Clinical Profile and Outcomes of Patients Presenting with H1N1 Pneumonia and Respiratory Failure at a Tertiary Care Centre of Central India

Background and Aims: Influenza, a lethal disease presenting with acute respiratory illness (ARI), has taken its toll on mankind through successive epidemics and pandemics. This study was conducted amidst the H1N1 influenza outbreak that struck central India in the latter half of 2022. Materials and Methods: Records of all patients admitted from 1 August 2022 to 7 September 2022 at a tertiary care centre of central India were reviewed and all patients admitted with acute respiratory failure who were suspected and tested for H1N1 influenza were included. Results: Thirty-two patients with respiratory failure were included in the study. They had a median age of 46 years, among which 50% patients were males. The median duration of illness was 6.8 (+/– 4.0) days, in which majority of patients were having fever (90.62%) and dyspnoea (93.75%). The median duration of hospital stay was nine days. Overall, 37.5% of the individuals had comorbidities, with diabetes mellitus (21.87%) and systemic hypertension (18.75%) being the most common. About 28.13% patients were confirmed positive for H1N1. The median oxygen saturation (SpO2) at presentation was 83% (with 13 patients having a saturation below 80% at room air) with a median respiratory rate of 25 breaths per minute. In 31 (96.8%) patients, chest imaging revealed an involvement in at least two zones. Eighteen (56.25%) patients had severe acute respiratory distress syndrome (ARDS). Overall mortality among the patients was 31.25%. All patients received full course oseltamivir. Conclusion: Our study H1N1 influenza virus-associated ARDS had a mortality rate of 31.25% with diabetes being a significant risk factor for severe disease and mortality.