Pulmonary Barotrauma in COVID-19 Patients With ARDS on Invasive and Non-Invasive Positive Pressure Ventilation

Pneumomediastinum in COVID-19: Risk factors and outcomes from a multicentre case-control study

BACKGROUND

An increased incidence of pneumomediastinum has been observed among patients hospitalized with coronavirus disease 2019 (COVID-19) pneumonia. The study aimed to identify risk factors for COVID-19-associated pneumomediastinum and investigate the impact of pneumomediastinum on clinical outcomes.

METHODS

In this multicentre retrospective case-control study, we included consecutive patients with COVID-19 pneumonia and pneumomediastinum hospitalized from March 2020 to July 2020 at ten centres; then, we identified a similarly sized control group of consecutive patients hospitalized with COVID-19 pneumonia and respiratory failure who did not develop pneumomediastinum during the same period. Clinical, laboratory, and radiological characteristics, as well as respiratory support and outcomes, were collected and compared between the two groups. Risk factors of pneumomediastinum were assessed by multivariable logistic analysis.

RESULTS

Overall 139 patients with pneumomediastinum and 153 without pneumomediastinum were analysed. Lung involvement ≥75 %, consolidations, body mass index (BMI) < 22 kg/m2, C-reactive protein (CRP) > 150 mg/L, D-dimer >3000 ng/mL FEUs, and smoking exposure >20 pack-year were all independently correlated with the occurrence of pneumomediastinum. Patients with pneumomediastinum had a longer hospital stay (mean ± SD 31.2 ± 20.2 days vs 19.6 ± 14.2, p < 0.001), higher intubation rate (73/139, 52.5 % vs 27/153, 17.6 %, p < 0.001), and in-hospital mortality (68/139, 48.9 % vs 36/153, 23.5 %, p < 0.001) compared to controls.

CONCLUSIONS

Extensive lung parenchyma involvement, consolidations, low BMI, high inflammatory markers, and tobacco exposure are associated with a greater risk of pneumomediastinum in COVID-19 pneumonia. This complication significantly worsens the outcomes.

Pneumomediastinum and pneumothorax in coronavirus disease-2019: Description of a case series and a matched cohort study

Objective

To describe the characteristics of COVID-19 patients with pneumothorax and pneumomediastinum (PTX/PM) and their association with patient outcomes.

Patients and methods

Adults admitted to five Mayo Clinic hospitals with COVID-19 between 03/2020-01/2022 were evaluated. PTX/PM was defined by imaging. Descriptive analyses and a matched (age, sex, admission month, COVID-19 severity) cohort comparison was performed. Hospital mortality, length of stay (LOS), and predisposing factors were assessed.

Results

Among 6663 patients, 197 had PTX/PM (3 %) (75 PM, 40 PTX, 82 both). The median age was 59, with 71 % males. Exposure to invasive and non-invasive mechanical ventilation and high-flow nasal cannula before PTX/PM were 42 %, 17 %, and 20 %, respectively. Among isolated PTX and PM/PTX patients 70 % and 53.7 % underwent an intervention, respectively, while 96 % of the PM-only group was followed conservatively.A total of 171 patients with PTX/PM were compared to 171 matched controls. PTX/PM patients had more underlying lung disease (40.9 vs. 23.4 %, p < 0.001) and lower median body mass index (BMI) (29.5 vs. 31.3 kg/m2, p = .007) than controls. Among patients with available data, PTX/PM patients had higher median positive end-expiratory and plateau pressures than controls; however, differences were not significant (10 vs. 8 cmH2O; p = 0.38 and 28 vs. 22 cmH2O; p = 0.11, respectively). PTX/PM patients had a higher odds of mortality (adjusted odds ratio [95%CI]: 3.37 [1.61-7.07]) and longer mean LOS (percent change [95%CI]: 39 [9-77]) than controls.

Conclusion

In COVID-19 patients with similar severity, PTX/PM patients had more underlying lung disease and lower BMI. They had significantly increased mortality and LOS.

Lingering effects of COVID-19 in the care of perioperative patients

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can lead to organ dysfunction and clinical symptoms beyond the acute infection phase. These effects may have significant implications for the management of perioperative patients. The purpose of this article is to provide a systems-based approach to the subacute and chronic effects of SARS-CoV-2 that are most relevant to anesthesiology practice.

RECENT FINDINGS

In 2024, COVID-19 remains a concern for anesthesiologists due ongoing new infections, evolving viral strains, and relatively low rates of booster vaccination in the general population. A growing body of literature describes the post-COVID-19 syndrome in which patients experience symptoms more than 12 weeks after acute infection. Recent literature describes the lingering effects of SARS-CoV-2 infection on all major organ systems, including neurologic, pulmonary, cardiovascular, renal, hematologic, and musculoskeletal, and suggests an increased perioperative mortality risk in some populations.

SUMMARY

This review offers anesthesiologists an organ system-based approach to patients with a history of COVID-19. Recognizing the long-term sequelae of SARS-CoV-2 infection can help anesthesiologists to better evaluate perioperative risk, anticipate clinical challenges, and thereby optimize patient care.

Ventilation Management in a Patient with Ventilation-Perfusion Mismatch in the Early Phase of Lung Injury and during the Recovery

Chest trauma is one of the most serious and difficult injuries, with various complications that can lead to ventilation-perfusion (V/Q) mismatch and systemic hypoxia. We are presenting a case of a 53-year-old male with no chronic therapy who was admitted to the Intensive Care Unit due to severe respiratory failure after chest trauma. He developed a right-sided pneumothorax, and then a thoracic drain was placed. On admission, the patient was hemodynamically unstable and tachypneic. He was intubated and mechanically ventilated, febrile (38.9 °C) and unconscious. A lung CT showed massive non-ventilated areas, predominantly in the right lung, guiding repeated therapeutic and diagnostic bronchoalveolar lavages. He was ventilated with PEEP of 10 cmH2O with a FiO2 of 0.6-0.8. Empirical broad-spectrum antimicrobial therapy was immediately initiated. Both high FiO2 and moderate PEEP were maintained and adjusted according to the current blood gas values and oxygen saturation. He was weaned from mechanical ventilation, and non-invasive oxygenation was continued. After Stenotrophomonas maltophilia was identified and treated with sulfamethoxazole/trimethoprim, a regression of lung infiltrates was observed. In conclusion, both ventilatory and antibiotic therapy were needed to improve the oxygenation and outcome of the patient with S. maltophilia pneumonia and V/Q mismatch.

High efficiency particulate air filters and heat & moisture exchanger filters increase positive end-expiratory pressure in helmet continuous positive airway pressure: A bench-top study

BACKGROUND

Helmet continuous positive airway pressure (CPAP) has been widely used during the COVID-19 pandemic. Specific filters (i.e. High Efficiency Particulate Air filter: HEPA; Heat & Moisture Exchanger Filter: HMEF) were used to prevent Sars-CoV2 environmental dispersion and were connected to the CPAP helmet. However, HEPA and HMEF filters may act as resistors to expiratory gas flow and increase the levels of pressure within the hood.

METHODS

In a bench-top study, we investigated the levels of airway pressure generated by different HEPA and HMEF filters connected to the CPAP helmet in the absence of a Positive End Expiratory Pressure (PEEP) valve and with two levels of PEEP (5 and 10 cmH2O). All steps were performed using 3 increasing levels of gas flow (60, 80, 100 L/min).

RESULTS

The use of 8 different commercially available filters significantly increased the pressure within the hood of the CPAP helmet with or without the use of PEEP valves. On average, the increase of pressure above the set PEEP ranged from 3 cmH2O to 10 cmH2O across gas flow rates of 60 to 100 L/min. The measure of airway pressure was highly correlated between the laboratory pressure transducer and the Helmet manometer. Bias with 95% Confidence Interval of Bias between the devices was 0.7 (-2.06; 0.66) cmH2O.

CONCLUSIONS

The use of HEPA and HMEF filters placed before the PEEP valve at the expiratory port of the CPAP helmet significantly increase the levels of airway pressure compared to the set level of PEEP. The manometer can detect accurately the airway pressure in the presence of HEPA and HMEF filters in the helmet CPAP and its use should considered.

Predictors of mechanical ventilation and mortality in critically ill patients with COVID-19 pneumonia

OBJECTIVE

To determine if potential predictors for invasive mechanical ventilation (IMV) are also determinants for mortality in COVID-19-associated acute respiratory distress syndrome (C-ARDS).

DESIGN

Single center highly detailed longitudinal observational study.

SETTING

Tertiary hospital ICU: two first COVID-19 pandemic waves, Madrid, Spain.

PATIENTS OR PARTICIPANTS

280 patients with C-ARDS, not requiring IMV on admission.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

Target: endotracheal intubation and IMV, mortality.

PREDICTORS

demographics, hourly evolution of oxygenation, clinical data, and laboratory results.

RESULTS

The time between symptom onset and ICU admission, the APACHE II score, the ROX index, and procalcitonin levels in blood were potential predictors related to both IMV and mortality. The ROX index was the most significant predictor associated with IMV, while APACHE II, LDH, and DaysSympICU were the most with mortality.

CONCLUSIONS

According to the results of the analysis, there are significant predictors linked with IMV and mortality in C-ARDS patients, including the time between symptom onset and ICU admission, the severity of the COVID-19 waves, and several clinical and laboratory measures. These findings may help clinicians to better identify patients at risk for IMV and mortality and improve their management.

CT features of acute COVID-19 and long-term follow-up

Since the first few cases of pneumonia attributed to infection with the highly contagious novel coronavirus 2 (SARs-CoV-2) were detected in Wuhan, China, in December 2019, imaging has proven an invaluable diagnostic tool throughout the resulting global pandemic. This review describes the imaging features of severe pulmonary disease caused by SARs-CoV-2, named COVID-19 by the World Health Organization (WHO), particularly focussing on computed tomography (CT). CT plays an important role in understanding the pathology behind the progression of disease, as well as helping to identify the potential complications of COVID-19 pneumonia and recognising possible alternative or concurrent diagnoses. This review also focusses on follow-up imaging of survivors of COVID-19, which continues to contribute substantially to our understanding of the longer-term pulmonary changes in patients who have survived severe COVID-19 pneumonia.

Severe SARS-CoV-2 Pneumonia and Pneumomediastinum/Pneumothorax: A Prospective Observational Study in an Intermediate Respiratory Care Unit

INTRODUCTION

The occurrence of pneumomediastinum (PM) and/or pneumothorax (PTX) in patients with severe pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was evaluated.

METHODS

This was a prospective observational study conducted in patients admitted to the intermediate respiratory care unit (IRCU) of a COVID-19 monographic hospital in Madrid (Spain) between December 14, 2020 and September 28, 2021. All patients had a diagnosis of severe SARS-CoV-2 pneumonia and required noninvasive respiratory support (NIRS): high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP). The incidences of PM and/or PTX, overall and by NIRS, and their impact on the probabilities of invasive mechanical ventilation (IMV) and death were studied.

RESULTS

A total of 1306 patients were included. 4.3% (56/1306) developed PM/PTX, 3.8% (50/1306) PM, 1.6% (21/1306) PTX, and 1.1% (15/1306) PM + PTX. 16.1% (9/56) of patients with PM/PTX had HFNC alone, while 83.9% (47/56) had HFNC + CPAP/BiPAP. In comparison, 41.7% (521/1250) of patients without PM and PTX had HFNC alone (odds ratio [OR] 0.27; 95% confidence interval [95% CI] 0.13-0.55; p < .001), while 58.3% (729/1250) had HFNC + CPAP/BiPAP (OR 3.73; 95% CI 1.81-7.68; p < .001). The probability of needing IMV among patients with PM/PTX was 67.9% (36/53) (OR 7.46; 95% CI 4.12-13.50; p < .001), while it was 22.1% (262/1185) among patients without PM and PTX. Mortality among patients with PM/PTX was 33.9% (19/56) (OR 4.39; 95% CI 2.45-7.85; p < .001), while it was 10.5% (131/1250) among patients without PM and PTX.

CONCLUSIONS

In patients admitted to the IRCU for severe SARS-CoV-2 pneumonia requiring NIRS, incidences of PM/PTX, PM, PTX, and PM + PTX were observed to be 4.3%, 3.8%, 1.6%, and 1.1%, respectively. Most patients with PM/PTX had HFNC + CPAP/BiPAP as the NIRS device, much more frequently than patients without PM and PTX. The probabilities of IMV and death among patients with PM/PTX were 64.3% and 33.9%, respectively, higher than those observed in patients without PM and PTX, which were 21.0% and 10.5%, respectively.

Pneumomediastinum in patients with COVID-19 undergoing CT pulmonary angiography: a retrospective cohort study

BACKGROUND

Various complications have been reported in patients with COVID-19 including pneumomediastinum.

METHODS

The primary objective of the study was to determine the incidence of pneumomediastinum in COVID-19 positive patients who underwent CT pulmonary angiography (CTPA). The secondary objectives were to analyse if the incidence of pneumomediastinum changed between March and May 2020 (peak of the first wave in the UK) and January 2021 (peak of the second wave in the UK) and to determine the mortality rate in patients with pneumomediastinum. We undertook an observational, retrospective, single-centre, cohort study of patients with COVID-19 admitted to Northwick Park Hospital.

RESULTS

74 patients in the first wave and 220 patients in the second wave met the study criteria. Two patients during the first wave and eleven patients during the second wave developed pneumomediastinum.

CONCLUSIONS

The incidence of pneumomediastinum changed from 2.7% during the first wave to 5% during the second wave and this change was not statistically significant (p value 0.4057). The difference in mortality rates of patients with pneumomediastinum in both waves of COVID-19 (69.23%) versus patients without pneumomediastinum in both waves of COVID-19 (25.62%) was statistically significant (p value 0.0005). Many patients with pneumomediastinum were ventilated, which could be a confounding factor. When controlling for ventilation, there was no statistically significant difference in the mortality rates of ventilated patients with pneumomediastinum (81.81%) versus ventilated patients without pneumomediastinum (59.30%) (p value 0.14).

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.

Pneumoperitoneum in a Patient With COVID-19 and Acute Respiratory Distress Syndrome Without Pneumothorax

We present a case report of pneumoperitoneum, pneumomediastinum, and subcutaneous emphysema in a patient with COVID-19 pneumonia-causing acute respiratory distress syndrome (ARDS) without any pneumothorax occurring. Pneumothorax, pneumomediastinum, and subcutaneous emphysema are known complications of barotrauma due to positive pressure from mechanical ventilation which is necessary for patients suffering from a severe case of COVID-19. In our literature search, we could not find any reported case of pneumoperitoneum without pneumothorax occurring. Our case is an important addition to the literature presenting a rare complication of mechanical ventilation in patients with ARDS.

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.

Risk factors of pneumothorax and pneumomediastinum in COVID-19: a matched case-control study

BACKGROUND

During the novel coronavirus disease-2019 pandemic, a considerable number of pneumothorax (PNX)/pneumomediastinum (PNM) associated with COVID-19 have been reported, and the incidence is higher in critically ill patients. Despite using a protective ventilation strategy, PNX/PNM still occurs in patients on invasive mechanical ventilation (IMV). This matched case-control study aims to identify the risk factors and clinical characteristics of PNX/PNM in COVID-19.

METHODS

This retrospective study enrolled adult patients with COVID-19, admitted to a critical care unit from March 1, 2020, to January 31, 2022. COVID-19 patients with PNX/PNM were compared, in a 1-2 ratio, to COVID-19 patients without PNX/PNM, matched for age, gender, and worst National Institute of Allergy and Infectious Diseases ordinal scale. Conditional logistic regression analysis was performed to assess the risk factors for PNX/PNM in COVID-19.

RESULTS

427 patients with COVID-19 were admitted during the period, and 24 patients were diagnosed with PNX/PNM. Body mass index (BMI) was significantly lower in the case group (22.8 kg/m² and 24.7 kg/m²; P = 0.048). BMI was statistically significant risk factor for PNX/PNM in univariate conditional logistic regression analysis [odds ratio (OR), 0.85; confidence interval (CI), 0.72-0.996; P = 0.044]. For patients on IMV support, univariate conditional logistic regression analysis showed the statistical significance of the duration from symptom onset to intubation (OR, 1.14; CI, 1.006-1.293; P = 0.041).

CONCLUSIONS

Higher BMI tended to show a protective effect against PNX/PNM due to COVID-19 and delayed application of IMV might be a contributive factor for this complication.

Bronchoscopic Endobronchial Valve Therapy for Persistent Air Leaks in COVID-19 Patients Requiring Veno-Venous Extracorporeal Membrane Oxygenation

COVID-19 acute respiratory distress syndrome (ARDS) can be associated with extensive lung damage, pneumothorax, pneumomediastinum and, in severe cases, persistent air leaks (PALs) via bronchopleural fistulae (BPF). PALs can impede weaning from invasive ventilation or extracorporeal membrane oxygenation (ECMO). We present a series of patients requiring veno-venous ECMO for COVID-19 ARDS who underwent endobronchial valve (EBV) management of PAL. This is a single-centre retrospective observational study. Data were collated from electronic health records. Patients treated with EBV met the following criteria: ECMO for COVID-19 ARDS; the presence of BPF causing PAL; air leak refractory to conventional management preventing ECMO and ventilator weaning. Between March 2020 and March 2022, 10 out of 152 patients requiring ECMO for COVID-19 developed refractory PALs, which were successfully treated with bronchoscopic EBV placement. The mean age was 38.3 years, 60% were male, and half had no prior co-morbidities. The average duration of air leaks prior to EBV deployment was 18 days. EBV placement resulted in the immediate cessation of air leaks in all patients with no peri-procedural complications. Weaning of ECMO, successful ventilator recruitment and removal of pleural drains were subsequently possible. A total of 80% of patients survived to hospital discharge and follow-up. Two patients died from multi-organ failure unrelated to EBV use. This case series presents the feasibility of EBV placement in severe parenchymal lung disease with PAL in patients requiring ECMO for COVID-19 ARDS and its potential to expedite weaning from both ECMO and mechanical ventilation, recovery from respiratory failure and ICU/hospital discharge.

An analysis of emergency surgery on coronavirus disease positive patients and their outcomes during the coronavirus pandemic: A retrospective observational study

Background

The primary objective of this study was to determine the outcome of emergency surgery in coronavirus disease 2019 (COVID-19) patients with regard to presently existing physical status, and highlight its subspecialty distribution.

Methods

This retrospective observational study was done on all patients who underwent emergency surgery between March 2020 and Dec 2021 and were positive for COVID-19. Data collection included the age of the patients, gender, diagnosis, the type of surgery performed, and outcome. Physical status was assessed, as per Modified Medical Research Council Dyspnoea Scale (MMRC) and Metabolic Equivalent Scale (METS).

Results

A total of 89 patients were analyzed from March 2020 to Dec 2021. There were 63 females and 26 males. The average age of the males was 53.8 ± 8.9 years and the average age of the females was 29.1 ± 4.6 years. The maximum number of surgeries done was lower segment cesarean section (57.3%). 55 out of 60 (91%) cases had a good grade on the MMRC scale (Grade 0 and 1). 3 patients had Grade 4 MMRC scale and all 3 were oncology cases. As per the METS scale, 56/60 (93.3%) patients had METS >10.

Conclusion

This study has demonstrated that 55 out of 60 (91%) of cases had a good grade on the MMRC scale (Grade 0 and 1) 6 months to 1-year post-surgery. As per the METS scale, 56/60 (93.3%) patients had METS >10. Most of the cases were asymptomatic COVID-19-positive and presently have good physical status as determined by the study.

What We Know (and Do not Know) Regarding the Pathogenesis of Pulmonary Thrombosis in COVID-19

The clinical course of coronavirus disease 2019 (COVID-19) is often complicated by the onset of venous thrombosis and thromboembolism (VTE), encompassing also pulmonary thrombosis. Recent statistics attests that the cumulative frequency of VTE can be as high as 30% in COVID-19 hospitalized patients, increasing to nearly 40 to 70% (depending on systematic screening) in those with severe illness, mechanical ventilation, or intensive care unit admission. The risk of venous thrombosis seems mostly limited to the active phase of disease, and is directly associated with some genetic (i.e., inherited prothrombotic predisposition) and demographical factors (male sex, overweight/obesity), disease severity (risk increasing progressively from hospitalization to development of severe illness, being the highest in patients needing mechanical ventilation and/or intensive care), presence and extent of pulmonary disease, coexistence of multiple risk factors (immobilization, mechanical ventilation, co- or superinfections), along with increased values of inflammatory and thrombotic biomarkers. At least three different phenotypes of pulmonary thrombosis may develop in COVID-19 patients, one caused by typical embolization from peripheral venous thrombosis (e.g., deep vein thrombosis), a second type triggered by local inflammation of nearby pulmonary tissue, and a third one mostly attributable to the prothrombotic state consequent to the pronounced systemic inflammatory response (i.e., the so-called cytokine storm) that is frequently observed in COVID-19. Although the pathogenesis of these three conditions has different features, their discrimination is essential for diagnostic and therapeutic purposes. The prognosis of COVID-19 patients who develop pulmonary thrombosis is also considerably worse than those who do not, thus probably needing frequent monitoring and more aggressive therapeutic management.

Non-invasive support for the hypoxaemic patient

Optimisation of oxygenation strategies in patients with hypoxaemic respiratory failure is a top priority for acute care physicians, as hypoxaemic respiratory failure is one of the leading causes of admission. Various oxygenation methods range from non-invasive face masks to high flow nasal cannulae, which have advantages and disadvantages for this heterogeneous patient group. Focus has turned toward examining the benefits of non-invasive ventilation, as this was heavily researched in resource-limited settings during the COVID-19 pandemic. The oxygenation strategy should be determined on an individualised basis for patients, and with new evidence from the COVID-19 pandemic, providers may now consider placing further emphasis on non-invasive approaches. As non-invasive ventilation continues to be used in increasing frequency, new methods of monitoring patient response, including when to escalate ventilation strategy, will need to be validated.

High incidence of barotrauma in patients admitted with COVID-19 to ICU and associated mortality in rural Appalachia: An observational study

OBJECTIVES

To assess the incidence of barotrauma and its impact on mortality in COVID-19 patients admitted to ICU.

DESIGN

Single-center retrospective study of consecutive COVID-19 patients admitted to a rural tertiary-care ICU. The primary outcomes were incidence of barotrauma in COVID-19 patients and all-cause 30-day mortality. Secondary outcomes were the length of stay (LOS) in the hospital and ICU. Kaplan-Meier method and log-rank test were used in the survival data analysis.

SETTING

Medical ICU, West Virginia University Hospital (WVUH), USA.

PATIENTS

All adult patients were admitted to the ICU for acute hypoxic respiratory failure due to coronavirus disease 2019 between September 1, 2020, and December 31, 2020. Historical controls were ARDS patients admitted pre-COVID.

INTERVENTION

Not applicable.

MEASUREMENTS AND MAIN RESULTS

One hundred and sixty-five consecutive patients with COVID-19 were admitted to the ICU during the defined period, compared to 39 historical non-COVID controls. The overall incidence of barotrauma in COVID-19 patients was 37/165 (22.4%) compared to 4/39 (10.3%) in the control group. Patients with COVID-19 and barotrauma had a significantly worse survival (HR = 1.56, p = 0.047) compared to controls. In those requiring invasive mechanical ventilation, the COVID group also had significantly higher rates of barotrauma (OR 3.1, p = 0.03) and worse all-cause mortality (OR 2.21, p = 0.018). COVID-19 with barotrauma had significantly higher LOS in the ICU and the hospital.

CONCLUSIONS

Our data on critically ill COVID-19 patients admitted to the ICU shows a high incidence of barotrauma and mortality compared to the controls. Additionally, we report a high incidence of barotrauma even in non-ventilated ICU patients.

Occurrence, Risk Factors, and Outcomes of Pulmonary Barotrauma in Critically Ill COVID-19 Patients: A Retrospective Cohort Study

Objective

Pulmonary barotrauma has been frequently observed in patients with COVID-19 who present with acute hypoxemic respiratory failure. This study evaluated the prevalence, risk factors, and outcomes of barotrauma in patients with COVID-19 requiring ICU admission.

Methods

This retrospective cohort study included patients with confirmed COVID-19 who were admitted to an adult ICU between March and December 2020. We compared patients who had barotrauma with those who did not. A multivariable logistic regression analysis was performed to determine the predictors of barotrauma and hospital mortality.

Results

Of 481 patients in the study cohort, 49 (10.2%, 95% confidence interval: 7.6-13.2%) developed barotrauma on a median of 4 days after ICU admission. Barotrauma manifested as pneumothorax (N = 21), pneumomediastinum (N = 25), and subcutaneous emphysema (N = 25) with frequent overlap. Chronic comorbidities and inflammatory markers were similar in both patient groups. Barotrauma occurred in 4/132 patients (3.0%) who received noninvasive ventilation without intubation, and in 43/280 patients (15.4%) who received invasive mechanical ventilation. Invasive mechanical ventilation was the only risk factor for barotrauma (odds ratio: 14.558, 95% confidence interval: 1.833-115.601). Patients with barotrauma had higher hospital mortality (69.4% versus 37.0%; p < 0.0001) and longer duration of mechanical ventilation and ICU stay. Barotrauma was an independent predictor of hospital mortality (odds ratio: 2.784, 95% confidence interval: 1.310-5.918).

Conclusion

s. Barotrauma was common in critical COVID-19, with invasive mechanical ventilation being the most prominent risk factor. Barotrauma was associated with poorer clinical outcomes and was an independent predictor of hospital mortality.

Integrated Chinese herbal medicine and Western medicine successfully resolves spontaneous subcutaneous emphysema and pneumomediastinum in a patient with severe COVID-19 in Taiwan: A case report

CASE

Serious complications of severe coronavirus disease 2019 (COVID-19) include subcutaneous emphysema (SE) and pneumomediastinum, which are complicated to treat with conventional Western medicine. We report how combining Chinese herbal medicine (CHM) with Western medicine quickly resolved a patient's COVID-19-associated pulmonary complications, shortened hospital stay and improved quality of life.

CLINICAL FEATURES AND OUTCOME

A 59-year-old male with a history of smoking and tumors was diagnosed with COVID-19 in May 2021. At hospitalization, his oxygen saturation (SpO2) was 80%, he had a continuous severe cough, rapid shallow breathing, spontaneous SE and pneumomediastinum. By Day 4 of hospitalization, his condition was worsening despite standard care, so CHM was added. After 3-5 days, his coughing had lessened and supplementary oxygen therapy was de-escalated. Nine days after starting CHM, the SE had completely resolved and the patient avoided intubation. His WHO OS 10-point Scale score had fallen from 6 to 3 points and the modified Medical Research Council Dyspnea Scale score from 4 to 2 points. He was hospitalized for 19 days. At 1 week post-discharge, the patient could handle most of his daily activities and experienced minor shortness of breath only when performing labor-intensive tasks. At 1 month, his work output was restored to pre-COVID-19 levels.

CONCLUSION

CHM combined with standard Western medicine improved pulmonary function, respiratory rate, blood oxygen saturation and shortened the hospital stay of a patient with severe COVID-19 complicated by SE and pneumomediastinum.

Time dependency and unique etiology of barotrauma in COVID-19: A retrospective cohort study with landmark analysis and pathological approach

BACKGROUND

Barotrauma frequently occurs in coronavirus disease 2019. Previous studies have reported barotrauma to be a mortality-risk factor; however, its time-dependent nature and pathophysiology are not elucidated. To investigate the time-dependent characteristics and the etiology of coronavirus disease 2019-related-barotrauma.

METHODS AND FINDINGS

We retrospectively reviewed intubated patients with coronavirus disease 2019 from March 2020 to May 2021. We compared the 90-day survival between the barotrauma and non-barotrauma groups and performed landmark analyses on days 7, 14, 21, and 28. Barotrauma within seven days before the landmark was defined as the exposure. Additionally, we evaluated surgically treated cases of coronavirus disease 2019-related pneumothorax. We included 192 patients. Barotrauma developed in 44 patients (22.9%). The barotrauma group's 90-day survival rate was significantly worse (47.7% vs. 82.4%, p < 0.001). In the 7-day landmark analysis, there was no significant difference (75.0% vs. 75.7%, p = 0.79). Contrastingly, in the 14-, 21-, and 28-day landmark analyses, the barotrauma group's survival rates were significantly worse (14-day: 41.7% vs. 69.1%, p = 0.044; 21-day: 16.7% vs. 62.5%, p = 0.014; 28-day: 20.0% vs. 66.7%, p = 0.018). Pathological examination revealed a subpleural hematoma and pulmonary cyst with heterogenous lung inflammation.

CONCLUSIONS

Barotrauma was a poor prognostic factor for coronavirus disease 2019, especially in the late phase. Heterogenous inflammation may be a key finding in its mechanism. Barotrauma is a potentially important sign of lung destruction.

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.

Incidence and Outcome of Pneumomediastinum in Non-ICU Hospitalized COVID-19 Patients

OBJECTIVES

Pneumomediastinum (PNM) is a rare complication of mechanical ventilation, but its reported occurrence in patients with acute respiratory distress syndrome secondary to COVID-19 is significant. The objective is to determine the incidence, risk factors, and outcome of PNM in non-ICU hospitalized patients with severe-to-critical COVID-19 pneumonia.

DESIGN

Retrospective observational study.

SETTING

Population-based, single-setting, tertiary-care level COVID treatment center.

PATIENTS

Individuals hospitalized with a diagnosis of COVID-19 pneumonia and severe to critical illness were included. Those hospitalized without respiratory failure, observed for less than 24 hours, or admitted from an ICU were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All patients underwent a complete clinical assessment and chest CT scan, and were followed up from hospitalization to discharge or death. The outcome was the number of cases of PNM, defined as the presence of free air in the mediastinal tissues diagnosed by chest CT scan, in non-ICU hospitalized patients and the subsequent risk of intubation and mortality. PNM occurred in 48 out of 331 participants. The incidence was 14.5% (95% CI, 10.9-18.8%). A CT-Scan Severity score greater than 15 was positively associated with PNM (odds ratio [OR], 4.09; p = 0.002) and was observed in 35.2% of the participants (95% CI, 26.2-44.9%). Noninvasive ventilation was also positively associated with PNM (OR, 4.46; p = 0.005), but there was no positive association with airway pressures. Fifty patients (15%) were intubated, and 88 (27%) died. Both the risk for intubation and mortality were higher in patients with PNM, with a hazard ratio of 3.72 ( p < 0.001) and 3.27 ( p < 0.001), respectively.

CONCLUSIONS

Non-ICU hospitalized patients with COVID-19 have a high incidence of PNM, increasing the risk for intubation and mortality three- to four-fold, particularly in those with extensive lung damage. These findings help define the risk and outcome of PNM in severe-to-critical COVID-19 pneumonia in a non-ICU setting.

Pneumothorax in Intubated Patients With COVID-19: A Case Series

Pneumothorax is a rare complication among mechanically ventilated patients since low tidal volumes are used nowadays instead of traditional high tidal volumes, but the incidence is slightly higher in patients with high positive end-expiratory pressure (PEEP). Herein we describe a case series of nine patients who were on mechanical ventilation due to acute respiratory distress syndrome (ARDS) secondary to coronavirus disease 2019 (COVID-19) and developed pneumothorax in due course. A retrospective analysis was done on COVID-19 intubated patients from March 2020 to June 2020 in a community hospital in Central New Jersey, which was one of the early hit states in the United States at the beginning of the pandemic. Outcomes were studied. The demographics of patients like age, gender, and body mass index (BMI); risk factors like smoking, comorbidities especially chronic lung disease, and the treatment they received were compared. We compared the total number of days on the ventilator, the highest PEEP they received, and the ventilator day when pneumothorax developed. All the patients who developed pneumothorax had a chest tube inserted to treat it. The mortality was noted to be 100% indicating that pneumothorax is a life-threatening complication of COVID-19 and COVID-19 by itself is a risk factor for pneumothorax likely due to a change in lung mechanics. There is a need for large-scale studies to confirm that these outcomes are related to COVID-19.

Fibrotic-like abnormalities notably prevalent one year after hospitalization with COVID-19

BACKGROUND

We investigated whether COVID-19 leads to persistent impaired pulmonary function, fibrotic-like abnormalities or psychological symptoms 12 months after discharge and whether severely ill patients (ICU admission) recover differently than moderately ill patients.

METHODS

This single-centre cohort study followed adult COVID-19 survivors for a period of one year after discharge. Patients underwent pulmonary function tests 6 weeks, 3 months and 12 months after discharge and were psychologically evaluated at 6 weeks and 12 months. Computed tomography (CT) was performed after 3 months and 12 months.

RESULTS

66 patients were analysed, their median age was 60.5 (IQR: 54-69) years, 46 (70%) patients were male. 38 (58%) patients had moderate disease and 28 (42%) patients had severe disease. Most patients had spirometric values within normal range after 12 months of follow-up. 12 (23%) patients still had an impaired lung diffusion after 12 months. Impaired pulmonary diffusion capacity was associated with residual CT abnormalities (OR 5.1,CI-95: 1.2-22.2), shortness of breath (OR 7.0, CI-95: 1.6-29.7) and with functional limitations (OR 5.8, CI-95: 1.4-23.8). Ground-glass opacities resolved in most patients during follow-up. Resorption of reticulation, bronchiectasis and curvilinear bands was rare and independent of disease severity. 81% of severely ill patients and 37% of moderately ill patients showed residual abnormalities after 12 months (OR 8.1, CI-95: 2.5-26.4). A minority of patients had symptoms of post-traumatic stress disorder, anxiety, depression and cognitive failure during follow-up.

CONCLUSION

Some patients still had impaired lung diffusion 12 months after discharge and fibrotic-like residual abnormalities were notably prevalent, especially in severely ill patients.

COVID-19 Pneumonia: Clinical Manifestations

Coronavirus disease-2019 (COVID-19) pneumonia has diverse clinical manifestations, which have shifted throughout the pandemic. Formal classifications include presymptomatic infection and mild, moderate, severe, and critical illness. Social risk factors are numerous, with Black, Hispanic, and Native American populations in the United States having suffered disproportionately. Biological risk factors such as age, sex, underlying comorbid burden, and certain laboratory metrics can assist the clinician in triage and management. Guidelines for classifying radiographic findings have been proposed and may assist in prognosis. In this article, we review the risk factors, clinical course, complications, and imaging findings of COVID-19 pneumonia.

Barotrauma in COVID 19: Incidence, pathophysiology, and effect on prognosis

Objectives

To investigate the incidence, risk factors, and outcomes of barotrauma (pneumomediastinum and subcutaneous emphysema) in mechanically ventilated COVID-19 patients. To describe the chest radiography patterns of barotrauma and understand the development in relation to mechanical ventilation and patient mortality.

Methods

We performed a retrospective study of 363 patients with COVID-19 from March 1 to April 8, 2020. Primary outcomes were pneumomediastinum or subcutaneous emphysema with or without pneumothorax, pneumoperitoneum, or pneumoretroperitoneum. The secondary outcomes were length of intubation and death. In patients with pneumomediastinum and/or subcutaneous emphysema, we conducted an imaging review to determine the timeline of barotrauma development.

Results

Forty three out of 363 (12%) patients developed barotrauma radiographically. The median time to development of either pneumomediastinum or subcutaneous emphysema was 2 days (IQR 1.0–4.5) after intubation and the median time to pneumothorax was 7 days (IQR 2.0–10.0). The overall incidence of pneumothorax was 28/363 (8%) with an incidence of 17/43 (40%) in the barotrauma cohort and 11/320 (3%) in those without barotrauma (p ≤ 0.001). In total, 257/363 (71%) patients died with an increase in mortality in those with barotrauma 33/43 (77%) vs. 224/320 (70%). When adjusting for covariates, barotrauma was associated with increased odds of death (OR 2.99, 95% CI 1.25–7.17).

Conclusion

Barotrauma is a frequent complication of mechanically ventilated COVID-19 patients. In comparison to intubated COVID-19 patients without barotrauma, there is a higher rate of pneumothorax and an increased risk of death.

Myths and Misconceptions of Airway Pressure Release Ventilation: Getting Past the Noise and on to the Signal

In the pursuit of science, competitive ideas and debate are necessary means to attain knowledge and expose our ignorance. To quote Murray Gell-Mann (1969 Nobel Prize laureate in Physics): "Scientific orthodoxy kills truth". In mechanical ventilation, the goal is to provide the best approach to support patients with respiratory failure until the underlying disease resolves, while minimizing iatrogenic damage. This compromise characterizes the philosophy behind the concept of "lung protective" ventilation. Unfortunately, inadequacies of the current conceptual model-that focuses exclusively on a nominal value of low tidal volume and promotes shrinking of the "baby lung" - is reflected in the high mortality rate of patients with moderate and severe acute respiratory distress syndrome. These data call for exploration and investigation of competitive models evaluated thoroughly through a scientific process. Airway Pressure Release Ventilation (APRV) is one of the most studied yet controversial modes of mechanical ventilation that shows promise in experimental and clinical data. Over the last 3 decades APRV has evolved from a rescue strategy to a preemptive lung injury prevention approach with potential to stabilize the lung and restore alveolar homogeneity. However, several obstacles have so far impeded the evaluation of APRV's clinical efficacy in large, randomized trials. For instance, there is no universally accepted standardized method of setting APRV and thus, it is not established whether its effects on clinical outcomes are due to the ventilator mode per se or the method applied. In addition, one distinctive issue that hinders proper scientific evaluation of APRV is the ubiquitous presence of myths and misconceptions repeatedly presented in the literature. In this review we discuss some of these misleading notions and present data to advance scientific discourse around the uses and misuses of APRV in the current literature.

Pulmonary Barotrauma in COVID-19 Patients: Experience From a Secondary Care Hospital in Oman

Background

During the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), many patients developed pulmonary barotrauma either self-inflicted or ventilator-induced. In pulmonary barotrauma, air leaks into extra-alveolar tissue resulting in pneumomediastinum, subcutaneous emphysema, pneumothorax, and pneumoperitoneum.

Methods

After obtaining institutional approval, we retrospectively reviewed data from March 1, 2021, to September 31, 2021. Being a retrospective study, informed consent was not applicable. Patient data were collected from the Al Shifa patient information portal, which is an electronic medical record system available to all hospitals in the Ministry of Health, Oman. After identifying patients with pulmonary barotrauma, the following details were recorded and entered into an Excel sheet (Microsoft Corporation, Albuquerque, New Mexico) and a database was created, which contained the following: age, sex, smoking history, comorbidities, type, location, mode of barotrauma, mode of ventilation, length of intensive care unit (ICU) stay, interventions performed, and overall outcome (survived/deceased).

Results

A total of 529 patients with COVID-19 pneumonia were admitted from March 2021 to September 2021 to the ICU. Twenty-eight patients developed barotrauma of variable severity and required interventions like the placement of intercostal drains. Out of 28, five patients developed spontaneous barotrauma, 14 patients had barotrauma after initiation of non-invasive ventilation, and nine patients had barotrauma as a result of invasive ventilation. The median number of days in the ICU was 19.5 (interquartile range: 12.5-26.5). Of the 28 patients, eight patients survived and were discharged from the hospital.

Conclusion

In this single-center, retrospective study at a secondary care hospital in Oman, we described our experience with patients who suffered pulmonary barotrauma during their ICU admission. We have also presented the incidence of spontaneous versus ventilator-induced barotrauma, the length of stay of these patients, the outcomes in terms of survival or death, the need for tracheostomy, secondary infections, and interventions performed as indicated.

Characteristics and Factors Associated With Mortality in Patients With Coronavirus Disease 2019 and Pneumothorax

Objective

To describe the incidence, clinical characteristics, and factors associated with mortality in patients hospitalized for coronavirus disease 2019 (COVID-19) in whom pneumothorax developed.

Patients and Methods

This study was a retrospective analysis conducted using a large administrative database of adult patients hospitalized for COVID-19 in the United States from February 1, 2020, to June 10, 2021. We characterized the clinical features of patients in whom pneumothorax developed and the factors associated with mortality and stratified pneumothorax by the timing of the initiation of invasive mechanical ventilation (IMV) and by the time of hospital admission (early versus late).

Results

A total of 811,065 adult patients had a positive test result for severe acute respiratory syndrome coronavirus 2, of whom 103,858 (12.8%) were hospitalized. Pneumothorax occurred in 1915 patients (0.24% overall and 1.84% among hospitalized patients). Over time, the use of steroids and remdesivir increased, whereas the use of IMV, pneumothorax rates, and mortality decreased. The clinical characteristics associated with pneumothorax were male sex; the receipt of IMV; and treatment with steroids, remdesivir, or convalescent plasma. Most patients with pneumothorax received IMV, but pneumothorax developed before the initiation of IMV and/or early during hospitalization in majority. Multivariable analysis revealed that pneumothorax increased the risk of death (adjusted hazard ratio [aHR], 1.15; 95% CI, 1.06-1.24). In patients who did not receive IMV, pneumothorax led to nearly twice the mortality (aHR, 1.99; 95% CI, 1.56-2.54). Increased mortality was also noted when pneumothorax occurred before IMV (aHR, 1.37; 95% CI, 1.11-1.69) and within 7 days of hospital admission (aHR, 1.60; 95% CI, 1.29-1.98).

Conclusion

The overall incidence of pneumothorax in patients hospitalized for COVID-19 was low. Pneumothorax is an independent risk factor for death.

The Use of Nitric Oxide as a Rescue Modality for Severe Adult ARDS Patients, Including COVID-19, in Critical Care Rotor Transport: A Retrospective Community Outcome Study

Objective

Severe acute respiratory distress syndrome (ARDS) mortality increases in smaller outlying facilities, and patients (especially those diagnosed with coronavirus disease 2019 [COVID-19]) are often “stuck” at these facilities. These patients are on maximal ventilator settings and are often in the prone position. Our purpose was to show that with the use of inhaled nitric oxide (iNO), a “community-based” rotor wing critical care transport (CCT) team can safely, consistently, and effectively transport these extremely precarious patients to the tertiary care that is needed.

Methods

This was a retrospective database review of 50 patients (39 patients with COVID-19) transported between 2017 and 2021 in whom iNO was brought to the bedside and initiated by the rotor wing critical care transport team. The review included patient demographics, vital signs, and ventilator settings from the sending hospital, in-flight, and the receiving hospital. We reviewed the transition from transport to venovenous extracorporeal membrane oxygenation (if applicable), hospital disposition, and length of stay from the receiving hospital side. Concerning the actual transport, we reviewed the mode of transport, the sending facility size, and the distances covered.

Results

Upon arrival at the sending facilities, we found severely ill patients with almost half (46%) in the prone position or recently transitioned from a prone position within the last 2 hours. Eighty-six percent were pharmaceutically paralyzed, and 44% were in shock. There was a younger and heavier predominance with an average age of 44 years and an average weight of 103 kg. Thirty-nine patients were diagnosed with COVID-19. The other 11 had a mix of non–COVID-19 ARDS, pulmonary embolism, and pulmonary edema. The patients presented from 27 different community hospitals. Forty-four percent were from small referring hospitals that had less than 200 beds. Twenty-eight patients were transported by a Bell 407 helicopter, 18 with an Airbus H135 helicopter, and 4 by ground ambulance. Forty-one percent of patients were transported within 25 miles, and 4 patients were transferred from > 100 miles away. All 50 patients were safely transported without significant deterioration or significant pulmonary pressure increases. Thirty-seven patients were placed on venovenous extracorporeal membrane oxygenation (34 of those patients cannulated within 2 hours of arrival). The overall mortality rate was 27%, and the COVID-19 mortality rate was 24%.

Conclusion

iNO retrieval for severe ARDS can be safely and effectively completed within the COVID-19 population and the nonacademic community setting using helicopters prevalent in the global air medical industry (Bell 407 and Airbus H135).

Chest CT-based Assessment of 1-year Outcomes after Moderate COVID-19 Pneumonia

Background

COVID-19 pneumonia may lead to pulmonary fibrosis in the long term. Chest CT is useful to evaluate changes in the lung parenchyma over time.

Purpose

To illustrate the temporal change of lung abnormalities on chest CT scans associated with COVID-19 pneumonia over 1 year.

Materials and Methods

In this prospective study, patients previously hospitalized due to COVID-19 pneumonia who visited the radiology department of a tertiary care center for imaging follow-up were consecutively enrolled between March 2020 and July 2021. Exclusion criteria were acute respiratory distress syndrome, requirement of intubation and/or mechanical ventilation, pulmonary embolism, and any interstitial lung disease. High-resolution volumetric noncontrast chest CT scans were acquired at 3, 6, and 12 months from the first diagnosis and were compared with baseline CT scans. The imaging features analyzed were ground-glass opacity (GGO), consolidation, pleuroparenchymal band, linear atelectasis, bronchiectasis and/or bronchiolectasis, reticulation, traction bronchiectasis and/or bronchiolectasis, and honeycombing. The prevalence distribution of lung abnormalities was recorded at all time points.

Results

Eighty-four participants (56 men; mean age, 61 years ± 11 [SD]) were studied. GGOs and consolidations represented the main baseline lung abnormalities, accounting for a median severity score of 9 (IQR, 7–12.7; maximum possible score, 20), which indicates moderate lung involvement. The baseline prevalence of GGOs decreased from 100% to 2% of participants at 1 year, and that of consolidations decreased from 71% to 0% at 6 months. Fibrotic-like abnormalities (pleuroparenchymal bands, linear atelectasis, bronchiectasis and/or bronchiolectasis) were detected at 3 months (50% of participants), 6 months (42% of participants), and 1 year (5% of participants). Among these, pleuroparenchymal bands were the most represented finding. Fibrotic changes (reticulation and traction bronchiectasis and/or bronchiolectasis) were detected at 3–6 months (2%) and remained stable at 1 year, with no evidence of honeycombing. At 1 year, lung abnormalities due to COVID-19 pneumonia were completely resolved in 78 of 84 (93%) participants.

Conclusion

Residual lung abnormalities in individuals hospitalized with moderate COVID-19 pneumonia were infrequent, with no evidence of fibrosis at 1-year chest CT.

© RSNA, 2022

Incidence, clinical characteristics and outcome of barotrauma in critically ill patients with COVID-19: a systematic review and meta-analysis

INTRODUCTION

Barotrauma is rare in patients with acute respiratory distress syndrome undergoing mechanical ventilation. Its incidence seems increased among critically ill COVID-19 patients. We performed a systematic review and meta-analysis to investigate the incidence, risk factors and clinical outcomes of barotrauma among critically ill COVID-19 patients EVIDENCE ACQUISITION: PubMed was searched from March 1st, 2020 to August 31st, 2021; case series and retrospective cohort studies concerning barotrauma in adult critically ill COVID-19 patients, either hospitalized in the Intensive Care Unit (ICU) or invasively ventilated were included. Primary outcome was the incidence of barotrauma in COVID-19 versus non-COVID-19 patients. Secondary outcomes were clinical characteristics, ventilator parameters, mortality and length of stay between patients with and without barotrauma.

EVIDENCE SYNTHESIS

We identified 21 studies (six case series, 15 retrospective cohorts). The overall incidence of barotrauma was 11 [95% CI: 8-14]% in critically ill COVID-19 patients, vs. 2 [1-3]% in non-COVID-19, P<0.001; the incidence in mechanically ventilated patients was 14 [11-17]% vs. 4 [2-5]% non-COVID-19 patients, P<0.001. There were no differences in demographic, clinical, ventilatory parameters between patients who did and did not develop barotrauma, while, on average, protective ventilation criteria were always respected. Among COVID-19 patients, those with barotrauma had a higher mortality (60 [55-66] vs. 48 [42-54]%, P<0.001) and a longer ICU length of stay (20 [14-26] vs. 13 [10,5-16] days, P=0.03).

CONCLUSIONS

Barotrauma is a frequent complication in critically ill COVID-19 patients and is associated with a poor prognosis. Since lung protective ventilation was delivered, the ventilatory management might not be the sole factor in the development of barotrauma.

Complications of Critical COVID-19: Diagnostic and Therapeutic Considerations for the Mechanically Ventilated Patient

Patients admitted to the ICU with critical COVID-19 often require prolonged periods of mechanical ventilation. Difficulty weaning, lack of progress, and clinical deterioration are commonly encountered. These conditions should prompt a thorough evaluation for persistent or untreated manifestations of COVID-19, as well as complications from COVID-19 and its various treatments. Inflammation may persist and lead to fibroproliferative changes in the lungs. Infectious complications may arise including bacterial superinfection in the earlier stages of disease. Use of immunosuppressants may lead to the dissemination of latent infections, and to opportunistic infections. Venous thromboembolic disease is common, as are certain neurologic manifestations of COVID-19 including delirium and stroke. High levels of ventilatory support may lead to ventilator-induced injury to the lungs and diaphragm. We present diagnostic and therapeutic considerations for the mechanically ventilated patient with COVID-19 who shows persistent or worsening signs of critical illness, and we offer an approach to treating this complex but common scenario.

Reduced levels of pulmonary surfactant in COVID-19 ARDS

To provide novel data on surfactant levels in adult COVID-19 patients, we collected bronchoalveolar lavage fluid less than 72 h after intubation and used Fourier Transform Infrared Spectroscopy to measure levels of dipalmitoylphosphatidylcholine (DPPC). A total of eleven COVID-19 patients with moderate-to-severe ARDS (CARDS) and 15 healthy controls were included. CARDS patients had lower DPPC levels than healthy controls. Moreover, a principal component analysis was able to separate patient groups into distinguishable subgroups. Our findings indicate markedly impaired pulmonary surfactant levels in COVID-19 patients, justifying further studies and clinical trials of exogenous surfactant.

Pulmonary barotrauma in COVID-19: A systematic review and meta-analysis

BACKGROUND

An ever-increasing number of studies have reported an increased incidence of spontaneous pulmonary barotrauma such as pneumothorax, pneumomediastinum, and subcutaneous emphysema in patients with COVID-19. We conducted this systematic review and meta-analysis to assess the value and significance of the available data.

METHODS

A thorough systematic search was conducted to identify studies of barotrauma in hospitalized patients with COVID-19. Data analysis of case reports was done using a statistical package for the social sciences (SPSS) version 22, and meta-analysis was performed using CMA-3.

RESULTS

We identified a total of 4488 studies after thorough database searching.118 case reports and series, and 15 observational studies were included in the qualitative analysis. Fifteen studies were included in the quantitative analysis. The observational studies reported barotrauma in 4.2% (2.4-7.3%) among hospitalized patients; 15.6% (11-21.8%) among critically ill patients; and 18.4% (13-25.3%) in patients receiving invasive mechanical ventilation, showing a linear relationship of barotrauma with the severity of the disease. In addition, barotrauma was associated with a longer length of hospital stay, more extended ICU stay, and higher in-hospital mortality. Also, a slightly higher odds of barotrauma was seen in COVID-19 ARDS compared with non-COVID-19 ARDS.

CONCLUSION

COVID-19 pneumonia is associated with a higher incidence of barotrauma. It presents unique challenges for invasive and non-invasive ventilation management. Further studies are required to unravel the underlying pathophysiology and develop safer management strategies.

Use of high-flow nasal cannula oxygen and risk factors for high-flow nasal cannula oxygen failure in critically-ill patients with COVID-19

BACKGROUND

High-flow nasal oxygen therapy (HFNC) may be an attractive first-line ventilatory support in COVID-19 patients. However, HNFC use for the management of COVID-19 patients and risk factors for HFNC failure remain to be determined.

METHODS

In this retrospective study, we included all consecutive COVID-19 patients admitted to our intensive care unit (ICU) in the first (Mars-May 2020) and second (August 2020- February 202) French pandemic waves. Patients with limitations for intubation were excluded. HFNC failure was defined as the need for intubation after ICU admission. The impact of HFNC use was analyzed in the whole cohort and after constructing a propensity score. Risk factors for HNFC failure were identified through a landmark time-dependent cause-specific Cox model. The ability of the 6-h ROX index to detect HFNC failure was assessed by generating receiver operating characteristic (ROC) curve.

RESULTS

200 patients were included: HFNC was used in 114(57%) patients, non-invasive ventilation in 25(12%) patients and 145(72%) patients were intubated with a median delay of 0 (0-2) days after ICU admission. Overall, 78(68%) patients had HFNC failure. Patients with HFNC failure had a higher ICU mortality rate (34 vs. 11%, p = 0.02) than those without. At landmark time of 48 and 72 h, SAPS-2 score, extent of CT-Scan abnormalities > 75% and HFNC duration (cause specific hazard ratio (CSH) = 0.11, 95% CI (0.04-0.28), per + 1 day, p < 0.001 at 48 h and CSH = 0.06, 95% CI (0.02-0.23), per + 1 day, p < 0.001 at 72 h) were associated with HFNC failure. The 6-h ROX index was lower in patients with HFNC failure but could not reliably predicted HFNC failure with an area under ROC curve of 0.65 (95% CI(0.52-0.78), p = 0.02). In the matched cohort, HFNC use was associated with a lower risk of intubation (CSH = 0.32, 95% CI (0.19-0.57), p < 0.001).

CONCLUSIONS

In critically-ill COVID-19 patients, while HFNC use as first-line ventilatory support was associated with a lower risk of intubation, more than half of patients had HFNC failure. Risk factors for HFNC failure were SAPS-2 score and extent of CT-Scan abnormalities > 75%. The risk of HFNC failure could not be predicted by the 6-h ROX index but decreased after a 48-h HFNC duration.

Continuous positive airway pressure for moderate to severe COVID-19 acute respiratory distress syndrome in a resource-limited setting

Management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-associated acute respiratory distress syndrome (coronavirus disease 2019 (COVID-19) ARDS or CARDS) has challenged the health systems of developed countries, and even more so the health systems of resource-poor settings [1]. Within this context, continuous positive airway pressure (CPAP) has been trialled as an alternative, less resource-intensive respiratory support to early invasive mechanical ventilation (IMV) [2] with promising results, and now features in some major guidelines [3]. However, there are limited studies from resource-poor settings that have been impacted massively by COVID-19. We retrospectively analysed the completed survival outcomes and characteristics for the exclusive use of CPAP for moderate-to-severe CARDS as defined by the Kigali criteria [4] in a cohort of patients admitted to Bach Christian Hospital (BCH; Abbottabad, Pakistan) between April and August 2021.

Continuous positive airway pressure is an efficacious and cost-effective modality of treatment for #COVID19 ARDS, particularly in resource-poor settings with late referrals to overwhelmed intensive care unitshttps://bit.ly/3dKwXwP

Management of COVID-19-Associated Acute Respiratory Failure with Alternatives to Invasive Mechanical Ventilation: High-Flow Oxygen, Continuous Positive Airway Pressure, and Noninvasive Ventilation

Patients admitted to hospital with coronavirus disease 2019 (COVID-19) may develop acute respiratory failure (ARF) with compromised gas exchange. These patients require oxygen and possibly ventilatory support, which can be delivered via different devices. Initially, oxygen therapy will often be administered through a conventional binasal oxygen catheter or air-entrainment mask. However, when higher rates of oxygen flow are needed, patients are often stepped up to high-flow nasal cannula oxygen therapy (HFNC), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), or invasive mechanical ventilation (IMV). BiPAP, CPAP, and HFNC may be beneficial alternatives to IMV for COVID-19-associated ARF. Current evidence suggests that when nasal catheter oxygen therapy is insufficient for adequate oxygenation of patients with COVID-19-associated ARF, CPAP should be provided for prolonged periods. Subsequent escalation to IMV may be implemented if necessary.

Management of COVID-19-Associated Acute Respiratory Failure with Alternatives to Invasive Mechanical Ventilation: High-Flow Oxygen, Continuous Positive Airway Pressure, and Noninvasive Ventilation

Patients admitted to hospital with coronavirus disease 2019 (COVID-19) may develop acute respiratory failure (ARF) with compromised gas exchange. These patients require oxygen and possibly ventilatory support, which can be delivered via different devices. Initially, oxygen therapy will often be administered through a conventional binasal oxygen catheter or air-entrainment mask. However, when higher rates of oxygen flow are needed, patients are often stepped up to high-flow nasal cannula oxygen therapy (HFNC), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), or invasive mechanical ventilation (IMV). BiPAP, CPAP, and HFNC may be beneficial alternatives to IMV for COVID-19-associated ARF. Current evidence suggests that when nasal catheter oxygen therapy is insufficient for adequate oxygenation of patients with COVID-19-associated ARF, CPAP should be provided for prolonged periods. Subsequent escalation to IMV may be implemented if necessary.

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.

Spontaneous pneumomediastinum and COVID-19 pneumonia: Report of three cases with emphasis on CT imaging

Spontaneous pneumomediastinum is a rare complication of coronavirus disease 2019. The published literature consists mainly of case reports and small case series. There are still many questions regarding the pathogenesis, the prognostic significance and the implications on patient management. In our hospital, 3 coronavirus disease 2019 patients developed spontaneous pneumomediastinum: 1 on admission at the emergency department and the other 2 during hospitalization. In this study we describe their clinical course and computed tomography (CT) findings. All of them had severe disease according to the total severity score on admission CT. The management of pneumomediastinum was conservative and follow-up CT showed resolution in all patients. As the correlation between extension of parenchymal lung lesions and development of pneumomediastinum is still under investigation, we highlight the importance of reporting the severity score on chest CT in order to obtain more comparable results between different studies. Furthermore, in this tragic circumstance we also had the opportunity to familiarize ourselves with the otherwise uncommon occurrence of air along the bronchovascular sheaths (Macklin effect) and evaluate the ability of CT to detect it.