Intra-operative culture swabs in acute appendicitis: a waste of resources

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.

Intraoperative bacterial cultures fail to reliably predict the bacterial spectrum encountered during infectious complications after appendicitis

Acute appendicitis is a common surgical emergency. Complicated appendicitis usually warrants perioperative antibiotic treatment in order to prevent infectious complications. Whether routine microbiological testing benefits the individual patient is a topic of debate. The goal of our study was to assess perioperative antibiotic prescriptions as well as the benefit of microbiological testing during the appendectomy as a predictor for bacteria encountered in infectious complications. This is a retrospective analysis of 1218 consecutive patients that underwent appendectomy at a tertiary referral center between 2014 and 2021. The patient charts were systematically analyzed regarding intraoperative outcome, microbiologic results, and postoperative infectious complications. 1218 patients were included in this study of which 768 were uncomplicated appendicitis (UA) and 450 were complicated appendicitis (CA). Microbiological testing was performed in 39.2% of UA cases (33.6% of which grew bacteria) compared to 74.9% of CA cases (78.6% positive cultures). The strongest individual predictors for SSI were gangrenous and perforated appendicitis. A total of 58 surgical-site infections developed, of which 49 were intra-abdominal fluid collections or abscesses. Thirty-two patients had revision surgery or CT-guided drainage for SSI. In the cases where microbiological testing was done both during the appendectomy and the SSI, 13/18 showed different bacteria on culture testing. The infectious outcome was favorable in 98.3%. While microbiological testing offers insights into resistance patterns, it is of little benefit for the individual patient, given the low predictive value for bacteria found during SSI. Achieving source control combined with empiric antibiotic coverage leads to favorable outcomes independent of culture results.

The role of intraoperative swab during appendectomy in patients with uncomplicated and complicated appendicitis

INTRODUCTION

Bacteria play an important role not only in pathogenesis of appendicitis but also in the postoperative course of patients. However, the usefulness of an intraoperative swab during appendectomy is controversial. The primary aim of this study was to investigate the impact of intraoperative swab during appendectomy on the postoperative outcome in patients with uncomplicated and complicated appendicitis.

METHODS

A retrospective analysis was conducted on a consecutive series of 1570 adult patients who underwent appendectomy for acute appendicitis at the University Hospital Erlangen between 2010 and 2020. Data regarding the intraoperative swab were collected and analyzed for the entire cohort as well as for patients with uncomplicated and complicated appendicitis.

RESULTS

An intraoperative swab was taken in 29% of the cohort. The bacterial isolation rate in the obtained intraoperative swabs was 51%, with a significantly higher rate observed in patients with complicated appendicitis compared to those with uncomplicated appendicitis (79% vs. 35%, p < 0.001). The presence of a positive swab was significantly associated with worse postoperative outcomes, including higher morbidity, increased need for re-surgery, and longer hospital stay, when compared to patients without a swab or with a negative swab. A positive swab was an independent risk factor for postoperative morbidity (OR 9.9 (95% CI 1.2-81.9), p = 0.034) and the need for adjustment of postoperative antibiotic therapy (OR 8.8 (95% CI 1.1-72.5), p = 0.043). However, a positive swab resulted in postoperative antibiotic therapy adjustment in only 8% of the patients with bacterial isolation in the swab.

CONCLUSION

The analysis of swab samples obtained during appendectomy for acute appendicitis can help identify patients at a higher risk of a worse postoperative outcome. However, the frequency of antibiotic regime changes based on the swab analysis is low.

Bacterial peritonitis in paediatric appendicitis; microbial epidemiology and antimicrobial management

BACKGROUND

Appendicitis remains a common surgical emergency in children. Empirical antibacterial treatment is indicated to reduce infective complications. We investigate the bacterial pathogens identified intra-operatively during appendectomies in children to guide empirical surgical antimicrobial prophylaxis options.

METHODS

A retrospective analysis of patients (< 18 years old) undergoing an appendectomy across a multisite London hospital (Nov 2019-March 2022) was undertaken. Patient-related outcomes including length of hospital stay (LOS), days of antibacterial therapy (DOT), intra-operative microbiology and post-operative radiology reports were interrogated.

RESULTS

304 patients underwent an appendectomy during this period; 39.1% of patients had intraoperative samples cultured. Bacterial pathogens were found in 73/119 (61.3%) cases; the most common isolates being Escherichia coli (42.0%), Pseudomonas aeruginosa (21.0%), milleri Streptococcus spp. (14.3%) and Bacteroides fragilis (5.9%). Polymicrobial infection was common (32/73). Isolation of Pseudomonas spp. from intra-operative sampling was associated with a greater LOS (7.0 vs. 5.0 days; p = 0.011) but nil effect on the incidence of postoperative collections. Presence of milleri Streptococcus spp. was associated with longer LOS (7.0 vs. 5.0 day; p = 0.007), DOT (12.0 vs. 8.5 day; p = 0.007) but had no observed outcome on postoperative collections (29.4% vs. 18.6%; p = 0.330). 48% of E. coli positive cultures were co-amoxiclav resistant and prolonged LOS compared to the non-resistant group (7.0 vs. 5.0 days; p = 0.040) but had no difference in post-operative collections (29.2% vs. 17.9%; p = 0.260).

CONCLUSION

A high proportion of children with appendicitis have Pseudomonas spp. isolated, leading to a prolonged LOS. Evolving Enterobacterales resistance and the presence of Pseudomonas spp. necessitate extended antibacterial coverage for paediatric appendectomies with evidence of peritonitis.

Using Microbiology Culture in Pediatric Appendicitis to Risk Stratify Patients: A Cohort Study

Background: We sought to investigate the value of intra-operative microbiology samples in pediatric appendicitis. Proposed benefits include tailoring post-operative antimicrobial management, risk-stratifying patients, and reducing post-operative intra-abdominal abscess formation. Patients and Methods: All cases of appendicitis managed with appendicectomy in a single center were collected from January 2015 to August 2020. Intra-operative microbiology samples were taken routinely. Post-operative outcomes were analyzed with reference to culture and sensitivity results. Histologic findings were further categorized as normal, simple, or complex. Results: Six hundred seventy-eight children had appendicectomies, and 608 had both microbiology and histology samples taken. Intra-abdominal fluid collection and subsequent intervention rates were 22% and 9%, respectively. There were more collections in those with a culture positive result (p < 0.001), and those growing each of three recognized organisms, Escherichia coli (p < 0.001), Pseudomonas aeruginosa (p = 0.01), and Streptococcus anginosus group (p < 0.001). Intervention rate was higher in the culture-positive result group (p = 0.002) and the Streptococcus anginosus group (p < 0.001). Conclusions: This study shows an increased risk of developing a collection with the isolation of one of three key organisms (Escherichia coli, Pseudomonas aeruginosa, Streptococcus anginosus group). Sersoal swabs are an effective and practical method of gathering information on organisms. Microbiologic yield was correlated to the severity of appendicitis. Isolation of Streptococcus anginosus increases the incidence of collections to 50%. This is useful to empower surgeons to prognosticate patients' potential outcomes based on both intra-operative, and microbiologic findings, and is useful in counseling patients and managing expectations. A prolonged course of antibiotic agents or higher dose may mitigate this risk.

The Management of Pediatric Acute Appendicitis-Survey among Pediatric Surgeons in Romania

Background and Objectives: To assess the current practice pattern in the management of pediatric acute appendicitis in Romania. Materials and Methods: A questionnaire was emailed to all the members of the Romanian Society of Pediatric Surgery between June-July 2022. Results: 118 answers were received, 79.7% responses being from permanent staff members. In the diagnosis of appendicitis, complete blood count, C-reactive protein and abdominal ultrasound are the most commonly used diagnostic tools, while appendicitis scores are not widely used (25% of surgeons). In the case of simple appendicitis, 49.2% of surgeons prefer the conservative approach-oral/intravenous antibiotics. Those who choose the operative approach begin preoperative antibiotics in 56.7% of patients. In case of a stable patient, only 16.7% of surgeons will operate during the night. Laparoscopic approach is chosen by 51.7% of surgeons. In the case of a complicated appendicitis, 92.4% of surgeons will perform the appendectomy, prescribing preoperative antibiotics in 94% of the cases and continuing the therapy postoperatively in 98.2%. Laparoscopic approach is used by 28.8% of surgeons in case of complicated appendicitis. In presence of appendicular mass, 80% prefer a conservative approach with a delayed appendectomy within 6 months. Appendicular abscesses are managed operatively in 82.2% of the cases. The appendix is sent for histological analysis by 95.8% of surgeons. If the peritoneal cavity is contaminated, 95% of the respondents will take a sample for microbiological analysis, 71% will always place a drainage and 44% will always irrigate (71.9%-saline). Conclusions: Clearly, there seems to be a lack of consensus regarding several aspects of the management of acute appendicitis in children. In addition, minimally invasive surgery is not as widely used as reported, despite literature support.

Antibiotic resistance is common in the cultures of intraabdominal abscess drainage after appendectomy

INTRODUCTION

Intraabdominal abscesses (IAA) are a common complication following appendectomy. Empiric antibiotic regimens may fail to prevent IAA due to changes in bacterial resistance. We aim to describe the bacteriology of pediatric patients requiring drainage of an IAA after an appendectomy for appendicitis.

METHODS

We performed a retrospective study of patients ≤18 years who underwent percutaneous drainage of an IAA following appendectomy a single U.S. children's hospital between 2015 and 2018. Patient demographics, appendicitis characteristics, antibiotic regimens, and culture data were collected.

RESULTS

In total, 71 patients required drainage of an IAA of which 48 (67%) were male, the average age was 9.81 (SD 3.31) years and 68 (95.7%) having complicated appendicitis. Ceftriaxone/metronidazole was the most common empiric regimen prior to IAA drainage occurring in 64 (90.1%) patients. IAA cultures isolated organisms in 34 (47.9%) patients. Of those with positive cultures, 17 (50%) cases demonstrated an antimicrobial resistant organism. Most notably, 20% of Escherichia coli was resistant to the empiric regimen. Empiric antimicrobial regimens did not appropriately cover 92.3% of Pseudomonas aeruginosa cultures or 100% of Enterococcus species cultures. Antimicrobial regimens were changed following IAA drainage in 30 (42.2%) instances with 23 (32.4%) instances due to resistance in culture results or lack of appropriate empiric antimicrobial coverage.

CONCLUSIONS

IAA culture data following appendectomy for appendicitis frequently demonstrates resistance to or lack of appropriate coverage by empiric antimicrobial regimens. These data support close review of IAA culture results to identify prevalent resistant pathogens along with local changes in resistance.

LEVEL OF EVIDENCE

Level III.

Are We Hitting the Target?: The Effectiveness of Distinct Antibiotic Regimens in Pediatric Appendectomies

BACKGROUND

Currently, a range of different antibiotics are administered perioperatively during appendectomy surgery in the pediatric population. One reason for the lack of a uniform treatment regimen is the paucity of large studies on microbiologic data and susceptibility patterns.

METHODS

A retrospective, monocentric study on antibiotic susceptibility, including 1258 pediatric patients undergoing appendectomy from 2012 to 2020 was performed. Predictors for prolonged length of stay (LOS) and complications were determined using regression analysis, and objective criteria for broad-spectrum antibiotic regimens were identified. Simulations of the effectiveness of different antibiotic regimens against identified bacterial susceptibility results were conducted.

RESULTS

The most important predictors for prolonged LOS and an increased incidence of infectious complications are elevated preoperative C-reactive protein levels, high intraoperative severity gradings and insufficient primary antibiotic treatment. Based on our results, a simple antibiotic treatment, consisting of cefuroxime-metronidazole (C-M) or ampicillin-sulbactam (AS), is sufficient in around 85% of all patients; both options being equally efficient. In severe appendicitis, the likelihood of resistance is 31% and 32% for C-M and AS, respectively. For piperacillin-tazobactam and C-M-tobramycin, the incidence of bacterial resistance decreases to 12%. Resistance is reduced to 8% for AS-tobramycin treatment. The patient populations benefiting most from an extended antibiotic regimen are those with a high intraoperative severity grading.

CONCLUSIONS

Evidence suggests that an insufficient antibiotic regimen is associated with a prolonged LOS and a higher rate of infectious complications, justifying the expansion of a simple antibiotic regimen in cases of severe intraabdominal findings. In all other cases, a simple antibiotic treatment with AS is recommended.

Is Routine Intra-operative Gram Stain, Culture, and Sensitivity during an Appendectomy is Effective in Decreasing the Rate of Post-operative Infective Complications?

BACKGROUND: Organisms blamed in acute appendicitis are right predictable and very susceptible to a wide range of broad-spectrum antibiotics. AIM: The aim of the study was to assess the clinical benefit of the routine intra-operative swab during an appendectomy in guiding antibiotic selection. METHODS: Four hundred and thirty patients underwent appendectomy halved into two groups, each 215. In Group 1, an intra-operative swab was routinely obtained for culture/sensitivity. The results of which were reviewed for helping direct antibiotic selection. No intra-operative swabs were obtained in Group 2. Both groups were given single-dose cefotaxime and metronidazole preoperatively intravenously at the time of induction of anesthesia. RESULTS: In swab group, 63/215 cultures (29.3%) revealed pathogens, while (70.7%) were negative or revealed isolated colonic commensals. Most cultures were negative or isolated colonic commensals. Fifty-two/63 cultures (82.54%) were sensitive to both cefotaxime and metronidazole, and only 11/63 (17.46%) reported resistant organisms to cefotaxime but not to metronidazole. Most pathogens were sensitive to empirical antibiotics. Twenty-two/215 patients (10.23%) developed infective complications, most (63.6%) had their cultures from the infected wound yielded different micro-organisms. Only 8/215 (3.72%) in the swab group needed a change in the empirical antibiotics for treating infective complications. In the non-swab group, 19/215 patients (8.83%) developed infective complications. Only 6/215 patients (2.8%) needed a change in the empirical antibiotics for treating infective complications. Collectively, only 14/430 patients (3.25%) required a change in the empirical antibiotics for treating infected wounds. CONCLUSIONS: Routine peritoneal swabs for culture/sensitivity during appendicectomy are of no clinical value. Such practice is considered a waste of laboratory resources and money. A single prophylactic dose of antibiotics has significant role in preventing surgical site infection.

Routine Intraoperative Bacterial Culture May Be Needed in Complicated Appendicitis

Purpose

Choosing the appropriate antibiotic is important for treatment of complicated appendicitis. However, increasing multidrug resistant bacteria have been a serious problem for successful treatment. This study was designed to identify bacteria isolated from patients with complicated appendicitis and reveal their susceptibilities for antibiotics and their relationship with patient clinical course.

Methods

This study included patients diagnosed with complicated appendicitis and examined the bacterial cultures and antimicrobial susceptibilities of the isolates. Data were retrospectively collected from medical records of Kangbuk Samsung Hospital from January 2008 to February 2018.

Results

The common bacterial species cultured in complicated appendicitis were as follows: Escherichia coli (n=113, 48.9%), Streptococcus spp. (n=29, 12.6%), Pseudomonas spp. (n=23, 10.0%), Bacteriodes spp. (n=22, 9.5%), Klebsiella (n=11, 4.8%), and Enterococcus spp. (n=8, 3.5%). In antibiotics susceptibility testing, the positive rate of extended-spectrum beta lactamase (ESBL) was 9.1% (21 of 231). The resistance rate to carbapenem was 1.7% (4 of 231), while that to vancomycin was 0.4% (1 of 231). E. coli was 16.8% ESBL positive (19 of 113) and had 22.1% and 19.5% resistance rates to cefotaxime and ceftazidime, respectively. Inappropriate empirical antibiotic treatment (IEAT) occurred in 55 cases (31.8%) and was significantly related with organ/space surgical site infection (SSI) (7 of 55, P=0.005).

Conclusion

The rate of antibiotic resistance organisms was high in community-acquired complicated appendicitis in Koreans. Additionally, IEAT in complicated appendicitis may lead to increased rates of SSI. Routine intraoperative culture in patients with complicated appendicitis may be an effective strategy for appropriate antibiotic regimen.

Usefulness of intraoperative culture swabs in laparoscopic appendectomy for complicated appendicitis

PURPOSE

Intraabdominal abscess (IAA) is a feared complication after laparoscopic appendectomy (LA) for complicated appendicitis. Benefits of obtaining intraoperative culture swabs (ICS) still remain controversial. We aimed to determine whether ICS modify the rate and management of IAA after LA for complicated appendicitis.

METHODS

A consecutive series of patients who underwent LA for complicated appendicitis from 2008 to 2018 were included. The cohort was divided into two groups: group 1 (G1), with ICS, and group 2 (G2), without ICS. Demographics, operative variables, pathogen isolation, antibiotic sensitivity, and postoperative outcomes were analyzed.

RESULTS

A total of 1639 LA were performed in the study period. Of these, 270 (16.5%) were complicated appendicitis; 90 (33%) belonged to G1 and 180 (67%) to G2. In G1, a higher proportion of patients had generalized peritonitis (G1, 63.3%; G2, 35%; p < 0.01). Seventy-two (80%) patients had positive cultures in G1. The most frequently isolated bacteria were E. coli (66.7%), Bacteroides spp. (34.7%), and Streptococcus spp. (19.4%). In 26 (36%) patients, the initial empiric antibiotic course was modified due to bacterial resistance. The rate of IAA was higher in patients with ICS (G1, 21.1%; G2, 9.4%; p = 0.01). IAA was treated similarly in both groups. A different type of bacteria was isolated in 7 (53.8%) patients with new culture swabs.

CONCLUSIONS

Obtaining ICS in LA for complicated appendicitis with further antibiotic adjustment to the initial pathogen did not lower the incidence of postoperative IAA and did not modify the treatment needed for this complication.

Intraoperative cultures during appendectomy in children are poor predictors of pathogens and resistance patterns in cultures from postoperative abscesses

BACKGROUND

Intraoperative cultures are commonly sent in complicated appendicitis. Culture-guided antibiotics used to prevent postoperative infectious complications are debated. In this study, we describe the microbial overlap between intraoperative and abscess cultures, and antibiotic resistance patterns.

METHOD

A local register of a children's hospital treating children 0-15 years old with appendicitis between 2006 and 2013 was used to find cases with intraoperative cultures, and cultures from drained or aspirated postoperative intraabdominal abscesses. Culture results, administered antibiotics, their nominal coverage of the identified microorganisms, and rationales given for changes in antibiotic regimens were collected from electronic medical records.

RESULTS

In 25 of 35 patients who met inclusion criteria, there was no overlap between the intraoperative and abscess cultures. In 33 of 35 patients, all identified intraoperative organisms were covered with postoperative antibiotics. In 14 patients, organisms in the abscess culture were not covered by administered antibiotics. Enterococci not found in the intraoperative culture were found in 12 of 35 abscesses. We found no difference in the antibiotic coverage between rationales given for antibiotic changes.

CONCLUSION

The overlap between intraoperative cultures and cultures from subsequent abscesses was small. Lack of antibiotic coverage of intraoperative cultures was not an important factor in abscess formation.

Microbiologic Analysis of Complicated and Uncomplicated Acute Appendicitis

BACKGROUND

Microbiologic studies suggest that complicated (CAA) and uncomplicated (UAA) acute appendicitis are different entities. Routine peritoneal fluid cultures continue to be controversially related to a low positive rate, found mainly in UAA; to isolation of typical micro-organisms with expected susceptibilities; and to a community-acquired intra-abdominal infection. The aim of this study was to describe microbiologic isolates in CAA and UAA and the usefulness of peritoneal fluid cultures to determine the susceptibilities to our antibiotic therapy guidelines.

METHODS

This study was a retrospective review of a prospective database collected at University San Juan Hospital (Spain) between June 2014 and June 2017. Complicated acute appendicitis was defined as gangrenous or perforated, whereas UAA was defined as phegmonous or suppurative. Our antibiotic recommendations are amoxicillin-clavulanic acid and in patients with β-lactam allergies, metronidazole plus aztreonam, and an aminoglycoside (gentamicin or tobramycin). Microbiologic cultures were performed in 264 patients, 157 with a CAA and 107 with a UAA.

RESULTS

The positive culture rate was significantly higher in CAA (59%) than in UAA (24.3%). Gram-positive cocci (51.6% CAA; 23.1% UAA), including Streptococcus constellatus (29% CAA; 3.8% UAA), and anaerobes (67.7% CAA; 42.3% UAA) were significantly more common in CAA. The rates of antibiotic resistance were amoxicillin-clavulanic acid 14% (17.2% CAA; 3.8% UAA), gentamicin or tobramycin 8.4% (9.7% CAA; 3.8% UAA), ciprofloxacin 5.9% (6.5% CAA; 3.8% UAA), and ertapenem 10.9% (14% CAA; 0 UAA).

CONCLUSIONS

The culture-positive rate was higher in CAA, with different isolates and susceptibilities than in UAA, identifying a higher frequency of gram-positive cocci (including S. constellatus) and anaerobes. We recommend obtaining peritoneal fluid cultures in CAA, which frequently will lead to a change in the antimicrobial drug therapy guidelines, creating specific recommendations in AA.

Simplification of first-line antibacterial regimen for complicated appendicitis in children is associated with better adherence to guidelines and reduced use of antibiotics

Acute appendicitis in children requires early surgery and short-course antibiotics active against Enterobacteriaceae and anaerobes. Although an aminoglycoside-containing three-drug regimen has been used successfully for decades, simpler regimens with similar efficacy are increasingly used. This study evaluated the impact of a switch from the combination of cefotaxime, metronidazole and gentamicin (regimen 1) to piperacillin/tazobactam (regimen 2) as first-line regimen for complicated acute appendicitis in children. In total, 171 children were enrolled [median (IQR) age, 10 (6-13) years], treated with regimen 1 (n = 80) or regimen 2 (n = 91) following surgery for complicated acute appendicitis. The two groups were comparable except for surgical approach (through laparoscopy in 46% vs. 88% for regimens 1 and 2, respectively; P < 0.001). Post-operative complications and duration of hospital stay were similar. Deviations from antibacterial treatment protocol decreased from 36% (29/80) to 14% (13/91) (P < 0.001), with a dramatic reduction in antibacterial treatment duration from median (IQR) of 15 (12-16) days to 5 (5-8) days (P < 0.001). Post-operative intra-abdominal abscess developed in 32 children (18.7%). Female sex (OR = 2.76, 95% CI 1.18-6.48; P = 0.02) and sepsis/septic shock on admission (OR = 4.72, 95% CI 1.12-19.97; P = 0.035) were independently associated with post-operative intra-abdominal abscess, but not antibacterial regimen. This study shows that simplification of first-line antibacterial regimen for complicated appendicitis in children was associated with reduced protocol deviation, reduced duration of antibiotics, and similar outcomes (post-operative complications and duration of hospital stay).

Streptococcus anginosus is associated with postoperative intraabdominal collections in appendicitis

AIM OF STUDY

Streptococcus anginosus group (SA) (formerly Streptococcus milleri) are pathogens recognised to have a high risk of postoperative collection in appendicitis, although little data exist specifically in children. We performed a retrospective review of all microbiological data from appendicectomies to assess whether there was an association in children.

METHODS

A retrospective case note review of patients admitted to a paediatric tertiary centre coded for appendicitis from January 2015 to October 2016 was completed. Initial length of stay (LOS), cumulative hospital days, histology, microbiology, and radiology reports were recorded. The postoperative antibiotic regimen was based on surgeon's choice and not standardised.

MAIN RESULTS

231 children were identified, and 18 were excluded. In the remainder, 169 (78.9%) had positive microbiology cultures, and of these 45 were positive for SA (26.6%). There was no significant variation in monthly incidence (P=0.58). Patients with SA+ve cultures were associated with complicated appendicitis on histology (P=0.01), longer LOS and cumulative hospital days (P=0.001), and increased likelihood of developing postoperative collections (P=0.001). The relative risk of developing a postoperative collection with SA+ve cultures was 2.40. There was no difference in time to presentation, histology, or intervention between SA and non-SA patients who developed collections. All SA cultures were sensitive to penicillin and erythromycin.

CONCLUSION

SA cultured from intraoperative serial swabs is associated with an increased risk of developing postoperative collection (2.40). Using this information with standardisation of antimicrobial management may reduce the rate of postoperative complications in paediatric appendicitis.

LEVEL OF EVIDENCE

Level II prognosis study.

The intra- and extraluminal appendiceal microbiome in pediatric patients: A comparative study

Intestinal microbiota is involved in metabolic processes and the pathophysiology of various gastrointestinal disorders. We aimed to characterize the microbiome of the appendix in acute pediatric appendicitis comparing extraluminal and intraluminal samples.Between January and June 2015, 29 children (3-17 years, mean age 10.7 ± 3.4 years, sex M:F = 2.6:1) undergoing laparoscopic appendectomy for acute appendicitis were prospectively included in the study. Samples for bacterial cultures (n = 29) and 16S ribosomal desoxyribonucleic acid (rDNA) sequencing (randomly chosen n = 16/29) were taken intracorporeally from the appendiceal surface before preparation ("extraluminal") and from the appendiceal lumen after removal ("intraluminal"). The degree of inflammation was histologically classified into catarrhal, phlegmonous, and gangrenous appendicitis.Seventeen bacterial species were cultivated in 28 of 29 intraluminal samples and 4 species were cultivated in 2 of 29 extraluminal samples. Using 16S rDNA sequencing, 267 species were detected in intraluminal but none in extraluminal samples. Abundance and diversity of detected species differed significantly between histological groups of acute appendicitis in bacterial cultures (P = .001), but not after 16S rDNA sequencing.The appendiceal microbiome showed a high diversity in acute pediatric appendicitis. The intraluminal microbial composition differed significantly depending on the degree of inflammation. As bacteria were rarely found extraluminally by culture and not at all by sequencing, the inflammation in acute appendicitis may start inside the appendix and spread transmurally.

Bad bacteria in acute appendicitis: rare but relevant

PURPOSE

Bacterial infections are a factor for morbidity in patients with acute appendicitis (AA). The spreading of multidrug-resistant (MDR) bacteria is a significant problem in surgery, and the most relevant MDR pathogens are summarized as Enterobacteriaceae, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococci (ESKAPE) bacteria. Data regarding the species and distribution of bacteria in AA are available, but information about the resistances and their relevance is deficient.

METHODS

In this retrospective study, we analyzed microbiological swabs of patients with AA. The outcome parameters of patients after laparoscopic appendectomy were analyzed against microbiological results, including antibiotic resistance testing. Positive swabs were compared with bacteria cultivated after alternative abdominal emergency surgery (AES).

RESULTS

In total, 584 patients with AA were included and had a mean age of 35.5 years. In 216 patients (36.9%), a swab was taken, and in 128 (59.3%) swabs, bacteria could be cultivated. The most frequent organisms were Escherichia coli, Bacteroides species, and Pseudomonas. In 9.4% of the positive AA swabs, MDR germs were cultivated, and all of them were ESKAPE pathogens. Patients with MDR bacteria in AA suffered more infectious complications (p = 0.006) and needed longer hospitalizations (p < 0.009). In AES, aside from appendicitis, a different spectrum containing more MDR bacteria was cultivated (5.9 vs. 20.9%; p < 0.0001).

CONCLUSIONS

Although they occur less frequently in appendectomy compared to emergency surgeries for other abdominal diseases, MDR bacteria are traceable in this common disease and contribute to additional morbidity.

The Role of DNA Amplification and Cultural Growth in Complicated Acute Appendicitis

Bacterial growth of peritoneal fluid specimens obtained during surgical procedures for acute appendicitis may be useful to optimize further antibiotic therapy in complicated cases. DNA amplification represents a fast technique to detect microbial sequences. We aimed to compare the potential of DNA amplification versus traditional bacterial growth culture highlighting advantages and drawbacks in a surgical setting. Peritoneal fluid specimens were collected during surgery from 36 children who underwent appendectomy between May and December 2012. Real-time polymerase chain reaction (RT-PCR) and cultures were performed on each sample. RT-PCR showed an amplification of 16S in 18/36 samples, Escherichia coli (in 7 cases), Pseudomonas aeruginosa (3), Fusobacterium necrophorum (3), Adenovirus (2), E.coli (1), Klebsiella pneumoniae (1), Serratia marcescens/Enterobacter cloacae (1). Bacterial growth was instead observed only in four patients (3 E.coli and 1 P.aeruginosa and Bacteroides ovatus). Preoperative C-reactive protein and inflammation degree, the most reliable indicators of bacterial translocation, were elevated as expected. DNA amplification was a quick and useful method to detect pathogens and it was even more valuable in detecting aggressive pathogens such as anaerobes, difficult to preserve in biological cultures; its drawbacks were the lack of biological growths and of antibiograms. In our pilot study RT-PCR and cultures did not influence the way patients were treated.

Treatment Modalities and Antimicrobial Stewardship Initiatives in the Management of Intra-Abdominal Infections

Antimicrobial stewardship programs (ASPs) focus on improving the utilization of broad spectrum antibiotics to decrease the incidence of multidrug-resistant Gram positive and Gram negative pathogens. Hospital admission for both medical and surgical intra-abdominal infections (IAIs) commonly results in the empiric use of broad spectrum antibiotics such as fluoroquinolones, beta-lactam beta-lactamase inhibitors, and carbapenems that can select for resistant organisms. This review will discuss the management of uncomplicated and complicated IAIs as well as highlight stewardship initiatives focusing on the proper use of broad spectrum antibiotics.

Pediatric appendicitis in a developing country: what are the clinical predictors and outcome of perforation?

OBJECTIVES

This study explored the risk factors and outcomes associated with perforation in children who underwent emergency appendicectomies.

METHODS

A retrospective cross-sectional study was conducted on children <13 years old who underwent appendicectomies in a Malaysian hospital in 2007.

RESULTS

One hundred thirty-four children underwent appendicectomies of which 118 were confirmed histologically. Sixty-one (52%) were perforated. Children with perforation had significantly longer duration of symptoms (p < 0.001), higher white cell count and absolute neutrophil counts (p = 0.013), with longer intra-operative period (p < 0.001) and post-operative recovery period (p < 0.001). Of the 52 samples of pus collected intra-operatively, 37 (71.1%) yielded positive cultures that were predominantly Escherichia coli (n = 27). Both the patients who had Staphylococcus aureus cultured from pus collected intra-operatively had significant pyogenic complications (scrotal pyocele and intra-abdominal abscess).

CONCLUSION

Children whose appendicitis were perforated had longer duration of symptoms, higher white cell counts and absolute neutrophil counts. Those with S.aureus cultured from intra-operative pus appeared to suffer more complications.

Bacteriology and changes in antibiotic susceptibility in adults with community-acquired perforated appendicitis

This study evaluated bacterial etiology and antibiotic susceptibility in patients diagnosed with community-acquired perforated appendicitis over a 12-year-period. We retrospectively reviewed records of adult patients diagnosed with perforated appendicitis at an 800-bed teaching hospital between January 2000 and December 2011. In total, 415 culture-positive perforated appendicitis cases were analyzed. Escherichia coli was the most common pathogen (277/415, 66.7%), followed by Streptococcus species (61/415, 14.7%). The susceptibility of E. coli to ampicillin, piperacillin/tazobactam, ceftriaxone, cefepime, amikacin, gentamicin, and imipenem was 35.1%, 97.1%, 97.0%, 98.2%, 98.9%, 81.8%, and 100%, respectively. The overall susceptibility of E. coli to quinolones (ciprofloxacin or levofloxacin) was 78.7%. During the study period, univariate logistic regression analysis showed a significant decrease in E. coli susceptibility to quinolones (OR = 0.91, 95% CI 0.84-0.99, P = 0.040). We therefore do not recommend quinolones as empirical therapy for community-acquired perforated appendicitis.

[Comparison of two protocols of prophylactic antibiotic therapy in childhood appendectomy]

OBJECTIVE

Antibiotic administration during acute appendicitis in children continues to be debated. The purpose of this study was to compare efficacy of two prophylactic antibiotic treatment guidelines in acute appendicitis and peritonitis in children.

MATERIEL AND METHODS

The infectious complication rate after appendicectomy was compared during two distinct periods (before/after study). During the first period, the guidelines for antibiotic administration were based on ticarcillin-clavulanic acid. During the second period, the guidelines were based on amoxicillin-clavulanic acid for non-perforated appendicitis or appendicitis with localized peritonitis, and clavulanic acid was reserved for general peritonitis. All children younger than 16 years of age who underwent appendicectomy during the periods studied were included. Data were retrospectively collected from surgical and anesthetics charts.

RESULTS

Ninety-five children during the first period and 238 during the second were included. In the children with non-perforated appendicitis, no postoperative infectious complication occurred in 74 children during the first period versus two out of 153 (1%) during the second period. In cases of perforated appendicitis, postoperative infectious complications occurred two cases (10%) during the first period versus nine (11%) during the second. There were no significant differences between the two periods.

CONCLUSION

In this population, antibiotic administration guidelines based on amoxicillin-clavulanic acid for stages I-III of appendicitis maintained a low rate of postoperative infectious complications and were not associated with a higher postoperative infectious complication rate than guidelines based on ticarcillin-clavulanic acid.

Factors influencing the course of acute appendicitis in adults and children

PURPOSE

Our aim was to determine predictive factors for the diagnosis and postoperative complications of acute appendicitis.

MATERIALS AND PATIENTS

Data sets of 1,439 consecutive adults and children who had an appendectomy between 1999 and 2008 were retrospectively analyzed.

RESULTS

A mild acute appendicitis was present in 50 % (n = 722) and a severe acute appendicitis in 25 % (n = 355) of the patients. No signs of any pathology were found in 6 % (n = 82). Gender, white blood count (WBC), C-reactive protein (CRP), and ultrasound (US) examination were important indicators of mild acute and severe acute appendicitis in adults and children. Postoperative complications occurred in 16 % (237/1,439), mainly consisting of wound infections (8 %, n = 122) and bowel dysfunction (5 %, n = 76). Sixty-two patients (4.3 %) required reoperations. One patient died (1/1,439, 0.07 % mortality rate). Age, pathology, and the presence of bacteria in the intraoperative swab were important predictive factors for postoperative complications in adults and children. Time since onset of symptoms and type of operation were also associated with postoperative complications among adults. Complications developed in 21 and 9 % of the adults (155/754 and 10/125) who had open and laparoscopic surgery, respectively.

CONCLUSIONS

Besides history and clinical examination, WBC, CRP, and US examination remain important factors for diagnosing acute appendicitis. Complications are related to the pathology, presence of bacteria, and type of operation. Early diagnosis within 48 h may be important. A laparoscopic procedure in adults may also cause fewer wound infections.

The need for culture swabs in laparoscopically treated appendicitis

INTRODUCTION

Appendicitis remains the most common cause of an acute abdomen. Obtaining intra-abdominal cultures is routine surgical practice. There are studies showing no efficacy of such procedures in cases where open appendectomies are performed.

AIM

The goal of this study was to assess the need for obtaining intra-abdominal cultures during laparoscopic appendectomies.

MATERIAL AND METHODS

Between 2007 and 2012, 369 patients were operated on with the diagnosis of histopathologically proven acute appendicitis. Sixty-two percent of them were operated on using laparoscopic techniques. The microbiological assessment was routinely done for the open procedures and in 42% of cases that underwent a laparoscopic operation.

RESULTS

In 57% (134) the swabbing results were negative. Among 43% (102) of the patients with a positive result, Escherichia coli was isolated in 76.5% (78), Proteus mirabilis in 13.7% (14), Pseudomonas aeruginosa in 4.9% (5) and Citrobacter freundii in 4.9% (5). Five cases had bacteria resistant to the antibiotic given preoperatively (that is 4.9% of all positive cultures and 1.4% of all operated patients). However, these cases did not affect the incidence of postoperative complications. Consideration of the postoperative morbidity showed that there was no statistically significant difference between the laparoscopic group with and without intra-operative swabbing (p > 0.05).

CONCLUSIONS

The postoperative patient outcome was more dependent on the pathology of the appendix than on the results of the microbiological assessment at the time of surgery. Hence, routine intra-operative cultures during laparoscopic appendectomies appear to have little value in patient management. Swabbing during laparoscopic procedures should be limited to only selected high-risk groups.

Epidemiology and susceptibility of Gram-negative appendicitis pathogens: SMART 2008-2010

BACKGROUND

The Study for Monitoring Antimicrobial Resistance Trends (SMART) has tracked the in vitro activity of ertapenem and comparators against aerobic gram-negative bacteria from intra-abdominal infections since 2002. This report describes the epidemiology and susceptibility for clinical isolates associated with appendicitis, collected from 2008 to 2010.

METHODS

A total of 1,720 gram-negative bacilli were collected from patients with appendicitis in 122 hospitals in 39 countries worldwide; of these, 23% of isolates were from pediatric patients (≤ 17 years old). Minimum inhibitory concentrations (MICs) and extended-spectrum β-lactamase (ESBL) phenotypes were determined by broth microdilution and interpreted using Clinical and Laboratory Standards Institute guidelines.

RESULTS

The global ESBL-positive rate was 16.3%, ranging from 2.2% for Proteus mirabilis to 16.6% for Escherichia coli and 20.1% for Klebsiella pneumoniae. The ESBL-positive rates differed by age group (17.7% in adults vs. 11.4% in children) and by geographic region, with significantly higher rates in Asia/Pacific (28.0%) and significantly lower rates in North America (9.1%), Africa/Middle East (4.8%), and Europe (4.4%). Amikacin, imipenem-cilastatin, piperacillin-tazobactam, and ertapenem were the most active of the tested agents against aerobic gram-negative appendicitis pathogens across pediatric and adult age groups and across geographic regions, including ESBL-positive isolates. Cefepime and ceftazidime were active against ≥ 90% of global pediatric isolates. E. coli, by far the most frequently isolated species (68% in adults and 75% in pediatric patients), was significantly less susceptible in adults than in pediatric patients (p<0.05; Fisher exact test) to all tested agents except amikacin, ertapenem, imipenem-cilastatin, piperacillin-tazobactam, and ampicillin-sulbactam (with the latter showing low activity in both age groups).

CONCLUSIONS

These in vitro data suggest that amikacin, imipenem-cilastatin, piperacillin-tazobactam, and ertapenem would perform well against aerobic gram-negative bacilli associated with appendicitis in both adults and children, especially in regions with high rates of ESBL-positive E. coli.

Iliac crest autograft versus alternative constructs for anterior cervical spine surgery: Pros, cons, and costs

Background:

Grafting choices available for performing anterior cervical diskectomy/fusion (ACDF) procedures have become a major concern for spinal surgeons, and their institutions. The “gold standard”, iliac crest autograft, may still be the best and least expensive grafting option; it deserves to be reassessed along with the pros, cons, and costs for alternative grafts/spacers.

Methods:

Although single or multilevel ACDF have utilized iliac crest autograft for decades, the implant industry now offers multiple alternative grafting and spacer devices; (allografts, cages, polyether-etherketone (PEEK) amongst others). While most studies have focused on fusion rates and clinical outcomes following ACDF, few have analyzed the “value-added” of these various constructs (e.g. safety/efficacy, risks/complications, costs).

Results:

The majority of studies document 95%-100% fusion rates when iliac crest autograft is utilized to perform single level ACDF (X-ray or CT confirmed at 6-12 postoperative months). Although many allograft studies similarly quote 90%-100% fusion rates (X-ray alone confirmed at 6-12 postoperative months), a recent “post hoc analysis of data from a prospective multicenter trial” (Riew KD et. al., CSRS Abstract Dec. 2011; unpublished) revealed a much higher delayed fusion rate using allografts at one year 55.7%, 2 years 87%, and four years 92%.

Conclusion:

Iliac crest autograft utilized for single or multilevel ACDF is associated with the highest fusion, lowest complication rates, and significantly lower costs compared with allograft, cages, PEEK, or other grafts. As spinal surgeons and institutions become more cost conscious, we will have to account for the “value added” of these increasingly expensive graft constructs.

Reducing the cost and frequency of explantations associated with single-level anterior diskectomy and fusion at a single institution through education

STUDY DESIGN

We prospectively evaluated the costs/frequency of explanted instrumentation (devices implanted but removed prior to closure) for all single-level anterior diskectomy (1-ADF) procedures performed in 2010 at a single institution before and after surgeon education.

OBJECTIVE

To determine whether surgeon education would reduce the costs/frequency of explantation for 1-ADF.

SUMMARY OF BACKGROUND DATA

In 2009, we reported that the cost of explanted devices was 9.2% of the cost of implanted devices.

METHODS

The costs/frequencies of explantation for 1-ADF performed in 2010 at the same institution by the same surgeons were analyzed before and after surgeon education. From January through April, surgeons were unaware of concerns regarding explantation. At the end of April 2010, spinal surgeons were educated about explantation costs/frequency at 2 meetings. Explantation costs/frequencies for the first 4 months of 2010 were compared with those for the last 8 months as well as with the results from 2009.

RESULTS

Prior to surgeon education, instrumentation was explanted in 45.5% of the cases, whereas after education explantation occurred in 16% of the cases. The explantation rate (the number of explanted devices as a percentage of implanted devices) was lower after education for screws (12.5% vs. 7.7%), plates (9.4% vs. 0%), and allograft spacers (7.1% vs. 2.9%), and lower than for rates from 2009. In 2010, the overall cost of explanted devices as a percentage of implanted devices was also lower after surgeon education (5.8%) than before surgeon education in 2010 (20.0%) or 2009 (9.2%).

CONCLUSION

The frequency and cost of explanted instrumentation used to perform 1-ADF were reduced through surgeon education.

Peritoneal fluid culture in appendicitis: review in changing times

Appendicectomy is one of the commoner operations with a lifetime risk as high as 12% or 23% in males or females, respectively. Since the 1940s intra-operative intra-peritoneal swabs have commonly been taken from the appendix site, the spectrum of infecting organisms and their antibiotic sensitivity may be gauged from the culture results. This approach remains common but in recent years, studies have claimed that intra-peritoneal swabs are unnecessary; however, they relied upon retrospective patient groups predating wider use of laparoscopic appendicectomy, increasing numbers of immunocompromised people at risk of appendicitis and the clinical/medicolegal significance of increasing risk of antibiotic-associated Clostridium difficile colitis. Therefore, a key-word literature research was done to identify relevant publications from 1930 to June 2009. Newer features relating to intra-peritoneal swabs in appendicectomy have been discussed against this background information for periabdominal appendicectomy with or without appendicular perforation, laparoscopic appendicectomy and appendicectomy in the growing numbers of immunocompromised patients. All studies questioning the use of intra-peritoneal swabs were open, non-randomised, and retrospective with incompletely matched control groups, non-standardised swab collection techniques, and consequently lacked power to inform surgical practice. They concluded that an appropriately powered randomised, blinded, prospective, controlled clinical trial is needed to test for absolute efficacy in the use of peritoneal swabs in patient management. Until controlled trial data becomes available, it may be wise to continue peritoneal swabs at least in high-risk patients to decrease clinical and medicolegal risk.

Evidence-based adjustment of antibiotic in pediatric complicated appendicitis in the era of antibiotic resistance

INTRODUCTION

Antibiotic resistance is a global issue especially in developed areas. With the emergence of antibiotic resistant-bacteria, the traditional choice of broad spectrum antibiotics may not be effective in complicated appendicitis. We herein report the bacteriology and antibiotic susceptibility of intra-operative peritoneal culture in children with acute appendicitis in Hong Kong. This may guide us to adjust the choice of antibiotics with evidence.

METHODS

A retrospective review of all cases of children who underwent laparoscopic appendicectomy from 2003 to 2007 was performed. Data including histology of appendixes, the choice of antibiotics, bacteriology, and antibiotic susceptibility of the intra-operative peritoneal cultures were analyzed.

RESULTS

Over a 5-year period, 250 children were included in this study. 41 children had gangrenous- and 77 had ruptured appendicitis, respectively. Peritoneal swab was taken in 158 children. Common bacteria isolated including E. coli, Streptococcus, and Bacteroides. Ampicillin, cefuroxime, and metronidazole were our choice of antibiotics. 26% of children with gangrenous and 25% with ruptured appendicitis were insensitive to the current regime. Using 3 antibiotics regime by switching cefuroxime to ceftazidime, it covered 77% resistant bacteria. Using 4 antibiotics regime by adding gentamycin, it covered 96% resistant bacteria.

CONCLUSIONS

One-fourth of children with gangrenous or ruptured appendicitis were insensitive to the current regime. This study provides evidence-based information on the choice of antibiotics.

Osteomyelitis of the iliac crest: a rare complication following perforated appendicitis

BACKGROUND

Appendicitis is a common surgical emergency with numerous postoperative infective complications. We report an unusual case of iliac crest osteomyelitis as a late complication following emergency appendectomy for perforated gangrenous appendicitis.

METHODS

Review of the pertinent English language literature.

RESULTS

To the best of our knowledge, this is the first report in the English literature to describe iliac crest osteomyelitis as an infective complication of perforated gangrenous appendicitis. The diagnosis was made with the aid of magnetic resonance imaging and radioisotope bone scans. The complication was treated successfully with broad-spectrum intravenous antibiotics and physiotherapy.

CONCLUSION

Iliac crest osteomyelitis is indeed a rare complication of appendicitis. A heightened awareness and better understanding of this complication would necessitate early diagnosis and treatment.