ABSTRACT
Purpose To compare the incidence and nature of secondary infections (SI) between critically ill patients with viral pneumonia due to COVID-19 and seasonal influenza and explore the association between SI and clinical outcomes. Methods We conducted a historical cohort study of patients admitted to the intensive care unit (ICU) at two tertiary care centers during the first wave of the COVID-19 pandemic and patients admitted with influenza during the 2018–2019 season. The primary outcome was the rate of SI. Secondary outcomes included rates of ICU and in-hospital mortality, organ-support-dependent disease, and length of ICU and hospital stay. Results Secondary infections developed in 55% of 95 COVID-19 patients and 51% of 47 influenza patients (unadjusted odds ratio [OR], 1.16;95% confidence interval [CI], 0.57 to 2.33). After adjusting for baseline differences between cohorts, there were no significant differences between the COVID-19 cohort and the influenza cohort (adjusted OR, 1.00;95% CI, 0.41 to 2.44). COVID-19 patients with SI had longer ICU and hospital stays and duration of mechanical ventilation. The SI incidence was higher in COVID-19 patients treated with steroids than in those not treated with steroids (15/20, 75% vs 37/75, 49%). Conclusion Secondary infections were common among critically ill patients with viral pneumonia including COVID-19. We found no difference in the incidence of SI between COVID-19 and influenza in our cohort study, but SI in patients with COVID-19 were associated with worse clinical outcomes and increased healthcare resource use. The small cohort size precludes any causal inferences but may provide a basis for future research. Supplementary Information The online version contains supplementary material available at 10.1007/s12630-022-02376-0.
ABSTRACT
PURPOSE: To compare the incidence and nature of secondary infections (SI) between critically ill patients with viral pneumonia due to COVID-19 and seasonal influenza and explore the association between SI and clinical outcomes. METHODS: We conducted a historical cohort study of patients admitted to the intensive care unit (ICU) at two tertiary care centers during the first wave of the COVID-19 pandemic and patients admitted with influenza during the 2018-2019 season. The primary outcome was the rate of SI. Secondary outcomes included rates of ICU and in-hospital mortality, organ-support-dependent disease, and length of ICU and hospital stay. RESULTS: Secondary infections developed in 55% of 95 COVID-19 patients and 51% of 47 influenza patients (unadjusted odds ratio [OR], 1.16; 95% confidence interval [CI], 0.57 to 2.33). After adjusting for baseline differences between cohorts, there were no significant differences between the COVID-19 cohort and the influenza cohort (adjusted OR, 1.00; 95% CI, 0.41 to 2.44). COVID-19 patients with SI had longer ICU and hospital stays and duration of mechanical ventilation. The SI incidence was higher in COVID-19 patients treated with steroids than in those not treated with steroids (15/20, 75% vs 37/75, 49%). CONCLUSION: Secondary infections were common among critically ill patients with viral pneumonia including COVID-19. We found no difference in the incidence of SI between COVID-19 and influenza in our cohort study, but SI in patients with COVID-19 were associated with worse clinical outcomes and increased healthcare resource use. The small cohort size precludes any causal inferences but may provide a basis for future research.
RéSUMé: OBJECTIF: Comparer l'incidence et la nature des infections secondaires entre les patients gravement malades atteints de pneumonie virale due à la COVID-19 et ceux atteints de la grippe saisonnière et explorer l'association entre les infections secondaires et les issues cliniques. MéTHODE: Nous avons réalisé une étude de cohorte historique de patients admis à l'unité de soins intensifs (USI) dans deux centres de soins tertiaires pendant la première vague de la pandémie de COVID-19 et de patients admis pour la grippe au cours de la saison 2018-2019. Le critère d'évaluation principal était le taux d'infections secondaires. Les critères d'évaluation secondaires comprenaient les taux de mortalité à l'USI et à l'hôpital, les maladies nécessitant un support d'organes et la durée du séjour à l'USI et à l'hôpital. RéSULTATS: Des infections secondaires se sont développées chez 55 % des 95 patients atteints de COVID-19 et 51 % des 47 patients grippaux (rapport des cotes [RC] non ajusté, 1,16; intervalle de confiance [IC] à 95 %, 0,57 à 2,33). Après ajustement pour tenir compte des différences initiales entre les cohortes, aucune différence significative n'a été observée entre la cohorte de COVID-19 et la cohorte de grippe (RC ajusté, 1,00; IC 95 %, 0,41 à 2,44). Les patients atteints de COVID-19 atteints d'infections secondaires ont séjourné plus longtemps aux soins intensifs et à l'hôpital et la durée de la ventilation mécanique était plus longue pour ces patients. L'incidence d'infections secondaires était plus élevée chez les patients atteints de COVID-19 traités par stéroïdes que chez ceux non traités par stéroïdes (15/20, 75 % vs 37/75, 49 %). CONCLUSION: Les infections secondaires étaient fréquentes chez les patients gravement malades atteints de pneumonie virale, y compris de COVID-19. Nous n'avons observé aucune différence dans l'incidence d'infections secondaires entre les patients atteints de COVID-19 et ceux atteints de grippe dans notre étude de cohorte, mais les infections secondaires chez les patients atteints de COVID-19 étaient associées à de moins bonnes issues cliniques et à une utilisation accrue des ressources de soins de santé. La petite taille de la cohorte exclut toute inférence causale, mais peut fournir une base pour les recherches futures.