Anesthesia and analgesia
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Anesthesia and analgesia · May 1996
Randomized Controlled Trial Clinical TrialBolus metoclopramide does not enhance morphine analgesia after cesarean section.
Intravenous metoclopramide potentiates the analgesic effects of opioids in postoperative patients. We speculate that increased spinal concentrations of acetylcholine from metoclopramide-induced acetylcholinesterase inhibition is the mechanism responsible for enhanced morphine analgesia from metoclopramide. Sixty patients undergoing elective cesarean section with subarachnoid anesthesia were randomized to receive either 20 mg metoclopramide or saline intravenously 30-60 min prior to subarachnoid injection. ⋯ CSF cholinesterase activity was similar to values in nonpregnant patients demonstrated previously. This study failed to confirm the morphine-enhancing action of 20 mg intravenous metoclopramide in postoperative patients. Furthermore, this dose of metoclopramide does not inhibit CSF acetylcholinesterase.
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Anesthesia and analgesia · May 1996
Comparative StudyThe use of a circumferential cathode improves amplitude of intraoperative electrical transcranial myogenic motor evoked responses.
Measurement of motor evoked responses to transcranial electrical stimulation (tc-MER) is a technique for intraoperative monitoring of motor pathways. Since most anesthetics significantly reduce motoneuronal excitability, optimal stimulation paradigms should be sought. We compared the efficiency of stimulus delivery using two different configurations of the cathode component of the stimulating electrode pair (circumferential: Fz, F3, F4, A1, and A2 versus a single cathode at Fz). ⋯ There was no significant difference in onset latency between electrode configurations. The observed tc-MER amplitude augmentation with the use of a circumferential cathode might allow tc-MER monitoring in those patients who do not have sufficiently reproducible responses when a single cathode is used. A possible explanation is that the circumferential cathode alters the direction of the electrical currents in the cortex, resulting in more efficient depolarization of cortical motor neurons.
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Anesthesia and analgesia · May 1996
Perioperative distribution of pulmonary vascular resistance in patients undergoing coronary artery surgery.
This study was undertaken to measure distribution of pulmonary vascular resistance (PVR) perioperatively in patients undergoing coronary artery bypass grafting (CABG) and to examine the effects of cardiopulmonary bypass (CPB) on pulmonary capillary pressure (Pc) relative to wedge pressure (Pw). Pulmonary artery catheters were placed before anesthetic induction in 18 patients scheduled for elective CABG and systemic hemodynamic variables were measured. Pulmonary artery pressure was recorded during balloon inflation and stored for off-line determination of Pc. ⋯ Administration of large-dose opioid anesthesia had no significant effect (P > 0.05) on total PVR or on segmental distribution of vascular resistance. At all data points, Pc was significantly larger than Pw (P < 0.05). This study demonstrates that perioperative measurement of Pc is feasible, that during CABG under these conditions, relative contribution of arterial and venous resistances remain relatively unchanged, that Pc is always larger than Pw, and that the administration of large-dose opioid anesthesia has a minimal effect on pulmonary vascular hemodynamics.
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Anesthesia and analgesia · May 1996
Randomized Controlled Trial Clinical Trial Retracted PublicationPostarthroscopic meniscus repair analgesia with intraarticular ketorolac or morphine.
Both ketorolac, a nonsteroidal antiinflammatory drug, and morphine, an opioid agonist, provide enhanced patient analgesia after arthroscopic knee surgery when administered via the intraarticular route. This study was designed to determine whether ketorolac or morphine results in better patient analgesia and whether their combination would provide superior analgesia to either drug alone. Patients undergoing arthroscopic knee meniscus repair under local anesthesia with sedation were evaluated. ⋯ This study revealed a significant benefit from the individual intraarticular administration of both morphine and ketorolac. The combination of these drugs did not result in decreased postoperative pain or need for postoperative analgesics, and it did not result in an increased analgesic duration. We conclude that the use of either intraarticular ketorolac or intraarticular morphine improves the comfort in patients undergoing arthroscopic meniscus repair and that their combination offers no advantage over either drug alone.
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Anesthesia and analgesia · May 1996
Lidocaine plasma concentrations in pediatric patients after providing airway topical anesthesia from a calibrated device.
The aim of this prospective study was to evaluate plasma lidocaine concentrations in infants and children after laryngeal spray using a calibrated device. Twenty-one patients aged 3 to 24 mo requiring laryngoscopy or bronchoscopy were included in the study. Anesthesia was induced via a mask with halothane up to 2% in 100% O2. ⋯ The dose of lidocaine administered ranged between 0.9 and 2.6 mg/kg. Maximum plasma lidocaine concentration (Cmax) was 1.05 +/- 0.55 micrograms/mL (mean +/- SD; range 0.24-2.29 micrograms/mL). With this procedure, we demonstrated the safety of administering lidocaine to children by laryngeal spraying using a 5% sprayer.