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.