To the Editor:—

I read with great interest Dr. Eisenach’s excellent article concerning combined spinal–epidural analgesia in obstetrics. Although the limitations of the technique are well stated, 1I have been using the technique routinely in obstetrics for several years and recently discovered what I regard as a somewhat unusual but useful indication.

I was recently called to consult on an obstetric patient who was being induced at 37 weeks’ gestation for severe preeclampsia. Her liver enzymes were mildly elevated and her platelet count was decreasing. At the time of the consult, platelet count was 130,000/μl but had been decreasing from an initial value of 200,000/μl over the preceding 24 h. The patient was moderately obese, was in early labor, and was considered to be at significant risk of dysfunctional labor and possible cesarean section. I advised the obstetricians that early placement of the epidural catheter was desirable. They requested that I do so without dosing the catheter. However, placement proved to be technically difficult because of a lack of firm resistance encountered in the ligament. I proceeded with the combined spinal–epidural technique to verify epidural placement, using free cerebrospinal fluid flow through the spinal needle (a 25-gauge sprotte) as my end point. There is some evidence that epidural placement is more reliable when a successful combined spinal–epidural technique is used. 2The patient subsequently underwent cesarean section with adequate analgesia using the epidural. Although other means are available to test epidural placement without establishing a significant sensory level, something considered undesirable in this case because of the early stage of labor, I suggest that confirmation using combined spinal–epidural analgesia is reliable, technically easy, and of relatively low risk.

Eisenach JC: Combined spinal–epidural analgesia in obstetrics. A NESTHESIOLOGY 1999; 91:299–302
Pratt SD, Hess PE, Kaon B, Soni AK, Miller CG, Sarna MC: Intra-partum epidural failure rates in a residency program: A quality improvement benchmark report (abstract). A NESTHESIOLOGY April 1999; SOAPSuppl:A63