including lobectomy or pneumonectomy for lung cancer and as such requires general anesthesia with endotracheal tube insertion and mechanical ventilation, rigid bronchoscope can be also used if necessary. Thoracotomies are thought to be one of the most difficult surgical incisions to deal with post-operatively, because they are extremely painful and the pain can prevent the patient from breathing effectively, leading to atelectasis or pneumonia. In the current review we will present the steps of this procedure.

Barotrauma and pneumothorax

Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or in contact with the body, and the surrounding fluid. This situation typically occurs when the organism is exposed to a significant change in ambient pressure, such as when a scuba diver, a free-diver or an airplane passenger ascends or descends, or during uncontrolled decompression of a pressure vessel, but it can also happen by a shock wave. Whales and dolphins are also vulnerable to barotrauma if exposed to rapid and excessive changes in diving pressures. In the current review we will focus on barotraumas from definition to treatment.

Pleura space anatomy

The pleural cavity is the potential space between the two pleurae (visceral and parietal) of the lungs. The pleurae are serous membranes which fold back onto themselves to form a two-layered membranous structure. The thin space between the two pleural layers is known as the pleural cavity and normally contains a small amount of pleural fluid. There are two layers; the outer pleura (parietal pleura) is attached to the chest wall and the inner pleura (visceral pleura) covers the lungs and adjoining structures, via blood vessels, bronchi and nerves. The parietal pleurae are highly sensitive to pain, while the visceral pleura are not, due to its lack of sensory innervation. In the current review we will present the anatomy of the pleural space.

Physiology of the pleural space

The pleural cavity is created between the 4(th) and 7(th) week of embryologic development. These embryonic components of visceral and parietal pleurae develop different anatomic characteristics with regard to vascular, lymphatic, and nervous supply. There are two layers: a superficial mesothelial cell layer facing the pleural space and an underlying connective tissue layer. The pleura might present inflammatory response and maintenance of the pleural fluid is observed. The latter function is especially important in the mechanical coupling of the lung and chest wall. Fluid is filtered into the pleural space according to the net hydrostatic oncotic pressure gradient. It flows downward along a vertical pressure gradient, presumably determined by hydrostatic pressure and resistance to viscous flow. There also may be a net movement of fluid from the costal pleura to the mediastinal and interlobar regions. In these areas, pleural fluid is resorbed primarily through lymphatic stomata on the parietal pleural surface. In the current review we will present the physiology of the pleural space in a step by step manner.

Postoperative pain management

Postoperative pain is a very important issue for several patients. Indifferent of the surgery type or method, pain management is very necessary. The relief from suffering leads to early mobilization, less hospital stay, reduced hospital costs, and increased patient satisfaction. An individual approach should be applied for pain control, rather than a fix dose or drugs. Additionally, medical, psychological, and physical condition, age, level of fear or anxiety, surgical procedure, personal preference, and response to agents given should be taken into account. The major goal in the management of postoperative pain is minimizing the dose of medications to lessen side effects while still providing adequate analgesia. Again a multidisciplinary team approach should be pursued planning and formulating a plan for pain relief, particularly in complicated patients, such as those who have medical comorbidities. These patients might appear increase for analgesia-related complications or side effects.