OBJECTIVE: 

To compare patient satisfaction with anesthesia after first-trimester surgical abortion among patients receiving intravenous (IV) ketamine compared with IV fentanyl for procedural sedation.

METHODS: 

This was a randomized noninferiority trial comparing IV ketamine to IV fentanyl for first-trimester surgical abortion up to 13 6/7 weeks of gestation. Patients were randomized to receive either ketamine 200–500 micrograms/kg IV over 2 minutes, repeated every 5 minutes until appropriate analgesia was achieved, or fentanyl 0.5–1 micrograms/kg IV over 2 minutes, repeated every 5 minutes until appropriate analgesia was achieved. All patients received midazolam 2 mg IV. The primary outcome, patient satisfaction, was measured using the Iowa Satisfaction with Anesthesia Scale immediately postprocedure. Secondary outcomes included postoperative pain, additional pain medication necessary during the procedure and on discharge, physician satisfaction, and time to discharge. We calculated a sample size of 84 with a noninferiority margin of 0.6 on the Iowa Satisfaction with Anesthesia Scale with 80% power, one-sided type 1 error of 0.025, and further increased this number to 110 to account for potential dropout.

RESULTS: 

From April to October 2021, 184 patients were screened and 110 were randomized (57 to ketamine and 53 to fentanyl). Demographics were similar between groups. The primary outcome, patient satisfaction with anesthesia, was noninferior in the ketamine group (mean score 2.4, SD 0.8) as compared with the fentanyl group (mean score 2.2, SD 0.9) with a risk difference of 0.20 (95% CI 0.11–0.52). More hallucinations were reported in the ketamine group. Otherwise, secondary outcomes were similar between the groups.

CONCLUSION: 

Compared with IV fentanyl, IV ketamine is noninferior for patient satisfaction with anesthesia when used for procedural sedation for first-trimester outpatient surgical abortion.

CLINICAL TRIAL REGISTRATION: 

ClinicalTrials.gov, NCT04871425.

中文翻译：

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氯胺酮与芬太尼用于手术流产的比较：一项随机对照试验

客观的： 

比较接受静脉注射 (IV) 氯胺酮和静脉注射芬太尼进行程序镇静的患者在妊娠早期手术流产后对麻醉的满意度。

方法： 

这是一项随机非劣效性试验，比较了静脉注射氯胺酮和静脉注射芬太尼对妊娠 13 6/7 周前妊娠手术流产的影响。患者被随机分配接受氯胺酮 200-500 微克/千克静脉注射超过 2 分钟，每 5 分钟重复一次直至达到适当的镇痛效果，或芬太尼 0.5-1 微克/公斤静脉注射超过 2 分钟，每 5 分钟重复一次直至达到适当的镇痛效果. 所有患者均接受咪达唑仑 2 mg 静脉注射。主要结果是患者满意度，在手术后立即使用爱荷华州麻醉满意度量表进行测量。次要结果包括术后疼痛、手术期间和出院时所需的额外止痛药、医生满意度和出院时间。我们计算出样本量为 84，非劣效性边际为 0。

结果： 

从 2021 年 4 月到 2021 年 10 月，对 184 名患者进行了筛查，并随机分配了 110 名患者（57 名接受氯胺酮，53 名接受芬太尼）。组间人口统计学相似。与芬太尼组（平均得分 2.2，标准差 0.9）相比，氯胺酮组（平均得分 2.4，标准差 0.8）的主要结果（患者对麻醉的满意度）非劣效性，风险差异为 0.20（95% CI 0.11–0.52） ). 氯胺酮组报告了更多的幻觉。否则，各组之间的次要结果相似。

结论： 

与静脉注射芬太尼相比，静脉注射氯胺酮用于妊娠早期门诊手术流产的程序镇静时，患者对麻醉的满意度并不差。

临床试验注册： 

临床试验.gov，NCT04871425。