Abstract
Background: Pre-existing comorbidities and addictions are common in critically ill patients, but their contribution to severity and mortality once acute respiratory distress syndrome (ARDS) is established is incompletely characterised in Indian cohorts. Methods: In this prospective observational study in the medical intensive care unit of a tertiary care hospital, 100 patients fulfilling the Berlin definition of ARDS were enrolled. Diabetes mellitus, hypertension, chronic respiratory disease, hypothyroidism, smoking and alcohol use were related to Berlin severity and in-hospital outcome using the chi-square and Fisher's exact tests. Results: Diabetes mellitus (42%) and hypertension (36%) were the commonest comorbidities. The prevalence of diabetes rose across severity strata from 26.1% of patients with mild disease to 45.2% with moderate and 69.6% with severe ARDS (p=0.002). Mortality was 42.9% in diabetic patients against 15.5% in non-diabetic patients (odds ratio [OR] 4.02, 95% confidence interval [CI] 1.46–11.81; p=0.003) and 41.7% versus 18.8% for hypertension (OR 3.06, 95% CI 1.13–8.53; p=0.019), although hypertension prevalence did not differ significantly across severity strata (p=0.066). Chronic respiratory disease and hypothyroidism were associated with neither endpoint. Smoking (17%) and alcohol use (12%) were likewise not significantly associated with severity or outcome, though mortality was numerically higher in both (41.2% and 41.7% respectively against a cohort value of 27%). Overall mortality was 27.0%. Conclusion: Diabetes mellitus was the comorbidity most consistently associated with both greater ARDS severity and higher mortality, followed by hypertension, which was associated with mortality alone. All associations are univariate and unadjusted.
Keywords: ARDS, Diabetes mellitus, Hypertension, comorbidity, smoking, alcohol, mortality