Spinal mepivacaine versus bupivacaine for ultrasound guided transvaginal oocyte retrieval. A comparative study

Abstract

Study objectiveThe most important limitation for spinal anesthesia in the ambulatory setting is the prolonged motor blockade and delayed postoperative ambulation. The current study was conducted to compare spinal mepivacaine–fentanyl combination versus conventional combination of spinal bupivacaine with fentanyl for surgical anesthesia of ultrasound-guided transvaginal oocyte retrieval for in vitro fertilization (IVF).Patients and methodsSixty female patients undergoing ultrasound-guided transvaginal oocyte retrieval for in vitro fertilization on ambulatory basis were enrolled in the current study. Patients were randomly distributed in to one of two equal groups: mepivacaine group (group M) and bupivacaine group (group B). Patients in group M received intrathecal 37.5 mg of isobaric mepivacaine 1.5% plus 10 μg fentanyl while patients in group B received intrathecal 12.5 mg of hyperbaric bupivacaine 0.5% plus 10 μg fentanyl. Primary outcome measure was the time to complete motor block regression. Secondary outcome measures included the peak sensory blockade level achieved, the times for sensory block regression to S1 dermatome, post-anesthesia stable ambulation, 1st voiding, and hospital discharge. The incidence of perioperative adverse events was also recorded.ResultsTwo patients (one in each group) were excluded from the study due to failed block and conversion to general anesthesia. The peak sensory blockade levels (T6–T10) were satisfactory for procedural anesthesia in the remaining patients of both groups. Patients in group M had significantly faster sensory block regression to S1 and motor block resolution when compared with group B (P < 0.05). Times to steady ambulation, voiding and hospital discharge were significantly shorter in group M when compared with group B (P < 0.05). There was no intergroup significant difference as regards the incidence of perioperative adverse events, and none of the patients reported transient neurological symptoms (TNS) or postdural puncture headache in both groups.ConclusionThe mepivacaine–fentanyl combination was superior to bupivacaine–fentanyl combination for spinal anesthesia of ultrasound-guided transvaginal oocyte retrieval on ambulatory basis because of faster sensory and motor block resolution and the shorter time to ambulation and hospital discharge with reliability of surgical anesthesia and no difference in the incidence of perioperative adverse events between both groups.