Cephalosporins in surgical prophylaxis

Adherence to Perioperative Antimicrobial Prophylaxis in Children in the Settings of Neurosurgery, Otorhinolaryngology, and Orthopedics

Introduction: Data about compliance with perioperative antimicrobial prophylaxis (PAP) guidelines in the pediatric population are limited. This study aims to evaluate PAP adherence in pediatric surgical subspecialty departments. Methods: A prospective cohort study was conducted from September 2023 to October 2024 at "Aghia Sophia" Children's Hospital, Athens, Greece. Children <16 years old undergoing surgical procedures in the neurosurgery (NS), orthopedics (OP), and otolaryngology (ORL) departments were included. Data on demographics, surgical characteristics, and PAP practices (timing, agent, duration, and redosing) were collected and compliance with the international guidelines was evaluated. Results: A total of 301 children were included, with a median age (IQR) of 7 (8) years. PAP was received by 249/301 (82.7%) children (100% in the OP and NS, and 48% in the ORL). However, indications for PAP had 50.8% of children: 102/103 (99%) in the NS, 47/98 (47.9%) in the OP, and 4/48 (8.3%) in the ORL. Most children received broad-spectrum or combination of antimicrobials and/or antibiotics for longer duration. Appropriate PAP according to the guidelines was administered in 0% children in NS, 2% in OP, and 2.1% in ORL. Multivariable analysis in the ORL regarding the use of PAP revealed that shorter procedures (≤60 min; OR: 22.9, p = 0.003) and clean wounds (OR: 33.4, p < 0.001) were significantly associated with not using PAP. Conclusions: This study highlights gaps in the PAP guideline adherence in pediatric surgical departments, and the need for educational interventions to improve compliance and reduce antimicrobial use. Based on these findings, we plan to implement an educational intervention in order to optimize PAP practices in the pediatric population.

Assessing the therapeutic efficacy of Cefoperazone Sodium and Sulbactam Sodium in managing surgical site infections: a retrospective analysis

Surgical site infections (SSIs) pose significant challenges in surgical care, impacting patient recovery and healthcare costs. The increasing prevalence of antibiotic-resistant bacteria necessitates effective antimicrobial strategies. This study assesses the therapeutic efficacy and safety of Cefoperazone Sodium and Sulbactam Sodium in managing SSIs and compares its effectiveness against a standard treatment. A retrospective analysis was conducted on 110 patients with clinically and microbiologically confirmed SSIs from December 2020 to December 2023. Patients were divided into two groups: 55 received Cefoperazone Sodium and Sulbactam Sodium, while 55 were treated with Cefuroxime. The efficacy was evaluated based on microbiological eradication and clinical improvement, assessed after 3 days of treatment. Statistical analyses were performed using SPSS version 27.0, with significance set at p < 0.05. Demographic and clinical characteristics showed no significant differences between groups, ensuring comparability. The observation group demonstrated a cure rate of 58.18% and an overall efficacy rate of 94.55%. In contrast, the control group showed a cure rate of 32.73% and an overall efficacy rate of 70.91%. Statistical analysis revealed a significant difference in therapeutic success between the groups (Chi-square value of 9.16, p-value < 0.05). The combination of Cefoperazone Sodium and Sulbactam Sodium could provide a more effective option for managing SSIs, potentially improving cure rates and overall treatment outcomes compared to Cefuroxime.

Quality corner: Safely using cephalosporins in almost all patients with penicillin allergies: Mini-review and suggested protocol to improve efficacy and surgical outcomes

Surgical site infections (SSI) are one of the most common gynecologic oncology postoperative complications and they have a significant deleterious impact on the healthcare system and in patients' outcomes. Cefazolin is the recommended antibiotic in women undergoing gynecologic surgical procedures that require that require prophylaxis. However, 10-20% of patients may report a penicillin allergy which can result in administration of a less effective antibiotic. This quality review evaluated the literature around this common perioperative issue and demonstrated that healthcare teams should consider the implementation of a protocol to safely use cefazolin in most patients with a penicillin allergy. Overall, literature shows this is a safe adjustment and would improve antimicrobial stewardship, decrease SSI rates, avoid acute kidney injury, and increase cost savings.

"A breach in the protocol for no good reason": a surgical antimicrobial prophylaxis experience in an Ethiopian academic medical center

BACKGROUND

An appropriately administered surgical antimicrobial prophylaxis decreases the rate of surgical site infections. Although evidence-based clinical practice guidelines have been published on surgical antimicrobial prophylaxis, the rate of adherence to the protocol and the impact of extending antimicrobial prophylaxis postoperatively is yet to be well elucidated.

METHOD

A total of general surgery and vascular surgery patients with clean and clean contaminated wound undergoing elective surgical procedures were included in the study. The rate of surgical antimicrobial prophylaxis utilization, the proportion of patients whom had their antimicrobial prophylaxis extended beyond 24 h and the rate of surgical site infections across groups were evaluated.

RESULTS

The surgical antimicrobial prophylaxis utilization rate was 90.5%. Of these patients, 12.6% were unnecessarily administered with antibiotics. An "extended" antibiotics administration beyond 24 h after the surgery was found in 40.2%. Gastrointestinal and hepato-pancreatico-biliary surgery patients had 7.9-fold rate of "extended" surgical antimicrobial prophylaxis beyond 24 h, AOR 7.89 (95% CI 3.88-20.715.62, p value < 0.0001). The overall rate of surgical site infection was 15(6.8%). The "extended" regimen of prophylactic antibiotics had no effect on the rate of surgical site infections.

CONCLUSION

Less than half of the patients included here had surgical antimicrobial prophylaxis regimen in accordance with the existing guidelines. The most common protocol violation was noted as extension of antimicrobial prophylaxis for more than 24 h after surgery. The extension of antimicrobial prophylaxis did not decrease the rate of surgical site infections, reaffirming the evidence that prophylactic extension of surgical antimicrobial prophylaxis is unnecessary.

Appropriateness of Surgical Antibiotic Prophylaxis in a Tertiary Care Teaching Hospital in Central India: A Retrospective Analysis

Surgical antibiotic prophylaxis (SAP) has been a boon in the prevention of surgical site infections (SSIs). This study was conducted to assess and evaluate the selection, timing, and duration of administration of SAP and their compliance with national and international guidelines in a tertiary care teaching hospital in India. This retrospective study included the data collected from the central records department in a tertiary care teaching hospital on major surgeries conducted between January 1, 2018, and December 31, 2018, from the departments of ENT, general surgery, orthopedic surgery, and obstetrics and gynecology. The data was analyzed for the appropriateness of their indication for SAP administration, choice, timing, and duration of antibiotics, and compliance with the American Society of Health-System Pharmacists (ASHP) and Indian Council of Medical Research (ICMR) guidelines. Results and interpretation Out of the total 394 case records included, only 2.53% (n = 10) of the cases were given an appropriate antibiotic. The duration of SAP was appropriate only in 6.53% (n = 24), and the timing of SAP administration was appropriate only in 50.76% (n = 204). The most commonly used antibiotic was ceftriaxone (pre-operative 58.12% (n = 229) and post-operative 43.14% (n = 170)). Major inappropriateness was observed in the selection of antibiotics which may be attributed to the non-availability of cefazolin in the institute. The inappropriateness of the duration of the SAP may be attributed to the extra precautions taken by the treating physicians to prevent SSIs. The overall compliance of the surgical cases with respect to the ASHP and ICMR guidelines was less than 1%. Conclusion This study identified the lacuna between the guidelines for SAP and the clinical application of the same. It also identified the areas where quality improvement was needed which can be improved by implementing antimicrobial stewardship, especially the choice and the duration of SAP administration.

Meta-Analysis of Clinical Trials Comparing Cefazolin to Cefuroxime, Ceftriaxone, and Cefamandole for Surgical Site Infection Prevention

Surgical site infections are among the most prevalent and costly healthcare-associated infections, resulting in poor patient outcomes and even death. Cefazolin is a first-generation cephalosporin antibiotic that is widely used for surgical prophylaxis in a variety of surgical disciplines. Although previous studies showed that cefazolin is effective in preventing surgical site infections, other agents, such as cefuroxime and ceftriaxone, were used excessively for surgical patients. The present analysis included only clinical trials comparing the efficacy of cefazolin to cefuroxime, ceftriaxone, and cefamandole in lowering SSIs using PubMed, Google Scholar, and ClinicalTrials.gov. Review Manager software (RevMan version 5.4) was used to conduct the meta-analyses. A total of 12,446 patients were included in the study. Among these patients, 6327 patients received cefazolin and 6119 patients received cefamandole, cefuroxime, or ceftriaxone. Our analysis showed that cefazolin is as effective as cefuroxime, cefamandole, and ceftriaxone in preventing surgical site infections. Hence, our findings have provided evidence for the use of cefazolin before surgeries because of its efficacy, as previous studies showed that it is inexpensive and safer than other agents.

Characterization of the human skin resistome and identification of two microbiota cutotypes

BACKGROUND

The human skin microbiota is considered to be essential for skin homeostasis and barrier function. Comprehensive analyses of its function would substantially benefit from a catalog of reference genes derived from metagenomic sequencing. The existing catalog for the human skin microbiome is based on samples from limited individuals from a single cohort on reference genomes, which limits the coverage of global skin microbiome diversity.

RESULTS

In the present study, we have used shotgun metagenomics to newly sequence 822 skin samples from Han Chinese, which were subsequently combined with 538 previously sequenced North American samples to construct an integrated Human Skin Microbial Gene Catalog (iHSMGC). The iHSMGC comprised 10,930,638 genes with the detection of 4,879,024 new genes. Characterization of the human skin resistome based on iHSMGC confirmed that skin commensals, such as Staphylococcus spp, are an important reservoir of antibiotic resistance genes (ARGs). Further analyses of skin microbial ARGs detected microbe-specific and skin site-specific ARG signatures. Of note, the abundance of ARGs was significantly higher in Chinese than Americans, while multidrug-resistant bacteria ("superbugs") existed on the skin of both Americans and Chinese. A detailed analysis of microbial signatures identified Moraxella osloensis as a species specific for Chinese skin. Importantly, Moraxella osloensis proved to be a signature species for one of two robust patterns of microbial networks present on Chinese skin, with Cutibacterium acnes indicating the second one. Each of such "cutotypes" was associated with distinct patterns of data-driven marker genes, functional modules, and host skin properties. The two cutotypes markedly differed in functional modules related to their metabolic characteristics, indicating that host-dependent trophic chains might underlie their development.

CONCLUSIONS

The development of the iHSMGC will facilitate further studies on the human skin microbiome. In the present study, it was used to further characterize the human skin resistome. It also allowed to discover the existence of two cutotypes on the human skin. The latter finding will contribute to a better understanding of the interpersonal complexity of the skin microbiome. Video abstract.

Decreasing surgical site infections in pediatric stoma closures

INTRODUCTION

Gastrointestinal (GI) operations represent a significant proportion of the surgical site infection (SSI) burden in pediatric patients, resulting in significant morbidity. We have previously demonstrated that a GI bundle decreases SSI rates, length of stay (LOS), and hospital charges. Following this success, we hypothesized that by targeting the preoperative antibiotics for stoma closures based on organisms found in infected wounds, we could further decrease SSI rates.

METHODS

As part of a broad quality improvement effort to reduce SSI rates, we reviewed the responsible pathogens and their sensitivities as well as the preoperative antibiotic used, and found that 15% of wound infections were caused by enterococcus. Based on this information, starting in April 2017, we changed the prior preoperative antibiotic cefoxitin to ampicillin-sulbactam, which more accurately targeted the prevalent pathogens from April 2017 to October 2018.

RESULTS

The baseline SSI rate for all stoma takedown patients was 21.4% (25 of 119). After bundle implementation, this decreased to 7.9% (17 of 221; p = 0.03) over a period of 2.5 years. Then, after changing the preoperative antibiotics, our rate of SSI decreased further to 2.2% (1 of 44; p = 0.039) over a period of 1.5 years.

CONCLUSION

Significant reduction of SSI in GI surgery can be accomplished with several prevention strategies (our GI bundle). Then a change of the preoperative antibiotic choice, chosen based on causative wound infection organisms, may further decrease SSI rates. We recommend an institution specific analysis of wound infections and modification of preoperative antibiotics if the responsible organisms are resistant to the original antibiotic choice.

TYPE OF STUDY

Retrospective cohort study.

LEVEL OF EVIDENCE

Level III.

Single-dose intra-procedural ceftriaxone during endoscopic ultrasound fine-needle aspiration of pancreatic cysts is safe and effective: results from a single tertiary center

Background

Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) is universally used for the investigation and diagnosis of pancreatic cystic lesions (PCL). Infectious complications following EUS-FNA of PCL are rare. Antibiotic prophylaxis to reduce the risk of infection is recommended; however, there is no consensus on the optimal regimen or route of administration. Potential advantages of a single-dose intravenous (IV) antibiotic over a prolonged oral regimen include simplicity, guaranteed delivery and fewer antibiotic related adverse events, but there are only limited data to support this. We aimed to investigate the safety and efficacy of a single 1 g dose of IV ceftriaxone in preventing infectious complications following EUS-FNA of PCL.

Methods

A retrospective analysis was conducted of EUS-FNA of PCL procedures performed at our center. We reviewed patient medical records for any presentation to a hospital in our district within 30 days of the procedure. An infectious complication was defined as fever/rigors, or bacteremia, or abdominal pain accompanied by imaging or laboratory results suggestive of infection, within 30 days of the procedure. Data collection included patient demographics, procedural data and outcome.

Results

EUS-FNA of 204 PCL (mean size 18.0 mm) was performed. Successful fluid aspiration was achieved in 94% of cases. Single-dose IV ceftriaxone was given in 146/204 (72%) cases. Four patients had a complication (pancreatitis n=1, post-procedural pain n=3). No infectious complications and no IV antibiotic-related adverse events were identified.

Conclusion

A single dose of IV ceftriaxone appears to be a safe, effective and convenient intervention for preventing infectious complications after FNA.

Effect of Antimicrobial Prophylaxis on the Incidence of Infections in Clean Surgical Wounds in Hospitals Undergoing Renovation

Objective.

To measure the effect of cephazolin prophylaxis on the rate of surgical site infection among patients with clean surgical wounds, categorized by risk group, in a hospital undergoing renovation.

Design.

Randomized, double-blind clinical trial.

Setting.

Saint Paul General Hospital, Coquimbo, Chile, during a period when it was undergoing significant interior remodeling.

Patients.

General surgery patients who received antibiotic prophylaxis before clean wound surgery between March 2003 and May 2004 and a matched control group of patients who did not receive such prophylaxis.

Results.

A total of 303 patients participated in the study. The rate of infection among patients with an American Society of Anesthesiologists (ASA) classification of 1 in the prophylaxis group was 7.3%, whereas among ASA 1 patients in a no-prophylaxis control group it was 10.3% (P = .40). In the prophylaxis group, the ASA 2 and ASA 3 patients combined had an infection rate of 10.5%, whereas in the no-prophylaxis group these patients had a rate of 30.0% (relative risk, 0.33 [95% confidence interval, 0.58-0.96]; P = .03). Both the ASA 2 and ASA 3 patients were protected from infection by prophylaxis; these patients had 1.7 and 2.2 times, respectively, more risk of developing a surgical site infection than did ASA 1 patients after a clean surgical procedure, but the ASA 2 and ASA 3 patients who did not receive prophylaxis had 4.3 and 4.8 times, respectively, greater risk of infection (relative risk, 0.91 [95% confidence interval, 0.83-0.99]; P = .02). Prophylaxis significantly reduced the rate of infection in the ASA 2 and ASA 3 groups.

Conclusions.

We recommend the use of antimicrobial prophylaxis with cephalosporins in ASA 2 and ASA 3 patients undergoing clean wound surgery during a period when significant renovations are being performed in the hospital.

Surgical site infection and timing of prophylactic antibiotics for appendectomy

BACKGROUND

Pre-operative prophylactic antibiotics may decrease the frequency of surgical site infection after appendectomy. However, the optimal timing for administration of pre-operative prophylactic antibiotics is unknown. The purpose of this study was to evaluate the effect of timing of prophylactic antibiotics on the frequency of surgical site infection after appendectomy.

METHODS

Medical records were reviewed retrospectively for 577 consecutive patients who had appendectomy for acute appendicitis from 2006 to 2009. Quality assurance guidelines for timing of prophylactic antibiotics before the skin incision were changed from 0 to 30 min before the skin incision (before June 2008) to 30 to 60 min before the skin incision (after June 2008).

RESULTS

Surgical site infection occurred in 28 patients (4.9%). There was no difference in frequency of surgical site infection with different timing of pre-operative prophylactic antibiotic (pre-operative time 0 to 30 min: 9 infections [3.6%]; 31 to 60 min: 13 infections [5.4%]; 61 to 120 min: 5 infections [7.0%]; >120 min: 1 infection [6.6%]). Multivariable analysis showed that surgical site infection was associated significantly with medical comorbidity but not perforated appendicitis.

CONCLUSIONS

The frequency of surgical site infection was independent of timing of preoperative prophylactic antibiotics but was associated with the presence of medical comorbidity.

Bioanalytical development and validation of liquid chromatographic-tandem mass spectrometric methods for the quantification of total and free cefazolin in human plasma and cord blood

OBJECTIVES

Cefazolin is a commonly prescribed β-lactam antibiotic for prophylaxis against skin infections following surgery, including caesarean sections. Assessment of maternal and neonatal exposure is important for correlating drug concentrations to clinical outcomes. Thus, bioanalytical methods for the quantification of both total and free cefazolin in maternal plasma and cord blood can assist in the comprehensive evaluation of cefazolin exposure.

DESIGN AND METHODS

Specimen preparation for the measurement of total cefazolin was performed via protein precipitation with acetonitrile containing the internal standard cloxacillin. Ultrafiltration was used to isolate free cefazolin. Processed samples were analyzed on a Prelude SPLC system coupled to a TSQ triple quadrupole Vantage mass spectrometer. Methods were validated following FDA bioanalytical guidelines.

RESULTS

The analytical measuring ranges of these methods were 0.48-480 µg/mL and 0.048-48 µg/mL for total and free drug, respectively. Calibration curves were generated using 1/x² weighted linear regression analysis. Total cefazolin demonstrated inter- and intra-assay precision of ≤20% at the LLOQ and ≤11.2% at other levels. Free cefazolin demonstrated inter- and intra-assay precision of ≤18.5% at the LLOQ and ≤12.6% at other levels, respectively. Accuracy (%DEV), carryover, matrix effects, recovery and stability studies were also acceptable based on FDA recommendations. Furthermore, it was demonstrated that samples prepared in cord blood can be accurately quantified from an adult plasma calibration curve, with recoveries ≤9.1% DIF and ≤11.9% DIF for total and free cefazolin, respectively.

CONCLUSIONS

The described LC-MS/MS methods allow for the measurement of total and free cefazolin in both plasma and cord blood.

Evaluating the optimal timing of surgical antimicrobial prophylaxis: study protocol for a randomized controlled trial

BACKGROUND

Surgical site infections are the most common hospital-acquired infections among surgical patients. The administration of surgical antimicrobial prophylaxis reduces the risk of surgical site infections . The optimal timing of this procedure is still a matter of debate. While most studies suggest that it should be given as close to the incision time as possible, others conclude that this may be too late for optimal prevention of surgical site infections. A large observational study suggests that surgical antimicrobial prophylaxis should be administered 74 to 30 minutes before surgery. The aim of this article is to report the design and protocol of a randomized controlled trial investigating the optimal timing of surgical antimicrobial prophylaxis.

METHODS/DESIGN

In this bi-center randomized controlled trial conducted at two tertiary referral centers in Switzerland, we plan to include 5,000 patients undergoing general, oncologic, vascular and orthopedic trauma procedures. Patients are randomized in a 1:1 ratio into two groups: one receiving surgical antimicrobial prophylaxis in the anesthesia room (75 to 30 minutes before incision) and the other receiving surgical antimicrobial prophylaxis in the operating room (less than 30 minutes before incision). We expect a significantly lower rate of surgical site infections with surgical antimicrobial prophylaxis administered more than 30 minutes before the scheduled incision. The primary outcome is the occurrence of surgical site infections during a 30-day follow-up period (one year with an implant in place). When assuming a 5% surgical site infection risk with administration of surgical antimicrobial prophylaxis in the operating room, the planned sample size has an 80% power to detect a relative risk reduction for surgical site infections of 33% when administering surgical antimicrobial prophylaxis in the anesthesia room (with a two-sided type I error of 5%). We expect the study to be completed within three years.

DISCUSSION

The results of this randomized controlled trial will have an important impact on current international guidelines for infection control strategies in the hospital. Moreover, the results of this randomized controlled trial are of significant interest for patient safety and healthcare economics.

TRIAL REGISTRATION

This trial is registered on ClinicalTrials.gov under the identifier NCT01790529.

Ceftriaxone Prophylaxis in Abdominal, Cardiovascular, Thoracic, Orthopaedic, Neurosurgical and General Surgery: A Review of Practice 1996 - 2003

The microbiology, efficacy and cost-effectiveness of ceftriaxone prophylaxis were compared with those of alternative antimicrobial agents in abdominal, cardiovascular, thoracic, orthopaedic, neurosurgical and general surgical procedures published since 1996. Ceftriaxone was compared with cefazolin +/- metronidazole, cefoxitin, cefuroxime, ceftazidime, cefotaxime, cefepime + metronidazole, penicillins, ticarcillin/clavulanic acid, ampicillin/sulbactam, vancomycin and combined clindamycin/gentamicin. Ceftriaxone, used primarily as 'single shot prophylaxis', was at least as clinically effective if not better than the comparative single- and multiple-dose agents over the broad range of surgical procedures. Furthermore the overall cost of ceftriaxone prophylaxis has often been shown to be markedly less than comparators, despite the relatively high acquisition cost of ceftriaxoe, when factors other than acquisition cost were considered. Advances in surgical techniques, the changes in bacterial ecology in hospitals, the spread of bacterial resistance and the substantial increase in the surgical population at risk suggest that third generation cephalosporins, particularly ceftriaxone, should be taken into consideration for surgical prophylaxis.

Validation of the cephalosporin intradermal skin test for predicting immediate hypersensitivity: a prospective study with drug challenge

BACKGROUND

Cephalosporin is a major offending agent in terms of drug hypersensitivity along with penicillin. Cephalosporin intradermal skin tests (IDTs) have been widely used; however, their validity for predicting immediate hypersensitivity has not been studied. This study aimed to determine the predictive value of cephalosporin intradermal skin testing before administration of the drug.

METHODS

We prospectively conducted IDTs with four cephalosporins, one each of selected first-, second-, third-, or fourth-generation cephalosporins: ceftezol; cefotetan or cefamandole; ceftriaxone or cefotaxime; and flomoxef, respectively, as well as with penicillin G. After the skin test, whatever the result, one of the tested cephalosporins was administered intravenously and the patient was carefully observed.

RESULTS

We recruited 1421 patients who required preoperative cephalosporins. Seventy-four patients (74/1421, 5.2%) were positive to at least one cephalosporin. However, none of responders had immediate hypersensitivity reactions after a challenge dose of the same or different cephalosporin, which were positive in the skin test. Four patients who suffered generalized urticaria and itching after challenge gave negative skin tests for the corresponding drug. The IDT for cephalosporin had a sensitivity of 0%, a specificity of 97.5%, a negative predictive value of 99.7%, and a positive predictive value (PPV) of 0%, when challenged with the same drugs that were positive in the skin test.

CONCLUSION

Routine skin testing with a cephalosporin before its administration is not useful for predicting immediate hypersensitivity because of the extremely low sensitivity and PPV of the skin test (CRIS registration no. KCT0000455).

A Critical Evaluation and Comparison of Antimicrobial Prophylaxis in Elective Surgeries Across three Hospitals

OBJECTIVES

1. To evaluate and compare the pattern and rationality of prophylactic antimicrobial therapy in elective surgeries. 2. To evaluate and compare the adherence of hospitals to the standard guidelines on prophylactic antimicrobial therapy.

METHODOLOGY

A total of 150 patients each from a government hospital (group I), medical college teaching hospital (group II), and corporate hospital attached to the institution (group III) who had undergone elective, non-complicated surgery were included. The number & types of antimicrobials used along with duration were noted. Rationality was assessed on the basis of Kunin's criteria, ASHP guidelines & SIGN guidelines. Statistical analysis was done using appropriate tests.

RESULTS

Cephalosporins were the most commonly used antimicrobials in all three groups (52.6%,85.7% & 84.8% respectively) followed by nitroimidazoles. Antimicrobial prophylaxis was appropriate in only 14.1%, 23.3% & 32.9% cases in the three groups respectively (p<0.01).The most common problem was prolonged duration of administration in 50.3%,58% & 45% respectively. The implementation of prophylaxis with respect to regimen & duration was erroneous in 20.1%, 12.7% & 4.7% respectively (p<0.01).

CONCLUSION

The rationality & regimen of antimicrobial prophylaxis was comparatively better in the corporate hospital followed by medical college hospital and the government hospital. The present study calls for an urgent review on rational use of antimicrobials for prophylaxis in all the 3 hospitals.

Comparative evaluation of prophylactic single-dose intravenous antibiotic with postoperative antibiotics in elective urologic surgery

BACKGROUND

Unrestricted antibiotic use is very common in Iran. As a result, emergence of resistant organisms is commonplace. Antibiotic prophylaxis in surgery consists of a short antibiotic course given immediately before the procedure in order to prevent development of a surgical site infection. The basic principle of prophylaxis is to maintain effective concentrations of an antibiotic active against the commonest pathogens during the entire surgery.

MATERIALS AND METHODS

We prospectively investigated 427 urologic surgery cases in our department between August 2008 and September 2009 (Group 1). As reference cases, we retrospectively reviewed 966 patients who underwent urologic surgery between May 2004 and May 2008 (Group 2) who were administered antibiotics without any restriction. Prophylactic antibiotics such as cefazolin were administered intravenously according to our protocol. Postoperative body temperature, peripheral white blood cell counts, urinalysis, and urine culture were checked.

RESULTS

To judge perioperative infections, wound condition and general condition were evaluated in terms of surgical site infection, as well as remote infection and urinary tract infection, up to postoperative day 30. Surgical site infection was defined as the presence of swelling, tenderness, redness, or drainage of pus from the wound, superficially or deeply. Remote infection was defined as occurrence of pneumonia, sepsis, or urinary tract infection. Perioperative infection rates (for surgical site and remote infection) in Group 1 and Group 2 were nine of 427 (2.6%) and 24 of 966 (2.5%), respectively. Surgical site infection rates of categories A and B in Group 1 were 0 and two (0.86%), respectively, while those in Group 2 were 0 and five (0.92%), respectively. There was no significant difference in infection rates in terms of remote infection and surgical site infection between Group 1 and Group 2 (P = 0.670). The amounts, as well as the prices, for intravenously administered antibiotics decreased to approximately one quarter.

CONCLUSION

Our protocol effectively decreased the amount of antibiotics used without increasing perioperative infection rates. Thus, our protocol of prophylactic antibiotic therapy can be recommended as an appropriate method for preventing perioperative infection in urologic surgery.

Novel approach to antibiotic prophylaxis in percutaneous endoscopic gastrostomy (PEG): randomised controlled trial

OBJECTIVE

To evaluate a new and simpler strategy of antibiotic prophylaxis in percutaneous endoscopic gastrostomy (PEG).

DESIGN

Single centre, two arm, randomised, controlled, double blind clinical trial.

SETTING

Endoscopy unit in Karolinska University Hospital, Stockholm, Sweden, between 3 June 2005 and 31 October 2009.

PARTICIPANTS

234 patients with an indication for PEG who gave informed consent to participate.

INTERVENTION

A single 20 ml dose of the oral solution of sulfamethoxazole and trimethoprim (also known as co-trimoxazole or Bactrim; F Hoffmann-La Roche Ltd, Basel, Switzerland) deposited in the PEG catheter immediately after insertion. The control group received standard prophylaxis consisting of a single intravenous dose of 1.5 g cefuroxime (Zinacef; GlaxoSmithKline, London) administered before insertion of the PEG tube.

MAIN OUTCOME MEASURE

Primary outcome was the occurrence of clinically evident wound infection within 14 days after insertion of the PEG catheter. Secondary outcomes were positive bacterial culture and blood tests (highly sensitive C reactive protein and white blood cell count). All randomised patients were included in an intention to treat analysis.

RESULTS

Of the 234 patients included in this study, 116 were randomly assigned to co-trimoxazole and 118 to cefuroxime. At follow-up 7-14 days after insertion of the PEG catheter, wound infection was found in 10 (8.6%) patients in the co-trimoxazole group and 14 (11.9%) in the cefuroxime group, which corresponds to a percentage point difference of -3.3% (95% confidence interval -10.9% to 4.5%). The per protocol analysis, which comprised 100 patients in each group, gave similar results-10% and 13% infection in the co-trimoxazole and cefuroxime groups, respectively (percentage point difference -3.0%, 95% CI -11.8% to 5.8%). Both these analyses indicate non-inferiority of co-trimoxazole compared with cefuroxime because the upper bounds of the confidence intervals are lower than the pre-determined non-inferiority margin of 15%. Analyses of the secondary outcomes supported this finding.

CONCLUSION

20 ml of co-trimoxazole solution deposited in a newly inserted PEG catheter is at least as effective as cefuroxime prophylaxis given intravenously before PEG at preventing wound infections in patients undergoing PEG. Trial registration Current Controlled Trials ISRCTN18677736.

Peri-operative antibiotic prophylaxis: adherence to guidelines and effects of educational intervention

BACKGROUND

This study was aimed to determine the propriety of perioperative antimicrobial prophylaxis, to evaluate the effects of a training intervention on correction.

METHODS

This prospective educational intervention study was performed on clean, clean-contaminated, and contaminated wounds in elective procedures. The accuracy of the antimicrobial prophylaxis was analyzed according to international guidelines. The outcome measures were appropriateness of prophylactic antibiotic indication, choice, dose and duration; and cost of inappropriate administration.

RESULTS

Before the intervention, 312 procedures were recorded compared with 322 after the intervention. Total compliance rate decreased from 34.3% to 28.5% after the intervention, though insignificantly (p=0.59). Educational training intervention did not change the rate of inappropriate antibiotic choice statistically, and prolonged antibiotic use was significantly higher after the intervention (p=0.01). The positive impact of the intervention was observed in decreased "not indicated but administered" rate (p=0.009) and absence of procedures with "indicated but not administered" and "inappropriate antibiotic dose" which also decreased significantly (both p<0.001). The total cost of irrational antibiotic use was US$26,230.20.

CONCLUSIONS

Although this educational intervention study achieved improvements in indications, choice, and dosing of surgical antimicrobial prophylaxis, it failed to improve prolonged use and total compliance rate, and to lower the costs sufficiently. It will probably provide better results by means of compulsory measures for surgeons to comply with available protocols and guidelines, as well as education programs, in order to change the antibiotic utility habits on surgical prophylaxis and to achieve accurate prophylactic administrations.

Microbiology and management of abdominal infections

This review describes the microbiology, diagnosis, and management of intra-abdominal infections. These infections include secondary peritonitis, abdominal abscesses, and cholangitis. The infection generally occurs because enteric microorganisms enter the peritoneal cavity through a defect in the wall of the intestine or other viscus as a result of obstruction, infarction, or direct trauma. Mixed aerobic and anaerobic flora can be recovered. The predominant aerobic isolates are Escherichia coli, etc. The aerobic isolates are Escherichia coli, and enterococci, and the main anaerobic bacteria are Bacteroides fragilis group Peptostreptococcus spp. and Clostridium spp. The treatment of abdominal infection includes surgical correction and drainage of pus and administration of antimicrobials effective against both the aerobic and anaerobic pathogens.

The timing of surgical antimicrobial prophylaxis

OBJECTIVE

To obtain precise information on the optimal time window for surgical antimicrobial prophylaxis.

SUMMARY BACKGROUND DATA

Although perioperative antimicrobial prophylaxis is a well-established strategy for reducing the risk of surgical site infections (SSI), the optimal timing for this procedure has yet to be precisely determined. Under today's recommendations, antibiotics may be administered within the final 2 hours before skin incision, ideally as close to incision time as possible.

METHODS

In this prospective observational cohort study at Basel University Hospital we analyzed the incidence of SSI by the timing of antimicrobial prophylaxis in a consecutive series of 3836 surgical procedures. Surgical wounds and resulting infections were assessed to Centers for Disease Control and Prevention standards. Antimicrobial prophylaxis consisted in single-shot administration of 1.5 g of cefuroxime (plus 500 mg of metronidazole in colorectal surgery).

RESULTS

The overall SSI rate was 4.7% (180 of 3836). In 49% of all procedures antimicrobial prophylaxis was administered within the final half hour. Multivariable logistic regression analyses showed a significant increase in the odds of SSI when antimicrobial prophylaxis was administered less than 30 minutes (crude odds ratio = 2.01; adjusted odds ratio = 1.95; 95% confidence interval, 1.4-2.8; P < 0.001) and 120 to 60 minutes (crude odds ratio = 1.75; adjusted odds ratio = 1.74; 95% confidence interval, 1.0-2.9; P = 0.035) as compared with the reference interval of 59 to 30 minutes before incision.

CONCLUSIONS

When cefuroxime is used as a prophylactic antibiotic, administration 59 to 30 minutes before incision is more effective than administration during the last half hour.

Effect of dosing and dosing frequency on the efficacy of ceftizoxime and the emergence of ceftizoxime resistance during the early development of murine abscesses caused by Bacteroides fragilis and Enterobacter cloacae mixed infection

The efficacy of beta-lactams is thought to be dependent on the time that the unbound concentrations exceed the MIC (fT>MIC). However, the pharmacokinetic/pharmacodynamic index (PDI) that correlates best to the selection of resistance is not yet clear. The selection of ceftizoxime (CZX)-resistant Enterobacter cloacae mutant strains during the development of murine mixed-infection abscesses was studied to determine the PDI that is important for the emergence of resistance and the PDI value needed for the prevention of resistance. Studies were carried out 24 h after inoculation with Bacteroides fragilis ATCC 23745 and E. cloacae 22491. Six to 1,536 mg of CZX/kg of body weight/day given every 2 h (q2h), q4h, q6h, or q8h was started 30 min before inoculation and continued for 24 h. Resistant mutants were isolated to determine mutant frequencies (MF). The fT>MIC varied from 9 to 98% for E. cloacae, the peak concentration (unbound fraction) was 0.6 to 578 mg/liter, and the area under the concentration-time curve (unbound fraction) (fAUC) was 1.9 to 553 mg.h/liter. The fAUC-to-MIC ratio best explained the in vivo efficacy. CZX-resistant B. fragilis and E. cloacae mutants were isolated from untreated controls at an MF of 10(-5) to 10(-7). The MF of resistant B. fragilis did not increase during therapy. The selection of resistant E. cloacae strains at an MF of 10(-1) to 10(-2) was related to the fT>MIC and the ratio of fAUC to MIC following an inverse U shape. However, the ratio of fAUC to MIC was the stronger driver of resistance. The highest MFs were 0.7 to 0.9 at an fAUC-to-MIC ratio of approximately 250. We conclude that the ratio of fAUC to MIC is the PDI that correlated best to the in vivo efficacy of CZX and probably also to the emergence of resistant E. cloacae mutants. An fAUC-to-MIC ratio of 1,000 was needed to prevent the emergence of this resistance.

Physiological Modeling for Indirect Evaluation of Drug Tissular Pharmacokinetics under Non-Steady-State Conditions: An Example of Antimicrobial Prophylaxis During Liver Surgery

Cefazolin, a time-dependent first-generation cephalosporin with non-linear binding to albumin, is widely recommended for antimicrobial prophylaxis during liver surgery to decrease the incidence of postoperative wound infections. The recommended protocol (2 g IV at anesthesia induction followed by 1 g 4 h later) is expected to maintain the free cefazolin concentration in exposed intratissular fluids above its minimal inhibitory concentration (MIC) for potentially encountered microorganisms, from skin incision to skin closure. Since this dosing protocol fails to take into account either of patients status (total body weight and renal function) or of surgical and anesthetic consequences (variations of cardiac output and regional blood flows, progressive decrease of plasma albumin concentration) on cefazolin tissular pharmacokinetics, a physiological modeling study was conducted to investigate protocol suitability for liver surgery in six populations: obese (body mass index >34), renal insufficiency (GFR = 10, 30 or 50 ml min(-1)) and high intraoperative blood loss (three times that usually observed during this surgery) and none of these features referred to as controls. A previously validated physiologically based pharmacokinetic (PB-PK) model for cefazolin in humans was used and then further adapted to simulate obese or renal insufficiency patients as well as the consequences of general anesthesia and liver surgery on cefazolin pharmacokinetics. Clinical data required for simulation (intraoperative kinetics of percent expired isoflurane and plasma albumin concentration, mean intraoperative blood loss) were obtained from 10 patients who underwent right hepatectomy in our institution. Using a fixed MIC of 2 microg ml(-1) against potentially encountered bacteria, it was concluded that the recommended dosing schedule was suitable in all tested populations, including obese patients, although prolongation of the interval between injections appeared advisable for renal insufficiency patients. Furthermore, when a MIC of 3 microg ml(-1) was considered, the recommended cefazolin-dosing regimen failed to maintain sufficient free cefazolin concentrations in the interstitial fluids during surgery in all tested populations except renal insufficiency patients (GFR < 50 ml min(-1)).

Comparative study of the effects of ceftizoxime, piperacillin, and piperacillin-tazobactam concentrations on antibacterial activity and selection of antibiotic-resistant mutants of Enterobacter cloacae and Bacteroides fragilis in vitro and in vivo in mixed-infection abscesses

The effects of ceftizoxime (CZX), piperacillin (PIP), and PIP-tazobactam (PT) concentrations on the antibacterial activity and selection of resistant mutants of Bacteroides fragilis and Enterobacter cloacae were investigated in vitro in a mixed-culture anaerobic time-kill study and in vivo in a mixed-infection abscess model. Mixed cultures were incubated for 24 h with 0.125 to 512 micro g of CZX per ml or 0.125 to 2,048 micro g of PIP or PT per ml. Mice were treated every 2 h for 24 h with CZX at 6 to 1,536 mg/kg/day or with PIP or PT at 24 to 6,144 mg/kg/day starting 30 min before inoculation with different B. fragilis-E. cloacae combinations. There was a good correlation between the in vitro and in vivo activities of the antibiotics and their MICs obtained with high inocula (10(8) CFU/ml). The respective 50% effective doses (milligrams per kilogram per day) with B. fragilis and E. cloacae 22491 were 771 and 521 for CZX, 416 and 643 for PIP, and 85 and 554 for PT, and with the B. fragilis-E. cloacae 032349 combination, they were 81 and 21 for CZX and 77 and 766 for PT. Resistant mutants of E. cloacae 22491 were preferentially selected in vitro with 2 to 64 micro g of CZX per ml and in vivo with CZX at 12 to 384 mg/kg/day. There was no preferential selection of CZX-resistant B. fragilis or E. cloacae 032349. For CZX-resistant E. cloacae 22491, we found a 16- to 512-fold increase in the MIC of CZX and increased MICs of other expanded-spectrum cephalosporins, owing in part to the production of a stably derepressed cephalosporinase. In vitro and in vivo, PT did not select resistant mutants of E. cloacae and B. fragilis. Results demonstrate the adverse microbiological outcome of choosing an expanded-spectrum cephalosporin like CZX for empirical treatment of mixed infections involving a susceptible Enterobacter strain.