A Lung ultrasound-based comparison of postoperative respiratory outcome after pediatric congenital heart surgery in COVID-19 recovered and COVID-19 unaffected children-a pilot study

Abstract

Background: COVID-19 is known to affect the alveolar-capillary membrane and interstitial tissue. Cardiopulmonary bypass (CPB) is proven to cause "pump-lung" syndrome. Little is known about the subgroup of COVID-19-recovered children undergoing cardiac surgeries under CPB.

Aim: To compare the lung ultrasound score (LUSS) and morbidity of COVID-19-recovered children to those without COVID-19 after congenital cardiac surgery.

Setting and design: Prospective observational pilot study at a tertiary care institution.

Materials and methods: The study was carried out on 15 COVID-recovered children and 15 matched controls (Group B) posted for congenital cardiac surgery. COVID-recovered children were further divided into those who received in-hospital care for COVID (Group C) and those who did not (Group A). LUSS measured immediately after cardiac surgery was compared between the groups. PaO₂/FiO₂ ratio, incidence of pulmonary infection, re-intubation rate, duration of ventilation, in-hospital mortality, and 30-day mortality were also compared between the groups.

Results: LUSS was comparable between Groups A and B (mean difference = 1.467, P = 0.721). Compared to the control group, Group C showed higher LUSS (mean difference = 11.67, P < 0.001), lower PaO₂/FiO₂ ratio (207.8 ± 95.49 Vs 357.6 ± 63.82, P = 0.003), and one in-hospital mortality. A significant negative correlation was seen between LUSS and PaO2/FiO2 ratio (r_s = -0.75, P < 0.001).

Conclusion: LUSS was not higher in COVID-recovered children. Children with a history of severe COVID-19 recorded higher LUSS, in-hospital mortality, duration of ICU stay, and duration of ventilation.

Keywords: COVID-19; Congenital heart surgery; lung ultrasound score; morbidity; mortality.