Perioperative outcomes for children with preoperative upper respiratory tract infection symptoms in elective non-cardiac surgery after COVID-19 pandemic at a large tertiary hospital in China: a retrospective cohort study

Technical Summary: Perioperative Outcomes for Children with Preoperative URTI Symptoms in the Post-COVID-19 Era

Problem Statement
Upper respiratory tract infections (URTI) are the leading cause of pediatric surgical cancellations and are associated with a significantly higher incidence of perioperative respiratory adverse events (PRAE) compared to children without recent infections. While guidelines recommend postponing surgery for at least two weeks after symptom resolution, the emergence of the COVID-19 pandemic, particularly the Omicron variant, altered the epidemiological landscape of pediatric respiratory infections. The study addresses a critical knowledge gap: how the post-pandemic environment affects the perioperative risk profile of children with preoperative URTI symptoms undergoing elective non-cardiac surgery. Specifically, it investigates whether the additional surgical risk historically associated with URTI persists, changes, or is abolished in the post-COVID-19 era.

Methodology
This retrospective cohort study was conducted at Tongji Hospital, a large tertiary center in China, covering the period from January 1, 2015, to December 31, 2024. The study population included children aged 0–12 years undergoing elective non-cardiac surgery, excluding those with severe underlying conditions, ASA physical status IV/V, or day surgery cases.

The study design involved two primary comparative frameworks:

1. Temporal Comparison (S1 vs. S2): Children with preoperative URTI symptoms were divided into a pre-pandemic group (S1: 2015–2019, n=213) and a post-pandemic group (S2: 2020–2024, n=385).
2. Risk Assessment (Symptomatic vs. Asymptomatic): To isolate the risk attributable to URTI, symptomatic children (S1 and S2) were matched with asymptomatic controls (C1 and C2) based on surgical type and year. This formed two cohorts: a pre-COVID-19 cohort (S1 + C1, n=852) and a post-COVID-19 cohort (S2 + C2, n=1,540).

URTI symptoms were defined clinically (nasal congestion, rhinorrhea, sneezing, sore throat, cough) on the day of surgery. The primary outcome was postoperative complications, while secondary outcomes included intraoperative and emergence respiratory adverse events (RAE), reoperation rates, PACU stay, and length of stay (LOS).

Statistical analysis employed multivariable logistic and linear regression models adjusted for covariates such as age, sex, BMI, pulmonary history, ASA status, and anesthesia details. To mitigate selection bias, 1:1 propensity score matching (PSM) with a caliper of 0.02 was performed to balance baseline characteristics between groups.

Key Results

• Impact of the Pandemic on URTI Incidence: The proportion of children presenting with preoperative URTI symptoms decreased post-pandemic (0.85% in S2 vs. 1.38% in S1), likely due to enhanced infection control measures.
• Perioperative Outcomes in Symptomatic Children (S1 vs. S2):
  • After multivariate adjustment, the S2 group (post-pandemic) exhibited a significantly higher incidence of emergence RAE (OR 1.55, P=0.029) and a longer PACU stay compared to the S1 group.
  • Conversely, the S2 group demonstrated a significantly shorter total length of stay and postoperative LOS.
  • The reoperation rate was significantly lower in the S2 group in unadjusted analyses, though this difference was not statistically significant after multivariate adjustment.
• Additional Surgical Risk of URTI (Symptomatic vs. Asymptomatic):
  • Pre-COVID-19 Cohort: Before matching, symptomatic children (S1) had significantly higher rates of emergence RAE and reoperation compared to asymptomatic controls (C1). After multivariate adjustment, these differences remained significant (Emergence RAE: OR 1.57, P=0.032; Reoperation: OR 7.92, P=0.006). However, after PSM, no significant differences were observed between S1 and C1 for any outcome.
  • Post-COVID-19 Cohort: In the post-pandemic period, no significant differences were found between symptomatic (S2) and asymptomatic (C2) children regarding postoperative complications, intraoperative RAE, emergence RAE, or reoperation rates, regardless of whether multivariate adjustment or PSM was applied.

Key Contributions

1. Temporal Shift in Risk Profile: The study provides evidence that the association between preoperative URTI symptoms and adverse perioperative outcomes has shifted in the post-COVID-19 era. While the absolute risk of emergence RAE increased in the post-pandemic period compared to the pre-pandemic period, the relative risk of URTI compared to asymptomatic children was abolished in the post-pandemic cohort.
2. Decoupling of URTI and Complications: The findings suggest that in the post-pandemic context, the presence of mild URTI symptoms does not independently predict higher rates of postoperative complications or reoperation when compared to asymptomatic peers, a contrast to pre-pandemic data where URTI was a significant predictor of reoperation.
3. Clinical Management Insights: The data indicates that while emergence RAE rates are elevated in the post-pandemic era (potentially due to persistent airway inflammation or altered immune responses), postoperative recovery (LOS) is faster, and the need for reoperation is not increased by URTI symptoms.

Significance and Claims
The authors claim that the risks associated with preoperative URTI are not static but are modulated by the child's baseline physiological status, anesthesia management strategies, and the temporal context of the pandemic. The study suggests that the "excess risk" of URTI observed in the pre-pandemic era has been abolished in the post-pandemic era.

Consequently, the paper argues that clinical decision-making for children with preoperative URTI symptoms should move away from rigid postponement protocols toward individualized risk assessment. The authors emphasize that URTI symptoms alone are not absolute risk factors for severe adverse outcomes in the current era. Instead, they advocate for optimized perioperative management strategies, including comprehensive preoperative assessment (e.g., using the COLDS scoring system) and specific anesthesia techniques (e.g., intranasal dexmedetomidine, LMA over ETT where appropriate, and IV propofol induction) to mitigate the elevated risk of emergence RAE observed in the post-pandemic period.

The study concludes that while the pandemic has altered the baseline risk landscape, leading to a higher incidence of emergence RAE in symptomatic children, it has simultaneously reduced the disparity in postoperative recovery and reoperation rates between symptomatic and asymptomatic children. Future large-scale, multicenter studies are recommended to validate these findings and further explore the impact of specific anesthesia management approaches.