EPIDURAL BLOCK FOR CESAREAN SECTION (C/S)

Abstract

S364 It is a common practice to insert the epidural catheter into the epidural space and to inject the local anesthetic solution through the catheter. Our practice has been to initiate epidural block through the needle by gravity technique and then to insert the catheter [1] (Figure 1). To determine whether administration of local anesthetic solution by gravity via the needle into the epidural space is associated with fewer adverse effects than the traditional injection through the catheter technique, we conducted, with IRB approval, a prospective, randomized double blind study of 104 consenting parturients who received epidural block for elective C/S.Figure 1: Gravity techniqueMethods: The patients were randomly allocated to two groups. Group I (n=52) received the anesthetic solution through the epidural catheter. Group II (n=52) received the anesthetic solution by gravity before insertion of the catheter. Following a standard lumbar epidural approach, Group I patients received incremental doses of 3ml, 5ml, 5ml, 5ml, 3ml to a total of 21 ml of 2% lidocaine with 5 [micro sign]g/ml epinephrine and 5 [micro sign]g/ml fentanyl. Group II received 3 ml, 5 ml, 5ml and 5ml of anesthetic solution administered by gravity through the needle, followed by catheter insertion and administration of 3ml of the anesthetic solution via the catheter to a total of 21 ml. Results: Values are mean +/- SD. Groups did not differ in age, height or parity. Average weight in Group I was slightly less than Group II (171 +/- 35 vs 188 +/- 37 kg, p<0.02). The groups did not differ in number of previous epidural or spinal blocks. No patient had a prior inadvertent dural puncture or blood patch. Groups did not differ in distance of epidural space from skin, duration of surgery or incidence of nausea or sedation. Apgar scores of babies in Groups I and II were similar at both 1 and 5 minutes. Incidence of blood vessel puncture was greater in Group I than Group II (8 vs 1, p<0.04). Group I required more additional local anesthetic than Group II to achieve T4-S5 level of anesthesia (2.2 +/- 3.6 ml vs 0.0 +/- 0.0, p<0.001) and had a greater incidence of discomfort from paresthesia (33 vs 21, p<0.03). There were 13 patients in Group I and none in Group II for whom the epidural block alone did not provide satisfactory analgesia p<0.001). Conclusion: These data show that epidural administration of local anesthetic solution for C/S by gravity via the needle is associated with a higher success rate, fewer paresthesias, and fewer epidural blood punctures than the traditional injection through the epidural catheter.