Pneumomediastinum as a complication of SARS-CoV-2 pneumonia

The incidence of pneumomediastinum in hospitalised patients diagnosed with SARS-CoV-2 pneumonia is by no means negligible, much higher compared to the general population. The pathophysiology of pneumomediastinum in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia is explained by the increase in alveolar-interstitial pressure gradient (dry coughing spells, respiratory work, barotrauma from ventilatory support) in the context of particularly "fragile" lungs due to diffuse alveolar-interstitial damage from infectious-inflammatory origin, all of which significantly increases the risk of alveolar wall rupture. The more severe the SARS-CoV-2 pneumonia, the more likely it is that pneumomediastinum will occur. The development of pneumomediastinum in patients with SARS-CoV-2 pneumonia is associated with higher frequencies of death, intensive care unit (ICU) admission and tracheostomy and longer hospital and ICU lengths of stay. In most cases, pneumomediastinum in SARS-CoV-2 pneumonia is a benign and self-limiting process that resolves with conservative treatment. © 2022 Sociedad Madrinela de Neumologia y Cirugia Toracica. All rights reserved.

Clinical characteristics and risk factors of patients with COVID-19 developing barotrauma

Background: At our hospital, people with COVID-19 (coronavirus disease 2019) had a high rate of pulmonary barotrauma. Therefore, the current study looked at barotrauma in COVID-19 patients getting invasive and non-invasive positive pressure ventilation to assess its prevalence, clinical results, and features. Methodology: Our retrospective cohort study comprised of adult COVID-19 pneumonia patients who visited our tertiary care hospital between April 2020 and September 2021 and developed barotrauma. Result(s): Sixty-eight patients were included in this study. Subcutaneous emphysema was the most frequent type of barotrauma, reported at 67.6%;pneumomediastinum, reported at 61.8%;pneumothorax, reported at 47.1%. The most frequent device associated with barotrauma was CPAP (51.5%). Among the 68 patients, 27.9% were discharged without supplemental oxygen, while 4.4% were discharged on oxygen. 76.5% of the patients expired because of COVID pneumonia and its complications. In addition, 38.2% of the patients required invasive mechanical breathing, and 77.9% of the patients were admitted to the ICU. Conclusion(s): Barotrauma in COVID-19 can pose a serious risk factor leading to mortality. Also, using CPAP was linked to a higher risk of barotrauma.Copyright © 2021 Muslim OT et al.

Barotrauma during Noninvasive Respiratory Support in COVID-19 Pneumonia Outside ICU: The Ancillary COVIMIX-2 Study.

BACKGROUND: Noninvasive respiratory support (NIRS) has been extensively used during the COVID-19 surge for patients with acute respiratory failure. However, little data are available about barotrauma during NIRS in patients treated outside the intensive care unit (ICU) setting. METHODS: COVIMIX-2 was an ancillary analysis of the previous COVIMIX study, a large multicenter observational work investigating the frequencies of barotrauma (i.e., pneumothorax and pneumomediastinum) in adult patients with COVID-19 interstitial pneumonia. Only patients treated with NIRS outside the ICU were considered. Baseline characteristics, clinical and radiological disease severity, type of ventilatory support used, blood tests and mortality were recorded. RESULTS: In all, 179 patients were included, 60 of them with barotrauma. They were older and had lower BMI than controls (p < 0.001 and p = 0.045, respectively). Cases had higher respiratory rates and lower PaO2/FiO2 (p = 0.009 and p < 0.001). The frequency of barotrauma was 0.3% [0.1-1.3%], with older age being a risk factor for barotrauma (OR 1.06, p = 0.015). Alveolar-arterial gradient (A-a) DO2 was protective against barotrauma (OR 0.92 [0.87-0.99], p = 0.026). Barotrauma required active treatment, with drainage, in only a minority of cases. The type of NIRS was not explicitly related to the development of barotrauma. Still, an escalation of respiratory support from conventional oxygen therapy, high flow nasal cannula to noninvasive respiratory mask was predictive for in-hospital death (OR 15.51, p = 0.001). CONCLUSIONS: COVIMIX-2 showed a low frequency for barotrauma, around 0.3%. The type of NIRS used seems not to increase this risk. Patients with barotrauma were older, with more severe systemic disease, and showed increased mortality.

Incidence of barotrauma in an intensive care unit: new data from COVID-19?

Introduction: During COVID-19 pandemic, the massive use of ventilatory support made its complications even more common. This study aimed to analyse the incidence of barotrauma in COVID-19 patients as well as its consequences. Method(s): Retrospective cohort study. All patients undergoing mechanical ventilation in an intensive care unit (ICU) during 2020- 2021 were included. The time of both noninvasive and invasive ventilation was considered together. Statistical analysis was performed using IBM SPSS Statistics 28.0. Result(s): A total of 967 patients were included, with 42 cases of barotrauma being reported (28 men and 14 women, median age 69 years [interval 22-94] and median APACHE 13). Out of those, 40 had severe COVID-19. Regarding patients with and without COVID-19, the incidence of barotrauma (episodes/1000 days of ventilation) was 0.64 and 9.22 (RR 14.86, p < 0.001) and the barotrauma rate (episodes/number of patients) was 0.4% and 8.5% (RR 21.25, p < 0.001), respectively. The most common type of barotrauma was subcutaneous emphysema (52.4%, CI 95% 37.3-67.5%), followed by pneumomediastinum (47.6%, CI 95% 32.5-62.7%) and pneumothorax (35.7%, IC 95% 21.2-50.2%). The median time to diagnosis was 11.5 days after initiation of ventilatory support [interval 1-67]. In the COVID-19 group, barotrauma was associated with longer ventilation (14.06 vs 7.91 days, p < 0.001), longer ICU stay (16.74 vs 8.17 days, p < 0.001) e higher mortality rates (45.0% vs 26.2%, RR 1.72, p 0.011). Conclusion(s): We found a higher susceptibility to developing barotrauma as a potential complication of COVID-19 patients undergoing mechanical ventilation. From those, subcutaneous emphysema and pneumomediastinum seem to be more prevalent than pneumothorax. Barotrauma seems to be associated with longer periods undergoing mechanical ventilation, longer ICU stays and higher hospital mortality rates.

Pneumomediastinum and pneumothorax as extrapulmonary complications of pneumonia due to SARS-CoV-2.

BACKGROUND: Barotrauma is a lesion generated for changes in the pressure and/or volume within a specific anatomic way;pneumo-mediastinum and pneumothorax are clear samples of this effect, frequently related to infectious symptoms. CLINICAL CASES: Two clinical cases are presented, 34 and 44 years old, that had pneumonia due to COVID-19, with subsequent exacerbation of the symptoms caused by barotrauma. Patients were evaluated at emergency unit of the Hospital Angeles Pedregal, Mexico City;their clinical presentation was similar and was unleashed by repeated cough in the context of pneumonia due to SARS-CoV-2. CONCLUSION(S): Now there is more experience on the complications associated during COVID-19, although more cases must be study to know their prognostic meaning and, in case it becomes a progression marker of the illness, to establish specific measures and therapeutic recommendations. The presentation of pneumonia stands out despite the vaccination, having to get the general population make consciousness of continuing with measures of respiratory isolation.Copyright © 2022 Comunicaciones Cientificas Mexicanas S.A. de C.V.. All rights reserved.

Incidence and outcomes following pulmonary barotrauma in COVID-19 ventilated and non-ventilated patients with acute respiratory failure: A retrospective study.

Background and Objectives: : Alveolar rupture following increased transalveolar pressure on positive pressure ventilation is associated with pulmonary barotrauma (PB). The spectrum varies from pneumothorax, pneumomediastinum, pneumopericardium, pneumoperitoneum, retro-pneumoperitoneum and subcutaneous emphysema. We studied the incidence of PB and their clinical characteristics in patients with coronavirus disease 19 (COVID-19)-associated acute respiratory failure. Methods: Patients aged >18 years with COVID-19-associated acute respiratory distress syndrome were included in the study. We recorded demographics (age, gender, comorbidities), severity scores (APACHE II on admission, SOFA on the day of barotrauma), type of PB and outcomes at discharge from the hospital. Patient characteristics are descriptively reported. Survival analysis was done using Kaplan-Meier survival tests after classifying by various factors. Survival was compared using the log-rank test. Results: Thirty-five patients experienced PB. Eighty per cent of patients in this cohort were males with mean age of 55.89 years. The commonest comorbidities were diabetes mellitus and hypertension. Twelve spontaneously breathing patients developed barotrauma. Eight patients experienced sequential events. In all, 18 patients required insertion of pigtail catheters. The median survival time in patients was 37 days (95% CI: 25-49 days). The overall survival rate was 34.3%. Mean serum ferritin levels were six times upper limit of normal in deceased, reflecting the severity of lung involvement. Conclusion: A high incidence of PB was noted following severe acute respiratory syndrome coronavirus (SARS CoV-2) infection even in the non-ventilated patients, a consequence of SARS CoV-2 effects on the pulmonary parenchyma causing widespread lung injury.

Barotrauma in COVID-19 acute respiratory distress syndrome: retrospective analysis of the COVADIS prospective multicenter observational database.

BACKGROUND: Despite evidence suggesting a higher risk of barotrauma during COVID-19-related acute respiratory distress syndrome (ARDS) compared to ARDS due to other causes, data are limited about possible associations with patient characteristics, ventilation strategy, and survival. METHODS: This prospective observational multicenter study included consecutive patients with moderate-to-severe COVID-19 ARDS requiring invasive mechanical ventilation and managed at any of 12 centers in France and Belgium between March and December 2020. The primary objective was to determine whether barotrauma was associated with ICU mortality (censored on day 90), and the secondary objective was to identify factors associated with barotrauma. RESULTS: Of 586 patients, 48 (8.2%) experienced barotrauma, including 35 with pneumothorax, 23 with pneumomediastinum, 1 with pneumoperitoneum, and 6 with subcutaneous emphysema. Median time from mechanical ventilation initiation to barotrauma detection was 3 [0-17] days. All patients received protective ventilation and nearly half (23/48) were in volume-controlled mode. Barotrauma was associated with higher hospital mortality (P < 0.001) even after adjustment on age, sex, comorbidities, PaO2/FiO2 at intubation, plateau pressure at intubation, and center (P < 0.05). The group with barotrauma had a lower mean body mass index (28.6 ± 5.8 vs. 30.3 ± 5.9, P = 0.03) and a higher proportion of patients given corticosteroids (87.5% vs. 63.4%, P = 0.001). CONCLUSION: Barotrauma during mechanical ventilation for COVID-19 ARDS was associated with higher hospital mortality.

Lung Ultrasound versus SpO2-guided as 'Best-PEEP' titration in SARS-CoV2 ARDS

Background: SARS-CoV2 pneumonia with respiratory failure may evolve to ARDS. The effects of high PEEP on respiratory compliance varies in different patients. Our study is based on the high accurancy and sensitivity of Lung Ultrasound (LUS) in evaluating the heterogeneous distribution of aeration loss, and use of LUS to individualize PEEP titration to produce the best lung aeration. Method(s): Retrospective trial on two cohorts of patients (15+15) with SARS-CoV2 ARDS mild-to-moderate(according to Berlin Criteria), aged 18 to 80 y.o. In Group I(GI) PEEP titration was LUS guided, in Group II(GII) titration was SpO2-guided. In GI LUS score was calculated dividing lungs in six regions per hemithorax. Patients were treated with NIV or CPAP Helmet. In GII FiO2 was initially set at 40% and increased if target oxygenation was not met. In GI PEEP was set at 5 cmH2O and guided by LUS aeration. Cases were managed by PEEP values from 7.5-15 cmH2O. Determination of optimal PaO2/FiO2 was the primary outcome. Secondary outcomes were adverse event: incidence of barotrauma/pneumothorax/pneumomediastinum, haemodynamics (MAP and HR), time spent on NIV/ CPAP, length of stay, weaning categories, and mortality at day 28. Result(s): P/F ratio was 282+/-38.6 in GI, and 243+/-43.2 in GII. We didn't detect significant statistical differences between the two groups in terms of mortality (6.2% in Gi vs 6.8% in GII) nor in time to weaning (5+/-6 in GI vs 16+/-4.5 in GII). In-stead there were fewer AE in GI vs GII. Length of stay was reduced with mean value of 4.3 days. Conclusion(s): Compared to SpO2-guided PEEP titration, LUS-based titration was associated with favorable effects on rate of adverse events and length of hospital stay.

The successful use of Pezzer Catheter in Covid-19 patients

Introduction: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was often during the pandemic era. Over 3500 patients were treated in our hospital and approximately 400 required mechanical ventilation and presented pneumothorax due to barotrauma. We present our experience in cases of recurrent or loculated pneumothoraces in Covid-19 patients treated successfully with the use of Pezzer catheter. Material(s) and Method(s): Cases were collected retrospectively based on author recall. Ninety-one intubated patients ranging in age from 65 to 78 years presented with pneumothoraces. A 28 French Argyle intercostal catheter was inserted initially, resulting in re-expansion. Despite the above treatment 41 patients (45%) were unstable with recurrent or loculated pneumothoraces and one found hard to ventilate them. So, a Pezzer catheter made of Latex was placed at the site of the loculated pneumothorax. Result(s): All pneumothoraces were resolved within 3 days after the insertion of a Pezzer catheter and the subcutaneous emphysema decreased significantly. There were no major complications recorded. Conclusion(s): 1. It is well known that the most basic issue that may have an impact on airleaks is chest tube management. That is the reason we concentrated on the type and position of chest drain. 2. Our experience supports the use of Pezzer catheter connected to water seal in cases of persistent pneumothorax with prolonged air leak and increasing subcutaneous emphysema, since it promotes pleurodesis, reduces significantly the duration of the intrapleural drainages and the length of the in-hospital stay. 3. The procedure is cost-effective, safe, and easy to perform.

Evaluation of risk factors for barotrauma complications in COVID-19 patients treated with high flow nasal cannula (HFNC)

Aim: To evaluate risk factors for barotrauma development in COVID-19 patients treated with HFNC. Method(s): 34 COVID-19 patients are studied retrospectively, 24 males, mean age 61,74 years. Symptoms (dyspnoea, cough, fever, hemoptoe, fatigue), comorbidities (arterial hypertension (AH), COPD, asthma, diabetes, heart and kidney diseases, bronchiectasis), blood tests (total blood count, neutrophils to lymphocytes (Neu:Ly) ratio, lactate dehydrogenase (LDH), ferritin, interleukin-6, C-reactive protein), chest X-ray findings at admission are assessed. Need for oxygen therapy (ambient air, low flow therapy, HFNC) during the hospitalisation, barotrauma development (pneumothorax (PT), pneumomediastinum (PM), subcutaneous emphysema (SE)) and disease outcome are analysed. Result(s): Age decrease by 1 year leads to increased risk of SE by 17% (hazard ratio (HR)0.852,p=0.018). LDH increase by 1 U/l leads to 0.4% increased risk of SE (HR1.004,p=0.020). Age and LDH level are proved as risk factors for SE. AH increases the risk of PM by 27.5% (HR1.275,p=0.087). Ferritin increase by 1 ug/l leads to 0.2% higher risk of PT (HR1.002,p=0.019). Multivariate model reveals AH (HR1.777,p=0.057) and ferritin level (HR1.004,p=0.013) as risk factors for barotrauma. Multivariate model shows LDH (HR1,003,p=0,023), ferritin (HR1,004,p=0,007), and Neu:Ly (HR1,123,p=0,059) as main risk factors for PT,PM, SE. Dyspnoea increases the death risk 11 times (HR11.2,p=0.034) while LDH increase by 1 U/l leads to 0.1% increased death risk (HR1.001,p=0.087). Conclusion(s): AH, age, ferritin, LDH, Neu:Ly levels are proved as risk factors for PT, PM and SE. Dyspnoea is a risk factor for death outcome.

Incidence of Air Leaks in Critically Ill Patients with Acute Hypoxemic Respiratory Failure Due to COVID-19.

Subcutaneous emphysema, pneumothorax and pneumomediastinum are well-known complications of invasive ventilation in patients with acute hypoxemic respiratory failure. We determined the incidences of air leaks that were visible on available chest images in a cohort of critically ill patients with acute hypoxemic respiratory failure due to coronavirus disease of 2019 (COVID-19) in a single-center cohort in the Netherlands. A total of 712 chest images from 154 patients were re-evaluated by a multidisciplinary team of independent assessors; there was a median of three (2-5) chest radiographs and a median of one (1-2) chest CT scans per patient. The incidences of subcutaneous emphysema, pneumothoraxes and pneumomediastinum present in 13 patients (8.4%) were 4.5%, 4.5%, and 3.9%. The median first day of the presence of an air leak was 18 (2-21) days after arrival in the ICU and 18 (9-22)days after the start of invasive ventilation. We conclude that the incidence of air leaks was high in this cohort of COVID-19 patients, but it was fairly comparable with what was previously reported in patients with acute hypoxemic respiratory failure in the pre-COVID-19 era.

Incidence of barotrauma in patients with COVID-19 (alpha- and beta-predominant period) requiring mechanical ventilation: Single-center retrospective study.

Objective: We sought to determine predictors, incidence, and interventions required for patients who developed barotrauma. Pneumothorax, subcutaneous emphysema, and pneumomediastinum have all been reported as complications related to COVID-19-positive patients requiring invasive mechanical ventilation. Methods: In this retrospective study, clinical and imaging data from COVID-19 patients were collected and reviewed by two independent intensivists between January 4, 2020 and January 10, 2020. Data were used to identify COVID-19-positive patients requiring invasive mechanical ventilation and the incidence of barotrauma. Two separate cohorts were created as non-injured (no barotrauma) and injured (barotrauma present). We then sought to identify the risk factors for barotrauma in the non-injured cohort on Days 0, 7, 10, and 14 after intubation and day of injury in the injured cohort. Results: Of the 264 patients with COVID-19, 55.8% were African American. The non-injured group was older (60 ± 15 versus 49 ± 16, p = 0.006), with male predominance in the injured group versus non-injured group (75% versus 55%). A total of 16 (6.5%) patients developed one or more complications of barotrauma, defined as subcutaneous emphysema, pneumothorax, or pneumomediastinum. Length of stay was longer for the injured group versus non-injured group (47 versus 25 days). Plateau pressure (p = 0.024), fraction of inspired oxygen (p < 0.001), and driving pressure (p = 0.001) were statistically significant in injured cohort. Mortality rate in non-injured versus injured was 49.4% versus 69%. Using random effect model, fraction of inspired oxygen (p = 0.003) and mean airway pressure (p = 0.010) were significant at the time of injury. When comparing alive versus deceased in the injured cohort, thoracostomy placement in alive versus deceased was 80% versus 54.5%. Conclusion: COVID acute respiratory distress syndrome patients requiring invasive mechanical ventilation had a higher rate of barotrauma and were younger than those who did not develop barotrauma. Possible interventions to be considered to decrease barotrauma are decreased driving pressure goal and universal use of esophageal balloon manometry.

"Pneumomediastinum: A marker of severity in Covid-19 disease".

Objective: The goal of this study was to look at the incidence, risk factors, clinical characteristics, and radiological aspects of COVID-19 patients who developed pneumomediastinum and compare these features between those who died and those who survived. Materials and methods: This retrospective observational study included COVID-19 patients having pneumomediastinum on CT from May 2020 to May 2021 in a COVID-19 care hospital. 1st wave patients were considered between the period of May 2020 to January 2021 and those in the second wave between February 2021 to May 2021. The clinical details were analyzed by a consultant intensivist and CT scans were read by a team of 6 resident radiologists and 5 experienced radiologists. Demographic data, co-morbidities, clinical parameters, hemodynamic markers, radiological involvement and associated complications were analyzed. Results: During the study period, 10,605 COVID-19 patients were admitted to our hospital of which 5689 underwent CT scan. 66 patients were detected to have pneumomediastinum on CT; 26 of them in the first wave and 40 in the second wave. Out of 66, 28 patients were admitted to ICU, 9 during the first wave and 18 during the second wave. The overall incidence of developing pneumomediastinum was 1.16%. Incidence in the 1st wave was 1.0% and in the 2nd wave was 1.29%. The overall mortality rate in admitted COVID-19 patients was 12.83% while it was 43.9% in COVID-19 patients who developed pneumomediastinum. Incidence of pneumomediastinum and pneumothorax was high in patients with extensive parenchymal involvement. 59/66 (89%) cases of pneumomediastinum had severe CT score on imaging. Conclusion: We conclude that pneumomediastinum is a marker of poor prognosis. Timely diagnosis of interstitial emphysema or pneumomediastinum will aid in planning early protective ventilation strategies and timely intervention of complications.

The Macklin effect closely correlates with pneumomediastinum in acutely ill intubated patients with COVID-19 infection.

PURPOSE: Patients with COVID-19 infection are frequently found to have pulmonary barotrauma. Recent work has identified the Macklin effect as a radiographic sign that often occurs in patients with COVID-19 and may correlate with barotrauma. METHODS: We evaluated chest CT scans in COVID-19 positive mechanically ventilated patients for the Macklin effect and any type of pulmonary barotrauma. Patient charts were reviewed to identify demographic and clinical characteristics. RESULTS: The Macklin effect on chest CT scan was identified in a total of 10/75 (13.3%) COVID-19 positive mechanically ventilated patients; 9 developed barotrauma. Patients with the Macklin effect on chest CT scan had a 90% rate of pneumomediastinum (p < 0.001) and a trend toward a higher rate of pneumothorax (60%, p = 0.09). Pneumothorax was most frequently omolateral to the site of the Macklin effect (83.3%). CONCLUSION: The Macklin effect may be a strong radiographic biomarker for pulmonary barotrauma, most strongly correlating with pneumomediastinum. Studies in ARDS patients without COVID-19 are needed to validate this sign in a broader population. If validated in a broad population, future critical care treatment algorithms may include the Macklin sign for clinical decision making and prognostication.

Clinical use of Macklin-like radiological sign (Macklin effect): A systematic review.

INTRODUCTION: Recent studies suggested that Macklin sign is a predictor of barotrauma in patients with acute respiratory distress syndrome (ARDS). We performed a systematic review to further characterize the clinical role of Macklin. METHODS: PubMed, Scopus, Cochrane Central Register and Embase were searched for studies reporting data on Macklin. Studies without data on chest CT, pediatric studies, non-human and cadaver studies, case reports and series including <5 patients were excluded. The primary objective was to assess the number of patients with Macklin sign and barotrauma. Secondary objectives were: occurrence of Macklin in different populations, clinical use of Macklin, prognostic impact of Macklin. RESULTS: Seven studies enrolling 979 patients were included. Macklin was present in 4-22% of COVID-19 patients. It was associated with barotrauma in 124/138 (89.8%) of cases. Macklin sign preceded barotrauma in 65/69 cases (94.2%) 3-8 days in advance. Four studies used Macklin as pathophysiological explanation for barotrauma, two studies as a predictor of barotrauma and one as a decision-making tool. Two studies suggested that Macklin is a strong predictor of barotrauma in ARDS patients and one study used Macklin sign to candidate high-risk ARDS patients to awake extracorporeal membrane oxygenation (ECMO). A possible correlation between Macklin and worse prognosis was suggested in two studies on COVID-19 and blunt chest trauma. CONCLUSIONS: Increasing evidence suggests that Macklin sign anticipate barotrauma in patients with ARDS and there are initial reports on use of Macklin as a decision-making tool. Further studies investigating the role of Macklin sign in ARDS are justified.

Symptomatic or asymptomatic SAR-CoV-2 positive divers should be medically evaluated before returning to scuba diving.

Introduction: In order to allow the resumption of diving activities after a COVID-19 infection, French military divers are required to undergo a medical fitness to dive (FTD) assessment. We present here the results of this medical evaluation performed 1 month after the infection. Methods: We retrospectively analyzed between April 2020 and February 2021 200 records of divers suspected of COVID-19 contamination. Data collected included physical examination, ECG, blood biochemistry, chest CT scan and spirometry. Results: 145 PCR-positive subjects were included, representing 8.5% of the total population of French military divers. Two divers were hospitalized, one for pericarditis and the other for non-hypoxemic pneumonia. For the other 143 divers, physical examination, electrocardiogram and blood biology showed no abnormalities. However 5 divers (3.4%) had persistent subjective symptoms including fatigability, exertional dyspnea, dysesthesias and anosmia. 41 subjects (29%) had significant decreases in forced expiratory flows at 25-75% and 50% on spirometry (n = 20) or bilateral ground-glass opacities on chest CT scan (n = 24). Only 3 subjects were affected on both spirometry and chest CT. 45% of these abnormalities were found in subjects who were initially asymptomatic or had non-respiratory symptoms. In case of abnormalities, normalization was obtained within 3 months. The median time to return to diving was 45 days (IQR 30, 64). Conclusion: Our study confirms the need for standardized follow-up in all divers after COVID-19 infection and for maintaining a rest period before resuming diving activities.

Ventilatory associated barotrauma in COVID-19 patients: A multicenter observational case control study (COVI-MIX-study).

BACKGROUND: The risk of barotrauma associated with different types of ventilatory support is unclear in COVID-19 patients. The primary aim of this study was to evaluate the effect of the different respiratory support strategies on barotrauma occurrence; we also sought to determine the frequency of barotrauma and the clinical characteristics of the patients who experienced this complication. METHODS: This multicentre retrospective case-control study from 1 March 2020 to 28 February 2021 included COVID-19 patients who experienced barotrauma during hospital stay. They were matched with controls in a 1:1 ratio for the same admission period in the same ward of treatment. Univariable and multivariable logistic regression (OR) were performed to explore which factors were associated with barotrauma and in-hospital death. RESULTS: We included 200 cases and 200 controls. Invasive mechanical ventilation was used in 39.3% of patients in the barotrauma group, and in 20.1% of controls (p<0.001). Receiving non-invasive ventilation (C-PAP/PSV) instead of conventional oxygen therapy (COT) increased the risk of barotrauma (OR 5.04, 95% CI 2.30 - 11.08, p<0.001), similarly for invasive mechanical ventilation (OR 6.24, 95% CI 2.86-13.60, p<0.001). High Flow Nasal Oxygen (HFNO), compared with COT, did not significantly increase the risk of barotrauma. Barotrauma frequency occurred in 1.00% [95% CI 0.88-1.16] of patients; these were older (p=0.022) and more frequently immunosuppressed (p=0.013). Barotrauma was shown to be an independent risk for death (OR 5.32, 95% CI 2.82-10.03, p<0.001). CONCLUSIONS: C-PAP/PSV compared with COT or HFNO increased the risk of barotrauma; otherwise HFNO did not. Barotrauma was recorded in 1.00% of patients, affecting mainly patients with more severe COVID-19 disease. Barotrauma was independently associated with mortality. TRIAL REGISTRATION: this case-control study was prospectively registered in clinicaltrial.gov as NCT04897152 (on 21 May 2021).

On the design of a compact emergency mechanical ventilator with negative expiratory exit pressure for COVID-19 patients.

The present work deals with the design of a cylinder-piston arrangement to deliver the required tidal volume (TV) of air to the patient through the respiratory tract especially in the setting of severe acute respiratory syndrome corona virus 2 (SARS CoV-2) or corona virus disease (COVID-19). The design ensures that only the desired volume of air is delivered in each breath and a negative pressure is retained at the delivery point in a separate cylinder. The frequency of piston motion is the same as that of the average human respiratory rate (RR). The effect of negative pressure on time of evacuation under the present condition has been verified. The present design provides a compact ventilator unit with a surface area of 0.8 × 0.4 m2 with a minimal power requirement of 116.48 W. An RR of 16 is obtained with a volume flow rate in lit/s by using a twin cylinder arrangement with bore diameter 0.1 m and length 0.4 m. The ratio of inspiration time to expiration time is designed to be 1:2 by controlling the stroke frequency as 16 and piston speed 0.32 m/s. The present design provides promising quantitative information on the design of an automated continuous mechanical ventilator (CMV), which is different from bag mask valve (BMV) operated ventilators, and on preventing and minimising barotrauma.

Effectiveness of Non-Invasive Ventilation with Awake Prone in Covid-19 Related-Acute Respiratory Distress Syndrome at Covid-19 Isolation Hospital Muzaffarabad

Background: Despite its widespread usage, invasive positive pressure ventilation (IPPV) has a dismal track record in COVID-19 patients with SARDS. Currently, there is a paucity of evidence supporting the usefulness of noninvasive positive pressure ventilation (NIPPV) in the treatment of severe ARDS, as well as a significant risk of aerosol formation in patients with COVID-19 infection. Objective(s): This study aims to assess the efficacy and safety of NIPPV administration to COVID-19 patients. Method(s): The trial included 130 participants with moderate tosevere ARDS based to the Berlin criteria (PaO2/FiO2 ratio of 200mmHg, GCS > 13, respiratory breathing index (RBI) of 105, and no systemic issues). They were treated with NIPPV with awake proaning up to 12 hours per day at a hospital in Muzaffarabad. The addition of a heat and moisture exchanger (HME) and viral/bacterial filters to the expiratory limb of the ventilator circuit represented a minor improvement. Result(s): In an average of six days, the PaO2/FiO2 ratio indicates that the severity of ARDS has improved from moderate/severe to mild in 64 percent of patients. 36 percent of individuals who had a defined airway experienced IPPV or failure of NIV. During the study period, 1 % the of healthcare workers (HCW) were infected with COVID19. The delivery of NIPPV was associated with claustrophobia, nasal crusting, aspiration, and barotrauma (0.7 percent). Conclusion(s): In selected patients, NIV with awake proaning up to 12 hours per day can be employed to give respiratory support without the need for IPPV, hence eliminating the need for IPPV in those patients. However, larger-scale investigations are required to validate our findings. Copyright © 2022 Wolters Kluwer Medknow Publications. All rights reserved.