Comparing India's Second COVID Wave with the First Wave-A Single-Center Experience.

Background: The COVID-19 pandemic has resurfaced in India as a hardhitting second wave. This study aims to compare the clinical profile of the first wave (April-June 2020) and the second wave (March-May 2021) of the severe acute respiratory syndrome coronavirus-2 pandemic (SARS-CoV-2) in a single tertiary care center in India.

Methods: In this retrospective observational study, we examined the demographic profile, symptoms at presentation, severity of illness, baseline investigations, treatments received, underlying comorbidities, and outcomes of the COVID-19 patients belonging to the first (W1) and the second wave (W2) of the pandemic in India.

Results: The age group affected most in the W2 is 50.5 (17.7) versus 37·1 (16·9) years for W1. The baseline oxygen saturation is lower in W2, being 84·0 (13·4) % compared with 91·9 (7·4) % in W1 [SpO2 < 90% OR 14.3 (6.1-33), P < 0.0001]. 70.2 % of the cases belonged to the severe category in W2 compared to 37.5% in W1. W2 has worse outcomes. Incidence of acute respiratory distress syndrome (ARDS) [48.7% v/s 6.45%; OR 15.4 (6.5-35.7), P<0.0001], Acute Kidney Injury (AKI) [18% v/s 2.4%; OR 6 (1.7- 22.2), P = 0.005], Acute Liver Injury (transaminitis) [12.8% v/s 6.4%, OR 7.3 (3.7- 14.3), P < 0.0001], and deaths (29% v/s 9.6%, standardized mortality ratio 3.5) is higher in W2. Similarly, the CT severity score for W2 [29.5 (6.7)] was higher than W1 [23·2 (11·5), P < 0.05]. The proportion of patients requiring oxygen [81.8% v/s 11.2%; OR 125 (40-333.3), P < 0.0001], high flow nasal cannula (HFNC) (11.4% v/s 5.6%), Non- Invasive Ventilation (NIV) (41.2% v/s 1.5%), invasive ventilation [24.5% v/s 0.9%; OR 22.72 (2.94-166.6), P = 0.003], as well as ICU/HDU admissions [56.4% v/s 12.0%; OR 10.5 (5.3-21.2), P < 0.0001] was higher for W2 as compared with W1. Cough, invasive ventilation, inotrope requirement, and ARDS are significantly related to higher mortality in the W2 than W1.

Conclusion: Higher age, oxygen requirement, ventilator requirement, ICU admission, and organ failure are more prevalent in the admitted COVID-19 cases during the second wave that hit India than in the first wave and are associated with more fatalities. Strategy for another wave should be planned accordingly.