Impact of Perioperative Urinary Tract Infection on Surgical Site Infection in Patients Undergoing Primary Hip and Knee Arthroplasty

BackgroundThe literature lacks clear consensus regarding the association between postoperative urinary tract infection (UTI) and surgical site infection (SSI). Additionally, in contrast to preoperative asymptomatic bacteriuria, SSI risk in patients with preoperative UTI has been incompletely studied. Therefore, our goal was to determine the effect of perioperative UTI on SSI in patients undergoing primary hip and knee arthroplasty.MethodsUsing the National Surgical Quality Improvement Program database, all patients undergoing primary hip and knee arthroplasty were identified. Univariate and multivariate regressions, as well as propensity matching, were used to determine the independent risk of preoperative and postoperative UTI on SSI, reported as odds ratios (ORs) with 95% confidence intervals (CIs).ResultsPostoperative UTI significantly increased the risk for superficial wound infection (OR 2.147, 95% CI 1.622-2.842), deep periprosthetic joint infection (PJI) (OR 2.288, 95% CI 1.579-3.316), and all SSIs (superficial and deep) (OR 2.193, 95% CI 1.741-2.763) (all P < .001). Preoperative UTI was not associated with a significantly increased risk of superficial infection (P = .636), PJI (P = .330), or all SSIs (P = .284). Further analysis of UTI present at the time of surgery using propensity matching showed no increased risk of superficial infection (P = 1.000), PJI (P = .624), or SSI (P = .546).ConclusionPostoperative UTI was associated with SSI, reinforcing the need to minimize factors which predispose patients to the risk of UTI after surgery. The lack of association between preoperative UTI and SSI suggests that hip and knee arthroplasty can proceed without delay, although initiating antibiotic treatment is prudent and future prospective investigations are warranted.     

Comparing the Analgesia Effects of Single-injection and Continuous Femoral Nerve Blocks with Patient Controlled Analgesia after Total Knee Arthroplasty

We compared the analgesic effects of single-injection or continuous femoral nerve block (FNB) with intravenous patient controlled analgesia (PCA) opioids. Two hundred patients undergoing knee arthroplasty were randomized to one of the three regimens. Significant knee pain on movement at postoperative 24 h was reduced with single-injection (OR 0.30; 95% CI 0.12 to 0.74; P = 0.009) or continuous (OR 0.21; 95% CI 0.08 to 0.51; P = 0.001) FNB, compared with PCA. Allocation to FNBs also resulted in significantly less opioid consumption, fewer episodes of nausea and vomiting, and achieved knee flexion 90° earlier than allocation to PCA. Compared to single-injection FNB, patients with continuous FNB had lower pain scores on movement at 24 h (mean difference − 0.57; 95% CI − 1.14 to − 0.01; P = 0.045), consumed less opioid, and had fewer incidences of nausea and vomiting. The analgesic efficacy of single-injection and continuous FNBs was superior to PCA in the immediate postoperative period; with continuous FNB providing better analgesia than single-injection FNB.     

Steroids in cardiac surgery: a systematic review and meta-analysis

Background

Cardiopulmonary bypass (CPB) induces a systemic inflammatory reaction that may contribute to postoperative complications. Preventing this reaction with steroids may improve outcomes. We performed a systematic review to evaluate the impact of prophylactic steroids on clinical outcomes in patients undergoing on-pump cardiac surgery.

Association Between Chronic Kidney Disease and Blood Transfusions for Knee and Hip Arthroplasty Surgery

The study aim is to assess associations between chronic kidney disease (CKD) and blood transfusions during hospitalization for joint arthroplasty. Patients with Stage IV–V CKD who underwent elective total knee or hip arthroplasty from 2007 to 2010 were matched 2:1 with age, gender, and surgery type controls without kidney disease. Multivariable analyses for transfusion risk with preoperative hemoglobin, body mass index, cardiovascular disease, and surgical complexity as explanatory variables were performed. Ninety CKD patients were identified and had lower preoperative hemoglobin, higher incidence of cardiovascular disease and blood transfusions. CKD was independently associated with increased odds of transfusions (2.88, 95% confidence interval 1.33–6.23, P = 0.007). Preoperative optimization of CKD patients should be considered to reduce transfusion rates.     

Mail Versus Telephone Administration of the Oxford Knee and Hip Scores

Telephone and postal methods of administration of the Oxford Knee Score (OKS) and the Oxford Hip Score (OHS) were compared on 85 and 61 patients undergoing total knee arthroplasty (TKA) and total hip arthroplasty (THA), respectively. The test for equivalence was significant for both the knee (P < 0.001) and hip participants (P < 0.001) indicating that the modes of administration yielded similar results. The ICCs of the OKS and OHS were 0.79 (95% Confidence Interval (CI) 0.70, 0.86) and 0.87 (0.79, 0.92) respectively. The 95% limits of agreement were wide for both scores (OKS LOA, − 8.6, 8.2; OHS LOA, − 7.7, 5.3). The two modes of administration of the OKS and OHS produce equivalent survey responses at a group level but the same method of administration should be constant for individual monitoring in a clinical setting.     

The Effect of Payer Type on Clinical Outcomes in Total Knee Arthroplasty

This was a retrospective cohort analysis of 112 patients undergoing primary total knee arthroplasty, wherein baseline demographics, resource utilization, and outcomes were compared by insurance type: Medicaid, Medicare, or private. At the time of surgery, Medicaid patients were younger (P < .0001) and had lower preoperative Knee Society Scores than Medicare and private patients (P = .0125). Medicaid postoperative scores were lower than those of private patients (P = .0223). The magnitude of benefit received by Medicaid patients was similar to Medicare and private patients. Medicaid patients had a higher number of cancelled (P = .01) and missed (P = .0022) appointments relative to Medicare and private patients. Medicaid patients also had shorter average follow-up periods compared to private patients (P = .0003). Access to care and socioeconomic factors may be responsible for these findings.     

Predictors of preoperative deep vein thrombosis in hip fractures: A systematic review and meta-analysis

BackgroundThe predictors of preoperative deep vein thrombosis (DVT) in patients with hip fractures remain unclear. Therefore, this study describes the results of a systematic review and meta-analysis of relevant peer-reviewed literature on this topic.MethodsWe searched PubMed, Google Scholar, Cochrane Library, Web of Science, and MEDLINE for articles published in English on the predictors of preoperative DVT in hip fractures. We calculated pooled odds ratios (OR) or mean differences (MD) for the DVT groups as compared with the non-DVT groups for each variable, including gender, age, body mass index, injury side, current smoking status, time from injury to admission, time from injury to surgery, fracture type, hypertension, arrhythmia, coronary artery disease, diabetes, stroke, kidney disease, liver disease, lung disease, malignancy, rheumatoid arthritis, D-dimer, fibrinogen, activated partial thromboplastin time, prothrombin time, thrombin time, hemoglobin, albumin, total cholesterol, and triglycerides.ResultsWe included 9 studies involving 3,123 Asian patients with hip fractures (DVT, n = 570; non-DVT, n = 2,553). Being female (OR = 1.27; 95% confidence interval [CI] 1.04–1.56; p = 0.02), being of advanced age (MD = 1.63; 95% CI 0.80–2.47; p = 0.0001), having a longer time from injury to admission (MD = 0.80; 95% CI 0.48–1.12; p < 0.00001), having a longer time from injury to surgery (MD = 2.20; 95% CI 1.53–2.88; p < 0.00001), and the presence of kidney disease (OR = 1.76; 95% CI 1.04–2.96; p = 0.03) were correlated with a high risk of DVT. However, we found no significant differences between the two groups in the other predictors.ConclusionsEvidence indicates that being female, being of advanced age, having a longer time from injury to admission, having a longer time from injury to surgery, and having kidney disease are significantly correlated with a high risk of preoperative DVT in Asian patients with hip fracture. Further investigations with patients of other ethnicities are required.     

Is it Safe to Continue Clopidogrel in Elective Hip and Knee Arthroplasty?

BackgroundNo evidence-based guidelines exist for the perioperative use of clopidogrel in elective hip and knee arthroplasty patients. This study compares the preoperative, intraoperative, and postoperative outcomes of total hip and knee arthroplasty in patients maintained on clopidogrel and with patients whose clopidogrel was held before surgery.MethodsWe retrospectively identified 158 patients taking clopidogrel before undergoing elective total hip or knee arthroplasty. Patients were stratified for having clopidogrel held or continued, based on the interval between latest dose and date of surgery. The primary end points were receipt of transfusion and readmission within 90 days of surgery. Secondary end points were the incidence of complications such as bleeding, infection, re-operation, and major cardiac or neurologic events such as myocardial infarction or stroke during the 90-day postoperative period.ResultsThe two cohorts had similar demographics. Patients who continued clopidogrel were more likely to receive a blood transfusion postoperatively (9.1% vs 0%, P = .005), but there was no difference in wound drainage (P = .65), wound infection (P = .24), readmission (P = .74), major complications (P = .64), length of stay (P = .70), or mortality (P = .42). Patients who continued clopidogrel before surgery were more likely to have received general anesthesia (P < .001) per anesthesia protocol, however, three such patients did receive spinal anesthesia without any complications. With cementless implants, blood loss was not different between clopidogrel groups.ConclusionPatients undergoing elective total hip and knee arthroplasty may be safely maintained on clopidogrel without an increased risk of wound complications, infections, length of stay, readmission, reoperation, major medical complications, or mortality. Further prospective research is warranted to confirm the effects of continuing clopidogrel in patients undergoing elective hip and knee arthroplasty.     

Romosozumab versus Teriparatide for the Treatment of Postmenopausal Osteoporosis: A Systematic Review and Meta‐analysis through a Grade Analysis of Evidence

ObjectiveTo provide a systematic review about the efficacy and safety of romosozumab and teriparatide for the treatment of postmenopausal osteoporosis.MethodRandomized controlled trials (RCTs) were searched from electronic databases, including PubMed (1996 to June 2019), Embase (1980 to June 2019), Cochrane Library (CENTRAL, June 2019), Web of Science (1998 to June 2019), and others. The primary outcomes included the following: the percentage change in bone mineral density of lumbar spine and total hip from baseline at month 6 and month 12 in each group. The secondary outcomes included the following: the percentage change in bone mineral density of femoral neck from baseline at month 6 and month 12 in each group and the incidence of adverse events at month 12 in each group.ResultsFour studies containing 1304 patients met our selection criteria. The result of our analysis indicated that romosozumab showed better effects in improving BMD of lumbar spine (month 6: MD = 3.54, 95% CI [3.13, 3.94], P<0.001; month 12: MD = 4.93, 95% CI [4.21, 5.64], P<0.001), total hip (month 6: MD = 2.27, 95% CI [0.62, 3.91], P = 0.007; month 12: MD = 3.17, 95% CI [2.68, 3.65], P<0.001), and femoral neck (month 6: MD = 2.30, 95% CI [0.51, 4.08], P = 0.01; month 12: MD = 3.04, 95% CI [2.29, 3.78], P<0.001). Also, the injection‐site reaction was less (month 12: RR = 2.84, 95% CI [1.22, 6.59], P = 0.02), but there were no significant difference in the incidence of serious adverse events (month 12: RR = 0.78, 95% CI [0.46, 1.33], P = 0.37) and death (month 12: RR = 0.61, 95% CI [0.08, 4.62], P = 0.63).ConclusionBased on the available studies, our current results demonstrate that romosozumab was better than teriparatide both in terms of efficacy and side effects.     

Risk factors for persistent pain after urological surgery

Objective

Ten to 50% of patients with post-surgical pain develop chronic pain depending on the type of surgery. The objective of this study was to assess the incidence of persistent post-surgical pain (PPSP) and to identify risk factors following urology surgery.

Design

Retrospective observational study.

Patients

Two hundred and twenty-eight patients scheduled for urology surgery. Reasons for non-inclusions: patients who underwent a procedure not defined as being associated with PPSP.

Methods

Surgical urologic procedures potentially associated with PPSP were defined. All patients who had one of these procedures during the study period received a questionnaire by mail at least 3 months after the surgery. The files of these patients were retrospectively studied.

Results

Eight percent of the patients had preoperative pain. PPSP, assessed approximately 6 months after the surgery, was reported by 24% of the patients. Twenty-five (36%) of them reported neuropathic pain. Patients with PPSP had significantly more preoperative pain and an increased postoperative morphine consumption. Postoperative NSAID administration led to less persistent pain. Multivariate logistic regression analysis identified two independent risk factors of developing persistent pain: preoperative pain (OR = 21.6, 95% CI 6.7–69.5, P < 0.0001), morphine consumption 48 hours after surgery higher than 6 mg (OR = 2.3, 95% CI 1.2–4.3, P = 0.0118).

Conclusion

These findings confirm the role of preoperative pain and morphine consumption in the genesis of PPSP and call for establishing clinical perioperative pathways tailored to the patient.     

Infection Rate Following Total Joint Arthroplasty in the HIV Population

The purpose of this study is to review a large series of HIV-infected patients who underwent total joint arthroplasty and identify potential risk-factors for infection. Sixty-nine HIV-infected arthroplasty cases were analyzed with 138 matched controls. Deep infection rate following total hip or knee arthroplasty was 4.4% (3 of 69) among HIV cases compared to 0.72% (1 of 138) among controls, yielding a non-significant 6.22 times increased odds of infection (95% CI 0.64–61.0, P = 0.11). Kaplan–Meier survival curves for infection free survival and revision free survival revealed non-significantly decreased survival in HIV cases compared to controls (P = 0.06 and P = 0.09). Our results suggest that the rate of early joint infection following primary total joint arthroplasty in the HIV-infected population is lower than reported in a number of previously published studies.     

Rheumatoid Arthritis vs Osteoarthritis in Patients Receiving Total Knee Arthroplasty: Perioperative Outcomes

There is a paucity of data available on perioperative outcomes of patients undergoing total knee arthroplasty (TKA) for rheumatoid arthritis (RA). We determined differences in demographics and risk for perioperative adverse events between patients suffering from osteoarthritis (OA) versus RA using a population-based approach. Of 351,103 entries for patients who underwent TKA, 3.4% had a diagnosis of RA. RA patients were on average younger [RA: 64.3 years vs OA: 66.6 years; P < 0.001] and more likely female [RA: 79.2% vs OA: 63.2%; P < 0. 001]. The unadjusted rates of mortality and most major perioperative adverse events were similar in both groups, with the exception of infection [RA: 4.5% vs. OA: 3.8%; P < 0.001]. RA was not associated with increased adjusted odds for combined adverse events.     

Preoperative Patient Factors and Postoperative Complications as Risk Factors for New-Onset Depression Following Total Hip Arthroplasty

BackgroundDepression is known to be a risk factor for complication following primary total hip arthroplasty (THA), but little is known about new-onset depression (NOD) following THA. The purpose of this study is to determine the incidence of NOD and identify risk factors for its occurrence after THA.MethodsThis is a retrospective cohort study of the Truven MarketScan database. Patients undergoing primary THA were identified and separated into cohorts based on the presence or not of NOD. Patients with preoperative depression or a diagnosis of fracture were excluded. Patient demographic and comorbid data were queried, and postoperative complications were collected. Univariate and multivariate regression analysis was then performed to assess the association of NOD with patient-specific factors and postoperative complications.ResultsIn total, 111,838 patients undergoing THA were identified and 2517 (2.25%) patients had NOD in the first postoperative year. Multivariate analysis demonstrated that preoperative opioid use, female gender, higher Elixhauser comorbidity index, preoperative anxiety disorder, drug or alcohol use disorder, and preoperative smoking were associated with the occurrence of NOD (P ≤ .001). The following postoperative complications were associated with increased odds of NOD: prosthetic joint infection (odds ratio [OR] 1.82, 95% confidence interval [CI] 1.42-2.34, P < .001), aseptic revision surgery (OR 1.47, 95% CI 1.06-2.04, P = .019), periprosthetic fracture (OR 1.72, 95% CI 1.13-2.61, P = .01), and non-home discharge (OR 1.59, 95% CI 1.42-1.77, P < .001).ConclusionsNOD is common following THA and there are multiple patient-specific factors and postoperative complications which increase the odds of its occurrence. Providers should use this information to identify at-risk patients so that pre-emptive prevention strategies may be employed.     

The effectiveness of positive airway pressure therapy in reducing postoperative adverse outcomes in surgical patients with obstructive sleep apnea: A systematic review and meta-analysis

ImportanceObstructive sleep apnea (OSA) is prevalent in surgical patients and is associated with an increased risk of adverse perioperative events.Study objectiveTo determine the effectiveness of positive airway pressure (PAP) therapy in reducing the risk of postoperative complications in patients with OSA undergoing surgery.DesignSystematic review and meta-analysis searching Medline and other databases from inception to October 17, 2021. The search terms included: “positive airway pressure,” “surgery,” “post-operative,” and “obstructive sleep apnea.” The inclusion criteria were: 1) adult patients with OSA undergoing surgery; (2) patients using preoperative and/or postoperative PAP; (3) at least one postoperative outcome reported; (4) control group (patients with OSA undergoing surgery without preoperative and/or postoperative PAP therapy); and (5) English language articles.PatientsTwenty-seven studies included 30,514 OSA patients undergoing non-cardiac surgery and 837 OSA patients undergoing cardiac surgery.InterventionPAP therapyMain resultsIn patients with OSA undergoing non-cardiac surgery, PAP therapy was associated with a decreased risk of postoperative respiratory complications (2.3% vs 3.6%; RR: 0.72, 95% CI: 0.51–1.00, asymptotic P = 0.05) and unplanned ICU admission (0.12% vs 4.1%; RR: 0.44, 95% CI: 0.19–0.99, asymptotic P = 0.05). No significant differences were found for all-cause complications (11.6% vs 14.4%; RR: 0.89, 95% CI: 0.74–1.06, P = 0.18), postoperative cardiac and neurological complications, in-hospital length of stay, and in-hospital mortality between the two groups. In patients with OSA undergoing cardiac surgery, PAP therapy was associated with decreased postoperative cardiac complications (33.7% vs 50%; RR: 0.63, 95% CI: 0.51–0.77, P < 0.0001), and postoperative atrial fibrillation (40.1% vs 66.7%; RR: 0.59, 95% CI 0.45–0.77, P < 0.0001).ConclusionIn patients with OSA undergoing non-cardiac surgery, PAP therapy was associated with a 28% reduction in the risk of postoperative respiratory complications and 56% reduction in unplanned ICU admission. In patients with OSA undergoing cardiac surgery, PAP therapy decreased the risk of postoperative cardiac complications and atrial fibrillation by 37% and 41%, respectively.     

Continuing Clopidogrel During Elective Total Hip and Knee Arthroplasty: Assessment of Bleeding Risk and Adverse Outcomes

Limited research assessing risks of continued clopidogrel perioperatively in patients undergoing elective orthopedic procedures exists. Patients that underwent elective primary or revision total knee arthroplasty (TKA) or total hip arthroplasty (THA) from 2007 to 2012 while taking clopidogrel at the time of surgical evaluation were retrospectively identified. Patient demographics, last dose of clopidogrel, intraoperative blood loss, blood transfusion, and presence of 30-day adverse cardiac events (ACE) were collected. Of 142 patients meeting criteria, 24 (16.9%) patients remained on clopidogrel perioperatively. Patients that continued clopidogrel were more likely to receive a blood transfusion within 24 hours of surgery (31.8% vs. 7.7%; P = 0.004) and during hospitalization (37.5% vs. 15.3%; P = 0.02), but the incidence of 30-day ACE was not significantly different. Continuation of clopidogrel perioperatively for elective THA or TKA should be carefully considered.     

Return to Work Following Total Knee and Hip Arthroplasty: The Effect of Patient Intent and Preoperative Work Status

BackgroundThe ability of total knee and hip arthroplasty (TKA/THA) to facilitate return to work (RTW) when it is the patient’s preoperative intent to do so remains unclear. We aimed at determining whether TKA/THA facilitated RTW in patients of working age who intended to return.MethodsThis is a prospective cohort study of 173 consecutive patients <65 years of age, undergoing unilateral TKA (n = 82: median age 58; range, 39-65; 36 [43.9%] male) or THA (n = 91: median age 59; range, 34-65; 42 [46.2%] male) during 2018. Oxford knee/hip scores, Oxford-Activity and Participation Questionnaire, and EuroQol-5 dimension (EQ-5D) scores were measured preoperatively and at 1 year when an employment questionnaire was also completed.ResultsOf patients who intended to RTW, 44 of 52 (84.6%) RTW by 1 year following TKA (at mean 14.8 ± 8.4 weeks) and 53 of 60 (88.3%) following THA (at mean 13.6 ± 7.5 weeks). Failure to RTW despite intent was associated with job physicality for TKA (P = .004) and negative preoperative EQ-5D for THA (P = .01). In patients unable to work before surgery due to joint disease, fewer RTW: 4 of 21 (19.0%) after TKA; and 6 of 17 (35.3%) after THA. Preoperative Oxford knee score >18.5 predicted RTW with 74% sensitivity (P < .001); preoperative Oxford hip score >19.5 predicted RTW with 75% sensitivity (P < .001). Preoperative EQ-5D indices were similarly predictive (P < .001).ConclusionIn this United Kingdom study, preoperative intent to RTW was the most powerful predictor of actual RTW following TKA/THA. Where patients intend to RTW following TKA/THA, 85% RTW following TKA and 88% following THA.     

Short-term outcomes of robotic-assisted right colectomy compared with laparoscopic surgery: A systematic review and meta-analysis

To assess the clinical efficacy and safety of robotic-assisted right colectomy (RRC) with conventional laparoscopic right colectomy (LRC) by performing a systematic review and meta-analysis of the published studies. All published literature for comparative studies reporting preoperative outcomes of RRC and LRC were searched. We searched the databases included Cochrane Library of Clinical Comparative Trials, MEDLINE, Embase, Web of Science and Chinese Biomedical Database (CBM) from 1973 to 2018. The censor date was up to January 2018. Operative time, estimated blood loss, length of hospital stay, conversion rates to open surgery, postoperative complications, and related outcomes were evaluated. All calculations and statistical tests were performed using Stata 12.0 software. A total of 7769 patients with colon cancer enrolled in 13 trials were divided into a study group (n = 674) and a control group (n = 7095). Meta-analysis suggested significantly greater length of hospital stay in the LRC group [MD = ?0.85; 95% CI: ?1.07 to ?0.63; P < 0.00001]. Robotic surgery was also associated with a significantly lower complication rate [OR = 0.73; 95% CI: 0.52 to 1.01; P = 0.05]. There were statistically significant differences between the groups in estimated blood loss [MD = ?16.89; 95% CI: ?24.80 to ?8.98; P < 0.00001] and the rate of intraoperative conversion to open surgery [OR = 0.34, 95% CI: 0.15 to 0.75; P = 0.008)], but these differences were not clinically relevant. The recovery of bowel function in two groups is no significant differences [MD = ?0.58, 95% CI: ?0.96 to ?0.20, P = 0.0008]. However, operation times [MD = 43.61, 95% CI: 39.11 to 48.10, P < 0.00001] were longer for RRC than for LRC. Compared to LRC, RRC was associated with reduced estimated blood loss, reduced postoperative complications, longer operation times. Recovery of bowel function and other perioperative outcomes were equivalent between the two surgeries.     

Antibioprophylaxie pour césarienne avant incision ou après clampage du cordon ? Méta-analyse

Objective

The objective of this systematic review was to assess the effect of preoperative rather than after umbilical cord clamping antimicrobial prophylaxis for caesarean delivery on maternal and neonatal infectious postoperative morbidity.

Study design

Meta-analysis.

Methods

Three electronic databases (Pubmed, Cochrane Central Register of Randomized Controlled Trials and Embase) were searched without language restriction and retrieved 201 potentially relevant trials. Five randomized controlled trials (n = 1108) studying the timing of antimicrobial prophylaxis for caesarean section were included. The quality of included trials was assessed on the modified Oxford validity scale.

Results

Preoperative administration of antibiotics (n = 456) rather than after cord clamping (n = 563) provides a significant reduction in the incidence of endometritis (Odds Ratio (OR) 0.59 [95% Confidence Interval (CI) 0.35–0.98]) and of total maternal infectious morbidity (OR 0.51 [95% CI 0.32–0.82]). This benefit was not observed regarding the incidence of wound infection (Peto OR 0.58 [95% CI 0.29–1.16]), neonatal infection (Peto OR 1.06 [95% CI 0.57–1.96]), neonatal sepsis workup (OR 1.02 [95% CI 0.67–1.54]), neonatal documented sepsis (Peto OR 0.93 [95% CI 0.43–2.02]) or neonatal intensive care unit admission (OR 0.97 [95% CI 0.61–1.56]). No significant heterogeneity was observed between the included studies.

Conclusion

This meta-analysis provides strong evidence that the preoperative rather than after cord clamping administration of antimicrobial prophylaxis for caesarean delivery provides a reduction in the incidence of endometritis and maternal total infectious morbidity without affecting the incidence of wound infection and neonatal infectious morbidity.