Department of Obstetrics and Gynecology, University of Oklahoma College of Medicine, Oklahoma City, OK.
Department of Obstetrics and Gynecology, University of Oklahoma College of Medicine, Oklahoma City, OK.
Am J Obstet Gynecol. 2021 Sep;225(3):335.e1-335.e7. doi: 10.1016/j.ajog.2021.05.023. Epub 2021 May 27.
A recent large clinical trial demonstrated an approximately 50% decrease in the rate of postoperative infection in women who were laboring and/or had rupture of membranes for >4 hours and who received azithromycin in addition to standard preoperative antibiotic prophylaxis at the time of cesarean delivery. Given these results, our institution made a policy change in May 2017 to add azithromycin to standard preoperative prophylaxis for all cesarean deliveries.
This study aimed to evaluate the clinical effectiveness of adding azithromycin to preoperative antibiotic prophylaxis for cesarean delivery.
We conducted a before-and-after cohort study of women delivered via cesarean delivery at our institution. The preimplementation group included women who delivered from March 1, 2016, to February 28, 2017, (before an institutional practice change of adding azithromycin to standard preoperative prophylaxis), and the postimplementation group included women who delivered from September 1, 2017, to August 31, 2018 (allowing a 6-month period for uptake of the practice change). The primary outcome was a composite of postoperative infections (endometritis, wound infection, other maternal infections). Unadjusted and adjusted risk ratios and 95% confidence intervals were estimated using a modified Poisson regression model.
In the preimplementation (n=1171) and postimplementation (n=1168) groups, the incidence rates of the composite outcomes were 4.7% and 5.3%, respectively (P=.49). Both unadjusted (relative risk, 1.13; 95% confidence interval, 0.78-1.62) and adjusted (adjusted relative risk, 1.06; 95% confidence interval, 0.74-1.52) comparisons were not significantly different. In addition, results were statistically nonsignificant, but in the direction of lower rates of infection, in the after cohort for women in labor and/or with rupture of membranes for ≥4 hours (relative risk, 0.88 [95% confidence interval, 0.56-1.39]; adjusted relative risk, 0.82 [95% confidence interval, 0.52-1.30]) and for women with clinical chorioamnionitis (relative risk, 0.37 [95% confidence interval, 0.08-1.67]; data too sparse for adjusted analysis). In the subgroup of women who were not in labor, the after cohort had a statistically nonsignificant increased risk of the composite outcome in both unadjusted (relative risk, 1.53; 95% confidence interval, 0.86-2.72) and adjusted (adjusted relative risk, 1.48; 95% confidence interval, 0.83-2.65]) comparisons.
In clinical practice, the addition of azithromycin to standard preoperative antibiotic prophylaxis for cesarean delivery may have an effect size smaller than seen in the large clinical trial prompting this practice change. Extrapolation of this regimen to women not in labor may be ineffective.
最近的一项大型临床试验表明，对于在分娩或破膜超过 4 小时后接受剖宫产的女性，在接受标准术前抗生素预防的基础上额外给予阿奇霉素，可以将术后感染率降低约 50%。鉴于这些结果，我院于 2017 年 5 月改变了政策，为所有剖宫产术增加了阿奇霉素作为标准术前预防用药。
本研究旨在评估在剖宫产术前抗生素预防中添加阿奇霉素的临床效果。
我们对我院行剖宫产分娩的女性进行了一项前后队列研究。实施前组包括 2016 年 3 月 1 日至 2017 年 2 月 28 日（在我院将阿奇霉素添加到标准术前预防用药之前）分娩的女性，实施后组包括 2017 年 9 月 1 日至 2018 年 8 月 31 日（允许 6 个月的时间来适应这种做法的改变）分娩的女性。主要结局是术后感染（子宫内膜炎、伤口感染、其他产妇感染）的复合结局。采用校正泊松回归模型估计未校正和校正风险比及其 95%置信区间。
在实施前（n=1171）和实施后（n=1168）组中，复合结局的发生率分别为 4.7%和 5.3%（P=0.49）。未校正（相对风险，1.13；95%置信区间，0.78-1.62）和校正（校正相对风险，1.06；95%置信区间，0.74-1.52）比较均无显著差异。此外，虽然结果统计学上无显著性，但感染率较低的方向在产时或破膜≥4 小时的后组（相对风险，0.88[95%置信区间，0.56-1.39]；校正相对风险，0.82[95%置信区间，0.52-1.30]）和有临床绒毛膜羊膜炎的女性中（相对风险，0.37[95%置信区间，0.08-1.67]；数据太少，无法进行校正分析）有统计学意义。在后组中，未产时的女性在未校正（相对风险，1.53；95%置信区间，0.86-2.72）和校正（校正相对风险，1.48；95%置信区间，0.83-2.65）比较中，复合结局的风险均有统计学意义的增加。
在临床实践中，与大型临床试验中提示的这一实践改变相比，在剖宫产术前抗生素预防中添加阿奇霉素的效果可能较小。将该方案推广到未产时的女性可能无效。
