Comparison of Spinal Block Levels between Laboring and Nonlaboring Parturients Using Combined Spinal Epidural Technique with Intrathecal Plain Bupivacaine
Background. It was suggested that labor may influence the spread of intrathecal bupivacaine using combined spinal epidural (CSE) technique. However, no previous studies investigated this proposition. We designed this study to investigate the spinal block characteristics of plain bupivacaine between nonlaboring and laboring parturients using CSE technique. Methods. Twenty-five nonlaboring (Group NL) and twenty-five laboring parturients (Group L) undergoing cesarean delivery were enrolled. Following identification of the epidural space at the L3-4 interspace, plain bupivacaine 10？mg was administered intrathecally using CSE technique. The level of sensory block, degree of motor block, and hemodynamic changes were assessed. Results. The baseline systolic blood pressure (SBP) and the maximal decrease of SBP in Group L were significantly higher than those in Group NL ( and , resp.). The median sensory level tested by cold stimulation was T6 for Group NL and T5 for Group L ( ). The median sensory level tested by pinprick was T7 for both groups ( ). The degree of motor block was comparable between the two groups ( ). Conclusion. We did not detect significant differences in the sensory block levels between laboring and nonlaboring parturients using CSE technique with intrathecal plain bupivacaine. 1. Introduction Combined spinal epidural (CSE) anesthesia is commonly used for cesarean delivery. It has been suggested that nonlaboring parturients have a higher sensory block level than those in labor during CSE anesthesia [1]. This proposition was derived from combining two independent randomized studies on spinal block levels designed separately for laboring and nonlaboring parturients [2, 3]. There was a 5-dermatome level difference between nonlaboring (C6) [2] and laboring (T3) [3] parturients using 10？mg hyperbaric bupivacaine with CSE technique. However, there has been no previous study examining the effect of labor on the level of the subarachnoid block during CSE. The effect of CSE technique on the spinal block level of hyperbaric bupivacaine in nonlaboring parturients was not consistent. Horstman et al. reported that sensory block level was at T3 with CSE in nonlaboring parturients using 20% higher dose of hyperbaric bupivacaine [4]. We speculate that baricity of the hyperbaric bupivacaine used by Ithnin et al. could be a confounding factor, because the block level could be easily manipulated with the positioning of the parturients when hyperbaric local anesthetic was used. The effect of labor on the spread of local anesthetics may be better examined by
References
[1]
A. J. Macarthur, “Gerard W. Ostheimer “What's new in obstetric anesthesia” lecture,” Anesthesiology, vol. 108, no. 5, pp. 777–785, 2008.
[2]
F. Ithnin, Y. Lim, A. T. Sia, and C. E. Ocampo, “Combined spinal epidural causes higher level of block than equivalent single-shot spinal anesthesia in elective cesarean patients,” Anesthesia and Analgesia, vol. 102, no. 2, pp. 577–580, 2006.
[3]
Y. Lim, W. Teoh, and A. T. Sia, “Combined spinal epidural does not cause a higher sensory block than single shot spinal technique for cesarean delivery in laboring women,” Anesthesia and Analgesia, vol. 103, no. 6, pp. 1540–1542, 2006.
[4]
D. J. Horstman, E. T. Riley, and B. Carvalho, “A randomized trial of maximum cephalad sensory blockade with single-shot spinal compared with combined spinal-epidural techniques for cesarean delivery,” Anesthesia and Analgesia, vol. 108, no. 1, pp. 240–245, 2009.
[5]
T. W. Breen, T. Shapiro, B. Glass, D. Foster-Payne, and N. E. Oriol, “Epidural anesthesia for labor in an ambulatory patient,” Anesthesia and Analgesia, vol. 77, no. 5, pp. 919–924, 1993.
[6]
A. M. Dubelman and A. R. Forbes, “Does cough increase the spread of subarachnoid anesthesia?” Anesthesia and Analgesia, vol. 58, no. 4, pp. 306–308, 1979.
[7]
Y. Hirabayashi, R. Shimizu, H. Fukuda, K. Saitoh, and M. Furuse, “Anatomical configuration of the spinal column in the supine position. II. Comparison of pregnant and mon-pregnant women,” British Journal of Anaesthesia, vol. 75, no. 1, pp. 6–8, 1995.
[8]
I. F. Russell and E. L. O. Holmqvist, “Subarachnoid analgesia for Caesarean section. A double-blind comparison of plain and hyperbaric 0.5% bupivacaine,” British Journal of Anaesthesia, vol. 59, no. 3, pp. 347–353, 1987.
[9]
M. G. Richardson, H. V. Collins, and R. N. Wissler, “Intrathecal hypobaric versus hyperbaric bupivacaine with morphine for cesarean section,” Anesthesia and Analgesia, vol. 87, no. 2, pp. 336–340, 1998.
[10]
R. M. Lewinsky and S. Riskin-Mashiah, “Autonomic imbalance in preeclampsia: evidence for increased sympathetic tone in response to the supine-pressor test,” Obstetrics and Gynecology, vol. 91, no. 6, pp. 935–939, 1998.
[11]
M. Cascio, B. Pygon, C. Bernett, and S. Ramanathan, “Labour analgesia with intrathecal fentanyl decreases maternal stress,” Canadian Journal of Anaesthesia, vol. 44, no. 6, pp. 605–609, 1997.
[12]
R. V. Brizgys, P. A. Dailey, S. M. Shnider, D. M. Kotelko, and G. Levinson, “The incidence and neonatal effects of maternal hypotension during epidural anesthesia for cesarean section,” Anesthesiology, vol. 67, no. 5, pp. 782–786, 1987.
[13]
N. P. Ekel？f, E. Jensen, J. Poulsen, and P. Reinstrup, “Weight gain during pregnancy does not influence the spread of spinal analgesia in the term parturient,” Acta Anaesthesiologica Scandinavica, vol. 41, no. 7, pp. 884–887, 1997.
[14]
M. C. Norris, “Patient variables and the subarachnoid spread of hyperbaric bupivacaine in the term parturient,” Anesthesiology, vol. 72, no. 3, pp. 478–482, 1990.
[15]
B. Carvalho, J. Collins, D. R. Drover, L. Atkinson Ralls, and E. T. Riley, “ED50 and ED95 of intrathecal bupivacaine in morbidly obese patients undergoing cesarean delivery,” Anesthesiology, vol. 114, no. 3, pp. 529–535, 2011.
