International journal of obstetric anesthesia
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Int J Obstet Anesth · Oct 2004
Interactive effect of sevoflurane with isradipine or indomethacin on spontaneous contractile activity of isolated pregnant rat myometrium.
Volatile anesthetics, calcium antagonists and non-steroidal anti-inflammatory drugs inhibit contractile activity of myometrial smooth muscle. The aim of this study was to investigate the interactive effect of sevoflurane with isradipine or indomethacin on spontaneous contractile activity of myometrial strips isolated from pregnant rats. The myometrial strips were excised from rats (250-300 g) at 19-21 days of gestation and mounted in tissue baths for recording of isometric tension. ⋯ Pretreatment with isradipine (10(-6) M) or indomethacin (10(-7) M), concentrations that themselves had no effect on spontaneous contractility, significantly increased the inhibitor responses to sevoflurane on amplitude and frequency of myometrial contractions, beginning at 1 MAC (P<0.05). Blockade of calcium channels in myometrial smooth muscle may increase the inhibitor effect of sevoflurane. Further work is needed to determine the cellular mechanism(s) of this interaction.
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Int J Obstet Anesth · Oct 2004
Spinal anesthesia for cesarean section following inadequate labor epidural analgesia: a retrospective audit.
An audit of 115 parturients requiring spinal anesthesia for cesarean section in the setting of an inadequate, pre-existing epidural block. Median dose of 9.38 mg of bupivacaine + 15 mcg fentanyl was used. No patients received an epidural bolus within 30 min of their subarachnoid block.
There were no cases of total spinal block.
Because total spinal after inadequate epidurals had been 'not uncommon' in the department, the researchers had altered the department's practice to be:
- Ensuring at least 30 min since last epidural bolus.
- Reducing spinal dose by 20%. (NB: plain bupivacaine used)
- Delay supine positioning for 2 min after spinal performed.
(Plus patient weight < 120 kg and height > 1.47 m)
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Int J Obstet Anesth · Oct 2004
Randomized Controlled Trial Clinical TrialEffect of varying doses of fentanyl with low dose spinal bupivacaine for caesarean delivery in patients with pregnancy-induced hypertension.
The purpose of this study was to evaluate haemodynamic stability, perioperative analgesia and neonatal outcome following intrathecal 0.5% bupivacaine 7.5 mg with varying doses of fentanyl, in parturients with pregnancy-induced hypertension. Forty-five parturients with pregnancy-induced hypertension scheduled for caesarean section were randomly allocated to receive 7.5 mg bupivacaine with saline 1 mL (group B), fentanyl 10 microg (group Bf10) or fentanyl 20 microg (group Bf20) intrathecally. Heart rate, blood pressure, and sensory block were recorded at regular intervals. ⋯ Duration of postoperative analgesia was significantly longer in group Bf20 (5.55+/-1.18 h) than in group Bf10 (3.97+/-2.12 h) and group B (3.27+/-1.8 h) (P<0.05). Neonatal outcome was similar in the three groups. Intrathecal fentanyl with low dose bupivacaine provides good surgical anaesthesia and prolongs the duration of analgesia without haemodynamic or neonatal compromise in patients with pregnancy-induced hypertension undergoing caesarean delivery.