Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1996
Randomized Controlled Trial Comparative Study Clinical TrialAttenuation of cardiovascular responses to tracheal extubation: verapamil versus diltiazem.
We studied the effect of intravenous injection of verapamil (0.05 mg/kg or 0.1 mg/kg) on cardiovascular changes during tracheal extubation and emergence from anesthesia and compared the efficacy of the drug with that of diltiazem (0.2 mg/kg). Eighty patients (ASA physical status I) who were to undergo elective gynecological surgery were randomly assigned to one of four groups (n = 20 each): saline (control), 0.05 mg/kg and 0.1 mg/kg verapamil, and 0.2 mg/kg diltiazem. These medications were given 2 min before tracheal extubation. ⋯ Both calcium channel blockers attenuated the increases in these variables. The inhibitory effect was greatest with verapamil 0.1 mg/kg, while the alleviative effect of verapamil 0.05 mg/kg was inferior to that of diltiazem 0.2 mg/kg. These findings suggest that a bolus injection of verapamil 0.1 mg/kg given 2 min before tracheal extubation is a more effective prophylactic for attenuating the cardiovascular changes associated with extubation than is diltiazem 0.2 mg/kg.
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Anesthesia and analgesia · Jun 1996
Randomized Controlled Trial Comparative Study Clinical TrialContinuous small-dose aprotinin controls fibrinolysis during orthotopic liver transplantation.
Large doses of aprotinin (1,000,000-2,000,000 kallikrein inhibitor units [KIU] initial dose and a 500,000 KIU/h infusion) have been used during orthotopic liver transplantation (OLT) to reduce the incidence and severity of fibrinolysis. This double-blinded study was designed to investigate whether a small-dose infusion of aprotinin (200,000 KIU/h) would control fibrinolysis. A controlled study was undertaken to compare small-dose aprotinin with a placebo in patients undergoing OLT with veno-venous bypass. ⋯ Blood levels of fibrin degradation products (FDP) were significantly higher in the control group (95% > 20 micrograms/mL) at the end of surgery compared to the aprotinin group (53% > 20 micrograms/mL, P < 0.01). The transfusion of cryoprecipitate units was more in the control group versus the aprotinin (12.6 +/- 12.8 vs 5.7 +/- 7.5; P < 0.04), as was the number of fresh frozen plasma units (6.6 +/- 3.5 vs 3.6 +/- 6.1; P < 0.05). We conclude that an infusion of a small dose of aprotinin can safely control fibrinolysis during liver transplantation with a concomitant reduction in transfusion of blood products.
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Anesthesia and analgesia · Jun 1996
Comparative Study Clinical TrialThe relationship between cerebral blood flow and transcranial Doppler blood flow velocity during hypothermic cardiopulmonary bypass in adults.
A noninvasive, simple, and continuous method to assess cerebral perfusion during cardiopulmonary bypass (CPB) could help prevent cerebral ischemia. Transcranial Doppler sonography (TCD) allows a noninvasive, on-line measurement of blood flow velocity in cerebral arteries. The correlation of TCD-estimated and actual cerebral blood flow (CBF) has not been well studied during CPB. ⋯ The pooled change in MCA velocity and CBF as percentage of baseline (prebypass) for all patients and at all time points had a correlation of 0.33 (r). A decrease or increase in MCA velocity did not necessarily indicate a corresponding decrease or increase in CBF. This technology may be of limited usefulness during the circulatory condition of hypothermic, nonpulsatile CPB.
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Anesthesia and analgesia · Jun 1996
Comparative Study Clinical TrialUnilateral spinal anesthesia using low-flow injection through a 29-gauge Quincke needle.
Restriction of sympathetic denervation during spinal anesthesia may minimize hemodynamic alterations. Theoretically, the use of nonisobaric anesthetics may allow unilateral anesthesia and thus restrict sympathetic denervation to one side of the body. The present prospective study investigates the incidence of unilateral spinal anesthesia using hyperbaric bupivacaine 0.5% (1.4 mL, 1.6 mL, 1.8 mL, or 2.0 mL) injected via a 29-gauge Quincke needle with a pump-controlled injection flow of 1 mL/min. ⋯ Twenty minutes after injection of the local anesthetic, mean arterial blood pressure decreased significantly in patients with bilateral sympathetic blockade from 87 +/- 8 to 83 +/- 8 mm Hg (P < 0.01) but not in patients with unilateral sympathetic blockade (from 87 +/- 11 to 85 +/- 10 mm Hg). In conclusion, low-flow injection (1 mL/min) of hyperbaric bupivacaine 0.5% via a 29-gauge Quincke needle prevented bilateral sympathetic blockade in more than 69% of the patients. The data further suggest that loss of temperature discrimination alone is not a reliable estimation of sympathetic block.