Sevoflurane as an Anesthetic During Dilation and Evacuation Procedures

Oregon Health and Science University160 enrolled

Overview

Sevoflurane is an FDA-approved anesthetic drug commonly used for anesthesia during second trimester abortion procedures. It has a few advantages, including ease of use by the anesthesia provider. However, the literature suggests that when used in doses higher than those used at Oregon Health \& Science University (OHSU) and Lovejoy, it is associated with an increase in the risk of bleeding. The investigators study aims to test whether the lower dose used at OHSU and Lovejoy during second trimester abortion procedures causes any difference in blood loss, when compared to similar abortion procedures for which this drug is not used.

This study seeks to examine the bleeding complications associated with use of sevoflurane in general anesthesia regimens for second trimester abortion procedures and assess anesthesia providers' use and beliefs regarding possible risks associated with newer inhalational agents such as sevoflurane in this setting. Participants' anesthesia will either be intravenous (IV) propofol, IV midazolam, IV fentanyl and nitrous oxide or this same regimen combined with sevoflurane during maintenance of anesthesia. Procedural outcomes, specifically those related to bleeding complications, including need to intervene for excess blood loss, will be recorded and analyzed to establish if such a relationship between use of sevoflurane and excess blood loss exists.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

SUPPORTIVE_CARE

Masking

DOUBLE

Enrollment

160

Conditions

Blood Loss

Eligibility

Sex: FEMALEMin age: 18 YearsMax age: 50 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Voluntarily requesting pregnancy termination * Estimated gestational age of 18 weeks - 23 weeks, 6 days gestational age as calculated by fetal biparietal diameter on clinic ultrasound. * Be able and willing to sign an informed consent and agree to terms of the study Exclusion Criteria: * Known severe maternal respiratory disease or upper respiratory infection or sinus blockage * Anticoagulation use: within 24 hours if Lovenox, or within 12 hours if heparin, (Must have a documented normal international normalized ratio (INR) prior to procedure if on anticoagulation) * Multiple pregnancy * Fetal demise, if more than 2 weeks difference exists between known gestational age (by previous US dating) and gestational size on current ultrasound. * Known allergy/sensitivity to sevoflurane or any other inhaled anesthetic agents

Outcomes

Primary Outcomes

Number of Participants Needing Intervention to Treat Blood Loss (a Composite of Use of Uterotonics, Re-aspiration, and Bimanual Massage)

Provider report for need to intervene due to blood loss (yes/no)

Time frame: At time of uterine evacuation and immediately post-operatively, an average of 7.1 minutes

Secondary Outcomes

Number of Participants With Estimated Blood Loss Greater Than 300 mL (Yes/no)

Procedural blood loss greater than 300 mL. Blood loss was measured in a standardized fashion (amniotic fluid was discarded, blood was separated from tissue, and all gauze surgical drapes weighed).

Time frame: At time of uterine evacuation, an average of 7.1 minutes

Procedure Time: T-test (Time of Speculum Placement to Time Speculum Removed)

Length of procedure from time of speculum placement to time of speculum removal, in minutes.

Time frame: Time of speculum place to time of speculum removal, an average of 7.1 minutes

Number of Participants Experiencing Side Effects (Nausea, Dizziness)

Time frame: Post-procedure, within 30 minutes

Patient and Provider Satisfaction With Anesthesia

Scores reported on 10-cm Visual Analog Scale (VAS anchors: 0= not satisfied at all, 10= completely satisfied) . Reported as mean +/- standard deviation. Subjects and providers were blinded to anesthesia method. Subjects and providers completed post-operative questionnaire within 30 minutes of procedure completion.