Clinical Characteristics and Outcomes of COVID-19 Acute Respiratory Distress Syndrome Patients Requiring Invasive Mechanical Ventilation in a Lower Middle-Income Country

Background: Covid-19 related acute respiratory distress syndrome (ARDS) requires intensive care, which is highly expensive in lower-income countries. Outcomes of COVID-19 patients requiring invasive mechanical ventilation in Pakistan have not been widely reported. Identifying factors forecasting outcomes will help decide optimal care levels and prioritise resources.
Methods: A single-centre, retrospective study on COVID-19 patients requiring invasive mechanical ventilation was conducted from 1st March to 31st May 2020. Demographic variables, physical signs, laboratory values, ventilator parameters, complications, length of stay, and mortality were recorded. Data were analysed in SPSS ver.23.
Results: Among 71 study patients, 87.3% (62) were males, and 12.7% (9) were females with a mean (SD) age of 55.5(13.4) years. Diabetes mellitus and hypertension were the most common comorbidities in 54.9% (39) patients. Median(IQR) SOFA score on ICU admission and at 48 hours was 7(5-9) and 6(4-10), and median (IQR) APACHE-II score was 15 (11-24) and 13(9-23), respectively. Overall, in-hospital mortality was 57.7%; 25% (1/4), 55.6% (20/36) and 64.5% (20/31) in mild, moderate, and severe ARDS, respectively. On univariate analysis; PEEP at admission, APACHE II and SOFA score at admission and 48 hours; Acute kidney injury; D-Dimer>1.5 mg/L and higher LDH levels at 48 hours were significantly associated with mortality. Only APACHE II scores at admission and D-Dimer levels> 1.5 mg/L were independent predictors of mortality on multivariable regression (p-value 0.012 & 0.037 respectively). Admission APACHE II scores, Area under the ROC curve for mortality was 0.80 (95%CI 0.69-0.90); sensitivity was 77.5% and specificity 70% (cut-off ≥13.5).
Conclusion: There was a high mortality rate in severe ARDS. The APACHE II score can be utilised in mortality prediction in COVID-19 ARDS patients. However, larger-scale studies in Pakistan are required to assess predictors of mortality.