The Effects of the Use of Diluted Bupivacaine in Sequential Combined Spinal and Epidural Anesthesia for Cesarean Delivery on Maternal Hypotension and Motor Block after Surgery: A Retrospective Observational Study.

Abstract

Maternal hypotension is a common hemodynamic consequence of spinal anesthesia during cesarean delivery, but low-dose spinal anesthesia (<9 mg bupivacaine) ensures stable hemodynamics and reduces motor block. The purpose of this retrospective observational study was to examine the effects of baricity of intrathecal administration of diluted bupivacaine in combined spinal-epidural anesthesia (CSEA) for cesarean delivery on maternal hypotension and motor block after surgery. The anesthesia and nursing records of 35 patients who had given birth by cesarean delivery under CSEA with intrathecal administration of plain or hyperbaric bupivacaine diluted in cerebrospinal fluid were reviewed. All patients were assigned to who received hyperbaric bupivacaine (hyperbaric group) or plain bupivacaine (plain group). Definition of feasibility of cesarean delivery by diluted low dose bupivacaine was set as no requirement of epidural administration of levobupivacaine during surgery. The incidences of hypotension (nadir blood pressure less than 80% of preanesthetic value) and motor block were reviewed. In 24 of the patients (68%), no additional epidural anesthesia was needed during surgery. One patient (3%) required additional epidural anesthesia before delivery. Feasibility of cesarean delivery was not different between hyperbaric group and plain group (p>0.99). Eighteen of the patients (51%) did not require vasopressors, while 17 (49%) developed hypotension. There was no difference in incidence of maternal hypotension between hyperbaric and plain group. Only 6 patients (17%) required more than 3 times of administration of vasopressors among all patients. Modified Bromage scale scores were recorded in 28 of the patients (80%); scores of 0 (no motor block) were recorded in seven of them, and 1 in eight of them. Low-dose either plain or hyperbaric bupivacaine diluted in cerebrospinal fluid to approximately twice the volume may provide sufficient analgesia, fast motor recovery. Incidence of maternal hypotension was similar in hyperbaric and plain group.