Remifentanil versus remifentanil with paracervical block on plasma remifentanil concentrations and pulmonary function tests for transvaginal ultrasound-guided oocyte retrieval

Abstract

The aim of this study is to compare plasma remifentanil concentrations and pulmonary function tests in subjects receiving remifentanil infusion (RI) versus RI with paracervical block (PCB) during transvaginal ultrasound-guided oocyte retrieval (TUGOR). Prospective, randomized. Assisted Conception Unit. Forty American Society ofAnesthesiologists I subjects requiring TUGOR. After ovarian hyperstimulation, subjects were randomly allocated into two groups to receive either RI (Group RI, n = 20) or RI with PCB (Group RI + PCB, n = 20). Heart rate (HR), mean arterial pressure (MAP), peripheral oxygen saturation (SpO2), end tidal carbon dioxide (ETCO2) tension, forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC), and amount of remifentanil used were collected. Plasma remifentanil concentrations were calculated with STANPUMP software. HR, MAP, ETCO2, SpO2, FEV1, and FVC did not differ between the groups. Total amount of remifentanil used were 486 +/- 1.81 microg and 321 +/- 0.87 microg in groups RI and RI + PCB, respectively, (p < 0.05). In Group RI, plasma remifentanil concentrations were 4.7 ng mL(-1) and 4.2 ng mL(-1) during the second transvaginal puncture, and at the end of TUGOR, respectively, whereas corresponding plasma remifentanil concentrations were 3.1 ng mL(-1) and 2.6 ng mL(-1) in Group RI + PCB (p < 0.05). Both anesthesia regimens provided satisfactory analgesia without affecting FEV1 and FVC, but significantly higher plasma remifentanil concentrations were calculated when only RI was used as an anesthetic technique.