OBSTETRIC ANESTHESIA Jocelyn Wertz T4 3/22/12 THE HISTORY OF OB ANESTHESIA First used in 1847 Ether and chloroform Originally linked with increased rate of puerperal fever Less pain more interventions Effect on fetus & labor denied for many years MODERN OB ANESTHESIA Non-pharmacologic Breathing techniques Doulas Water bath Local anesthesia Bilateral pudendal nerve block Systemic medications Opioids Sedatives Regional anesthesia Spinal Epidural Combined SpinalEpidural General anesthesia Reserved for rare cases of contraindication to/failed regional anesthesia SPINAL TECHNIQUE Follow sterile technique Position patient Traverse: skin, subQ tissue, supraspinous ligament, interspinous ligament, ligamentum flavum, epidural space and dura Administer meds EPIDURAL TECHNIQUE Follow sterile technique Position patient Traverse: skin, subQ tissue, supraspinous ligament, interspinous ligament and ENTER ligamentum flavum Use loss of resistance technique to enter epidural space without dura puncture Insert catheter Administer test dose Monitor Administer medication KEY DIFFERENCES Spinal Subarachnoid space Small volume (1.53.5mL) Single shot Onset typically in 5 minutes Often causes significant neuromuscular block Epidural Epidural space More volume (1020mL) Catheter placed Onset typically in 1530 minutes Causes neuromuscular block only when specific local anesthetics are used COMBINED SPINAL EPIDURAL TECHNIQUE Combines the certainty of a spinal (appearance of CSF) with the flexibility of an epidural (continuous analgesia) No unique complications VAGINAL VERSUS CESAREAN Motor block is desired for C-section but not for vaginal Vaginal should have analgesia to the T10 dermatome, C-section to T4 C-section needs stronger analgesia to block pain of surgery WHAT SHOULD I USE? Spinal Preferred option for simple Cesarean Sections Increased risk of hypotension requiring treatment Epidural A good option for women in whom spinal analgesia is contraindicated CSE Preferred option for laboring women who need pain relief NOW and for the forseeable future Preferred option for Cesareans expected to last >90 minutes Growing in popularity and now used for women in all stages of labor REFERENCES 1 . Grant G and Hepner D. Anesthesia for Cesarean Delivery. Up To Date. March 6, 2012. 2. Ng K, Parsons J, Cyna AM, Middleton P. Spinal versus epidural anaesthesia for caesarean section (Review ). 2007 The Cochrane Collaboration. 3. Eisenach JC. Combined Spinal -Epidural Analgesia in Obstetrics. Anesthesiology. 1999; 91:299 -302. 4. Bali A, Sharma J, Gupta SD. Combined Spinal Epidural Anaesthesia. JK Science. 2007; (9)4:161 -163. 5. Nageotte MP et al. Epidural Analgesia Compared With Combined Spinal-Epidural Analgesia During Labor in Nulliparous Women. NEJM. 1997; (337)24:1715 -1720. 6. Wong C, Nathan N, Brown D. Obstetric Analgesia: Chapter 12 Spinal, Epidural, and Caudal Anesthesia: Anatomy, Physiology, and Technique. 4 th edition 1999; p223-249.