Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1997
Randomized Controlled Trial Comparative Study Clinical TrialPreoperative acute hypervolemic hemodilution with hydroxyethylstarch: an alternative to acute normovolemic hemodilution?
Acute normovolemic hemodilution (ANH) may help to reduce demand for homologous blood but requires extra time and apparatus. A more simple procedure is acute hypervolemic hemodilution (HHD), where hydroxyethylstarch is administered preoperatively without removal of blood. In a prospectively randomized study we compared ANH (preoperatively 15 mL/kg autologous blood removal and replacement with 15 mL/kg of hydroxyethylstarch with HHD (15 mL/kg of hydroxyethylstarch administered preoperatively) in 49 patients undergoing hip arthroplasty. ⋯ Mean time required to perform ANH was 58 (46-62) min versus HHD 16 (12-19) min (P < 0.05). Costs for ANH were $63.60 USD and for HHD $32.75 USD (labor costs not included). In orthopedic patients undergoing hip replacement with a predicted blood loss of about 1000 mL, HHD seems to be a simple as well as time- and cost-saving alternative for ANH.
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Anesthesia and analgesia · Jan 1997
Randomized Controlled Trial Comparative Study Clinical TrialPrevention of hypotension during spinal anesthesia: a comparison of intravascular administration of hetastarch versus lactated Ringer's solution.
This study was designed to compare the efficacy of 6% hetastarch to that of crystalloid administration in reducing the incidence and severity of hypotension during spinal anesthesia. Forty ASA grade I patients scheduled for postpartum tubal ligations under spinal anesthesia were randomly allocated to receive either 500 mL of hetastarch solution or 1000 mL of lactated Ringer's solution prior to spinal anesthesia. Spinal anesthesia was managed identically in both groups by anesthesiologists who were unaware of the type of fluid administered. ⋯ The difference in the incidence of hypotension was significant (P < 0.05). The requirement of 5-mg bolus doses of ephedrine to maintain systolic arterial blood pressure > 75% of baseline was significantly greater in the lactated Ringer's group than in the hetastarch group (15 vs 4, P < 0.05). We conclude that an intravenous infusion of 500 mL of 6% hetastarch solution is more effective than 1000 mL lactated Ringer's solution in attenuating spinal anesthesia induced hypotension in women undergoing postpartum tubal ligation.
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Anesthesia and analgesia · Jan 1997
Biotransformation of halothane, enflurane, isoflurane, and desflurane to trifluoroacetylated liver proteins: association between protein acylation and hepatic injury.
In susceptible patients, halothane, enflurane, isoflurane, and desflurane can produce severe hepatic injury by an immune response directed against reactive anesthetic metabolites covalently bound to hepatic proteins. The incidence of hepatotoxicity appears to directly correlate with anesthetic metabolism catalyzed by cytochrome P450 2E1 to trifluoroacetylated hepatic proteins. In the present study, we examined whether the extent of acylation of hepatic proteins in rats by halothane, enflurane, isoflurane, and desflurane correlated with reported relative rates of metabolism. ⋯ Sera from patients with a clinical diagnosis of halothane hepatitis showed antibody reactivity against hepatic proteins from rats exposed to halothane or enflurane. No reactivity was detected in rats exposed to isoflurane, desflurane, or oxygen alone. These results indicate that production of acylated proteins may be an important mediator of anesthetic-induced hepatotoxicity.
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Anesthesia and analgesia · Jan 1997
Randomized Controlled Trial Comparative Study Clinical TrialPrevention of spinal anesthesia-induced hypotension in the elderly: comparison between preanesthetic administration of crystalloids, colloids, and no prehydration.
The practice of routinely prehydrating patients by infusing a crystalloid or colloid solution (up to 1.0 L/70 kg) for prevention of spinal anesthesia-induced hypotension has been challenged recently, after several reports of failure to demonstrate its efficacy in young women. We compared the incidence and frequency of hypotension and vasopressor therapy after spinal anesthesia and no prehydration with crystalloid and colloid prehydration in elderly patients. Eighty-five ASA grade I or II patients (aged 60-89 yr) for elective total hip replacement were randomized to receive 500 mL crystalloid solution (Hartmanns, n = 29), 500 mL colloid (Haemaccel, n = 28), or no prehydration (n = 28) over 10 min prior to spinal anesthesia. ⋯ Although absolute systolic BP readings were significantly higher in the colloid group between 6 and 30 min (P < 0.05), the incidence of hypotension was not significantly different between the groups. The incidence of ephedrine use, incidence of nausea/vomiting, and median total dose of ephedrine were similar in all groups. We conclude that, in elderly patients undergoing elective procedures, withholding prehydration is not associated with any greater degree of hypotension or need for vasopressor therapy compared with crystalloid or colloid prehydration.
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Anesthesia and analgesia · Jan 1997
Randomized Controlled Trial Clinical TrialEffects of epidural and intravenous buprenorphine on halothane minimum alveolar anesthetic concentration and hemodynamic responses.
There is limited information regarding the effects of epidural or intravenous (i.v.) buprenorphine on minimum alveolar anesthetic concentration (MAC) of volatile anesthetic and hemodynamic responses to tracheal intubation and surgical incision. This study was conducted to find the effects of i.v. and epidural buprenorphine required for postoperative pain relief on halothane MAC and hemodynamic responses to tracheal intubation and surgical incision in 126 female patients. Patients were randomly assigned to the four groups: Group I received i.v. and epidural saline as a control; Group II was given buprenorphine 4 micrograms/kg i.v.; and Groups III and IV received buprenorphine 2 and 4 micrograms/kg epidurally, respectively. ⋯ Systolic blood pressure did not change significantly in Groups II-OR and IV-OR after tracheal intubation and in Group III-Ward and IV-Ward after surgical incision but increased significantly (P < 0.05) in the remaining groups in response to noxious stimuli. Heart rate responses to tracheal intubation and surgical incision were similar to those in systolic blood pressure. These results indicate that preanesthetic administration of epidural or IV buprenorphine required for postoperative analgesia reduces halothane MAC and attenuates hemodynamic responses to tracheal intubation and surgical incision according to the dose, route, and timing of administration.