Respiratory Support Patterns, Pneumothorax Incidence, and Factors Associated with Invasive Intubation among Critically Ill COVID-19 Patients Admitted to the ICU

Abstract

Background: Critically ill patients with coronavirus disease 2019 (COVID-19) often require escalation of respiratory support, such as non-invasive ventilation and invasive mechanical ventilation. While invasive ventilation can be lifesaving, it is associated with risks of ventilator-induced lung injury and barotrauma, including pneumothorax. The present study evaluated respiratory support patterns, clinically documented pneumothorax, and factors associated with invasive intubation among critically ill COVID-19 patients admitted to the intensive care unit of Al-Zahra Hospital in Isfahan, Iran.
Methods: This retrospective observational cohort study included 152 adult patients with confirmed COVID-19 admitted to the intensive care unit. Demographic characteristics, recorded hospital stay/duration, early laboratory values, arterial blood gas indices, respiratory support modalities, airway interventions, and clinically documented pneumothorax were extracted from medical records. Patients were compared according to invasive intubation status. Continuous variables were compared using the Mann–Whitney U test, and categorical variables were compared using the chi-square test with continuity correction or Fisher’s exact test, as appropriate. Exploratory multivariable logistic regression was performed to identify variables independently associated with invasive intubation.
Results: The mean age was 58.49 ± 13.94 years, and 87 patients (57.2%) were male. Non-invasive ventilation was required in 34 patients (22.4%), while 82 patients (53.9%) underwent endotracheal intubation and invasive mechanical ventilation. Re-intubation occurred in 7 patients (4.6% of the total cohort; 8.5% of intubated patients), and tracheotomy was performed in 6 patients (3.9% of the total cohort; 7.3% of intubated patients). Clinically documented pneumothorax occurred in 2 patients, corresponding to 1.3% of the total cohort and 2.4% of intubated patients. Compared with non-intubated patients, intubated patients were older and had higher blood urea nitrogen, creatinine, PaCO₂, activated partial thromboplastin time, D-dimer, C-reactive protein, and ferritin levels, as well as lower hemoglobin concentration, lower platelet count, and lower arterial pH. In exploratory multivariable analysis, higher blood urea nitrogen, lower hemoglobin concentration, lower platelet count, and higher C-reactive protein were independently associated with invasive intubation.
Conclusion: In this single-center cohort of critically ill COVID-19 patients, the requirement for invasive respiratory support was substantial, while clinically documented pneumothorax was infrequent. Patients who required invasive intubation exhibited greater renal, inflammatory, hematologic, coagulation, and acid-base abnormalities compared to non-intubated patients. These findings are hypothesis-generating and non-causal due to the retrospective design, limited ventilatory mechanics data, and the small number of pneumothorax events.