Contemporary Microbiology and Antimicrobial Treatment of Complicated Appendicitis: The Value of a Short-term Study

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.

Do Cultures From Percutaneously Drained Intra-abdominal Abscesses Change Treatment? A Retrospective Review

BACKGROUND

Routinely obtaining intraoperative cultures for abdominal infections is not a currently recommended evidence-based practice. Yet, cultures are frequently sent from these infections when they are managed by image-guided percutaneous drains.

OBJECTIVE

This study aimed to determine the utility of cultures from percutaneously drained intra-abdominal abscesses.

DESIGN

Retrospective medical record review.

SETTING

Single university-affiliated institution.

PATIENTS

Inpatients with an intra-abdominal abscess secondary to diverticulitis or appendicitis between 2013 and 2021 managed with image-guided percutaneous drain, excluding those with active chemotherapy, HIV, or solid organ transplant, were included in the study.

MAIN OUTCOME MEASURES

Frequency culture data from percutaneous drains changed antimicrobial therapy.

RESULTS

There were 221 patients who met the inclusion criteria. Of these, 56% were admitted for diverticulitis and 44% for appendicitis. Patients were 54% female and had a median age of 62 years (range, 18-93), and 14% were active smokers. The median length of hospitalization was 8 days (range, 1-78) and the median antibiotics course was 8 days (range, 1-22). Culture data from percutaneous drains altered antimicrobial therapy in 8% of patients (16/211). A culture was obtained from 95% of drains, with 78% of cultures with growth. Cultures grew multiple bacteria in 66% and mixed variety without speciation in 13%. The most common pathogen was the Bacteroides family at 33% of all bacteria. The most common empiric antibiotic regimens were ceftriaxone used in 33% of patients and metronidazole used in 40% of patients. Female sex ( p = 0.027) and presence of bacteria with any antibiotic resistance ( p < 0.01) were associated with higher likelihood of cultures influencing antimicrobial therapy.

LIMITATIONS

Retrospective and single institution's microbiome.

CONCLUSIONS

Microbiology data from image-guided percutaneous drains of abdominal abscesses altered antimicrobial therapy in 8% of patients, which is lower than reported in previously published literature on cultures obtained surgically. Given this low rate, similar to the recommendation regarding cultures obtained intraoperatively, routinely culturing material from drains placed in abdominal abscesses is not recommended. See Video Abstract at http://links.lww.com/DCR/C64 .

LOS CULTIVOS DE ABSCESOS INTRA ABDOMINALES DRENADOS PERCUTNEAMENTE CAMBIAN EL TRATAMIENTO UNA REVISIN RETROSPECTIVA

ANTECEDENTES:La obtención rutinaria de cultivos intra-operatorios para infecciones abdominales no es una práctica basada en evidencia actualmente recomendada. Sin embargo, con frecuencia se envían cultivos de estas infecciones cuando se manejan con drenajes percutáneos guiados por imágenes.OBJETIVO:Determinar la utilidad de los cultivos de abscesos intra-abdominales drenados percutáneamente.DISEÑO:Revisión retrospectiva de gráficos.ESCENARIO:Institución única afiliada a la universidad.PACIENTES:Pacientes hospitalizados con absceso intra-abdominal secundario a diverticulitis o apendicitis entre 2013 y 2021 manejados con drenaje percutáneo guiado por imagen, excluyendo aquellos con quimioterapia activa, VIH o trasplante de órgano sólido.PRINCIPALES MEDIDAS DE RESULTADO:Los datos de cultivo de frecuencia de los drenajes percutáneos cambiaron la terapia antimicrobiana.RESULTADOS:Hubo 221 pacientes que cumplieron con los criterios de inclusión. De estos, el 56% ingresaron por diverticulitis y el 44% por apendicitis. El 54% de los pacientes eran mujeres, tenían una edad media de 62 años (18-93) y el 14% eran fumadores activos. La duración de hospitalización media fue de 8 días (rango, 1-78) y la mediana del curso de antibióticos fue de 8 días (rango, 1-22). Los datos de cultivo de drenajes percutáneos alteraron la terapia antimicrobiana en el 7% (16/221) de los pacientes. Se obtuvo cultivo del 95% de los drenajes, con un 79% de cultivos con crecimiento. Los cultivos produjeron múltiples bacterias en el 63% y variedad mixta sin especiación en el 13%. El patógeno más común fue la familia Bacteroides con un 33% de todas las bacterias. El régimen de antibiótico empírico más común fue ceftriaxona y metronidazol, utilizados en el 33% y el 40% de los pacientes, respectivamente. El sexo femenino ( p = 0,027) y la presencia de bacterias con alguna resistencia a los antibióticos ( p < 0,01) se asociaron con una mayor probabilidad de que los cultivos influyeran en la terapia antimicrobiana.LIMITACIONES:Microbioma retrospectivo y de una sola institución.CONCLUSIONES:Los datos microbiológicos de los drenajes percutáneos guiados por imágenes de los abscesos abdominales alteraron la terapia antimicrobiana en el 7% de los pacientes, que es inferior a la literatura publicada previamente sobre cultivos obtenidos quirúrgicamente. Dada esta baja tasa, similar a la recomendación sobre cultivos obtenidos intraoperatoriamente, no se recomienda el cultivo rutinario de material de drenajes colocados en abscesos abdominales. Consulte Video Resumen en http://links.lww.com/DCR/C64 . (Traducción-Dr. Mauricio Santamaria.

A Six-Year Retrospective Study of Microbiological Characteristics and Antimicrobial Resistance in Specimens from a Tertiary Hospital’s Surgical Ward

Surgery has revolutionized the practice of medicine by allowing the treatment of conditions amenable to conservative medical management with some of them pathophysiologically involving the prevalence of pathogenic microorganisms. On the other hand, infections such as surgical site infections or urinary tract infections may complicate patients hospitalized in surgical wards leading to considerable morbidity, mortality, and increased healthcare-associated costs. The aim of this study was to present the microbiological characteristics and antimicrobial resistance of all isolates identified in microbiological specimens from a surgical ward of a tertiary hospital in Greece during a six-year period. Only specimens that yielded at least one microorganism were included in the analysis. In total, 1459 strains in 789 positive cultures were isolated. The most common sample sent to the microbiology department was pus from surgical wounds. The most common pathogens among all 1459 strains isolated were Enterobacterales at 33% (n = 482), however, the most common genus was Enterococcus at 22.3% (n = 326). Antimicrobial resistance against third-generation cephalosporins was 23% (n = 111/482) among Enterobacterales, while, the rate of vancomycin-resistant enterococci (VRE) was 18.5% (n = 60/324) among Enterococcus species and was increasing in the last years of the study. Antimicrobial resistance of Acinetobacter baumannii to carbapenems was 68.8% (n = 11/16), which was lower than the corresponding rate in other wards in Greece. The antimicrobial resistance rates noted herein raise questions regarding the appropriateness of currently suggested antimicrobials in guidelines and imply that a revision could be required. Practicing clinicians should always be aware of local microbiological data that allow the selection of appropriate antimicrobials for the management of infections. Finally, the increasing rates of VRE noted herein mandate further actions from the point of infection control and antimicrobial stewardship.

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.

Streptococcus anginosus group infections in hospitalised children and young people

AIM

The Streptococcus anginosus group (SAG) comprises three bacterial species colonising the mouth and gastrointestinal and genitourinary tracts and capable of serious pyogenic infections. Although well-described in adults, studies in children are limited. Here, we characterise paediatric SAG infections from a single Australian centre.

METHODS

Hospitalised patients aged ≤18 years with positive SAG cultures from January 2009 to December 2019 were identified from Pathology Queensland's Gold Coast Laboratory database and their medical records were reviewed.

RESULTS

Two-hundred children (62% male), median age 12 years (interquartile range 6-16), with positive SAG cultures were identified. Overall, 90% received intravenous antibiotics, 89% underwent surgical drainage, 23% were readmitted and 15% required additional surgery. The most common sites were the abdomen (39%), soft tissues (36%) and head and neck regions (21%). Since 2011, Pathology Queensland reported SAG at the species level (n = 133). Of these, S. anginosus was the most prevalent (39%), then S. constellatus (34%) and S. intermedius (27%). Compared with the other two species, S. intermedius was most commonly associated with head and neck infections (relative risk (RR) = 2.2, 95% confidence interval (CI) 1.4-3.5), while S. constellatus (RR = 1.7, 95% CI 1.2-2.4) and S. anginosus (RR = 1.5, 95% CI 1.0-2.0) were each associated with a higher risk of intra-abdominal infection than S. intermedius. Since February 2015, the number of children admitted with SAG-associated intra-abdominal infection per 1000 hospitalisations increased by 29% annually compared with an annual decline of 8% in previous years.

CONCLUSIONS

SAG infections occur at various anatomical sites. Despite antibiotics and surgical management, almost one-quarter are re-hospitalised for further treatment.

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.

The intraperitoneal bacteriology and antimicrobial resistance in acute appendicitis among children: a retrospective cohort study between the years 2007-2017

This study aims to describe the microbiology and susceptibility profile of the intraperitoneal flora in complicated appendicitis. It is a retrospective cohort study including children < 18-year-old with pathologically confirmed appendicitis, from 2007 to 2017. It included 1466 children. Intraperitoneal samples were obtained from 655 (44.7%) patients, and 201 (30.7%) had positive culture with 395 pathogens. Gram-negative rods comprised 67.6%, Gram-positive cocci 21.5%, and anaerobes 10.9% of the isolates. Gram-positive cocci were detected in 67 (37.8%) patients. Milleri group Streptococci was the most frequently isolated Gram-positive (44.7%). The proportional rate of Milleri group Streptococci from Gram-positive cocci increased from 9.5 to 56.3% (P < 0.001, OR 12.214). Patients with Gram-positive cocci had longer hospital stay (mean 9.36 + 6.385 vs 7.72 + 4.582, P = 0.036, (CI -3.165, -0.105)) and more complicated disease (89.5% vs 78.4%, P = 0.045, OR 2.342). Patients with Milleri group Streptococci isolates readmitted more frequently (26.5% vs 13.2%, P = 0.05, OR 2.37). Resistance to amoxicillin-clavulanate, gentamicin, ceftazidime, piperacillin-tazobactam, and amikacin were detected in 29.1%, 6.5%, 2.3%, 1.2%, and 0.7% of the Gram-negative rods, respectively.Conclusion: The rates of Gram-positive cocci and particularly Milleri group Streptococci in peritoneal fluid are increasing. More complicated disease and longer hospital stay in Gram-positive cocci and higher readmission rate in Milleri group Streptococci. These emphasize the role of anti-Gram-positive antimicrobials. What is known: • Gram-negative rods are the main isolates in complicated appendicitis. • The choice of antibiotic regimen is an unsettled issue due to resistance. What is new: • Increased rate of Gram-positive cocci and Milleri group Streptococci. • More complicated disease, longer hospital stay, and higher readmission rate.

Effects of a Paediatric Antimicrobial Stewardship Program on Antimicrobial Use and Quality of Prescriptions in Patients with Appendix-Related Intraabdominal Infections

The effectiveness of antimicrobial stewardship programs (ASP) in reducing antimicrobial use (AU) in children has been proved. Many interventions have been described suitable for different institution sizes, priorities, and patients, with surgical wards being one of the areas that may benefit the most. We aimed to describe the results on AU and length of stay (LOS) in a pre-post study during the three years before (2014–2016) and the three years after (2017–2019) implementation of an ASP based on postprescription review with feedback in children and adolescents admitted for appendix-related intraabdominal infections (AR-IAI) in a European Referral Paediatric University Hospital. In the postintervention period, the quality of prescriptions (QP) was also evaluated. Overall, 2021 AR-IAIs admissions were included. Global AU, measured both as days of therapy/100 patient days (DOT/100PD) and length of therapy (LOT), and global LOS remained unchanged in the postintervention period. Phlegmonous appendicitis LOS (p = 0.003) and LOT (p < 0.001) significantly decreased, but not those of other AR-IAI diagnoses. The use of piperacillin–tazobactam decreased by 96% (p = 0.044), with no rebound in the use of other Gram-negative broad-spectrum antimicrobials. A quasisignificant (p = 0.052) increase in QP was observed upon ASP implementation. Readmission and case fatality rates remained stable. ASP interventions were safe, and they reduced LOS and LOT of phlegmonous appendicitis and the use of selected broad-spectrum antimicrobials, while increasing QP in children with AR-IAI.

Drug use evaluation (DUE) of ceftriaxone: A quality metric in a pediatric hospital

BACKGROUND

Ceftriaxone is frequently used as empiric therapy because of its broad spectrum and dosing characteristics. The purpose of this study was to evaluate the appropriateness of ceftriaxone therapy among hospitalized children using drug use evaluation (DUE) methodology.

METHODS

Hospitalized patients who received one or fewer dose of intravenous ceftriaxone at Children's Hospital of Eastern Ontario between January 1, 2018, and June 30, 2018, were identified. Duration was defined as empiric if 72 or less and definitive if more than 72 hours. Two infectious disease physicians reviewed the charts and rated appropriateness using a previously developed scale.

RESULTS

A total of 276 ceftriaxone courses in 248 patients (mean age 6.0 y) were reviewed. Of these, 153 (55.4%) were assessed as definitively or possibly indicated. The most common reason for inappropriate empiric use was an overly broad spectrum. Of the 120 courses given empirically for which there was no indication, the three most common reasons were lower respiratory infections (51; 42.5%), head and neck infections (18; 15.0%), and intra-abdominal infections (15; 12.5%). Of the 39 (14.1%) courses of ceftriaxone that were given for more than 72 hours, 14 (35.9%) met criteria for a definitive or possible indication.

CONCLUSION

Ceftriaxone is still overused as empiric therapy. Although 85% of courses were discontinued after three doses, 14% were continued for longer than 72 hours, with approximately one-third ultimately meeting an indication. DUE using Canadian pediatric and local guidelines criteria is useful to identify clinical presentations for which narrower spectrum antimicrobials should be used.

Antibiotic therapy in pediatric acute appendicitis: Compliance with local protocol to reduce antibiotic overuse

PURPOSE

Acute appendicitis is one of the commonest surgical emergencies in pediatrics. Treatment usually consists of a combination of surgery and antibiotics. The present study was designed to assess compliance with our local antibiotic protocol and analyse the consequences of non-compliance.

METHODS

Children presenting with acute appendicitis between 2015 and 2017 were included in this study. The diagnosis of acute appendicitis was confirmed during surgery. Data concerning the antibiotic therapy received and infectious complications were reviewed.

RESULTS

A total of 142 children with acute appendicitis were included. Antibiotic therapy complied with the protocol in 27.4% of cases, while an excessive duration of antibiotic therapy was observed in 65% of cases. A total of 270 days of non-recommended antibiotic therapy was noted; 32% of patients received a non-recommended combination of antibiotics. The infectious complications rate was 12.8% in the group of patients receiving appropriate antibiotic therapy, and 11.6% in the group with non-compliance to the protocol. No statistically significant difference between the groups was found (P=0.85).

CONCLUSION

Poor compliance with the antibiotic guidelines for appendicitis resulted in antibiotic overuse with no benefit in terms of anti-infective efficacy. Better information for the medical team and repeated evaluation of our practices are essential.