Viral Respiratory Infection, a Risk in Pediatric Cardiac Surgery: A Propensity-Matched Analysis*
Authors: Li Xia , Wang Xu , Li Shengli , Zeng Min , Li Dan 
Published: March 2020

Objectives:
1) To describe the postoperative course and outcomes of cardiac surgery in children with perioperative viral respiratory infection, 2) to evaluate optimal surgical timing for preoperative viral respiratory infection patients, and 3) to define risk stratification.

Design:
Retrospective study of children undergoing cardiac surgery. Children were tested using a multiplex polymerase chain reaction (respiratory virus polymerase chain reaction) panel capturing seven respiratory viruses. Respiratory virus polymerase chain reaction testing was routinely performed in patients under 2 years old. Those with negative results yet highly suspected of viral respiratory infection after surgeries would be tested again.

Setting:
A pediatric cardiac surgical ICU of pediatric cardiac surgery department at Fuwai Hospital.

Patients:
Children admitted between January 1, 2014, and December 31, 2016, to perform respiratory virus polymerase chain reaction testing and cardiac surgery were included.

Interventions:
None.

Measurements and Main Results:
A total of 2,831 patients had respiratory virus polymerase chain reaction testing, and viruses were detected in 91 patients (3.2%), including 35 preoperative and 56 postoperative. Of the 35 preoperative viral respiratory infection patients, there were 29 viral respiratory infection-resolved (patients for whom surgery was postponed until resolution of viral respiratory infection symptoms and negative respiratory virus polymerase chain reaction) and six viral respiratory infection-unresolved (who underwent cardiac surgery before resolution of symptoms and clearance of carriage) patients. Furthermore, there were seven deaths, including one in the preoperative viral respiratory infection-unresolved group and six in the postoperative viral respiratory infection group. A propensity score matching was performed to correct the selection bias and identify the comparable patient groups. Compared to their matched nonviral respiratory infection patients, viral respiratory infection-resolved patients had similar duration of mechanical ventilation and length of stay, while viral respiratory infection-unresolved patients had longer durations of postoperative mechanical ventilation (p = 0.033), PICU (p = 0.028) and hospital length of stay (p = 0.010), and postoperative viral respiratory infection patients had significantly greater duration of postoperative recovery (p < 0.001) and higher mortality (p < 0.001). Earlier diagnosis of postoperative viral respiratory infection was associated with longer mechanical ventilation duration (r
2 = 0.422; p < 0.001). Palliative cardiac surgery was the only variable significantly associated with mortality in multivariate analysis (odds ratio, 12.0; 95% CI, 1.6–87.5; p = 0.014).

Conclusions:
The preoperative-unresolved and postoperative viral respiratory infection were associated with prolonged postoperative recovery, increased severity, and mortality in children with cardiac surgeries. Our results suggested the optimal surgical timing may be after the resolution of viral respiratory infection symptoms and carriage unless the perceived benefits of early surgery outweigh the risk of death, prolonged ventilation, and PICU length of stay. Palliative surgeries were associated with increasing mortality.