ABSTRACT
It is commonly accepted that females and males differ in their experience of pain. Gender differences have been found in the prevalence and severity of pain in both clinical and animal studies. Sex-related hormones are found to be involved in pain transmission and have critical effects on visceral pain sensitivity. Studies have pointed out the idea that serum estrogen is closely related to visceral nociceptive sensitivity. This review aims to summarize the literature relating to the role of estrogen in modulating visceral pain with emphasis on deciphering the potential central and peripheral mechanisms.
Subject(s)
Animals , Female , Humans , Male , Estrogens/metabolism , Hyperalgesia/therapy , Immune System , Nociceptors , Ovariectomy , Pain Management , Pain Threshold , Sex Factors , Visceral Pain/therapyABSTRACT
<p><b>BACKGROUND</b>Spinal anesthesia was considered as a reasonable anesthetic option in severe preeclampsia when cesarean delivery is indicated, and there is no indwelling epidural catheter or contraindication to spinal anesthesia. However, the ideal dose of intrathecal bupivacaine has not been quantified for cesarean delivery for severe preeclamptic patients. This study aimed to determine the ED 50 and ED 95 of intrathecal bupivacaine for severely preeclamptic patients undergoing elective cesarean delivery.</p><p><b>METHODS</b>Two hundred severely preeclamptic patients are undergoing elective cesarean delivery under combined spinal-epidural anesthesia enrolled in this randomized, double-blinded, dose-ranging study. Patients received 4 mg, 6 mg, 8 mg, or 10 mg intrathecal hyperbaric bupivacaine with 2.5 μg sufentanil. Successful spinal anesthesia was defined as a T6 sensory level achieved within 10 minutes after intrathecal drug administration and/or no epidural supplement was required during the cesarean section. The ED 50 and ED 95 were calculated with a logistic regression model.</p><p><b>RESULTS</b>ED 50 and ED 95 of intrathecal bupivacaine for successful spinal anesthesia were 5.67 mg (95% confidence interval [CI]: 5.20-6.10 mg) and 8.82 mg (95% CI: 8.14-9.87 mg) respectively. The incidence of hypotension in Group 8 mg and Group 10 mg was higher than that in Group 4 mg and Group 6 mg (P < 0.05). The sensory block was significantly different among groups 10 minutes after intrathecal injection (P < 0.05). The use of lidocaine in Group 4 mg was higher than that in other groups (P < 0.05). The use of phenylephrine in Group 8 mg and Group 10 mg was higher than that in the other two groups (P < 0.05). The lowest systolic blood pressure before the infant delivery of Group 8 mg and Group 10 mg was lower than the other two groups (P < 0.05). The satisfaction of muscle relaxation in Group 4 mg was lower than other groups (P < 0.05). There was no significant difference in patients' satisfaction and the newborns' Apgar score and the blood gas analysis of umbilical artery serum (P > 0.05).</p><p><b>CONCLUSION</b>Our study showed that the ED 50 and ED 95 of intrathecal bupivacaine for severely preeclamptic patients undergoing elective cesarean delivery were 5.67 mg and 8.82 mg, respectively. In addition, decreasing the dose of intrathecal bupivacaine could reduce the incidence of maternal hypotension.</p>
Subject(s)
Adult , Female , Humans , Male , Anesthesia, Epidural , Anesthesia, Spinal , Methods , Blood Pressure , Physiology , Bupivacaine , Therapeutic Uses , Cesarean Section , Double-Blind Method , Sufentanil , Therapeutic UsesABSTRACT
<p><b>BACKGROUND</b>Spinal hyperbaric ropivacaine may produce more predictable and reliable anesthesia than plain ropivacaine for cesarean section. The dose-response relation for spinal hyperbaric ropivacaine is undetermined. This double-blind, randomized, dose-response study determined the ED50 (50% effective dose) and ED95 (95% effective dose) of spinal hyperbaric ropivacaine for cesarean section anesthesia.</p><p><b>METHODS</b>Sixty parturients undergoing elective cesarean section delivery with use of combined spinal-epidural anesthesia were enrolled in this study. An epidural catheter was placed at the L1 approximately L2 vertebral interspace, then lumbar puncture was performed at the L3 approximately L4 vertebral interspace, and parturients were randomized to receive spinal hyperbaric ropivacaine in doses of 10.5 mg, 12 mg, 13.5 mg, or 15 mg in equal volumes of 3 ml. Sensory levels (pinprick) were assessed every 2.5 min until a T7 level was achieved and motor changes were assessed by modified Bromage Score. A dose was considered effective if an upper sensory level to pin prick of T7 or above was achieved and no intraoperative epidural supplement was required. ED50 and ED95 were determined with use of a logistic regression model.</p><p><b>RESULTS</b>ED50 (95% confidence interval) of spinal hyperbaric ropivacaine was determined to be 10.37 (5.23 approximately 11.59) mg and ED95 (95% confidence interval) to be 15.39 (13.81approximately 23.59) mg. The maximum sensory block levels and the duration of motor block and the rate of hypotension, but not onset of anesthesia, were significantly related to the ropivacaine dose.</p><p><b>CONCLUSION</b>The ED50 and ED95 of spinal hyperbaric ropivacaine for cesarean delivery under the conditions of this study were 10.37 mg and 15.39 mg, respectively. Ropivacaine is suitable for spinal anesthesia in cesarean delivery.</p>