Perforated appendicitis: Short duration antibiotics are noninferior to traditional long duration antibiotics

Diagnosis and treatment of appendicitis: systematic review and meta-analysis

BACKGROUND

The optimal diagnosis and treatment of appendicitis remains controversial. This systematic review details the evidence and current best practices for the evaluation and management of uncomplicated and complicated appendicitis in adults and children.

METHODS

Eight questions regarding the diagnosis and management of appendicitis were formulated. PubMed, Embase, CINAHL, Cochrane and clinicaltrials.gov/NLM were queried for articles published from 2010 to 2022 with key words related to at least one question. Randomized and non-randomized studies were included. Two reviewers screened each publication for eligibility and then extracted data from eligible studies. Random effects meta-analyses were performed on all quantitative data. The quality of randomized and non-randomized studies was assessed using the Cochrane Risk of Bias 2.0 or Newcastle Ottawa Scale, respectively.

RESULTS

2792 studies were screened and 261 were included. Most had a high risk of bias. Computerized tomography scan yielded the highest sensitivity (> 80%) and specificity (> 93%) in the adult population, although high variability existed. In adults with uncomplicated appendicitis, non-operative management resulted in higher odds of readmission (OR 6.10) and need for operation (OR 20.09), but less time to return to work/school (SMD - 1.78). In pediatric patients with uncomplicated appendicitis, non-operative management also resulted in higher odds of need for operation (OR 38.31). In adult patients with complicated appendicitis, there were higher odds of need for operation following antibiotic treatment only (OR 29.00), while pediatric patients had higher odds of abscess formation (OR 2.23). In pediatric patients undergoing appendectomy for complicated appendicitis, higher risk of reoperation at any time point was observed in patients who had drains placed at the time of operation (RR 2.04).

CONCLUSIONS

This review demonstrates the diagnosis and treatment of appendicitis remains nuanced. A personalized approach and appropriate patient selection remain key to treatment success. Further research on controversies in treatment would be useful for optimal management.

Antibiotic therapy and necrotizing enterocolitis

Antibiotic therapy remains a cornerstone of treatment of both medical and surgical presentations of necrotizing enterocolitis (NEC). However, guidelines regarding the administration of antibiotics for the treatment of NEC are lacking and practices vary amongst clinicians. Although the pathogenesis of NEC is unknown, there is consensus that the infant gastrointestinal microbiome contributes to the disease. The presumed connection between dysbiosis and NEC has prompted some to study whether early prophylactic enteral antibiotics can prevent NEC. Yet others have taken an opposing approach, studying whether perinatal antibiotic exposure increases the risk of NEC by inducing a state of dysbiosis. This narrative review summarizes what is known about antibiotics and their association with the infant microbiome and NEC, current antibiotic prescribing practices for infants with medical and surgical NEC, as well as potential strategies to further optimize the use of antibiotics in this population of infants.

A shortened course of Amoxicillin/Clavulanate is the preferred antibiotic treatment after surgery for perforated appendicitis in children

BACKGROUND/PURPOSE

Despite evidence supporting short course outpatient antibiotic treatment following appendectomy for perforated appendicitis, evidence of real-world implementation and consensus for antibiotic choice is lacking. We therefore aimed to compare outpatient antibiotic treatment regimens in a national cohort.

METHODS

We identified children who underwent surgery for perforated appendicitis between 2010 and 2018 using the PearlDiver database and compared 45-day disease-specific readmission between children who received shortened (5-8 days) versus prolonged (10-14 day) total antibiotic courses (inpatient intravenous and/or oral) completed with outpatient Amoxicillin/Clavulanate versus Ciprofloxacin/Metronidazole, and compared antibiotic type (5-14 days) to each other.

RESULTS

4916 children were identified, 2001 (90.0%) treated with Amoxicillin/Clavulanate (5-14 days), 381 (19.0%) with shortened (5-8 days), 1464 (73.2%) with prolonged (10-14 days) courses. 222 (10.0%) were treated with Ciprofloxacin/Metronidazole, 44 (19.8%) with shortened, 174 (78.4%) with prolonged courses. Freedom from readmission was not different between prolonged and shortened course whether they received Amoxicillin/Clavulanate (adjusted hazard ratio [AHR] 1.54, 95%CI 0.95-2.5) or Ciprofloxacin/Metronidazole (AHR 3.49, 95%CI 0.45-27.3). Antibiotic type did not affect readmission rate (Amoxicillin/Clavulanate versus Ciprofloxacin/Metronidazole, AHR 1.21, 95%CI 0.71-2.05).

CONCLUSION

Prolonged antibiotic regimens are routinely prescribed despite evidence suggesting shorter courses and antibiotic choice are not associated with greater treatment failure. As it is better tolerated, we recommend a shortened course of Amoxicillin/Clavulanate for oral management of perforated appendicitis.

STUDY DESIGN

Retrospective.

LEVEL OF EVIDENCE

Level III.

Implications of bacteriological study in complicated and uncomplicated acute appendicitis

Purpose

Bacteriological sample in the presence of intraabdominal free fluid is necessary to adapt the antibiotherapy and to prevent the development of resistance. The aim was to evaluate the differences between uncomplicated (UAA) and complicated acute appendicitis (CAA) in terms of bacterial culture results and antibiotic resistance, and to evaluate the factors linked with CAA.

Methods

We performed a single-center, retrospective observational study of all consecutive patients who presented with appendicular peritonitis and underwent emergent surgery in a tertiary referral hospital in Brussels, Belgium, between January 2013 and December 2020. The medical history, parameters at admission, bacterial culture, antibiotic resistance, and postoperative outcomes of 268 patients were analyzed. UAA was considered catarrhal or phlegmonous inflammation of the appendix. CAA was considered gangrenous or perforated appendicitis.

Results

Positive microbiological cultures were significantly higher in the CAA group (68.2% vs. 53.4%). The most frequently isolated bacteria in UAA and CAA cultures were Escherichia coli (37.9% and 48.6%). Most observed resistances were against ampicillin (28.9% and 21.7%) and amoxicillin/clavulanic acid (16.4% and 10.5%) in UAA and CAA, respectively. A higher Charlson comorbidity index, an elevated white blood cell count, an open procedure, and the need for drainage were linked to CAA. Culture results, group of bacterial isolation, and most common isolated bacteria were not related to CAA.

Conclusion

CAA presented a higher rate of positive cultures with increased identification of gram-negative bacteria. Bacterial culture from the peritoneal liquid does not reveal relevant differences in terms of antibiotic resistance.

Inverted Appendix in a Patient With Weakness and Occult Bleeding

BACKGROUND

Appendiceal mucinous neoplasms (AMNs) are rare adenomatous primary tumors of the appendix. Although of low malignant potential, these neoplasms can cause serious potentially fatal complications such as bowel obstruction and pseudomyxoma peritonei, making prompt identification and removal of utmost importance. AMNs often present with nonspecific gastrointestinal symptoms or are asymptomatic and found incidentally.

CASE PRESENTATION

A patient aged 72 years presented with generalized weakness and appeared on imaging to have acute appendicitis complicated by rupture. On colonoscopy, the patient was found to have an inverted appendix that after appendectomy was revealed to harbor a perforated low-grade AMN.

CONCLUSIONS

Although AMNs are rare, physicians should still consider it when imaging suggests appendicitis. Having AMNs as part of the differential diagnosis is especially necessary in cases, such as this one, in which the patient has appendiceal inversion, is aged > 50 years, and has concurrent colorectal neoplasms.

Evaluation of Preoperative Clinical and Serological Determinations in Complicated Acute Appendicitis: A Score for Predicting Complicated Appendicitis

BACKGROUND

To analyze whether clinical and analytical parameters differ according to histopathology in cases of acute appendicitis (AA).

METHODS

This is a retrospective, observational study including patients (>14 years of age) admitted for suspicion of AA from 1 April 2014 to 31 July 2016. Histopathology was divided into complicated (including perforated and gangrenous AA) and uncomplicated appendicitis (phlegmonous). Sex, age, temperature of patients on admission to the Emergency Department, symptom duration, preoperative white blood cell (WBC) count, neutrophil percentage, mean platelet volume (MPV), platelet distribution width (PDW), C-reactive protein (CRP) and hospital stay were compared in the two groups.

RESULTS

Three hundred and thirty-five patients were analyzed, and 284 were included. Appendicitis was uncomplicated in 194 (68.3%) and complicated in 90 (31.7%). Age, symptom duration, neutrophil percentage, CRP and hospital stay were higher in the complicated AA group (P < .05). The mean differences between uncomplicated and complicated AA were: age 13.2 years (95% CI: 8.2-18.2), symptom duration 14.1hours (95% CI: 6.3-21.9), neutrophil percentage 5.0% (95% CI: 3.2-6.8), CRP 73.6mg/l (95% CI: 50.0-97.2) and hospital stay 2.2 days (95% CI: 1.4-3.0), with p<0.05 for all these variables. A model based on the preoperative parameters (age, symptom duration, neutrophil percentage and CRP) was calculated to predict the likelihood of complicated AA. The receiver operating characteristic (ROC) of the model had an area under the curve of 0.80 (95% CI 0.75-0.85).

CONCLUSION

This model is able to diagnose complicated AA without the need for imaging techniques, although it must be validated with prospective analysis.

Duration of post-operative antibiotic treatment in acute complicated appendicitis: systematic review and meta-analysis

BACKGROUND

Appendicitis is the most frequent aetiology of acute abdominal pain requiring surgical treatment, with an estimated lifetime risk between 7% and 8%. Antibiotics play a substantial role in treatment, and there is considerable debate regarding the duration of antibiotics in treating appendicitis.

METHODS

We searched multiple databases from inception until June 2019 for peer-reviewed studies that compared different durations of antibiotic treatment after appendicectomy for acute complicated appendicitis in adults. We dichotomized reported data into short- and extended-term antibiotic use and controlled for different definitional thresholds in the meta-analysis. We generated risk ratios using restricted maximum likelihood methods and mixed effects modelling for each outcome of interest.

RESULTS

Four observational studies involving 847 participants were included in the meta-analysis. For the primary outcomes of intra-abdominal infection, we did not find a statistically significant difference between extended- and short-term antibiotic strategies for intra-abdominal infection (Risk ratio 0.92, 95% confidence interval (CI) 0.49-1.74). Three randomized controlled trials involving 291 participants were included in a separate meta-analysis. We found that extended antibiotic usage was not associated with a statistically significant reduced risk for intra-abdominal infection (RR 0.52, 95% CI 0.21-1.29) or surgical site skin infection (RR 1.44, 95% CI 0.43-4.81).

CONCLUSION

This systematic review and meta-analysis found that extended post-operative antibiotic treatment may not be associated with a reduced risk of intra-abdominal infection; however, meta-analysis was significantly limited by heterogeneity between studies and underpowered trials. Further large randomized controlled trials are needed to confirm these findings.