Sevoflurane as an Anesthetic During Dilation and Evacuation Procedures

Sevoflurane as an Anesthetic During Dilation and Evacuation Procedures: Does it Increase Blood Loss and Interventions for Blood Loss and Why Do Anesthesiologists Choose to Use It?

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.

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