To investigate whether intrathecal administration of 10% glucose increases functional impairment and histologic damage in rats when mixed with 5% lidocaine. After implanted intrathecal catheter, 32 male Sprague-Dawley rats were randomly assigned to one of four groups: lidocaine group (Group L, n=8) received 5% lidocaine 20 µL, lidocaine with glucose group (Group LG, n=8) received 5% lidocaine with 10% glucose 20 µL, glucose group (Group G, n=8) received 10% glucose 20 µL and normal saline group received normal saline 20 µL (Group NS, n=8). Four days after intrathecal injection, sensory impairments of rats in the four groups were evaluated by using the tail-flick test. The histologic changes of spinal cord and nerve roots were observed by electron microscopy and light microscopy. There was no significant difference in baseline tail-flick latencies between the four groups (P=0.284). On the 4th day after intrathecal injection, the assessment result of sensory function was similar to baseline (P=0.217) in saline-treated animals. Sensory impairment occurred after intrathecal administration of 5% lidocaine, and 10% glucose with 5% lidocaine worsen this satiation (P=0.0001); histologic changes in 10% glucose with 5% lidocaine-treated group has differ significantly from lidocaine-treated group (P=0.001). Sensory function after intrathecal administration of 10% glucose was similar to baseline and did not differ from the saline group (P=0.995); histologic changes in 10% glucose-treated rats did not differ significantly from saline controls (P=0.535). These results suggest that 5% lidocaine can induce spinal neurotoxicity and 10% glucose with 5% lidocaine could worsen spinal neurotoxicity.
The combined technique of programmed intermittent epidural boluses (PIEB) and dural puncture epidural (DPE) is currently considered a more effective mode for labor analgesia. We investigated the optimal interval time for PIEB administration with different concentrations of ropivacaine combined with the DPE for labor analgesia. Ninety patients with cervical dilation of <5 cm and a VAS score >5 were randomly assigned to receive labor analgesia with ropivacaine at concentrations of 0.075% (0.075% group), 0.1% (0.1% group), and 0.125% (0.125% group). In each group, an initial administration of a combination of ropivacaine 12 mL and sufentanil 0.3 μg/mL was followed by an additional dose of ropivacaine 10 mL and sufentanil 0.3 μg/mL after 30 min. The initial PIEB interval time was set at 40 min for the first patient in each group, and subsequent interval times for the following patients were adjusted based on meeting analgesic needs (VAS score ≤1) with a gradient of 10 min. The primary outcome was the ED90 of interval time required to achieve analgesic needs during PIEB with different concentrations of ropivacaine, employing an up-and-down sequential allocation method. The optimal PIEB interval times for ropivacaine concentrations of 0.075%, 0.1%, and 0.125% were determined to be 40.9 (95% CI, 35.3-45.8), 45.3 (95% CI, 39.3-51.5), and 52.9 (95% CI, 46.8-59.3) minutes respectively, while comparable maternal and neonatal outcomes were observed across all groups. When PIEB is combined with DPE for labor analgesia, the optimal PIEB interval times for ropivacaine concentrations of 0.075%, 0.1%, and 0.125% were determined to be 41, 45, and 53 min respectively.
Background: Fluid loading improves hemodynamic stability and reduces the incidence rate of post-spinal anesthesia hypotension when prophylactic vasopressors are administered. We investigated the impact of different crystalloid coload volumes on the 90% effective dose (ED) of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension in non-hypertensive patients undergoing cesarean section. Methods: Patients were randomly allocated to receive one of the different crystalloid coload volumes (0mL/kg [0mL/kg Group], 5mL kg [5mL/kg Group], and 10mL kg [10mL/kg Group]) in combination with prophylactic norepinephrine infusion immediately after the induction of spinal anesthesia. The prophylactic norepinephrine infusion doses were determined using the up-and-down sequential allocation methodology, with an initial dose of 0.025 μg/kg/min and a gradient of 0.005 μg/kg/min. The primary endpoint was the effective dose at which 90% (ED 90) of patients responded to prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension. Results: The estimated effective dose of norepinephrine infusion, at which 90% (ED 90) of patients responded, was found to be 0.084 (95% CI, 0.070 to 0.86), 0.074 (95% CI, 0.059 to 0.077), and 0.063 (95% CI, 0.053 to 0.064) μg/kg/min in the three groups, respectively. Conclusion: A crystalloid coload of 5 mL/kg or 10 mL/kg, as opposed to the groups receiving 0 mL/kg crystalloid coloads, resulted in a reduction of approximately 11.9% and 25.0%, respectively, in the ED90 of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean section. Keywords: crystalloid, coload, norepinephrine, postspinal anesthesia hypotension, cesarean section
Vasopressors remain an important strategy for managing spinal anesthesia-induced hypotension in women with preeclampsia. The aim of this study was to investigate the ED90s and efficacy ratio of phenylephrine and norepinephrine in managing spinal anesthesia-induced hypotension in women with preeclampsia during cesarean delivery.