Letter: Risk Factors for Organ/Space Infections Following Appendectomy for Complicated Appendicitis in Children

To the Editor:

Complicated appendicitis (CA) remains a common surgical emergency in children, with significant post-operative morbidity.^1,2 Among post-operative complications, organ/space infections (OSIs) are particularly concerning because of their association with prolonged hospitalization, increased healthcare costs, and, in some cases, the need for reoperation. ³ The reported incidence of OSIs following CA ranges widely, from 5% to 20%, depending on the clinical severity of the initial presentation and peri-operative management strategies.^3,4 Although many studies have investigated post-operative outcomes after pediatric appendectomy, the ability to predict which patients are at highest risk of OSIs is still limited. The aim of this study was to examine the risk factors for OSIs after appendectomy for CA in children.

Following approval by our institutional ethics committee, we conducted a retrospective study from January 1, 2013, to December 31, 2024, in a pediatric surgery department. All children under 14 years of age who underwent appendectomy for CA were included. CA was defined as gangrenous appendicitis, perforated appendicitis, abscess formation, or diffuse peritonitis. Patient’s pre-existing comorbidities were recorded and quantified using the Sun’s Pediatric Comorbidity Index (SPCI), developed and validated by Sun et al. ⁵ As per our institutional protocol, all children with CA receive an initial intravenous bi-therapy of cefotaxime and metronidazole for 5 days. This may be followed by oral antibiotics, usually lasting from 2 to 5 days, depending on the surgeon’s clinical judgment.

During the 12-year study period, 549 children underwent appendectomy for CA. The median age was 9 years, and 62.7% were male. The median duration of symptoms was 40 hours. A total of 113 (20.6%) patients received antibiotics in the three days prior to hospital admission. The median SPCI, Alvarado score, and C-reactive protein (CRP) were 1, 7, and 101 mg/L, respectively. The overall incidence of OSIs was 7.8% (n = 43).

The uni-variable analysis comparing OSI and non-OSI groups revealed that duration of symptoms >48 hours, SPCI ≥3, pre-hospital antibiotic use, CRP >150 mg/L, Alvarado score ≥8, a large amount of free intraperitoneal fluid, and procedure duration >100 min were potential risk factors for OSIs (Table 1). On multi-variable logistic regression analysis, three factors emerged as independent predictive factors of OSIs. These factors included SPCI ≥3 (odds ratio [OR] = 3.038; 95% confidence interval [CI]: 1.393–6.628; p = 0.005), Alvarado score ≥8 (OR = 3.819; 95% CI: 1.781–8.185; p = 0.001), and CRP >150 mg/L (OR = 4.321; 95% CI: 2.023–9.228; p < 0.001).

Beyond their statistical significance, the risk factors for OSIs highlighted by this study are of practical value in the day-to-day management of children with CA. By integrating simple clinical and biological indicators available on admission, clinicians can better anticipate the risk of serious post-operative infections. This risk stratification approach not only allows for more personalized peri-operative care but also guides clear, evidence-based discussions with families about expected outcomes and potential complications. Ultimately, these tools can help improve both clinical decision-making and communication with caregivers.