Effect of using silver nylon dressings to prevent superficial surgical site infection after cesarean delivery: a randomized clinical trial

Effect of Using Silver Nylon Dressings on Postoperative Pain after Cesarean Delivery

OBJECTIVE

Silver dressings have been associated with a decrease in postoperative pain in selected populations, but it is unknown if the benefit can be observed after cesarean deliveries. We sought to evaluate the impact of silver nylon dressings in reducing postoperative pain after cesarean delivery.

STUDY DESIGN

A secondary analysis of data from a blinded randomized clinical trial of women undergoing cesarean delivery scheduled and unscheduled at a single site was conducted. Women were recruited for participation from a single site and randomized to a silver nylon dressing or an identical-appearing gauze wound dressing. Wounds were evaluated in the outpatient clinic at 1 and 6 weeks after delivery and patient responded to the modified patient scar assessment scale. The primary outcome of this analysis was inpatient opioid and nonopioid analgesic dispensed. The secondary outcome was patient-reported pain at the 1- and 6-week postpartum visits. Data were analyzed using chi-square test, Student's t-test, Fisher's exact test, Wilcoxon-Mann-Whitney's test, and logistic regression where appropriate. A p-value of < 0.05 was considered significant.

RESULTS

Among the 649 participants, women allocated to the silver nylon dressing group, when compared with the gauze group, were similar in the amount of dispensed opioid and nonopioid analgesic medications (morphine equivalent milligrams of opioids dispensed [82.5 vs. 90 mg, p = 0.74], intravenous nonsteroidal anti-inflammatory drugs (NSAIDs) [120 vs. 120 mg, p = 0.55], and oral NSAIDs [4,800 vs. 5,600 mg in the gauze group, p = 0.65]). After adjusting for confounding variables, postoperative wound infection (adjusted odds ratio [aOR]: 11.70; 95% confidence interval [CI]: 4.51-30.31) at 1-week postoperative and again at 6-week postoperative (aOR: 5.59; 95% CI: 1.03-30.31) but not gauze dressing was associated with patient-reported postoperative pain.

CONCLUSION

Among women undergoing cesarean delivery, silver nylon dressing was not associated with a reduction in postoperative pain.

KEY POINTS

· Silver dressings showed no decrease in pain medications.. · Wound infection is associated with pain postoperatively.. · Silver dressings did not reduce postoperative pain..

Prevention of Postoperative Surgical Site Infection Following Cesarean Delivery

Cesarean delivery is the most common major surgical procedure performed among birthing persons in the United States, and surgical-site infection is a significant complication. Several significant advances in preventive measures have been shown to reduce infection risk, while others remain plausible but not yet proven in clinical trials.

Preventing caesarean section wound complications: use of a silver-impregnated antimicrobial occlusive dressing

OBJECTIVE

To investigate the role of an adherent soft silicone antimicrobial occlusive foam silver-impregnated dressing for reduction of surgical site infections (SSI) in primary low-transverse caesarean section (1°LTCS) delivery.

METHOD

Women aged 18-45 years admitted to the labour and delivery or the antepartum unit undergoing a 1°LTCS were recruited. Exclusion criteria included repeat caesarean, vertical skin incision, intrapartum fever and closure with staples. Consented participants delivered by scheduled or unscheduled 1°LTCS received the silver-impregnated dressing. Those who declined to participate and were delivered by scheduled or unscheduled caesarean received a standard gauze with tape dressing (controls). Surgical preparation and preoperative antibiotics were administered as per hospital policy.

RESULTS

A total of 362 participants were consented for use of the silver-impregnated dressing, with 190 participants undergoing 1°LTCS, of whom 185 were included in the final analysis. Of those who declined to participate, 190 ultimately underwent 1°LTCS during the same time period. Cases and controls were similar in demographics, body mass index, diabetes status, labour and procedure length, and tobacco use. The overall incidence of SSI was 3.7%. A 50% reduction in incidence of SSI was observed in the silver-impregnated dressing group compared with control group (2.7% versus 4.7%, respectively), but this was not statistically significant (p=0.08; odds ratio 0.55; 95% confidence interval: 0.18-1.67).

CONCLUSION

Among women undergoing 1°LTCS with subcuticular closure of a transverse incision, use of a silver-impregnated dressing reduced the rate of SSI by >50% but was not statistically significant.

Effectiveness of moist dressings in wound healing after surgical suturing: A Bayesian network meta-analysis of randomised controlled trials

The moist healing theory proves that a moderately moist and airtight environment is conducive to wound healing. However, different moist dressings have different functions. We aim to evaluate the effects of moist dressings on wound healing after surgical suturing and identify superior moist dressings. Randomised controlled trials investigating the application of moist dressings were retrieved from electronic databases, including PubMed, EMBASE, Web of Science, and the Cochrane Library. Wound healing, surgical site infection (SSI), and times of dressing change were assessed. The values of the surface under the cumulative ranking (SUCRA) curve were calculated based on the Bayesian network meta-analysis. Inconsistency tests and funnel plots were applied to analyse the consistency and publication bias. All the analysis complies with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 Checklist and AMSTAR (Assessing the Methodological Quality of Systematic Reviews) Guidelines. Sixteen randomised controlled trials involving 4444 patients were pooled in the network meta-analysis. The ionic silver dressing (SUCRA, 93%) ranked first in wound healing, the metallic silver dressing (SUCRA, 75.9%) ranked first in SSI, and the hydrocolloid dressing (SUCRA, 73.9%) ranked first in times of dressing change. Inconsistency was only observed in wound healing, and no publication bias was observed in this study. The effects of moist dressings are better than gauze dressings in the process of wound healing. The ionic silver dressing is effective in wound healing, whereas the metallic silver dressing is effective in SSI prevention. The hydrocolloid dressing requires the fewest times of dressing change. More high-quality RCTs are required to support the network meta-analysis.

Advanced dressings for the prevention of surgical site infection in women post-caesarean section: A systematic review and meta-analysis

OBJECTIVE(S)

Surgical site infections (SSIs) are a common complication post-caesarean section. Advanced dressings aim to provide an optimal wound environment, primarily by physically or chemically controlling moisture, in order to promote timely healing. A systematic review and meta-analysis was conducted to evaluate the effectiveness of advanced dressings in SSI prevention post-caesarean section. Secondary effectiveness outcomes included superficial SSI, endometritis, wound dehiscence, rehospitalisation and length of rehospitalisation.

STUDY DESIGN

We conducted a systematic review and meta-analysis according to PRISMA guidelines. A protocol was registered a priori. MEDLINE, EMBASE, CENTRAL and CINAHL databases were searched from inception to May 2021, without date or language restrictions. Keywords included: caesarean section; bandages; dressing and surgical wound infection. Randomised controlled trials (RCTs) were included if they investigated any advanced dressing in women post-caesarean section compared to simple dressings and assessed SSI incidence. Relative risks (RR), with 95% confidence intervals (CIs) and p-values, were calculated using Review Manager software (RevMan version 5.0, The Cochrane Collaboration). I² percentages were reported to assess heterogeneity and a funnel plot was produced to assess publication bias. Quality assessment was performed using the Cochrane Risk of Bias Assessment Tool. All data were double-extracted and discrepancies were finalised by a third reviewer.

RESULTS

From 253 citations identified, six RCTs were included in the systematic review and meta-analysis. Two studies investigated dialkylcarbamoyl chloride (DACC)-impregnated dressings; two investigated silver-impregnated dressings; one investigated copper-impregnated dressings and one investigated chlorhexidine gluconate dressings. The overall meta-analysis showed that advanced dressings did not reduce SSI risk (RR 0.81 [95% CI 0.52-1.24; p = 0.32]). However, subgroup analysis revealed that DACC-impregnated dressings reduced SSI risk (RR 0.33 [95% CI 0.14-0.77; p = 0.01]). Silver-impregnated dressings caused a nonsignificant increase in SSI risk (RR 1.20 [95% CI 0.77-1.88; p = 0.41]). All studies showed a high risk of bias.

CONCLUSION

This systematic review and meta-analysis suggests DACC dressings potentially reduce SSI. However we have shown no benefit of silver dressings. Further high-quality RCTs are required to recommend a change in clinical practice.

Number and quality of randomized controlled trials in obstetrics published in the top general medical and obstetrics and gynecology journals

BACKGROUND

There has been an increasing number of randomized controlled trials published in obstetrics and maternal-fetal medicine to reduce biases of treatment effect and to provide insights on the cause-effect of the relationship between treatment and outcomes.

OBJECTIVE

This study aimed to identify obstetrical randomized controlled trials published in top weekly general medical journals and monthly obstetrics and gynecology journals, to assess their quality in reporting and identify factors associated with publication in different journals.

STUDY DESIGN

The 4 weekly medical journals with the highest 2019 impact factor (New England Journal of Medicine, The Lancet, The Journal of the American Medical Association, and British Medical Journal), the top 4 monthly obstetrics and gynecology journals with obstetrics-related research (American Journal of Obstetrics & Gynecology, Ultrasound in Obstetrics & Gynecology, Obstetrics & Gynecology, and the British Journal of Obstetrics and Gynaecology), and the American Journal of Obstetrics & Gynecology Maternal-Fetal Medicine were searched for obstetrical randomized controlled trials in the years 2018 to 2020. The primary outcome was the number of obstetrical randomized controlled trials published in the obstetrics and gynecology journals vs the weekly medical journals and the percentage of trials published, overall and per journal. The secondary outcomes included the proportion of positive vs negative trials overall and per journal and the assessment of the study characteristics of published trials, including quality assessment criteria.

RESULTS

Of the 4024 original research articles published in the 9 journals during the 3-year study period, 1221 (30.3%) were randomized controlled trials, with 137 (11.2%) randomized controlled trials being in obstetrics (46 in 2018, 47 in 2019, and 44 studies in 2020). Furthermore, 33 (24.1%) were published in weekly medical journals, and 104 (75.9%) were published in obstetrics and gynecology journals. The percentage of obstetrical randomized controlled trials published ranged from 1.5% to 9.6% per journal. Overall, 34.3% of obstetrical trials were statistically significant or "positive" for the primary outcome. Notably, 24.8% of the trials were retrospectively registered after the enrollment of the first study patient. Trials published in the 4 weekly medical journals enrolled significantly more patients (1801 vs 180; P<.001), received more often funding from the federal government (78.8% vs 35.6%; P<.001), and were more likely to be multicenter (90.9% vs 42.3%; P<.001), non-United States based (69.7% vs 49.0%; P=.03), and double blinded (45.5% vs 18.3%; P=.003) than trials published in the obstetrics and gynecology journals. There was no difference in study type (noninferiority vs superiority) and trial quality characteristics, including pretrial registration, ethics approval statement, informed consent statement, and adherence to the Consolidated Standards of Reporting Trials guidelines statement between studies published in weekly medical journals and studies published in obstetrics and gynecology journals.

CONCLUSION

Approximately 45 trials in obstetrics are being published every year in the highest impact journals, with one-fourth being in the weekly medical journals and the remainder in the obstetrics and gynecology journals. Only about a third of published obstetrical trials are positive. Trials published in weekly medical journals are larger, more likely to be funded by the government, multicenter, international, and double blinded. Quality metrics are similar between weekly medical journals and obstetrics and gynecology journals.

A Systematic Review and Meta-Analysis of Wound Complications after a Caesarean Section in Obese Women

(1) Background: Caesarean sections in obese patients are associated with an increased risk of surgical wound complications, including hematomas, seromas, abscesses, dehiscence, and surgical site infections. The aim of the present study is to perform a meta-analysis and systematic review of the current literature focusing on the strategies available to decrease wound complications in this population. (2) Methods: We reviewed the data available from the PubMed and the Science Direct databases concerning wound complications after caesarean sections in obese women. The following key words were used: “caesarean section”, “cesarean section”, “wound complication”, “wound morbidity”, and “wound infection”. A total of 540 papers were retrieved, 40 of which were selected for the final systematic review and whereas 21 articles provided data for meta-analysis. (3) Results: The conducted meta-analyses revealed that the use of prophylactic drainage does not increase the risk of wound complications in obese women after a caesarean sections (pooled OR = 1.32; 95% CI 0.64–2.70, p = 0.45) and that vertical skin incisions increase wound complications (pooled OR = 2.48; 95% CI 1.85–3.32, p < 0.01) in obese women, including extremely obese women. (4) Conclusions: Subcutaneous drainage does not reduce the risk of a wound complications, wound infections, and fever in obese women after caesarean sections. Negative prophylactic pressure wound therapy (NPWT) may reduce the risk of surgical site infections. The evidence of using a prophylactic dose of an antibiotic before the caesarean section is still lacking.

Study To Reduce Infection Prior to Elective Cesarean Deliveries (STRIPES): a randomized clinical trial of chlorhexidine

BACKGROUND

Surgical site infections after cesarean delivery are a cause of maternal morbidity and are typically caused by skin microbial flora. Preadmission application of chlorhexidine gluconate using impregnated cloths may decrease surgical site infections by decreasing the abundance of microbial flora.

OBJECTIVE

To determine whether the application of chlorhexidine gluconate cloths the night before and the morning of scheduled cesarean delivery decreases the risk of surgical site infections by 6 weeks postoperatively compared with placebo.

STUDY DESIGN

In this single-center, double-blind, placebo-controlled trial, patients were randomized (1:1) to receive either Sage 2% chlorhexidine cloths or Sage Comfort Bath fragrance-free cloths (placebo) to apply to 6 skin sites on the body (neck, shoulders and chest, armpits, arm and hands, abdomen and groin, left leg and foot, right leg and foot, back and buttocks) the night before and after a shower the morning of scheduled cesarean delivery. Routine clinical and operative procedures were followed. The primary outcome was surgical site infections (superficial or deep incisional with or without organ space endometritis) by 6 weeks after cesarean delivery. The secondary outcomes were surgical site infections by 2 weeks and other wound-related complications by 2 and 6 weeks after cesarean delivery.

RESULTS

From April 2015 to August 2019, 1356 patients were enrolled: 682 were assigned to the chlorhexidine group and 674 to the placebo group. The groups were similar in demographic and medical characteristics. A total of 14 patients were lost to follow-up before cesarean delivery (10 in chlorhexidine and 4 in placebo) and 33 were lost to follow-up after cesarean delivery (10 in chlorhexidine and 23 in placebo). Among the remaining 1309 (97%), no difference was found in surgical site infections by 6 weeks between the 2 groups (2.6% in chlorhexidine vs 3.7% in placebo; P=.24). There were no differences in secondary outcomes at 2 or 6 weeks and no differences in primary outcome in a per-protocol analysis.

CONCLUSION

Preadmission use of chlorhexidine gluconate cloths compared with placebo does not reduce the risk of surgical site infection after scheduled cesarean deliveries. Following the standard of care guidelines results in a low risk of surgical site infections in this group of patients.