Anesthesia and analgesia
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Anesthesia and analgesia · Dec 1982
Fentanyl infusion anesthesia for aortocoronary bypass surgery: plasma levels and hemodynamic response.
Plasma fentanyl concentrations were measured by radioimmunoassay in patients during aortocoronary bypass surgery and correlated with hemodynamic responses to surgical stimulation. Thirty patients scheduled for aortocoronary bypass surgery were divided into three groups of 10. Patients in group 1 received fentanyl, 30 micrograms/kg, as a loading dose followed by an infusion of 0.3 microgram/kg/min; those in group 2 received 40 micrograms/kg as a loading dose followed by an infusion of 0.4 microgram/kg/min; and those in group 3 received 50 micrograms/kg as the loading dose followed by an infusion of 0.5 microgram/kg/min. ⋯ Response to stimulation was treated by the administration of droperidol or volatile anesthetic agents. At a plasma concentration of 15 ng/ml, 50% of patients had an increase in systolic blood pressure which required treatment. This minimal intra-arterial concentration, analogous to MAC, can be achieved by the administration of fentanyl as a loading dose of 50 micrograms/kg followed by an infusion of 0.5 microgram/kg/min.
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Anesthesia and analgesia · Dec 1982
Comparative StudyA double-blind comparison of cimetidine and ranitidine as prophylaxis against gastric aspiration syndrome.
Preoperative cimetidine, ranitidine, or placebo were administered, orally or intravenously to 190 patients in a double-blind study. The volume and pH of gastric aspirate samples, obtained after tracheal intubation and before extubation, were measured. ⋯ Oral ranitidine, 150 mg, produced a significantly higher mean pH level than did oral cimetidine, 300 mg, and tended to give fewer patients at risk. The volumes of gastric contents aspirated were similar following each of the drugs except that the volume was significantly less two hours following oral ranitidine, 150 mg, than after oral cimetidine, 300 mg.
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Anesthesia and analgesia · Dec 1982
Comparative StudyA comparative in vivo study of local neurotoxicity of lidocaine, bupivacaine, 2-chloroprocaine, and a mixture of 2-chloroprocaine and bupivacaine.
This study was undertaken because of several recent reports of adverse neurologic reactions following the use of 2-chloroprocaine. Carotid sheaths containing undisturbed vagus nerve were surgically exposed in rabbits and bathed in situ for up to 1 hour in one of the following-isotonic solutions: physiologic salt solution, lidocaine 2%, bupivacaine 0.75%, 2-chloroprocaine 3%, or a mixture of 2-chloroprocaine 1.5% and bupivacaine 0.375%. Each solution contained epinephrine, 5 micrograms/ml, (1:200,000). ⋯ Histologic sections revealed the presence of epineurial cellular infiltration and fibrosis, perineurial fibrosis, and axonal degeneration in nerves that had been exposed to 2-chloroprocaine or the mixture of 2-chloroprocaine and bupivacaine. Histologic abnormalities were minor or absent following exposure to lidocaine, to bupivacaine, or to physiologic salt solution. These findings suggest that, under the conditions of the experiments, 2-chloroprocaine is more neurotoxic than lidocaine or bupivacaine.
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Anesthesia and analgesia · Dec 1982
Brachial plexus block for pain relief after modified radical mastectomy.
Brachial plexus block using an intraclavicular approach was performed at the completion of surgery in 47 patients having modified radical mastectomies. In 48 control patients having similar operations, brachial plexus block was not performed. ⋯ The time elapsed between the end of anesthesia and requirement of the first analgesic was significantly longer when the brachial plexus was blocked (p less than 0.001). The efficacy, simplicity, and safety of blocking the brachial plexus at the completion of surgery following modified mastectomy demonstrate that this technique could be routinely used for the relief of postoperative pain in patients having modified radical mastectomies.