Summary
This retrospective single-center study evaluated predictors for escalation of antibiotic therapy in children with complicated appendicitis (CA). Since 2013, the institutional protocol has recommended postoperative Ceftriaxone/Metronidazole (CM) for five days, with a switch to Piperacillin/Tazobactam (PT) only if fever persists beyond 72 hours. The authors aimed to identify factors associated with the need for this switch and to assess whether certain patients might benefit from PT as first-line therapy.
The study included 256 children aged 0–16 years who underwent appendectomy for CA between 2013 and 2023. Of these, 39 patients (15%) required a switch to PT. Baseline demographics were similar between groups. Several preoperative variables were significantly associated with switching: overweight/obesity, generalized peritonitis, dehydration requiring IV bolus, higher CRP levels, and the presence of an intra-abdominal collection on preoperative imaging. Intraoperatively, the presence of an abscess and longer operative times were also associated with switching. Postoperatively, patients who ultimately required PT had more frequent fever spikes within the first 72 hours.
Multivariate logistic regression identified two independent predictors of antibiotic escalation: elevated preoperative CRP and intraoperatively confirmed intra-abdominal abscess. Each 10 mg/L increase in CRP was associated with a 6% increase in the odds of switching. The presence of an abscess increased the odds nearly sixfold.
The authors conclude that one in seven children with CA required escalation from CM to PT. Those with markedly elevated CRP or intra-abdominal abscess may benefit from first-line PT, potentially reducing hospital stay by avoiding delayed escalation. The study highlights the limitations of relying solely on postoperative fever as a trigger for antibiotic change and suggests that incorporating preoperative and intraoperative risk factors could improve protocol efficiency.
Interview with Estelle Studer, Carla Flament-Viricel, Ana-Maria Calinescu AM and Barbara Wildhaber (Geneva)
What inspired you to conduct this study?
In our daily practice, we noticed that some children with complicated appendicitis were not responding “well” to first-line Ceftriaxone/Metronidazole, finally requiring escalation to Piperacillin/Tazobactam, and we started to have a feeling about the profile of these patients. Rather than waiting for a fever during 72 hours to trigger the switch, we wanted to understand whether we could identify these patients earlier - ideally before or during surgery - to avoid unnecessary delays in appropriate antibiotic coverage.
Were there any unexpected findings?
We were somewhat surprised by how strongly the presence of an intra-abdominal abscess predicted escalation - nearly a sixfold increase in odds. While intuitively this makes sense, having it quantified so clearly reinforced that abscess formation is not just a “finding” but might also be a meaningful antibiotic decision point. We also found it noteworthy that the number of postoperative fever spikes within the first 72 hours, while associated with switching, was not an independent predictor - suggesting it is more a consequence than a cause, and perhaps not the most reliable trigger for escalation decisions. Last, but not least, intuitively, we would have predicted that obesity/overweight would have been an independent predictor. This negative finding should be interpreted with caution, given the relatively small cohort size, and the potential role of body habitus in antibiotic escalation warrants investigation in larger prospective studies.
What is the direct impact on the surgeon’s work?
The practical takeaway is that surgeons now have two concrete, actionable triggers to consider at the time of surgery: a markedly elevated preoperative CRP and the intraoperative finding of an abscess. Rather than defaulting to a wait-and-see approach based on postoperative fever, surgeons can discuss first-line PT with their team at the time of the operation, potentially shortening hospital stay and reducing the burden of fever management in the postoperative period. In our clinic, we are about to discuss changing our protocol.
What is your learning point from this project?
That protocol-driven medicine benefits from periodic re-evaluation with real-world data. Our protocol was designed with good intentions, but this analysis revealed that a one-size-fits-all approach may not serve all patients equally. Risk stratification - even with just two variables - can meaningfully guide clinical decisions. It also reminded us of the value of looking beyond postoperative parameters and paying closer attention to what we already know before and during the operation.
Are there any subsequent projects planned?
Yes! We are interested in analyzing clinical outcomes - specifically hospital length of stay, complication rates, and readmissions - in patients who will receive first-line PT versus those who were escalated (historical cohort). Second, antibiotic stewardship is an increasingly important topic in pediatric surgery, and we hope this work contributes to a broader effort to individualize postoperative antibiotic regimens in children with complicated appendicitis.
