Intranasal fentanyl for first-trimester uterine aspiration pain: A randomized controlled trial

Abstract

Objective: To evaluate whether administration of intranasal fentanyl reduces reported pain during first-trimester uterine aspiration.

Study design: We conducted a multicenter, randomized, double-blind, placebo-controlled trial of patients with pregnancies less than or equal to 14 weeks gestation seeking uterine aspiration for induced abortion, early pregnancy loss, or failed medication abortion. We randomized participants 1:1 to either intranasal fentanyl 100 mcg or intranasal placebo. All participants received ibuprofen and a standardized paracervical block. The primary outcome was pain indicated at the time of uterine aspiration on a 100 mm visual analog scale (VAS). We designed the study to detect a 15 mm difference in mean pain scores, which required 53 people in each arm for a total of 106 participants. Secondary outcomes included postprocedure pain and patient satisfaction with pain control.

Results: From March 2017 through June 2018, we screened 355 people for eligibility and enrolled 107 participants. Those who received intranasal fentanyl reported similar uterine aspiration pain to participants who received placebo (58.4 ± 28.0 fentanyl vs 58.6 ± 24.5 placebo, p = 0.97). Participants who received intranasal fentanyl also reported similar postprocedure pain scores compared to participants who received placebo (19.1 ± 19.4 fentanyl vs 17.2 ± 19 placebo, p = 0.63), and were equally satisfied with procedure pain control (66.8 ± 31.2 fentanyl vs 63.3 ± 29.2 placebo, p = 0.57).

Conclusion: Intranasal fentanyl did not decrease reported pain with first-trimester uterine aspiration, nor did it decrease postprocedure pain compared to placebo. As an adjunct to ibuprofen and paracervical block, intranasal fentanyl did not improve patient satisfaction with pain control.

Implications: Intranasal fentanyl does not reduce reported pain with first-trimester uterine aspiration, however abortion-seeking patients are amenable to receiving intranasal medications for pain management.

Keywords: Analgesia; Anesthesia; First-trimester surgical abortion; Induced abortion; Pain; Vacuum curettage.