Updates on bacterial resistance and empirical antibiotics treatment of complicated acute appendicitis in children

Use of Antipseudomonal Antibiotics is Not Associated With Lower Rates of Postoperative Drainage Procedures or More Favorable Culture Profiles in Children With Complicated Appendicitis: Results From a Multicenter Regional Research Consortium

OBJECTIVE

To compare rates of postoperative drainage and culture profiles in children with complicated appendicitis treated with the 2 most common antibiotic regimens with and without antipseudomonal activity [piperacillin-tazobactam (PT) and ceftriaxone with metronidazole (CM)].

BACKGROUND

Variation in the use of antipseudomonal antibiotics has been driven by a paucity of multicenter data reporting clinically relevant, culture-based outcomes.

METHODS

A retrospective cohort study of patients with complicated appendicitis (7/2015-6/2020) using NSQIP-Pediatric data from 15 hospitals participating in a regional research consortium. Operative report details, antibiotic utilization, and culture data were obtained through supplemental chart review. Rates of 30-day postoperative drainage and organism-specific culture positivity were compared between groups using mixed-effects regression to adjust for clustering after propensity matching on measures of disease severity.

RESULTS

In all, 1002 children met the criteria for matching (58.9% received CM and 41.1% received PT). In the matched sample of 778 patients, children treated with PT had similar rates of drainage overall [PT: 11.8%, CM: 12.1%; odds ratio (OR): 1.44 (OR: 0.71-2.94)] and higher rates of drainage associated with the growth of any organism [PT: 7.7%, CM: 4.6%; OR: 2.41 (95% CI: 1.08-5.39)] and Escherichia coli [PT: 4.6%, CM: 1.8%; OR: 3.42 (95% CI: 1.07-10.92)] compared to treatment with CM. Rates were similar between groups for drainage associated with multiple organisms [PT: 2.6%, CM: 1.5%; OR: 3.81 (95% CI: 0.96-15.08)] and Pseudomonas [PT: 1.0%, CM: 1.3%; OR: 3.42 (95% CI: 0.55-21.28)].

CONCLUSIONS AND RELEVANCE

The use of antipseudomonal antibiotics is not associated with lower rates of postoperative drainage procedures or more favorable culture profiles in children with complicated appendicitis.

Perforated Appendicitis in Children: Management, Microbiology, and Antibiotic Stewardship

Although appendicitis has been described for more than 300 years, its optimal management remains a topic of active investigation. Acute appendicitis is the most common cause of peritonitis in children, and rates of perforated appendicitis are much higher in children than in adults. Increased risk for perforated appendicitis in children is related to a delay in diagnosis due to age, size, access to care, and more. Surgical options include immediate appendectomy versus nonoperative management with intravenous antibiotics ± a drainage procedure, with a subsequent interval appendectomy. Microbiota of perforated appendicitis in children most often includes Escherichia coli, Bacteroides fragilis, Streptococcus, and more. Even though the most common organisms are known, there is a large variety of practice when it comes to postoperative antibiotic management in these patients. Studies discuss the benefits of mono- versus dual or triple therapy without a particular consensus regarding what to use. This is reflected across differing practices at various institutions. In this review, we aim to explore the implications of perforated appendicitis in pediatrics, common organisms seen, antibiotic regimen coverage, and the implications of variations of practice. Resistance to commonly used broad-spectrum antibiotics is evolving, therefore minimization of care variability is needed for improved patient outcomes and proper antibiotic stewardship.

Postoperative Antibiotics for Complicated Appendicitis in Children: Piperacillin/Tazobactam versus Ceftriaxone with Metronidazole

INTRODUCTION

Recent studies are discordant regarding postoperative use of piperacillin/tazobactam (PT) versus ceftriaxone/metronidazole (CM) for pediatric complicated appendicitis. Some argue that the broader spectrum PT decreases intraabdominal abscess formation; however, antibiotic stewardship, and once-a-day dosing favor CM. We aim to compare outcomes of postoperative antibiotic utilization using a large administrative database.

METHODS

We queried the Pediatric Health Information System for patients 2-18 years old who underwent laparoscopic appendectomy for complicated appendicitis between 2016 and 2021. Patients were grouped into PT, CM, or other using the first postoperative day antibiotics. Adverse events and antibiotic use trends were evaluated.

RESULTS

We included 29,015 children from 45 hospitals. CM was used in 51.9% and 31.3% received PT. Wide variation was seen among hospitals with PT use decreasing over the years. Overall rate of abscess was 9.2%. On multivariable regression, PT was associated with higher risk for abscess formation (RR 1.35, 99% CI 1.04-1.75) and readmission (RR 1.38, 99% CI 1.13-1.68) compared to the CM group. However, following adjustment for hospitals with high CM prevalence, these associations were no longer significant.

CONCLUSION

Postoperative use of PT for complicated appendicitis is associated with higher rates of readmissions and intraabdominal abscess when compared to CM. However, this effect is mitigated when adjusting for common practice patterns.

LEVEL OF EVIDENCE

Level III.

STUDY TYPE

Retrospective Comparative Study.

Differences in isolated bacteria between perforated and non-perforated appendicitis: an analysis of 680 consecutive appendicectomies in a single institution

PURPOSE

Escherichia coli and Bacteroides species are the most frequently detected species in ascites in perforated appendicitis and are generally sensitive to non-empiric cephalosporins like cefazolin or cefmetazole. However, monotherapy with such antibiotics is mostly insufficient for perforated appendicitis. To investigate this issue, this study aimed to compare bacterial floras in ascites culture between perforated and non-perforated appendicitis.

METHODS

Ascites culture results in perforated and non-perforated appendicitis cases were analyzed using a departmental database. The duration of symptoms before surgery, pre-surgical white blood cell count, C-reactive protein value, postsurgical length of stay, length of antibiotic treatment, and the rate of using second-line antibiotics or complications were also compared.

RESULTS

A total of 608 and 72 cases of non-perforated and perforated appendicitis were included. Escherichia coli and Bacteroides species were the dominant bacteria in both conditions. However, the total proportions of Pseudomonas aeruginosa, Streptococcus anginosus group, and Enterococcus group were significantly higher in perforated appendicitis than in non-perforated appendicitis.

CONCLUSION

Pseudomonas aeruginosa, Streptococcus anginosus group, and Enterococcus group have better susceptibility to penicillin-based empiric antibiotics than cephalosporins. The abundance of these bacteria might explain why non-empiric cephalosporins are not effective in perforated appendicitis and the superiority of penicillin-based empiric antibiotics.

Microbiota Assessment of Pediatric Simple and Complex Acute Appendicitis

Background and Objectives. The aim of this study is to determine the prevailing microbiota in samples from pediatric patients with acute appendicitis, as well as evaluate the antibacterial sensitivity of the isolated microorganisms, comparing the data obtained with the clinic’s antibacterial therapy guidelines. Materials and Methods. The study group consisted of 93 patients between the ages of 7 and 18. All patients underwent a laparoscopic or conventional appendectomy. The children were hospitalized with signs and symptoms suggestive of acute appendicitis. Microbiological cultures from the appendix and abdominal cavity were collected intraoperatively. Results. E. coli was identified in most cases irrespective of the clinical presentation of acute appendicitis. Most strains were susceptible to ampicillin and amoxicillin/clavulanic acid. Five strains of E. coli produced extended spectrum beta-lactamase (ESBL). Pseudomonas aeruginosa (P. aeruginosa) was the second most commonly isolated causative agent. Furthermore, it was common in cases of acute complex appendicitis. Most strains of P. aeruginosa were resistant to amoxicillin/clavulanic acid, ertapenem, ampicillin and cefotaxime, yet were susceptible to ceftazidime. Regardless of the clinical presentation, the samples yielded mixed isolates. Conclusion. E. coli is the main causative agent of acute appendicitis in the pediatric population displaying susceptibility to various antibiotics. P. aeruginosa was more prevalent in cases of acute complex appendicitis. P. aeruginosa isolates were susceptible to ceftazidime; however, they were resistant to cefotaxime, which should, therefore, be removed from guidelines for empirical antibacterial treatment of acute appendicitis due to phenotypic resistance of P. aeruginosa. We recommend antibiotics with distinct implementation to avoid antibiotic resistance.

Clinical, Laboratory and Radiographic Features Associated With Prolonged Hospitalization in Children With Complicated Appendicitis

OBJECTIVE

In children with appendicitis, rupture of the appendix is associated with a significant increase in morbidity. We sought to characterize the spectrum of illness in children with complicated appendicitis and to define those factors associated with a longer hospital stay.

STUDY DESIGN

We conducted a retrospective review of 132 children, 18 years of age or younger at a large urban teaching hospital in the Bronx, NY between October 2015 and April 2018 with an intraoperative diagnosis of perforated appendix. Clinical, laboratory and radiologic findings were reviewed, and the primary study outcome was length of stay (LOS) dichotomized at the median, which was 7 days. Statistical analyses were done to characterize morbidity and define variables predictive of longer stay.

RESULTS

Children in the longer LOS group experienced significantly more morbidity, including ICU stay, ileus, and need for multiple drainage procedures. A longer duration of symptoms prior to presentation was associated with a longer stay. Multivariable logistic regression analysis indicated that the presence of abscess and presence of free fluid in the right upper quadrant (RUQ FF) on initial imaging and C-reactive protein (CRP) level >12 at admission, were independently associated with a longer stay.

CONCLUSION

There is considerable variation in the morbidity of complicated appendicitis. The association between longer stay and the findings of abscess and RUQ FF on initial imaging along with an elevated CRP may provide a useful tool in identifying those children at risk for worse outcomes.