Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1999
Clinical TrialDevelopment and psychometric testing of a quality of recovery score after general anesthesia and surgery in adults.
A variety of methods have been used to quantify aspects of recovery after anesthesia. Most are narrowly focused, are not patient-rated, and have not been validated. We therefore set out to develop a patient-rated quality of recovery score. We constructed a 61-item questionnaire that asked individuals (patients and relatives, medical and nursing staff; total n = 136) to rate various postoperative items describing features a patient may experience postoperatively. The most highly ranked items were included in a final nine-point index score, which we called the "QoR Score." We then studied two cohorts of surgical patients (n = 449). There was good convergent validity between the QoR Score and the visual analog scale score (rho = 0.55, P < 0.0001). Discriminant construct validity was supported by comparing resultant QoR Scores in patients undergoing day-stay, minor, and major surgery (P = 0.008), as well as a negative correlation with duration of hospital stay (rho = -0.20, P < 0.0001), and, using multivariate regression, demonstrating a significant negative relationship between QoR Score and female gender (P = 0.048) and older age (P = 0.041). There was also good interrater agreement (rho = 0.55, P < 0.0001), test-retest reliability (median rho = 0.61, P < 0.0001), and internal consistency (alpha = 0.57 and 0.90, P < 0.0001). There was a significant difference between the groups of patients recovering from major and minor surgery (P < 0.001). This study demonstrates that the QoR Score has good validity, reliability, and clinical acceptability in patients undergoing many types of surgery. ⋯ We set out to develop a patient-rated quality of recovery score (QoR) that could be used both as a measure of outcome in perioperative trials and for clinical audit. We first surveyed patients and staff to identify important aspects of recovery, then developed a nine-point QoR Score. This was then compared with other measures of postoperative outcome. We found that the QoR Score is a useful measure of recovery after anesthesia and surgery.
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Anesthesia and analgesia · Jan 1999
Comparative StudyA comparison of the effects of propofol and sevoflurane on the systemic toxicity of intravenous bupivacaine in rats.
We compared the effects of propofol and sevoflurane on bupivacaine-induced central nervous system and cardiovascular toxicity in rats. Thirty-four male Sprague-Dawley rats were anesthetized with 70% N2O/30% O2 plus the 50% effective dose (ED50) of propofol (propofol group, n = 12); 70% N2O/30% O2 plus ED50 of sevoflurane (sevoflurane group, n = 11); or 70% N2O/30% O2 (control group, n = 11). Bupivacaine was infused at a constant rate of 2 mg x kg(-1) x min(-1) while electrocardiogram, electroencephalogram, and invasive arterial pressure were continuously monitored. The cumulative doses of bupivacaine that induced dysrhythmias, seizures, and 50% reduction of heart rate were larger in the propofol and sevoflurane groups than in the control group. The cumulative dose of bupivacaine that induced a 50% reduction in the mean arterial blood pressure was larger in the propofol group than in the sevoflurane and control groups. The margin of safety, assessed by the time between the onset of dysrhythmias and 50% reduction of mean arterial blood pressure, was wider in the propofol group than in the sevoflurane group. We conclude that propofol and sevoflurane attenuate bupivacaine-induced dysrhythmias and seizures and that propofol has a wider margin of safety than sevoflurane. ⋯ In anesthetized patients, dysrhythmias may be the only warning sign of intravascular injection of bupivacaine. Because propofol has a wider margin of safety than sevoflurane, life-threatening cardiovascular depression may be prevented by stopping the injection of bupivacaine at the onset of dysrhythmias during propofol anesthesia.
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Anesthesia and analgesia · Jan 1999
Clinical TrialThe intensity of preoperative pain is directly correlated with the amount of morphine needed for postoperative analgesia.
The aim of this study was to examine whether severity of preoperative pain intensity is related to postoperative pain and morphine consumption. Sixty consecutive patients scheduled for total hip surgery during intrathecal anesthesia were studied. Preoperative visual analog scale (VAS) scores and analgesic intake was assessed 1 day before surgery. Three groups of patients were identified: those with mild pain (n = 12, VAS score 0-4), moderate pain (n = 18, VAS score 4-7), and severe pain (n = 28, VAS score 7-10). Postoperative pain scores were recorded in the first 24 h, as was the amount of morphine delivered by the patient-controlled analgesia pump. There were no differences among the groups in VAS scores at any time. Severe preoperative pain levels correlated with significantly greater postoperative morphine intake. The mean morphine intake during the first 24 h postoperatively was 19.2 mg in the mild pain group, 21.2 mg in the moderate pain group, and 29.5 mg in the severe pain group (P < 0.05 compared with both other groups). We conclude that patients with severe preoperative pain self-medicate to achieve postoperative pain scores equivalent to those of patients with mild and moderate pain and require a greater postoperative morphine intake for adequate analgesia than patients with mild or moderate preoperative pain. ⋯ In this study, we showed that severity of preoperative pain intensity relates to postoperative pain levels and morphine consumption. Patients scheduled for total hip surgery with severe preoperative pain require more postoperative morphine in the first 24 h.
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Anesthesia and analgesia · Jan 1999
Anesthesia for cesarean section and acid aspiration prophylaxis: a German survey.
We surveyed routine anesthetic practice and measures to prevent acid aspiration syndrome (AAS) in patients undergoing cesarean section (CS) throughout Germany. Of 1061 questionnaires, 81.9% were returned. For scheduled CS, general anesthesia was used in 63% of cases, and for urgent CS, it was used in 82% of cases. Regional anesthesia was used less often for both scheduled and urgent CS in smaller (< or =500 deliveries/yr; 28% and 16%, respectively) than in medium-sized (500-1000 deliveries/yr; 42% and 19%, respectively) or major obstetric departments (>1000 deliveries/yr; 45% and 21%, respectively). Among the regional techniques, epidural anesthesia (59%) was preferred more than spinal anesthesia (40%) in scheduled CS. In urgent CS, spinal anesthesia predominated (56% vs 42%). Pharmacological AAS prophylaxis is routinely used in 69% (68%) of departments before elective (urgent) CS under general anesthesia and in 52% under regional anesthesia. H2-blocking drugs are preferred for AAS prophylaxis over H2-blocker plus sodium citrate and sodium citrate alone. Both the incidence of and the mortality from AAS at CS are very low in Germany (<1 fatality per year). Nevertheless, AAS prophylaxis deserves more widespread use in obstetric anesthesia and in other patients at risk (e.g., children, outpatients). ⋯ According to a countrywide survey, the use of regional anesthesia for cesarean section and pharmacological prophylaxis of acid aspiration syndrome is considerably less common in Germany than in the United States, United Kingdom, or other European countries.
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Anesthesia and analgesia · Jan 1999
Clinical TrialOxygen delivery during retrograde cerebral perfusion in humans.
Retrograde cerebral perfusion (RCP) potentially delivers metabolic substrate to the brain during surgery using hypothermic circulatory arrest (HCA). Serial measurements of O2 extraction ratio (OER), PCO2, and pH from the RCP inflow and outflow were used to determine the time course for O2 delivery in 28 adults undergoing aortic reconstruction using HCA with RCP. HCA was instituted after systemic cooling on cardiopulmonary bypass for 3 min after the electroencephalogram became isoelectric. RCP with oxygenated blood at 10 degrees C was administered at an internal jugular venous pressure of 20-25 mm Hg. Serial analyses of blood oxygen, carbon dioxide, pH, and hemoglobin concentration were made in samples from the RCP inflow (superior vena cava) and outflow (innominate and left carotid arteries) at different times after institution of RCP. Nineteen patients had no strokes, five patients had preoperative strokes, and four patients had intraoperative strokes. In the group of patients without strokes, HCA with RCP was initiated at a mean nasopharyngeal temperature of 14.3 degrees C with mean RCP flow rate of 220 mL/min, which lasted 19-70 min. OER increased over time to a maximal detected value of 0.66 and increased to 0.5 of its maximal detected value 15 min after initiation of HCA. The RCP inflow-outflow gradient for PCO2 (slope 0.73 mm Hg/min; P < 0.001) and pH (slope 0.007 U/min; P < 0.001) changed linearly over time after initiation of HCA. In the group of patients with preoperative or intraoperative strokes, the OER and the RCP inflow-outflow gradient for PCO2 changed significantly more slowly over time after HCA compared with the group of patients without strokes. During RCP, continued CO2 production and increased O2 extraction over time across the cerebral vascular bed suggest the presence of viable, but possibly ischemic tissue. Reduced cerebral metabolism in infarcted brain regions may explain the decreased rate of O2 extraction during RCP in patients with strokes. ⋯ Examining the time course of oxygen extraction, carbon dioxide production, and pH changes from the retrograde cerebral perfusate provided a means to assess metabolic activity during hypothermic circulatory arrest.