Abstract
Background: Acute respiratory distress syndrome (ARDS) has diverse aetiologies and a variable course. Indian intensive care unit (ICU) data on how demographic factors, mode of admission and aetiology relate to Berlin severity and mortality remain limited. Methods: In this prospective observational study in the medical ICU of a tertiary care hospital (1 January 2019 to 30 April 2020), 100 patients aged over 14 years fulfilling the Berlin definition of ARDS were enrolled and classified as mild, moderate or severe. Demographic profile, mode of admission, aetiology and presenting symptoms were related to severity and in-hospital outcome using the chi-square and Fisher's exact tests. Results: Forty-six patients had mild, 31 moderate and 23 severe ARDS. Mean age rose across severity strata (41.7, 47.7 and 61.9 years; p=0.001), and non-survivors were older than survivors (54.9 versus 45.7 years; p=0.002). Sex was unrelated to severity or outcome. Referred (inter-hospital transfer) admissions rose from 26.1% of mild to 56.5% of severe cases (p=0.046) and carried a mortality of 51.4% against 12.7% for direct admissions (odds ratio 7.09, 95% confidence interval 2.47–22.21; p<0.001); 70.4% of non-survivors were referred, against 24.7% of survivors. Sepsis led the aetiologies (38%) and tropical infections a further 24%; aetiology predicted neither severity (p=0.493) nor outcome (p=0.391). Mortality rose steeply with severity — 10.9%, 25.8% and 60.9% (p for trend <0.001) — overall mortality being 27.0%. Conclusion: Older age and referral from another facility were strong markers of both greater severity and worse outcome, whereas the underlying aetiology was not discriminating.
Keywords: ARDS, Berlin definition, aetiology, referral, demographics, mortality, medical ICU