Copyright © 2006 Massachusetts Medical Society. |
In investigating if spinal anesthesia might be the best anestheticand analgesic approach for oocyte retrieval, I found a recent and complete
review. This Cochrane review was not designed to
make a conclusion regarding spinal anesthesia versus procedural
sedation/general anesthesia for oocyte retrieval, but provides a good overview
of the limited literature, concluding only that the use of more than one pain relief
modality improves patient comfort. My informal on-line survey of information for patients provided by fertility clinics suggests TIVA
incorporating propofol as procedural sedation/general anesthesia is likely the
most common method employed for oocyte retrieval in the US.
Outside of this review, several prospective1,2,3
and retrospective4 studies have found an association between spinal
anesthesia and improved outcomes either in the process of anesthesia care3,
or in ultimate pregnancy outcomes1,2,4. As for other regio-local anesthetics, paracervical
block has been associated with better pain control during these procedures11
and epidural anesthesia11 and topical EMLA cream12 has
been associated with improved pregnancy outcomes. In some of these clinical
trials the distinction between procedural sedation and general anesthesia is
not clear or inhalational anesthesia was compared to spinal anesthesia. As has been shown for regional anesthesia and
major surgical procedures, the use of spinal anesthesia for oocyte retrieval attenuates hormonal stress responses5. Several studies have compared the effectiveness of low dose
spinals using different doses, baricities, and the addition of fentanyl6-9.
All spinal doses that were studied showed a
high success rate with 2-3 hour injection to discharge times. No comparisons using 2-chloroprocaine were
found but doses as low as 3.75 mg of hyperbaric bupivacaine with fentanyl were studied.
In the absence of a dose ranging study, I suspect that the success of lowering the dose of ultra-low dose spinal
anesthesia to speed discharge after oocyte retrieval may be limited y two factors. One factor is that during
oocyte retrieval pain is not limited to a somatic area but is visceral as well. Another is that good surgical conditions are
required to improve procedural success for
this usually bilateral procedure (where success is complete retrieval from two
ovaries quickly). Taken together this
may mean that a "walking" or "unilateral" spinal where
local anesthetic is administered in extremely small doses or directed away from motor
nerves by baricity may not be adequate.
However, the argument for the utility of spinal anesthesia rests
in the idea that spinal anesthesia is well suited to provide the dense analgesia,
procedural success, and very best pregnancy outcome important to this population of patients and
their reproductive gynecologist. Though perhaps commonly used, the provision of anxiolysis and unconsciousness-- provided by propofol--
may be of less importance. Could the attenuation of hormonal responses by
regional anesthesia during oocyte retrieval be beneficial to pregnancy outcomes
in the same way this attenuation is hypothesized to improve outcomes after major cancer
and orthopedic surgeries? While this
remains speculation, in nine months time--don't these same patients often
choose epidural analgesia for labor or spinal anesthesia for C-section for some of the same patient-centered reasons that spinal anesthesia might make sense here
as well?
References:
1. Toon H et
al. Is Spinal Anesthesia Preferable to General Anesthesia for Oocyte Retrieval?
Anesthesiology 2000 abstract A24. (not published as a full study)
2. Azmude A
et al. Pregnancy Outcome Using General Anesthesia Versus Spinal Anesthesia forIn Vitro Fertilization Anesthesiology
and Pain Medicine. 2013 September; 3:239-42.
3. Viscomi CM
et al. Spinal anesthesia versus intravenous sedation for transvaginal oocyteretrieval: reproductive outcome, side-effects and recovery profiles. Int J
Obstet Anesth. 1997;6:49-51.
4. Aghaamoo S
et al. Does Spinal Analgesia have Advantage over General Anesthesia forAchieving Success in In-Vitro Fertilization? Oman Med J. 2014;29:97-101.
5. Guasch E
et al. [Comparison of 4 anesthetic techniques for in vitro fertilization]. Rev
Esp Anestesiol Reanim. 2005;52:9-18. Spanish.
6. Manica VS
et al. Anesthesia for in vitro fertilization: a comparison of 1.5% and 5%
spinal lidocaine for ultrasonically guided oocyte retrieval. Anesth Analg.
1993;77:453-6.
7. Omi S et
al. [Spinal anesthesia with 2% plain lidocaine for ultrasonically guided
vaginal oocyte retrieval]. Masui.
1996;45:1507-10. Japanese.
8. Martin R
et al. Anesthesia for in vitro fertilization: the addition of fentanyl to 1.5%
lidocaine. Anesth Analg. 1999;88:523-6.
9. Tsen LC et
al. Intrathecal low-dose bupivacaine versus lidocaine for in vitro
fertilization procedures. Reg Anesth Pain Med. 2001;26:52-6.
10. Corson SL
et al. Is paracervical block anesthesiafor oocyte retrieval effective? Fertil Steril. 1994;62:133-6.
11. Gonen O
et al.The impact of different types of anesthesia on in vitrofertilization-embryo transfer treatment outcome. Assist Reprod Genet.
1995:12:678-82.
12. Piroli A
et al. Comparison of different anaesthetic methodologies for sedation during invitro fertilization procedures: effects on patient physiology and oocytecompetence. Gynecol Endocrinol. 2012;28:796-9.