Skin preparation for preventing infection following caesarean section.

backgroundThe risk of maternal mortality and morbidity is higher after caesarean section than for vaginal birth. With increasing rates of caesarean section, it is important to minimise risks to the mother as much as possible. This review focused on different skin preparations to prevent infection. This is an update of a review last published in 2018.

objectivesTo compare the effects of different antiseptic agents, different methods of application, or different forms of antiseptic used for preoperative skin preparation for preventing postcaesarean infection. SEARCH

methodsFor this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (9 July 2019), and reference lists of retrieved studies. SELECTION CRITERIA: Randomised and quasi-randomised trials, evaluating any type of preoperative skin preparation (agents, methods or forms). We included studies presented only as abstracts, if there was enough information to assess risk of bias. Comparisons of interest in this review were between: different antiseptic agents (e.g. alcohol, povidone iodine), different methods of antiseptic application (e.g. scrub, paint, drape), different forms of antiseptic (e.g. powder, liquid), and also between different packages of skin preparation including a mix of agents and methods, such as a plastic incisional drape, which may or may not be impregnated with antiseptic agents. We mainly focused on the comparison between different agents, with and without the use of drapes. Only studies involving the preparation of the incision area were included. This review did not cover studies of preoperative handwashing by the surgical team or preoperative bathing. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed all potential studies for inclusion, assessed risk of bias, extracted the data and checked data for accuracy. We assessed the certainty of the evidence using the GRADE approach. MAIN

resultsWe included 13 individually-randomised controlled trials (RCTs), with a total of 6938 women who were undergoing caesarean section. Twelve trials (6916 women) contributed data to this review. The trial dates ranged from 1983 to 2016. Six trials were conducted in the USA, and the remainder in India, Egypt, Nigeria, South Africa, France, Denmark, and Indonesia. The included studies were broadly at low risk of bias for most domains, although high risk of detection bias raised some specific concerns in a number of studies. Length of stay was only reported in one comparison. Antiseptic agents Parachlorometaxylenol with iodine versus iodine alone We are uncertain whether parachlorometaxylenol with iodine made any difference to the incidence of surgical site infection (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.04 to 2.99; 1 trial, 50 women), or endometritis (RR 0.88, 95% CI 0.56 to 1.38; 1 trial, 50 women) when compared with iodine alone, because the certainty of the evidence was very low. Adverse events (maternal or neonatal) were not reported. Chlorhexidine gluconate versus povidone iodine Moderate-certainty evidence suggested that chlorhexidine gluconate, when compared with povidone iodine, probably slightly reduces the incidence of surgical site infection (RR 0.72, 95% CI 0.58 to 0.91; 8 trials, 4323 women). This effect was still present in a sensitivity analysis after removing four trials at high risk of bias for outcome assessment (RR 0.87, 95% CI 0.62 to 1.23; 4 trials, 2037 women). Low-certainty evidence indicated that chlorhexidine gluconate, when compared with povidone iodine, may make little or no difference to the incidence of endometritis (RR 0.95, 95% CI 0.49 to 1.86; 3 trials, 2484 women). It is uncertain whether chlorhexidine gluconate reduces maternal skin irritation or allergic skin reaction (RR 0.64, 95% CI 0.28 to 1.46; 3 trials, 1926 women; very low certainty evidence). One small study (60 women) reported reduced bacterial growth at 18 hours after caesarean section for women who had chlorhexidine gluconate preparation compared with women who had povidone iodine preparation (RR 0.23, 95% CI 0.07 to 0.70). Methods Drape versus no drape This comparison investigated the use of drape versus no drape, following preparation of the skin with antiseptics. Low-certainty evidence suggested that using a drape before surgery compared with no drape, may make little or no difference to the incidence of surgical site infection (RR 1.29, 95% confidence interval (CI) 0.97 to 1.71; 3 trials, 1373 women), and probably makes little or no difference to the length of stay in the hospital (mean difference (MD) 0.10 days, 95% CI -0.27 to 0.46; 1 trial, 603 women; moderate-certainty evidence). One trial compared an alcohol scrub and iodophor drape with a five-minute iodophor scrub only, and reported no surgical site infection in either group (79 women, very-low certainty evidence). We were uncertain whether the combination of a one-minute alcohol scrub and a drape reduced the incidence of metritis when compared with a five-minute scrub, because the certainty of the evidence was very low (RR 1.62, 95% CI 0.29 to 9.16; 1 trial, 79 women). The studies did not report on adverse events (maternal or neonatal). AUTHORS'

conclusionsModerate-certainty evidence suggests that preparing the skin with chlorhexidine gluconate before caesarean section is probably slightly more effective at reducing the incidence of surgical site infection in comparison to povidone iodine. For other outcomes examined there was insufficient evidence available from the included RCTs. Most of the evidence in this review was deemed to be very low or low certainty. This means that for most findings, our confidence in any evidence of an intervention effect is limited, and indicates the need for more high-quality research. Therefore, it is not yet clear what sort of skin preparation may be most effective for preventing postcaesarean surgical site infection, or for reducing other undesirable outcomes for mother and baby. Well-designed RCTs, with larger sample sizes are needed. High-priority questions include comparing types of antiseptic (especially iodine versus chlorhexidine), and application methods (scrubbing, swabbing, or draping). We found two studies that are ongoing; we will incorporate the results of these studies in future updates of this review.