Best practice perioperative strategies and surgical techniques for preventing caesarean section surgical site infections: a systematic review of reviews and meta-analyses

Evidence-based surgical procedures to optimize caesarean outcomes: an overview of systematic reviews

Background

Caesarean section (CS) is the most performed major surgery worldwide. Surgical techniques used for CS vary widely and there is no internationally accepted standardization. We conducted an overview of systematic reviews (SR) of randomized controlled trials (RCT) to summarize the evidence on surgical techniques or procedures related to CS.

Methods

Searches were conducted from database inception to 31 January 2024 in Cochrane Database of Systematic Reviews, PubMed, EMBASE, Lilacs and CINAHL without date or language restrictions. AMSTAR 2 and GRADE were used to assess the methodological quality of the SRs and the certainty of evidence at outcome level, respectively. We classified each procedure-outcome pair into one of eight categories according to effect estimates and certainty of evidence. The overview was registered at PROSPERO (CRD 42023208306).

Findings

The analysis included 38 SRs (16 Cochrane and 22 non-Cochrane) published between 2004-2024 involving 628 RCT with a total of 190,349 participants. Most reviews were of low or critically low quality (AMSTAR 2). The SRs presented 345 procedure-outcome comparisons (237 procedure versus procedure, 108 procedure versus no treatment/placebo). There was insufficient or inconclusive evidence for 256 comparisons, clear evidence of benefit for 40, possible benefit for 17, no difference of effect for 13, clear evidence of harm for 14, and possible harm for 5. We found no SRs for 7 pre-defined procedures. Skin cleansing with chlorhexidine, Joel-Cohen-based abdominal incision, uterine incision with blunt dissection and cephalad-caudal expansion, cord traction for placental extraction, manual cervical dilatation in pre-labour CS, changing gloves, chromic catgut suture for uterine closure, non-closure of the peritoneum, closure of subcutaneous tissue, and negative pressure wound therapy are procedures associated with benefits for relevant outcomes.

Interpretation

Current evidence suggests that several CS surgical procedures improve outcomes but also reveals a lack of or inconclusive evidence for many commonly used procedures. There is an urgent need for evidence-based guidelines standardizing techniques for CS, and trials to fill existing knowledge gaps.

Funding

UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), a cosponsored programme executed by the World Health Organization (WHO).

Evaluation of independent risk factors associated with surgical site infections from caesarean section

BACKGROUND

The present study assessed factors associated with the risk of surgical site infections (SSI) after a caesarean section (C-section).

METHODS

Data were collected in 1682 women undergoing elective (53.9%) and emergency (46.1%) C-sections between 1st August 2020, and 30th December 2021, at a National Health Service hospital (Surrey, UK).

RESULTS

At the time of C-section, the mean age was 33.1 yr (SD ± 5.2). Compared to women with BMI < 30 kg/m2, those with a BMI ≥ 35 kg/m2 had a greater risk of SSI, OR 4.07 (95%CI 2.48-6.69). Women with a history of smoking had a greater risk of SSI than those who had never smoked, OR 1.69 (95%CI 1.05-2.27). Women with a BMI ≥ 30 kg/m2 and had a smoking history or emergency C-section had 3- to tenfold increases for these adverse outcomes. Ethnic minority, diabetes or previous C-section did not associate with any of the outcomes.

CONCLUSIONS

High BMI, smoking, and emergency C-section are independent risk factors for SSI from C-section. Women planning conception should avoid excess body weight and smoking. Women with diabetes and from ethnic minority backgrounds did not have increased risks of SSI, indicating a consistent standard of care for all patients.

Reducing urinary tract infection in female pelvic surgery: A retrospective cohort study

OBJECTIVE

To compare prebundle versus postbundle implementation urinary tract infection (UTI) rates among inpatients within 6 weeks of clean-contaminated pelvic reconstructive surgery.

METHODS

The authors conducted a retrospective cohort study from September 2019 to December 2021 at a tertiary hospital. The bundle strategy included the following: universal preoperative UTI check with treatment if positive, replacing prolonged postoperative voiding trials on the ward with earlier discharge and indwelling catheter removal by a nurse continence advisor the next day, and daily cranberry extract for 6 weeks postoperatively. UTI was defined as positive urine culture (≥100 000 colony-forming unit per mL) in a symptomatic patient. Data analysis involved hypothesis testing and logistic regression.

RESULTS

The authors reviewed 132 postbundle inpatient charts and retained 93 for analyses. The results were compared with 204 prebundle inpatient charts. The rate of postoperative UTI decreased from 17.6% in the prebundle group to 6.5% after bundle implementation (P = 0.01). The adjusted odds ratio for postbundle versus prebundle likelihood of UTI was 0.35 (95% confidence interval, 0.13-0.98; P = 0.045). Significantly more postbundle patients compared with prebundle patients were discharged home on the first day postoperatively (76.3% vs. 37.7%, P < 0.001).

CONCLUSIONS

A clinical bundle can significantly decrease both UTI rates and hospital stay after pelvic reconstructive surgery.

Inter-rater agreement of CDC criteria and ASEPSIS score in assessing surgical site infections after cesarean section: a prospective observational study

Objective

To assess and compare the inter-rater agreement of the CDC criteria and the ASEPSIS score in identifying surgical site infections after cesarean section.

Methods

Prospective observational study including 110 patients subjected to a cesarean section at our institution. Surgical wounds were managed according to standard care and were photographed on the third, seventh, and thirtieth postoperative day or during any evaluation in case of complications. Three expert surgeons reviewed the prospectively gathered data and photographs and classified each wound using CDC criteria and the ASEPSIS score. The inter-rater agreements of CDC criteria and ASEPSIS score were determined with Krippendorff's Alpha with linear weights and compared with a confidence interval approach.

Results

The weighted α coefficient for CDC criteria was 0.587 (95%CI, 0.411-0.763, p < 0.001, "moderate" agreement according to Altman's interpretation of weighted agreement coefficient), while the weighted α coefficient for the ASEPSIS score was 0.856 (95%CI, 0.733-0.980, p < 0.001, "very good" agreement).

Conclusion

ASEPSIS score presents a "very good" inter-rater agreement for surgical site infections identification after cesarean, resulting in a more objective method than CDC criteria ("moderate" inter-rater agreement). ASEPSIS score could represent an objective tool for managing and monitoring surgical site infections after cesarean section, also by photographic evaluation.

Reducing post-caesarean infection in the Kimberley region of Western Australia: An audit-based observational study

BACKGROUND

The higher burden of post-caesarean infection in the remote Kimberley region of Australia is intimately associated with poorer social determinants of health. This results in a confluence of environmental factors such as overcrowding and limited access to clean water and host factors such as diabetes mellitus and obesity which result in heightened susceptibility and vulnerability to infection.

AIM

To ascertain infection rates following caesarean section in Broome Hospital, before and after the implementation of evidence-based strategies intended to reduce bacterial load and mitigate the impact of poor underlying social determinants of health.

MATERIALS AND METHODS

This is a retrospective observational longitudinal audit study including women who underwent caesarean section in Broome Hospital between the time of 1 January 2019 and 1 May 2019 or 1 January 2021 and 1 May 2021. Files and theatre records were audited to determine demographic, surgical and post-partum infection in women who underwent caesarean section at Broome Hospital. The main outcome measure was infection within six weeks post-caesarean section.

RESULTS

This study found a statistically significant improvement in post-operative infection rates in women who underwent caesarean section at Broome Hospital (41.7% vs 11.6%, P = 0.002). The two groups were statistically similar in background.

CONCLUSION

The combination of various infection prevention initiatives targeted at reducing infection burden can result in clinical and statistically significant reductions in post-caesarean infections in high-risk populations with poor underlying social determinants of health.

The glitz and glamour randomized trial: the effect of fingernail polish on post-caesarean surgical site infection

Current surgical scrub guidelines suggest that fingernail polish should not be worn by healthcare providers despite collective evidence not demonstrating a relationship between fingernail polish and surgical-site infection (SSI). The purpose of this study was to determine the effect of surgical staff wearing nail polish on the incidence of SSI after caesarean delivery. In this calendar block-randomised clinical trial, surgical staff were assigned to wear nail polish or to have unpainted nails for alternating two-week periods. The primary outcome was surgical site infection within 6 weeks of caesarean delivery. There were 372 patients in the nail polish arm and 465 in the polish-free arm. The rate of SSIs was not significantly different between the nail polish arm and the polish-free arm (1.3% vs 2.8% p = .155). We found the rate of SSI following caesarean delivery is not significantly affected by surgical staff wearing fingernail polish.Impact StatementWhat is already known on this subject? Current surgical scrub guidelines state that fingernail polish should not be worn by healthcare providers even though the collective evidence has not been able to show the relationship between fingernail polish and surgical site infection. Previous studies have only used bacterial colony count after handwashing as a primary endpoint. The evidence they provide for developing scrub guidelines have been contradictory and inconclusive.What do the results of this study add? To better inform surgical scrub guidelines, evidence is needed that evaluates the effect of fingernail polish on clinically significant endpoints. Our study, Glitz & Glamour, examined 885 non-emergent Caesarian sections using a calendar-block schedule to determine if wearing nail polish had an impact on rates of surgical site infection.What are the implications of these findings for clinical practice and/or further research? Results suggested that fingernail polish had no difference on frequency of surgical site infections, and neither condition of the polish (chipped vs. freshly applied) nor the type of polish (gel vs. regular) had any impact either.

Implementation of an evidence-based bundle to reduce surgical site infection after caesarean section - Review of the interventions

BACKGROUND

Surgical site infection (SSI) is the most common complication post caesarean section (CS) with a significant impact on women and health services. A bundle approach incorporating previously studied individual interventions has shown increased reductions in SSI.

AIM

To assess compliance with a SSI intervention bundle and to examine readmission rates for SSI.

METHODS

A retrospective audit of women who underwent CS at a regional hospital in Queensland, Australia pre-intervention (February 2015-January 2017) and post-intervention (February 2018-December 2020).

RESULTS

There was good compliance with vaginal cleansing (27.7% vs 84.8%), chlorhexidine skin preparation (90.4% vs 98.4%), BMI-based antibiotic dose adjustment (48.8% vs 74.3%), and Alexis retractor use (9.9% vs 66%), pre and post-implementation periods respectively. There was a reduction in documented hair shaving (2.1% vs 0.5%). There was a trend towards less admission for SSI, a trend that could have been even better had there not been an increasing number of women with high BMI over the years. Fewer cases needed return to theatre post-implementation. Endometritis rates were unchanged.

CONCLUSIONS

Good compliance can be achieved with good collaboration. There was a reduction in admission rates for SSI. Larger prospective studies are needed to further examine these findings.

Documented β-Lactam Allergy and Risk for Cesarean Surgical Site Infection

Objective. To examine the relationship between documented β-lactam allergy and cesarean delivery (CD) surgical site infection (SSI). Study Design. We conducted a retrospective cohort analysis of women who underwent CD at Ben Taub Hospital and Texas Children’s Pavilion for Women (Houston, TX) from August 1, 2011, to December 31, 2019. The primary exposure was a documented β-lactam allergy, and the second exposure of interest was the type of perioperative antibiotic received. The primary outcome was the prevalence of SSI. Maternal characteristics were stratified by the presence or absence of a documented β-lactam allergy, and significance was evaluated using Pearson’s chi-squared test for categorical variables and $t$ -test for continuous variables. A logistic regression model estimated odds of SSI after adjusting for possible confounders. Results. Of the 12,954 women included, 929 (7.2%) had a documented β-lactam allergy while 12,025 (92.8%) did not. Among the 929 women with a β-lactam allergy, 495 (53.3%) received non-β-lactam perioperative prophylaxis. SSI occurred in 38 (4.1%) of women who had a β-lactam allergy versus 238 (2.0%) who did not ( $p\le 0.001$ ). β-Lactam allergy was associated with higher odds of SSI compared to no allergy ( $\text{adjusted}\text{odds}\text{ratio}\left(\text{aOR}\right)=1.97$ ; $95\%\text{confidence}\text{interval}\left(\text{CI}\right)=1.24$ -3.14; $p=0.004$ ) after controlling for age, race, ethnicity, insurance status, delivery body mass index (BMI), tobacco use, intra-amniotic infection in labor, duration of membrane rupture, preterm delivery, delivery indication, diabetes, hypertension, group B Streptococcus colonization, and type of perioperative antibiotic received. Conclusion. The presence of a β-lactam allergy is associated with increased odds of developing a CD SSI after controlling for possible confounders, including the type of perioperative antibiotic received.

Real-world implementation of a vaginal preparation policy prior to cesarean delivery

OBJECTIVE

Surgical site infections (SSIs) are a major source of morbidity and mortality for women who undergo cesarean section (c-section). SSIs following c-section include wound infection, infection of the endometrium (endometritis) and intra-abdominal infections. Perioperative interventions to prevent these infections continue to be studied, including the use of vaginal preparation prior to c-section. Although literature has shown that the use of vaginal preparation prior to c-section decreases the rate of SSI, real-world clinical data regarding effective implementation of these policies are lacking. The objectives of this study were to determine (1) if a vaginal preparation policy could be implemented in a real-world setting with a high compliance rate and (2) to identify factors led to differences in compliance with policy.

STUDY DESIGN

This was a secondary analysis of a retrospective cohort study designed to examine the incidence of SSI after c-section before and after the implementation of vaginal preparation policy. The primary outcomes included implementation rates of the vaginal preparation for the post policy cohort. Secondary outcomes included subgroup analysis of policy adherence based on time of day, urgency of delivery, membrane status, labor status, and maternal factors.

RESULTS

Overall adherence to the vaginal preparation policy was 87.2% of patients. Maternal factors did not impact the rate of policy adherence. 81.4% of patients undergoing c-section at night had vaginal prep completed compared to 89.9% of patients undergoing c-section during the day (p = .016). 63.8% of patients undergoing emergent c-section had vaginal prep completed, compared to 90.1% of patients undergoing non-emergent c-section (p < .001). Laboring patients were more likely to have vaginal preparation completed (143 (95.3%) vs. 225 (82.7%), p = .009).

CONCLUSIONS

Compliance with vaginal preparation policy was high. Patients who are undergoing evening deliveries and emergent deliveries are less likely to have vaginal preparation completed. Some of these differences are likely attributable to perceived urgency of the c-section. It is important that interventions are identified such as staff education and standardization of documentation to improve rates of policy adherence.

Worldwide incidence of surgical site infections in general surgical patients: A systematic review and meta-analysis of 488,594 patients

BACKGROUND

Establishing worldwide incidence of general surgical site infections (SSI) is imperative to understand the extent of the condition to assist decision-makers to improve the planning and delivery of surgical care. This systematic review and meta-analysis aimed to estimate the worldwide incidence of SSI and identify associated factors in adult general surgical patients.

MATERIALS AND METHODS

A systematic review was undertaken using MEDLINE (Ovid), CINAHL (EBSCO), EMBASE (Elsevier) and the Cochrane Library to identify cross-sectional, cohort and observational studies reporting SSI incidence or prevalence. Studies of less than 50 participants were excluded. Data extraction and quality appraisal were undertaken independently by two review authors. The primary outcome was cumulative incidence of SSI occurring up to 30 days postoperative. The secondary outcome was the severity/depth of SSI. The I² statistic was used to explore heterogeneity. Random effects models were used in the presence of substantial heterogeneity. Subgroup, meta-regression sensitivity analyses were used to explore the sources of heterogeneity. Publication bias was assessed using Hunter's plots and Egger's regression test.

RESULTS

Of 2091 publications retrieved, 62 studies were included. Of these, 57 were included in the meta-analysis across six anatomical locations with 488,594 patients. The pooled 30-day cumulative incidence of SSI was 11% (95% CI 10%-13%). No prevalence data were identified. SSI rates varied across anatomical location, surgical approach, and priority (i.e., planned, emergency). Multivariable meta-regression showed SSI is significantly associated with duration of surgery (estimate 1.01, 95% CI 1.00-1.02, P = .014).

CONCLUSIONS

and Relevance: 11 out of 100 general surgical patients are likely to develop an infection 30 days after surgery. Given the imperative to reduce the burden of harm caused by SSI, high-quality studies are warranted to better understand the patient and related risk factors associated with SSI.

Incidence and predictors of surgical site infection in women who are obese and give birth by elective caesarean section: A secondary analysis

BACKGROUND

Surgical site infection (SSI) after a caesarean section is of concern (CS) is of concern to both clinicians and women themselves.

AIMS

The aim of this study is to identify the cumulative incidence and predictors of SSI in women who are obese and give birth by elective CS.

MATERIALS AND METHODS

The method used was planned secondary analysis of data from women with a pre-pregnancy body mass index (BMI) ≥30 kg/m² giving birth by elective CS in a multicentre randomised controlled trial of a prophylactic closed-incision negative pressure wound therapy dressing. Data were collected from medical records, direct observations of the surgical site and self-reported signs and symptoms from October 2015 to December 2019. The Centers for Disease Control and Prevention definition was used to identify SSI. Women were followed up once in hospital just before discharge and then weekly for four weeks after discharge. Blinded outcome assessors determined SSI. After the cumulative incidence of SSI was calculated, multiple variable logistic regression models were used to identify independent risk factors for SSI.

RESULTS

SSI incidence in 1459 women was 8.4% (122/1459). Multiple variable-adjusted odds ratios (OR) for SSI were BMI ≥40 kg/m² (OR 1.55, 95% confidence interval (CI) 1.30-1.86) as compared to BMI 30-34.9 0 kg/m² , ≥2 previous pregnancies (OR 1.38, 95% CI 1.00-1.80) as compared to no previous pregnancies and pre-CS vaginal cleansing (OR 0.55, 95% CI 0.33-0.99).

CONCLUSIONS

Our findings may inform preoperative counselling and shared decision-making regarding planned elective CS for women with pre-pregnancy BMI ≥30 kg/m² .

Implementation of vaginal preparation prior to caesarean section

Introduction

Surgical site infections following caesarean section are associated with significant morbidity. Vaginal preparation is the cleansing of the vaginal epithelium with an antibacterial solution to reduce the bacterial load and therefore reduce ascending genital tract infection. It is recommended by the WHO and a Cochrane review in 2018 concluded that vaginal preparation immediately before caesarean section probably reduces the rates of postoperative endometritis.

Objective

To implement vaginal preparation prior to caesarean section at Guy’s and St Thomas’ Hospital NHS Foundation Trust and reduce rates of deep surgical site infections.

Methods

The protocol (included within the appendices) for vaginal preparation prior to caesarean section was developed after reviewing the available evidence. Two vaginal preparation champions, a midwife and a scrub nurse, were selected to help promote and assist in the implementation. The first implementation cycle included elective and category II and III caesarean sections. To ensure acceptability, 20 women were asked to complete a questionnaire following vaginal preparation. Once the intervention was being performed in >85% of eligible women, the inclusion criteria was expanded to include category I caesarean sections.

Results

Twelve months following implementation, vaginal preparation was still being performed in 89% of eligible women. The deep surgical site infection rate is now the lowest recorded in the last 6 years. Vaginal preparation prior to caesarean section was acceptable to pregnant women and no adverse effects were reported.

Conclusions

Vaginal preparation prior to caesarean section has been successfully implemented at Guy’s and St Thomas’ Hospital NHS Foundation Trust. This simple, cheap intervention, performed with readily available materials, is still being performed in a high number of caesarean sections 12 months post-implementation. It has resulted in a reduction in deep surgical site infections. Involvement of key stakeholders and the recruitment of vaginal preparation champions were key to success.

The risk factors and care measures of surgical site infection after cesarean section in China: a retrospective analysis

Background

Surgical site infections after cesarean section are very common clinically, it is necessary to evaluate the risk factors of surgical site infections after cesarean section, to provide evidences for the treatment and nursing care of cesarean section.

Methods

This study was a retrospective cohort study design. Patients undergone cesarean section in a tertiary hospital of China from May 2017 to May 2020 were identified, we collected the clinical data of the included patients, and we analyzed the infection rate, etiological characteristics and related risk factors of surgical site infection after caesarean section.

Results

A total of 206 patients with cesarean section were included, and the incidence of surgical site infection in patients with cesarean section was 23.30%. A total of 62 cases of pathogens were identified, Enterococcus faecalis (33.87%) and Escherichia coli (29.03%) were the most common pathogens. Both Enterococcus faecalis and Escherichia coli were highly sensitive to Cefoperazone, Meropenem, and Levofloxacin. Logistic regression analyses indicated that Age ≥ 30y (OR 4.18, 95%CI: 1.23–7.09), BMI ≥ 24 (OR 2.39, 95%CI: 1.02–4.55), duration of cesarean section ≥ 1.5 h (OR 3.90, 95%CI: 1.28–5.42), estimated blood loss ≥ 400 ml (OR 2.35, 95%CI: 1.10–4.37) and the duration of urinary catheter ≥ 24 h (OR 3.18, 95% CI: 1.21–5.71) were the independent risk factors of surgical site infection after cesarean section (all p < 0.05).

Conclusions

Age, BMI, duration of surgery, blood loss and urinary catheter use were associated with higher risk of the surgical site infection after cesarean section. Clinical preventions and interventions are warranted for those population to reduce the occurrence of surgical site infection.

Adherence to best practice: Preventing surgical site infection following caesarean section in Australia

BACKGROUND

Surgical site infection (SSI) following caesarean section is a serious but underreported problem with an estimated incidence of 5-9%. It is essential to identify adherence to established prevention strategies to reduce the incidence rate.

AIMS

The aims of this study were to quantify unwarranted variation from evidence-based practice on the prevention of SSI at caesarean section in Australia; and to identify predictors of not implementing an existing infection prevention bundle: pre-incision antibiotic prophylaxis, vaginal preparation and spontaneous placenta removal.

MATERIALS AND METHODS

An online cross-sectional survey of obstetricians and obstetric Diplomates was conducted in 2016. The primary outcome was adherence to an existing infection prevention bundle, with demographic and clinical variables predicting adherence through multivariable binary logistic regression.

RESULTS

Forty-nine percent of respondents (response rate 39.6%) reported implementing zero or only one element of the infection prevention bundle. The types of respondents most likely to have poor adherence were Diplomates (adjusted odds ratio (aOR) 2.58), obstetricians practising in private hospitals (aOR 3.34), those usually practising in public and private hospitals (aOR 2.23), and those not usually implementing a surgical safety checklist (aOR 3.77).

CONCLUSIONS

Adherence to best practice at caesarean section is low among many Australian obstetricians. Infection control practitioners and obstetricians need to collaboratively implement surgical safety checklists at caesarean section, and monitor implementation using process key performance indicators, and audit and feedback. These strategies will reduce unwarranted variation from evidence-based infection control practice.

Different classes of antibiotics given to women routinely for preventing infection at caesarean section

BACKGROUND

Caesarean section increases the risk of postpartum infection for women and prophylactic antibiotics have been shown to reduce the incidence; however, there are adverse effects. It is important to identify the most effective class of antibiotics to use and those with the least adverse effects.  OBJECTIVES: To determine, from the best available evidence, the balance of benefits and harms between different classes of antibiotic given prophylactically to women undergoing caesarean section, considering their effectiveness in reducing infectious complications for women and adverse effects on both mother and infant.

SEARCH METHODS

For this 2020 update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (2 December 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different classes of prophylactic antibiotics given to women undergoing caesarean section.  RCTs published in abstract form were also included. We excluded trials that compared drugs with placebo or drugs within a specific class; these are assessed in other Cochrane Reviews. We excluded quasi-RCTs and cross-over trials. Cluster-RCTs were eligible for inclusion but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 39 studies, with 33 providing data (8073 women). Thirty-two studies (7690 women) contributing data administered antibiotics systemically, while one study (383 women) used lavage and was analysed separately. We identified three main comparisons that addressed clinically important questions on antibiotics at caesarean section (all systemic administration), but we only found studies for one comparison, 'antistaphylococcal cephalosporins (1st and 2nd generation) versus broad spectrum penicillins plus betalactamase inhibitors'.   We found no studies for the following comparisons: 'antistaphylococcal cephalosporins (1st and 2nd generation) versus lincosamides' and 'antistaphylococcal cephalosporins (1st and 2nd generation) versus lincosamides plus aminoglycosides'. Twenty-seven studies (22 provided data) included comparisons of cephalosporins (only) versus penicillins (only). However for this update, we only pooled data relating to different sub-classes of penicillins and cephalosporins where they are known to have similar spectra of action against agents likely to cause infection at caesarean section. Eight trials, providing data on 1540 women, reported on our main comparison, 'antistaphylococcal cephalosporins (1st and 2nd generation) versus broad spectrum penicillins plus betalactamase inhibitors'. We found data on four other comparisons of cephalosporins (only) versus penicillins (only) using systemic administration: antistaphylococcal cephalosporins (1st and 2nd generation) versus non-antistaphylococcal penicillins (natural and broad spectrum) (9 studies, 3093 women); minimally antistaphylococcal cephalosporins (3rd generation) versus non-antistaphylococcal penicillins (natural and broad spectrum) (4 studies, 854 women); minimally antistaphylococcal cephalosporins (3rd generation) versus broad spectrum penicillins plus betalactamase inhibitors (2 studies, 865 women); and minimally antistaphylococcal cephalosporins (3rd generation) versus broad spectrum and antistaphylococcal penicillins (1 study, 200 women). For other comparisons of different classes of antibiotics, only a small number of trials provided data for each comparison, and in all but one case data were not pooled. For all comparisons, there was a lack of good quality data and important outcomes often included few women. Three of the studies that contributed data were undertaken with drug company funding, one was funded by the hospital, and for all other studies the funding source was not reported. Most of the studies were at unclear risk of selection bias, reporting bias and other biases, partly due to the inclusion of many older trials where trial reports did not provide sufficient methodological information. We undertook GRADE assessment on the only main comparison reported by the included studies, antistaphylococcal cephalosporins (1st and 2nd generation) versus broad spectrum penicillins plus betalactamase inhibitors, and the certainty ranged from low to very low, mostly due to concerns about risk of bias, wide confidence intervals (CI), and few events. In terms of the primary outcomes for our main comparison of 'antistaphylococcal cephalosporins (1st and 2nd generation) versus broad spectrum penicillins plus betalactamase inhibitors': only one small study reported sepsis, and there were too few events to identify clear differences between the drugs (risk ratio (RR) 2.37, 95% CI 0.10 to 56.41, 1 study, 75 women, very low-certainty evidence). There may be little or no difference between these antibiotics in preventing endometritis (RR 1.10; 95% CI 0.76 to 1.60, 7 studies, 1161 women; low-certainty evidence). None of the included studies reported on infant sepsis or infant oral thrush. For our secondary outcomes, we found there may be little or no difference between interventions for maternal fever (RR 1.07, 95% CI 0.65 to 1.75, 3 studies, 678 women; low-certainty evidence). We are uncertain of the effects on maternal: wound infection (RR 0.78, 95% CI 0.32 to 1.90, 4 studies, 543 women), urinary tract infection (average RR 0.64, 95% CI 0.11 to 3.73, 4 studies, 496 women), composite adverse effects (RR 0.96, 95% CI 0.09 to 10.50, 2 studies, 468 women), and skin rash (RR 1.08, 95% CI 0.28 to 4.1, 3 studies, 591 women) (all very low certainty evidence). Although maternal allergic reactions were reported by two studies, there were no events. There were no infant outcomes reported in the included studies. For the other comparisons, the results for most outcomes had wide CIs, few studies and few women included. None of the included trials reported on longer-term maternal outcomes, or on any infant outcomes.

AUTHORS' CONCLUSIONS

Based on the best currently available evidence, 'antistaphylococcal cephalosporins' and 'broad spectrum penicillins plus betalactamase inhibitors' may have similar efficacy at caesarean section when considering immediate postoperative infection, although we did not have clear evidence for several important outcomes. Most trials administered antibiotics at or after cord clamping, or post-operatively, so results may have limited applicability to current practice which generally favours administration prior to skin incision. We have no data on any infant outcomes, nor on late infections (up to 30 days) in the mother; these are important gaps in the evidence that warrant further research. Antimicrobial resistance is very important but more appropriately investigated by other trial designs.

The Case for Standardizing Cesarean Delivery Technique: Seeing the Forest for the Trees

In this Commentary, we explain the case for a standardized cesarean delivery surgical technique. There are three strong arguments for a standardized approach to cesarean delivery, the most common major abdominal surgery performed in the world. First, standardization within institutions improves safety, efficiency, and effectiveness in health care delivery. Second, surgical training among obstetrics and gynecology residents would become more consistent across hospitals and regions, and proficiency in performing cesarean delivery measurable. Finally, standardization would strengthen future trials of cesarean delivery technique by minimizing the potential for aspects of the surgery which are not being studied to bias results. Before 2013, more than 155 randomized controlled trials, meta-analyses or systematic reviews were published comparing various aspects of cesarean delivery surgical technique. Since 2013, an additional 216 similar studies have strengthened those recommendations and offered evidence to recommend additional cesarean delivery techniques. However, this amount of cesarean delivery technique data creates a forest for the trees problem, making it difficult for a clinician to synthesize this volume of data. In response to this difficulty, we propose a comprehensive, evidence-based and standardized approach to cesarean delivery technique.

Urinary tract infection after clean-contaminated pelvic surgery: a retrospective cohort study and prediction model

INTRODUCTION AND HYPOTHESIS

Postoperative urinary tract infection (UTI) leads to increased patient morbidity and health care costs. A prediction model may identify patients at highest risk for UTI development. Our primary objective was to determine the rate of UTI in the first 6 weeks after benign gynecologic surgery. Our secondary objective was to identify risk factors and build a predictive model for postoperative UTI.

METHODS

We reviewed 310 patient records, which represent all patients who underwent clean-contaminated surgery at a tertiary center (2016-2017). UTI was defined as positive urine culture (> 100,000,000 CFU/l) in a symptomatic patient. Pre-, intra- and postoperative variables were collected. The relation between these variables and UTI was assessed through logistic regression. A clinical prediction model was built.

RESULTS

Patients' mean age was 58.5 years and mean body mass index was 27.5 kg/m². Most were inpatients (65.8%) and 269 had urogynecologic procedures, with the remainder undergoing pelvic surgery for other indications. The most common operation was vaginal reconstruction for prolapse (59.7%), associated with concomitant synthetic midurethral sling in 1/3 cases. Forty patients (12.9%) developed UTI. Multivariate prediction modeling showed increasing age (OR 1.33, CI 1.01-1.75), increasing number of procedures (OR 1.42, CI 1.14-1.78) and prolonged voiding dysfunction (OR 3.78, CI 1.66-8.60) to be significant UTI predictors.

CONCLUSIONS

Urinary tract infection in the first 6 weeks after complex pelvic surgery is common. Our prediction model identifies that patients who are older women, have prolonged voiding dysfunction and have a greater number of concomitant pelvic floor surgeries have higher risk of postoperative UTI.

Reducing post-caesarean delivery surgical site infections: a narrative review

Surgical site infection complicates 1-10% of caesarean deliveries. With the rate of caesarean delivery increasing, it is important to identify effective measures of preventing surgical site infection and to consider their impact on maternal and neonatal outcomes. Compelling evidence supports the use of prophylactic antibiotics, prior to skin incision, to reduce surgical site infection. However, there remain international variations in terms of the recommended agent, dose and body weight-adjusted dosing. Advances in wound dressings are an evolving area of interest and surgical technique can influence outcomes. This narrative review explores pharmacological and non-pharmacological methods of preventing surgical site infection following caesarean delivery.

Efficacy of perioperative cefuroxime as a prophylactic antibiotic in women requiring caesarean section: A systematic review

Intravenous (IV) Cefuroxime (CFX) is widely used in Caesarean Section (CS) as a prophylactic antibiotic. The objective of this systematic review to compare CFX concentration in maternal blood and adipose tissue with the incidence of surgical site infection (SSI) following IV CFX in non-obese and obese women undergoing CS. A search in Medline, EMBASE, Cochrane, Web of Science, CINHAL Plus, Scopus and Google Scholar was conducted without language or date restrictions. Published articles or abstracts reporting CFX concentration or rates of SSI following CFX IV administration in adult women requiring CS were included. Studies were screened by title and abstract. Quality of studies was assessed via the ClinPK Statement checklist (Pharmacokinetics studies), or Joanna Briggs Institute Critical Appraisal Tools (SSI studies). The Cochrane Effective Practice and Organisation of Care checklist evaluated the risk of bias (SSI studies). There were no studies evaluating CFX concentrations in obese women undergoing CS. For non-obese women, CFX plasma concentrations ranged from 9.85 to 95.25 mg/L within 30-60 min of administration (1500 mg dose; 4 articles, n = 108 women). Plasma CFX concentrations were above the minimum inhibitory concentration (8 mg/L) for up to 3 h post-dose. No studies reported on CFX concentration in adipose tissue. Reported rates of SSI were 4.7% and 6.8% after administration of a single 1500 mg dose of CFX administrated after cord clamping (n = 144 women). There is limited data on pharmacokinetics of CFX for CS. There were no studies that reported CFX concentrations or SSI in obese women.

Incisional surgical site infection following cesarean section: A national retrospective cohort study

OBJECTIVE

To determine the rate and associated risk factors for incisional surgical site infection following cesarean section in Ireland.

STUDY DESIGN

This study was a retrospective population-based cohort study, conducted using the Hospital In-Patient Enquiry database (HIPE) for the period 2005-2016. All women who underwent cesarean section between 2005 and 2016 in Ireland were included. Potential risk factors for incisional surgical site infection were selected based on the existing literature and their availability within the HIPE database. The risk of incisional surgical site infection following cesarean section with exact Poisson 95% confidence intervals were reported. Multivariable Poisson regression included all potential risk factors simultaneously. Risk ratios are reported with their 95% confidence intervals and P-values.

RESULTS

There were 802,182 deliveries during the study period, 219,859 of which (27.4%) were by cesarean section. There were 1396 cases of incisional surgical site infection, a risk of 0.63% (95% confidence interval: 0.60-0.67%). Public patients had approximately 20% higher risk and the risk was almost 40% higher among women aged over 35 years compared with those aged under 25 years. Most notable, related to the morbidities assessed, was the twofold increased risk of incisional surgical site infection associated with pre-existing diabetes and with urinary tract infection in pregnancy. Premature rupture of membranes, pyrexia during labour and postpartum haemorrhage each increased risk by 40-60%. Hematoma of a cesarean section wound remained by far the strongest risk factor for incisional surgical site infection.

CONCLUSION

Of all the risk factors we studied, hematoma had the strongest association with development of incisional surgical site infection. Of all women birthing by cesarean section in Ireland during 2005-2016, 25% had at least one of the risk factors identified by our study. Approximately 40% of the incisional surgical site infection cases came from this 25%. This might suggest that a universal approach to reducing risk of surgical site infection is warranted.

Predictors of surgical site skin infection and clinical outcome at caesarean section in the very severely obese: A retrospective cohort study

INTRODUCTION

The optimal surgical approach for caesarean section is uncertain in women with very severe obesity (body mass index (BMI) >40kg/m2). We aimed to assess maternal and surgical predictors of surgical site skin infection (SSSI) in very severely obese women and to undertake an exploratory evaluation of clinical outcomes in women with a supra-panniculus transverse compared to an infra-panniculus transverse skin incision.

MATERIAL AND METHODS

Using a retrospective cohort design, case-records were reviewed of very severely obese women with a singleton pregnancy delivered by caesarean between August 2011 and December 2015 (n = 453) in two maternity hospitals in Scotland. Logistic regression analysis was used to determine predictors for SSSI. Outcomes were compared between women who had a supra-panniculus transverse compared to infra-panniculus transverse skin incision.

RESULTS

Lower maternal age was predictive of SSSI, with current smoking status and longer wound open times being marginally significant. Maternal BMI, suture method and material demonstrated univariate associations with SSSI but were not independent predictors. Women with a supra-panniculus transverse skin incision were older (32.9 (4.4), vs. 30.6 (5.7), p = 0.002), had higher BMI (49.2 (7.1), vs. 43.3 (3.3), p<0.001), shorter gestation at delivery (days) (267.7 (14.9), vs. 274.8 (14.5), p<0.001) and higher prevalence of gestational diabetes mellitus (42.6% vs. 21.9%, p = 0.002). SSSI rates did not differ between supra-panniculus transverse (13/47; 27.7%) and infra-panniculus transverse (90/406; 22.2%; p = 0.395) skin incisions.

CONCLUSION

SSSI rates are high in very severely obese women following caesarean section, regardless of location of skin incision.

Standardising intraoperative irrigation with 0.05% chlorhexidine gluconate in caesarean delivery to reduce surgical site infections: A single institution experience

Background

Surgical site infection is a significant cause of morbidity and mortality following caesarean delivery.

Objective

To determine whether standardising intraoperative irrigation with 0.05% chlorhexidine gluconate during caesarean delivery could decrease infection rates.

Methods

This was a process improvement project involving 742 women, 343 of whom received low-pressured 0.05% chlorhexidine gluconate irrigation during caesarean delivery over a one-year period. Infection rates were compared with a standard-of-care control group (399 women) undergoing caesarean delivery the preceding year.

Results

The treatment group infection rate met the study goal by achieving a lower infection rate than the control group, though this was not statistically significant. A significant interaction effect between irrigation with 0.05% chlorhexidine gluconate and antibiotic administration time existed, such that infection occurrence in the treatment group was not dependent on antibiotic timing, as opposed to the control group infection occurrence, which was dependent on antibiotic timing.

Conclusion

Intraoperative irrigation with 0.05% chlorhexidine gluconate during caesarean delivery did not statistically significantly reduce the rate of infections. It did render the impact of antibiotic administration timing irrelevant in prevention of surgical site infection. This suggests a role for 0.05% chlorhexidine gluconate irrigation in mitigating infection risk whether antibiotic prophylaxis timing is suboptimal or ideal.