ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

This study was undertaken to evaluate the analgesic effect of the combination of epidural morphine and clonidineversusepidural morphine alone in patients with postoperative pain. A randomized double-blind design was used, and 91 patients scheduled for postoperative pain relief by epidural morphine were studied. Patients received either a continuous epidural infusion of morphine and clonidine (group 1; n = 45) or morphine alone (group 2; n = 46) over the 72 h after major abdominal surgery. In the first 24 h, the dose of morphine was 6 mg per 24 h; during the second 24 h, it was decreased to 4 mg per 24 h; and in the final 24 h, it was decreased to 2 mg per 24 h in both groups. Group 1 patients received clonidine (450μg) during each 24-h period. Additional epidural bolus injections of 2 mg morphine and intravenous meperidine were given on demand. The pain score, blood pressure, heart rate, respiratory rate, and relative forced vital capacity were measured at fixed times during the first 72 h after operation. Total consumption of analgesics and side effects were recorded. Although the total consumption of analgesics was significantly higher in group 2 (p< 0.05), pain scores were lower in group 1 than group 2 during the entire observation periodP< 0.05). Epidural clonidine produced a significant decrease (P< 0.05) in heart rate and blood pressure, whereas the respiratory rate was not affected. Due to the better pain relief in group 1, the forced vital capacity was increased (P< 0.05). The incidence of side effects was similar in both groups. The authors concluded that epidural clonidine enhances the analgesic effect of epidural morphine after major abdominal surgery without causing more side effects. Circulatory effects resulting from combined administration of epidural clonidine and morphine should be considered when using this combined therapy.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

To determine the extent to which different electrocardiographic systems account for differences in reported incidence of perioperative myocardial ischemia, the authors simultaneously recorded in 109 patients undergoing coronary artery bypass grafting (CABG) the V5 or modified CMS lead on five ECG systems by means of a specially constructed common V5 lead. The systems included a Spacelabs@Alpha 14 Model Series 3200 ECG Cardule at bandwidths of 0.05–125 Hz and 0.5–30 Hz (a typical operating room monitor), a Marquette@Electronics MAC II ECG at 0.05–40 Hz and 0.05–100 Hz (a standard ECG), and a Del Mar@Holler recorder at 0.1–100 Hz. Relative ST-segment position and Incidence of new ischemia compared to the preoperative ECG were determined in 109 sets of preinduction traces and 877 sets of intraoperative traces. ST-segment position on the three recording systems conforming with the American Heart Association (AHA) low-frequency response recommendations (0.05 Hz) were similar. Compared to the standard ECG, ST-segment position on the Spacelabs at 0.5–30 Hz was consistently more negative. Displacement on the Holter was consistently less negative and less positive. By the 0.1-mV displacement criterion for diagnosis of myocardial ischemia on any one ECG system, 16.5% of patients on arrival and 32.1% of patients intraoperatively suffered new myocardial ischemia. Based on the operating room monitor, arrival and intraoperative ischemia were present in 15.6 and 27.5% of patients, respectively. Ischemia at the same periods was less frequent by the standard ECG system (5.5 and 12.8%, respectively) and least frequent by the Holter recorder (4.6 and 8.3%, respectively). If the criterion for ischemia was reduced to the least measurable ST-segment displacement (0.025 mV), the incidence would have been approximately the same with all ECG systems. These data confirm the higher sensitivity of the operating room monitoring system in diagnosing myocardial ischemia with no apparent loss of specificity. The authors suggest that the criterion of 0.1-mV displacement of the ST segment derived from exercise electrocardiography may be too stringent for perioperative patients with documented coronary artery disease.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Computer-assisted continuous infusion (CACI) is a pharmacokinetic model-driven infusion device that enables physicians to administer intravenous (iv) drugs in a quantitative fashion, specifying a theoretical blood or plasma concentration. This study evaluated the accuracy of CACI administration of fentanyl using a newly developed CACI device programmed with a well-known set of pharmacokinetic parameters for fentanyl. Patients received diazepam 1 or 2 h before surgery. Anesthesia was induced by a combination of 70% N2O and fentanyl administered by CACI to a predicted concentration of 15–25 ng.ml–1. After neuromuscular blockade and tracheal intubation, the desired plasma fentanyl concentration (setpoint) entered into CACI was 3–6 ng.ml−1, and then the setpoint fentanyl concentration was titrated according to strict criteria of adequate or inadequate anesthesia. Plasma samples for subsequent assay of fentanyl concentration then were taken: at predefined stimuli, when inadequate anesthesia occurred, or 5 min before an anticipated decrease in the fentanyl setpoint. The predictive accuracy of CACI was assessed by calculating for each patient the tenth, 50th, and 90th percentile of the performance error and absolute performance error from each measured and predicted plasma sample pair. Cumulative probability functions for each of these were then plotted. Precision was defined as the dispersion of the tenth to 90th percentile of the median percent performance error for the population and was found to be –31–26%. The median population performance error was –4%, and the median population absolute performance error was 21%. It was concluded that a CACI device using a single set of pharmacokinetic parameters can provide sufficient accuracy within a relatively homogeneous patient population to allow fentanyl to be administered to a concentration (rather than dose) that provides the desired therapeutic effect.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Fentanyl was administered to 21 patients using a computer-controlled infusion pump (CCIP) based on a pharmacokinetic model. Eleven of the patients were doted according to the pharmacokinetics described by McClain and Hug, and ten of the patients were dosed according to the pharmacokinetics described by Scott and Stanski. The authors measured the difference between the measured arterial fentanyl concentrations and the concentrations predicted by the CCIP for each pharmacokinetic parameter set. The median absolute performance error (MDAPE) in patients dosed according to McClain and Hug's parameters was 61%, and the MDAPE in patients dosed according to Scott and Stanski's parameters was 33%. The population pharmacokinetics in these 21 patients were analysed using a pooled data technique. The pharmacokinetics of fentanyl in this population showed a smaller central compartment volume and a more rapid initial distribution half-life than previously estimated for fentanyl. The derived pharmacokinetic parameters described these patients well and also predicted the observed fentanyl concentrations from four previously published fentanyl studies with reasonable accuracy. Comparison of the parameters used by the authors with those of McClain and Hug demonstrated that dosing regimens designed from pharmacokinetic models can be fairly accurate at the times sampled in the original study but may not be accurate at time points not sampled in the original research. The authors concluded that although the pharmacokinetics of fentanyl administered by CCIP are the same as the pharmacokinetics of fentanyl administered by a bolus or constant rate infusion, a pharmacokinetic study using a CCIP may be particularly effective at characterizing the most rapid distribution pharmacokinetic parameters, and thus may provide parameters appropriate for subsequent use in a CCIP.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

This study compared the effects of general and regional anesthesia on cognitive and psychosocial functioning in elderly persons. Sixty-four patients between 60 and 86 yr of age undergoing knee arthroplasty were randomly assigned to receive either general or regional anesthesia. A battery of psychometric tests, including the Satz-Mogel form of the Wechsler Adult Intelligence Scale–Revised), the Wechsler Memory Scale-Revised), and the Sickness Impact Profile, and various neuropsychological measures were administered by a blinded observer just before surgery and again 3 months later. Analyses of covariance revealed Improvements in most measures that were equivalent between groups. The results Indicated that there were no cognitive or psychosocial effects of general or regional anesthesia after 3 months in elderly persons undergoing knee arthroplasty. In this patient population, general anesthesia poses no more risk to long-term mental function than regional anesthesia.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The pattern of breathing and lung mechanics were evaluated during the first 7 h of life in full-term healthy newborns delivered by cerarean section with bupivacaine epidural anesthesia, without (group 1) or with the addition of 100 μg of fentanyl (group 2). Respiration and oxyhemoglobin saturation (Spo2) were measured with calibrated inductive plethysmography and pulse oximetry, respectively, and recorded from 60–420 min following birth. Compliance of respiratory system (CRS) was measured using a multiple occlusion technique at 60 and 420 min. Pattern of breathing was compared during period I (60–240 min) and II (240–420 min) with the following results: 1) the number of apnea spells was similar in both groups during both periods; 2) in both groups, from period I to period II a significant decrease in apnea duration was observed (7.6 ± 0.7 s–4.1 ± 0.5 s in group 1 and 6.7 ± 1.2 s–5.1 ± 1.0 s in group 2, respectively (P< 0.05); 3 respiratory rate (RR) and minute ventilation (VE) were similar in both groups during both study periods; and 4) both RR and VEsignificantly decreased in the two groups from period 1 to period II (i.e., 59 ± 5–46 ± 2 breath per min−1and 313 ± 60–248 ± 24 ml. kg−1. min−1in group 1, and 60 ± 2–51 ± 1 breath. min−1and 318 ± 12–290 ± 12 ml. kg−1. min−1in group 2, respectively;P< 0.05). For newborns without apnea breathing room air, Spo2was always greater than 95%, and the lowest Spo2after the occurrence of apnea was never less than 91%. Between both groups, CRSwere similar at 60 or 420 min but significantly Increased in each group (P< 0.05) from 60–420 min (i.e., 0.59 ± 0.19–0.72 ± 0.12 ml.kg−1.cmH2O−1in group 1 and 0.54 ± 0.12–0.67 ± 0.14 ml. kg−1. cmH2O−1in group 2, respectively). The authors concluded that in healthy newborns, no respiratory impairment occurred during the first 7 h of life after cesarean section for which epidural fentanyl had been administered to the mother.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Hypothermia in anesthetized adults provokes centrally mediated, peripheral thermoregulatory vasoconstriction at threshold temperatures ≈ 2.5° C below normal. The weight dependence of thermoregulatory vasoconstriction was evaluated in 33 unpremeditated pediatric patientt receiving isoflurane/oxygen anesthesia (end-tidal concentrations ≈0.9%) and caudal anesthesia with bupivacaine. The patients were prospectively assigned to four weight groups (5–10 kg, 10–20 kg, 20–30 kg, and 30–50 kg). Central temperature was measured at the tympanic membrane, and average skin surface temperature was determined from four cutaneous sites; mean body temperature was calculated from central and average skin temperatures. Finger blood flow was determined using laser Doppler flowmetry and forearm-fingertip skin temperature gradients. Significant peripheral vasoconstruction was prospectively defined as a laser Doppler flow index 50% of the value recorded 10 min after induction of anesthesia. Thermoregulatory thresholds were defined as the tympanic membrane or mean body temperatures at which significant vasoconstriction occurred. Vasoconstriction occurred in 32 of the patients at temperatures ranging from 34.4 to 35.5° C. Central and mean body threshold temperatures did not differ among the groups, and were similar to those observed previously in adults. There was a good correlation between laser Doppler flowmetry and forearm-fingertip skin temperature gradients in Individual patients.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Intraoperative administration of the proteinase Inhibitor aprotinin causes reduction in blood loss and homologous blood requirement in patients undergoing cardiac surgery. To ascertain the blood-saving effect of aprotinin and to obtain further information about the mode of action, 40 patients undergoing primary myocardial revascularization were randomly assigned to receive either aprotinin or placebo treatment. Aprotinin was given as a bolus of 2 X 105kallikrein inactivator units (KIU) before surgery followed by a continuous infusion of 5 X 105KIU/h during surgery. Additionally, 2 X 105KIU were added to the pump prime. Strict criteria were used to obtain a homogeneous patient selection. Total blood loss was reduced from 1,431 ± 760 ml in the control group to 738 ± 411 ml in the aprotinin group (P< 0.05) and the homologous blood requirement from 838 ± 963 ml to 163 ± 308 ml (P< 0.05). In the control group, 2.3 ± 2.2 U of homologous blood or blood products were given, and in the aprotinin group, 0.63 ± 0.96 U were given (P< 0.05). Twenty-five percent of patients in the control group and 63% in the aprotinin group did not receive banked blood or homologous blood products. The activated clotting time as an indicator of inhibition of the contact phase of coagulation was significantly Increased before heparinization in the aprotinin group (141 ± 13 s vs. 122 ± 25 s) and remained significantly Increased until heparin was neutralized after cardiopulmonary bypass (CPB). The concentration of the thrombin-antithrombin III complex was significantly decreased at the end of CPB in the aprotinin group, indicating less thrombin generation in the aprotinin-treated group. The total concentration of the fibrinogen-fibrin split products (FSP) and the split products of the cross-linked fibrin (D-dimers) were also significantly reduced due to attenuated proteolytic activities of thrombin and plasmin. The results of the fibrin plate assay revealed higher fibrinolytic activity during CPB in the control group. The results demonstrate the beneficial effect of high-dose aprotinin treatment on blood loss and homologous blood requirement. This effect can be attributed to the inhibition of the contact phase of coagulation and the consequently reduced thrombotic and fibrionolytic activity during and after CPB.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Using Implanted pulsed Doppler microprobes sutured on saphenous bypass grafts in ten patients we studied, 6 h after cardiac surgery, the effects of 5 and 10 μg. kg−1. min−1of dobutamine on mean (&OV0422;m, systolic (&OV0422;d), and diastolic (&OV0422;d) coronary bypass graft flows, as well as on coronary systolic (&OV0422;dand diastolic (∞&OV0422;d) blood volumes entering the myocardium per cardiac beat. &OV0422;mincreased during the inotropic stimulation from 61.8 ± 19.2 to 81.1 ± 21.8 ml.min−1(P< 0.001) and resulted from an unchanged &OV0422;mand from a large increase in &OV0422;d(P< 0.01). &OV0422;dincreased more than did diastolic arterial pressure and was related to rate pressure product taken as an index of myocardial oxygen consumption (r = 0.76,P< 0.001). Despite the dobutamine-induced increase in heart rate (P< 0.01), &OV0422;d, and &OV0422;dthe systolic and diastolic inflow volumes per cardiac beat were unchanged. We conclude that increased myocardial blood supply through the saphenous vein bypass graft during inotropic stimulation by dobutamine resulted from different systolic and diastolic events. The oxygenated Mood volume entering the coronary vascular bed per beat was unchanged despite tachycardia.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID