[The Effect of Different Positions on Block Plane of Isobaric Bupivacaine for Caesarean Section with Combined Spinal-Eqidural Analgesia].

OBJECTIVE: To evaluate the effect of horizontal and trendelenburg left lateral position on the onset time and the spread of intrathecal isobaric bupivacaine for elective cesarean delivery.

METHODS: 180 parturients were enrolled to undergo elective cesarean delivery with combined spinal-epidural anesthesia (CSE). They were randomly divided into 3 groups (n = 60) according to the different positions during anesthesia: Group I horizontal position, Group II trendelenburg position 5 degrees, Group III trendelenburg position 10 degrees. A combined spinal-eqidural (CSE) analgesia was performed at the L3-4 interspace in either horizontal or trendelenburg left lateral position, according to randomization. 2 mL of 0.5% isobaric bupivacaine was injected into subarachnoid space when cerebrospinal fluid outflew. Then the patient was placed in a supine position. The success criteria of anesthesia was: T6 sensory block, Bromage grade 2 or 3 (motor block), anesthesia effect ≥ grade III. The systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), sensory block, motor block and adverse reactions such as hypotension, bradycardia, chest distress were observed after the 3 groups parturients entered into operating room. The numbers and success rate of Group I, II and III which got T6 sensory block in ten minutes were observed.

RESULTS: Among Group I, II and III, there were no significant differences in onset time of sensory block and motor block (P > 0.05). The cold and pinprick sensation level in 10 min of Group I1 and Group III were higher than that of Group I (P < 0.05). The success rate of Group II or III was higher than Group I (P < 0.05). The success rate of Group III was higher than that of Group II, but not with significant difference (P > 0.05). There were no significant differences in hemodynamics, adverse reactions such as hypotension, bradycardia, chest distress among three groups (P > 0.05).

CONCLUSION: The trendelenburg 5 degrees position can meet the requirement of operation without high anesthesia level.