Spinal anesthesia versus intravenous sedation for transvaginal oocyte retrieval: Reproductive outcome, side-effects and recovery profiles

Pain Management during Ultrasound Guided Transvaginal Oocyte Retrieval - A Narrative Review

Transvaginal oocyte retrieval (TVOR), done for the purpose of assisted reproduction can instigate enormous pain and therefore requires adequate analgesia with the least adverse effects. As the procedure involves retrieving oocytes for in vitro fertilisation, the effect of the anaesthetic drugs on the oocyte quality should also be considered. This review focuses on the various modes of anaesthesia and the anaesthetic drugs which can be administered safely to provide effective analgesia in normal and in special conditions such as women with pre-existing comorbidities. Medline, Embase, PubMed and Cochrane electronic databases were searched according to modified Preferred Reporting Items for Systemic Reviews and Meta-Analyses guidelines. According to this review, conscious sedation appears to be the most preferred mode of anaesthesia in women undergoing TVOR owing to fewer adverse effects, faster recovery, better patient and specialist comfort and the least effect on oocyte quality and embryo development. Combining it with paracervical block resulted in lesser consumption of the anaesthetic drug, which may have a beneficial effect on the oocyte quality.

Comparison of chemical pregnancy rates according to the anesthetic method during ultrasound-guided transvaginal oocyte retrieval for in vitro fertilization: a retrospective study

Background

Oocyte retrieval is the most important procedure in in vitro fertilization (IVF). Various anesthetic methods are used to control a patient’s anxiety and pain during IVF; however, there are no recommended anesthetic methods at present. In this study, we retrospectively investigated chemical pregnancy rates according to the anesthetic method used for oocyte retrieval.

Methods

We reviewed records of patients who underwent oocyte retrieval between January 1, 2012 and December 31, 2017. Patients were divided into the spinal anesthesia (SA) and monitored anesthesia care (MAC) groups. The primary outcome was chemical pregnancy rate after IVF.

Results

The study included 95 patients. SA was administered in 77 (81%) and MAC in 18 (19%). The overall chemical pregnancy rate was 32.6% (31/95). According to the anesthetic method, the pregnancy rate was 32.5% (25/77) in the SA group and 33.3% (6/18) in the MAC group. There was no statistical difference in the pregnancy rate between the groups (P = 0.575). The procedural time was significantly shorter in the SA group than in the MAC group (P < 0.001).

Conclusions

Chemical pregnancy rates were not significantly different between the SA and MAC groups. However, the procedure duration was shorter in the SA group than in the MAC group.

Effect of nitrous oxide on propofol requirement during target-controlled infusion for oocyte retrieval

BACKGROUND

Oocyte (egg) retrieval for in-vitro fertilization is a relatively short procedure, usually performed as an outpatient. Propofol is a suitable anesthetic agent. Target-controlled infusion is a recently developed system that aids rapid recovery from propofol anesthesia. This study sought to determine the target concentration of propofol required to prevent movement in 50% (Cp50) and 95% (Cp95) of women during oocyte retrieval, and investigated whether supplemental nitrous oxide (N2O) modified the Cp50 and Cp95.

METHODS

Forty-seven women scheduled for oocyte retrieval were randomly selected to receive either O2-air mixture (control group; n = 23) or 50% O2-N2O mixture (Nitrous oxide group; n = 24). Propofol was infused using a target-controlled infusion system with the concentration determined by up-down sequential allocation using 0.5 microg/mL step size. Transvaginal oocyte retrieval was performed after reaching target blood concentration. Patient responses to oocyte retrieval were noted as either no movement or movement.

RESULTS

Using target-controlled infusion the Cp50 was 4.1 microg/mL in the control group and 3.3 microg/mL in the nitrous oxide group. Calculated Cp95 values were 4.0 microg/mL and 5.1 microg/mL with and without 50% nitrous oxide respectively.

CONCLUSIONS

The Cp50 value for target-controlled infusion propofol during oocyte retrieval was significantly reduced by a factor of 1.24 (95% CI 1.07-1.44) with the use of 50% nitrous oxide.

Anesthesia for in vitro fertilization: the addition of fentanyl to 1.5% lidocaine

Ultrasonically guided transvaginal oocyte retrieval is relatively short procedure that is performed on an out-patient basis. The optimal anesthetic technique should allow good surgical anesthesia with minimal side effects, a short recovery time, and, if possible, a high rate of successful pregnancy. Spinal anesthesia is often used in this institution, as well as many others, for this procedure. The addition of fentanyl may be effective for both intraoperative and postoperative pain relief. We assessed the effect of adding fentanyl to 1.5% lidocaine in women undergoing ultrasonically guided oocyte retrieval. Seventy-eight women were randomized to receive 45 mg of hyperbaric 1.5% lidocaine with or without 10 microg of fentanyl. Visual analog scale (VAS) pain scores were lower in the operating room (OR) (P < 0.05) and postanesthesia care unit (PACU) (P < 0.0005) for the group that received fentanyl. In addition, the amount of narcotic required in the PACU was less in the fentanyl group (P < 0.005). There was no difference in VAS scores the evening of or 24 h after the procedure. The amount of analgesics and narcotics required after discharge was the same for both groups. Timed variables, such as time to urination, ambulation, and discharge, were the same for both groups of women. The addition of fentanyl to lidocaine for transvaginal oocyte retrieval results in a more comfortable patient in the OR and PACU.

IMPLICATIONS

This study demonstrates that when fentanyl is added to a local anesthetic, lidocaine, with spinal anesthesia for egg retrieval procedures, patients are more comfortable during the procedure compared with those who receive lidocaine alone. In addition, the narcotic requirements of patients are less in the postanesthesia care unit.

Spinal analgesia for transvaginal oocyte retrieval

Day case transvaginal ultrasound-guided needle puncture is currently the method of choice for oocyte retrieval. The risk of morbidity from this procedure increases with sudden patient movement in response to needle manipulation. The provision of effective pain relief can limit this risk, but is complicated by the need to balance efficacy with day case compatibility. The aim of this pilot study was to establish whether spinal analgesia using a mixture of bupivacaine and fentanyl could be useful in this context. The results identify several advantages of this technique over current clinical practice, and merit further comparative investigation.