Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of variable-dose patient-controlled analgesia with fixed-dose patient-controlled analgesia.
We examined the effect on the quality of analgesia and side effects of increasing the patient control component of morphine patient-controlled analgesia (PCA) by offering the patient a choice of bolus dose sizes. Using a three-button hand piece, patients could choose between 0.5-, 1.0-, and 1.5-mg boluses of morphine (variable-dose PCA, VDPCA). Successful demands were delivered by a modified Graseby 3400 Anaesthesia Pump controlled by a Toshiba T1900 computer. ⋯ Treatment groups did not differ in their duration of PCA therapy, total morphine consumption, or time spent with mild or severe oxyhemoglobin desaturation. There were no differences in their ease of controlling pain, satisfaction with pain control, experience of pain on movement, quality of sleep, severity of nausea, or incidence of vomiting. Although the more complex VDPCA technique provides adequate postoperative analgesia, it does not offer any advantage over conventional FDPCA.
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of isoflurane versus fentanyl as primary anesthetics for mitral valve surgery.
We conducted a randomize study of fentanyl compared to isoflurane anesthesia in patients with pulmonary hypertension undergoing mitral valve surgery. Patients were premedicated and randomly assigned to one of two groups: 21 patients had anesthesia induced with thiopental and maintained with isoflurane; 23 patients had anesthesia induced with a fentanyl bolus and maintained with a fentanyl infusion. Adjustments of fentanyl infusion and isoflurane concentration, as well as fentanyl boluses and vasoactive/positive inotropic medication, were administered to maintain preoperative arterial blood pressure. ⋯ Adequate hemodynamic profiles were achieved in both groups with comparable use of inotropic and vasoactive medication, with the exception of norepinephrine that was administered intraoperatively to significantly (P < 0.05) more patients in the isoflurane-based anesthesia group. Neither technique was associated with acute improvement of right heart performance or pulmonary hypertension, in large part because of morphologic changes of the pulmonary arterial bed, occurring with long-standing mitral valve disease. We conclude that isoflurane-based anesthesia is adequate for this type of surgery, although there is a higher anesthetic algorithm failure rate than with fentanyl-based anesthetic technique.
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of cisatracurium and atracurium: onset of neuromuscular block after bolus injection and recovery after subsequent infusion.
Cisatracurium is a new nondepolarizing muscle relaxant. In patients randomized to receive either cisatracurium (n = 40) or atracurium (n = 20) we compared the time course of neuromuscular block. The initial bolus dose of cisatracurium was 0.1 mg/kg, that of atracurium 0.5 mg/kg. ⋯ The infusion rates for a 95% +/- 4% neuromuscular block were 1.5 +/- 0.4 micrograms.kg-1.min-1 for cisatracurium and 6.6 +/- 1.7 micrograms.kg-1.min-1 for atracurium, 3.3 times those of cisatracurium when referenced to the active cations. After the infusion, the spontaneous recovery intervals 25%-75% of 18 +/- 11 min and 18 +/- 8 min for cisatracurium and atracurium (P = 0.896) were shortened to 5 +/- 2 min and 4 +/- 3 min (P = 0.921) after neostigmine. While attributing different onset times also to differences in the initial doses, we conclude that time profiles for neuromuscular block of both muscle relaxants, when given in equipotent doses, are not different.
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Clinical TrialDexamethasone decreases vomiting by children after tonsillectomy.
We evaluated the effect of dexamethasone on vomiting after elective tonsillectomy in 133 healthy children aged 2-12 yr in a randomized, stratified, blocked, double-blind, placebo-controlled study. General anesthesia was induced by inhalation of N2O and halothane or intravenously (IV) with propofol. Anesthesia was maintained with N2O and halothane. ⋯ Vomiting, both in-hospital and postdischarge, was decreased by the prophylactic administration of dexamethasone. Each episode of in-hospital vomiting prolonged discharge by 13 +/- 2 min, mean +/- SD (P < 0.001). In conclusion, dexamethasone markedly decreased vomiting by healthy children after elective tonsillectomy in an ambulatory hospital setting.
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Anesthesia and analgesia · Nov 1996
Randomized Controlled Trial Clinical TrialEffects of a hemoglobin-based oxygen carrier (HBOC-201) on hemodynamics and oxygen transport in patients undergoing preoperative hemodilution for elective abdominal aortic surgery.
We conducted a pilot study to evaluate the effects of HBOC-201, a bovine hemoglobin-based oxygen carrier, on hemodynamics and oxygen transport in patients undergoing preoperative hemodilution for elective abdominal aortic surgery. After induction of anesthesia and isovolemic hemodilution with 1 L of lactated Ringer's solution, 13 patients were randomly assigned to receive, within 30 min, 3 mL/kg of either HBOC-201 or 6% hydroxyethyl starch (HES). Monitored variables included invasive arterial and pulmonary artery pressures, arterial and mixed venous blood gases, and calculations of cardiac index (CI), systemic and pulmonary vascular resistance indices, oxygen delivery index (DO2I), oxygen consumption index (VO2I), and oxygen extraction ratio (O2ER). ⋯ No significant changes were noticed in heart rate and pulmonary vascular resistance index. DO2I and VO2I, 30 min after the infusion of HBOC-201, were 79% (P = 0.046) and 76% (P = 0.028) of the preinfusion values, respectively, whereas CaO2 and O2ER remained unaffected. We conclude that HBOC-201, at a dose of 3 mL/kg, impairs oxygen delivery because of adverse effects on cardiac output.