Cervical Cerclage Insertion

Summary

  • Dose: 1.5 ml (7.5 mg) 0.5% hyperbaric bupivacaine + 15 mcg fentanyl

  • Position: Sitting, immediately supine. Lithotomy when block T12.

  • Expectation: Surgical block for up to 60 minutes post-spinal.

Evidence

  • Similar doses of anaesthetic will block higher dermatomes as gestation increases [1,2,3]. Sensory block increases by one dermatome for every 26 days of gestation during second trimester [3].

  • 7 mg (1.4 ml) 0.5% hyperbaric bupivacaine (patient lateral, immediately supine, move to lithotomy  after 3-5 min) will achieve a sensory block (temperature) from T9 in early pregnancy (~13/40) to T5 in later pregnancy (~22/40) [1,2]. Two segment regression time ~ 60 minutes.

  • 5.25 mg of hyperbaric bupivacaine with 20 mcg fentanyl (patient sitting, immediately supine, lithotomy once block to T12) will achieve a sensory block (temperature) ~T7 (median 13/40 gestation) [4]. Ambulation ~ 2 hours and micturition ~ 3 hours after block.

  • Operating times in these studies were roughly 15 minutes.

  • Patients receiving low dose (<10 mg) bupivacaine for cervical cerclage have a time to ambulation of approximately 3 hours, and time to void of roughly 3.5 hours [5].

  • Brendan Carvalho (Stanford University) recommends 7.5 mg bupivacaine plus 15 mcg fentanyl [6].

Removal of Suture

  • Often done without anaesthesia.

  • If anaesthesia required, dose as above.

  • If removed in labour, consider CSE.

References

  1. Lee et al. Spread of subarachnoid sensory block with hyperbaric bupivacaine in second trimester of surgery. Journal of Clinical Anaesthesia 2009; 21: 482-485.

  2. Lee et al. Comparison of spread of subarachnoid sensory block and incidence of hypotension in early and late second trimester of pregnancy. Korean J Anesthesiol 2013;65(4):322-326.

  3. Kim. Correlation between gestational age and level of sensory block in spinal anaesthesia. Reg Anesth Pain Med 2019;44:793-795.

  4. Beilin et al. Subarachnoid small-dose bupivacaine versus lidocaine for cervical cerclage. Anesth Analg 2003;97(1): 56-61.

  5. Hsu et al. Optimal bupivacaine spinal for cervical cerclage: Effect on ambulation, urination, PACU time and pain control. Abstract T 29 at SOAP 2013.

  6. Abir & Carvalho. Anaesthesia for nondelivery obstetric procedures. In: Hepner (Ed), UpToDate. Retrieved April8, 2020, from https://www.uptodate.com/contents/anesthesia-for-nondelivery-obstetric-procedures.