Anesthesia and analgesia
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Anesthesia and analgesia · Feb 1995
Randomized Controlled Trial Clinical TrialHemodynamic and analgesic effects of clonidine added repetitively to continuous epidural and spinal blocks.
Clonidine in spinal and epidural blocks prolongs anesthesia, but can cause hypotension and bradycardia. The aim of our study was to compare hemodynamic and analgesic effects of spinal versus epidural clonidine alone and after repetitive dosing. In a prospective, randomized, double-blind study, we evaluated 40 patients scheduled for lower extremity orthopedic surgery under continuous spinal or epidural anesthesia with bupivacaine 0.5% (initial dose 5 mg and 50 mg, respectively). ⋯ Duration of spinal and epidural anesthesia was increased more than two fold by clonidine. In summary, the addition of clonidine prolongs analgesia by either route. These results may be explained by clonidine's sites of action in hemodynamic control and the density of bupivacaine-induced block.
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Anesthesia and analgesia · Feb 1995
Preoperative antiplatelet therapy does not increase the risk of spinal hematoma associated with regional anesthesia.
One thousand orthopedic procedures in 924 patients given spinal or epidural anesthesia were prospectively studied to determine the risk of hemorrhagic complications associated with regional anesthesia. A history of excessive bruising or bleeding was elicited in 115 (12%) patients. Preoperative antiplatelet medications were taken by 386 (39%) patients. ⋯ Preoperative antiplatelet therapy did not increase the incidence of minor hemorrhagic complications. However, female gender, increased age, a history of excessive bruising/bleeding, surgery to the hip, continuous catheter anesthetic technique, large needle gauge, multiple needle passes, and moderate or difficult needle placement were all significant risk factors. The lack of correlation between antiplatelet medications and bloody needle or catheter placement (producing clinically insignificant collections of blood in the spinal canal or epidural space) is strong evidence that preoperative antiplatelet therapy is not a significant risk factor for the development of neurologic dysfunction from spinal hematoma in patients who undergo spinal or epidural anesthesia while receiving these medications.
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Anesthesia and analgesia · Feb 1995
Randomized Controlled Trial Clinical TrialVomiting after outpatient tonsillectomy and adenoidectomy in children: the role of nitrous oxide.
The role of nitrous oxide anesthesia in causing postoperative vomiting (POV) was studied in 60 children undergoing outpatient tonsillectomy and adenoidectomy. In this controlled, randomized, double-blind investigation, anesthesia was induced by inhalation of a volatile anesthetic in both groups. ⋯ Pharmacologic intervention was administered on the basis of evaluation by the nurses. Although a high incidence of POV was noted in both groups, there was no difference in either the incidence or the severity of POV between the group receiving nitrous oxide and the group receiving no nitrous oxide.
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Anesthesia and analgesia · Feb 1995
Randomized Controlled Trial Clinical TrialRopivacaine 0.25% versus bupivacaine 0.25% for continuous epidural analgesia in labor: a double-blind comparison.
We compared the effects of continuous epidural infusion of ropivacaine 0.25% with bupivacaine 0.25% on pain relief and motor block during labor, and on the neonate. Seventy-six full-term parturients in active labor requiring epidural analgesia were randomly allocated to receive either bupivacaine 0.25% or ropivacaine 0.25%. Fifteen minutes after a loading dose of 10 mL of the study drug, an epidural infusion with the same drug was started at 6-12 mL/h to maintain an adequate block. ⋯ There was a higher proportion of the neonates in the ropivacaine group (26/31 = 84%) who had a neurologic and adaptive capacity score (NACS) > or = 35 2 h after delivery than in the bupivacaine group (18/29 = 62%). We conclude that ropivacaine 0.25% and bupivacaine 0.25% are equally effective for epidural pain relief during labor. Ropivacaine may have an advantage over bupivacaine regarding neonatal neurobehavioral performance during the first few hours after delivery, although further studies will be required to substantiate this.
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Anesthesia and analgesia · Feb 1995
Randomized Controlled Trial Clinical TrialThe influence of the duration of control stimulation on the onset and recovery of neuromuscular block.
The onset of action of atracurium 450 micrograms/kg, mivacurium 160 micrograms/kg, and vecuronium 80 micrograms/kg was measured after train-of-four (TOF) stimulation had been applied for 1, 5, 10, 15, or 20 min in groups of 10 patients each during anesthesia with thiopental, nitrous oxide-oxygen, and fentanyl. TOF stimulation was applied to the ulnar nerve at 2 Hz every 12 s and the force of contraction of the adductor pollicis muscle recorded. There was a progressive and significant reduction in the time to onset of maximum block with increasing times of control stimulation with all three relaxants (P < 0.0001). ⋯ The time to recovery of T1 (first response in the TOF stimulation) to 25% of control (duration of clinical relaxation) increased from 33 +/- 5.7 to 52 +/- 13.4 min with atracurium, 25 +/- 7.6 to 38 +/- 9.4 min with vecuronium, and 13 +/- 2.5 to 18 +/- 3.5 min with mivacurium with the period of control stimulation increasing from 1 to 20 min. The differences were significant for atracurium and vecuronium (P < 0.05-0.0001). We conclude that increasing periods of control stimulation are associated with decreasing time to onset of neuromuscular block with atracurium, vecuronium, and mivacurium at the adductor pollicis muscle.(ABSTRACT TRUNCATED AT 250 WORDS)