Prognosis and sequelae of severe COVID-19 patients after 6 months of hospital discharge: A retrospective cohort study

BACKGROUND: We investigated the prognosis, sequelae, and related factors of severe coronavirus disease (COVID-19) patients who required invasive mechanical ventilation 6 months after discharge from the hospital. METHODS: COVID-19 patients admitted to Kishiwada Tokusyukai Hospital between April 1, 2020, and May 31, 2021, and treated with an invasive mechanical ventilator were included in this study. We conducted a telephone visit 6 months after discharge to confirm survival and asked questions about sequelae. RESULTS: The mortality rate 6 months after discharge was 7.4%. Tracheostomy (odds ratio [OR], 0.03; 95% confidence interval [CI], 0.003–0.26), high Acute Physiology and Chronic Health Evaluation II score (16.0 [interquartile range [IQR], 11.5–17.2] vs. 11.0 [IQR, 8.0–14.0]), prolonged hospital stay (17.0 [IQR, 12.7–24.5] vs. 10.0 [IQR, 8.0–13.0]), and prolonged ventilation duration (12.5 [IQR, 10.7–20.0] vs. 8.0 [IQR, 6.0–11.0]) were associated with the risk of death. Moreover, 49% of the patients had residual disability. The most common sequelae were hoarseness, respiratory distress on exertion (31% of symptomatic patients), and muscle weakness (22%). The prone positioning therapy (OR, 5.55; 95% CI, 1.35–32.97) was associated with hoarseness, and the use of muscle relaxants (OR, infinity; 95% CI, 1.14–infinity) was a risk factor for muscle weakness. CONCLUSION: Although the mortality rate after the acute phase of COVID-19 was not high, many patients experienced sequelae. Careful treatment should be continued after the end of acute treatment for patients with prolonged respiratory failure due to COVID-19. Muscle relaxants and prone positioning therapy may cause sequelae and should be performed carefully.