Mortality of Patients With Severe COVID-19 in the Intensive Care Unit: An Observational Study From a Major COVID-19 Receiving Hospital

Objective To determine the mortality of patients with severe COVID-19 in the intensive care unit (ICU) in relation to age, gender, co-morbidities, ventilatory status, and length of stay (LOS). Methods This was a cross-sectional study based on data retrieved for 204 patients admitted to the ICU of Hayatabad Medical Complex, Peshawar, Pakistan, from April to August 2020. Study variables were age, gender, co-morbid conditions, ventilatory status, and length of stay (LOS). The data were analyzed using SPSS version 21 (IBM Corp., Armonk, NY). The independent t-test and the chi-square test were used to compare the means and frequencies of variables. Multivariate regression analysis was used to predict the likelihood of mortality. Results The overall mortality was 77%. Non-invasive ventilation (NIV) was administered to 61.8% of patients. Mortality was higher for invasive mechanical ventilation (IMV) (93.6% vs 66.7%, p<0.001) and for over 60 years (87.3% vs 72.3%, p=0.019). Mortality without co-morbidities was 75.2%. Comparative mortality rates for at least one co-morbidity (79.7%), diabetes mellitus (80.0%), hypertension (100%), diabetes mellitus and hypertension both (87.1%), and chronic obstructive pulmonary disease (75%) were insignificant. The LOS for survivors was longer (8.9±8.9 versus 5.4±5.2 days, p=0.017). The LOS < 24h was associated with higher mortality (85.9% vs 72.9%, p=0.040). On multivariable regression, the likelihood of mortality was high for IMV (7.330, 95% CI 2.667 - 20.143, p<0.001) and elderly (>60 years) patients (2.607, 95%CI 1.063 - 6.394, p=0.036). Mortality decreased with LOS longer than 24h (0.412, 95%CI 0.173 - 0.982, p=0.045). Co-morbidities did not have any effect on mortality. Conclusions Age more than 60 years and IMV were independent risk factors for higher mortality. Longer ICU stay, specifically more than 24 hours, was associated with lower mortality but LOS less than 24 hours might not have a causal relationship with mortality. The odds of survival were not affected by co-morbidities.