Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Comparative Study Clinical TrialPostoperative analgesic effects of celecoxib or rofecoxib after spinal fusion surgery.
Nonsteroidal antiinflammatory drugs are recommended for the multimodal management of postoperative pain and may have a significant opioid-sparing effect after major surgery. The analgesic efficacy of the cyclooxygenase-2 nonsteroidal antiinflammatory drugs, celecoxib and rofecoxib, have not been evaluated after major orthopedic surgery. This study was designed to determine whether the administration of a preoperative dose of celecoxib or rofecoxib to patients who have undergone spinal stabilization would decrease patient-controlled analgesia (PCA) morphine use and/or enhance analgesia. We evaluated 60 inpatients undergoing spine stabilization by one surgeon. All patients received PCA morphine. The patients were divided into three groups. Preoperatively, they were given oral celecoxib 200 mg, rofecoxib 50 mg, or placebo. The outcome measures included pain scores and 24-h morphine use at six times during the first 24 postoperative h. The total dose of morphine and the cumulative doses for each of the six time periods were significantly more in the placebo group than in the other two groups. The morphine dose was significantly less in five of the six time intervals in the rofecoxib group compared with the celecoxib group. The pain scores were significantly less in the rofecoxib group than in the other two groups at two of the six intervals, and less than the placebo group in an additional interval. Although both rofecoxib and celecoxib produce similar analgesic effects in the first 4 h after surgery, rofecoxib demonstrated an extended analgesic effect that lasted throughout the 24-h study. We thus recommend that rofecoxib be used as a preoperative component of pain management that includes PCA morphine in patients undergoing spine stabilization surgery. ⋯ The cyclooxygenase-2-specific nonsteroidal antiinflammatory drugs, celecoxib and rofecoxib, both demonstrate an opioid-sparing effect after spinal fusion surgery. Celecoxib resulted in decreased morphine use for the first 8 h after surgery, whereas rofecoxib demonstrated less morphine use throughout the 24-h study period.
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Anesthesia and analgesia · Nov 2000
Perianesthetic risks and outcomes of pheochromocytoma and paraganglioma resection.
Pheochromocytomas and paragangliomas are often surgically curable. However, resection of these tumors can be life threatening. We undertook this study to determine the frequency of, and risk factors for, perioperative complications in patients undergoing resection of pheochromocytoma or paraganglioma. We retrospectively reviewed the medical records of patients during 1983-1996 who underwent surgical resection of catecholamine-secreting pheochromocytoma or paraganglioma. Preoperative risk factors, adverse intraoperative events, and complications occurring in the 30 days after operation were recorded. Blood pressures were collected from manual records. The ranked sum test and Fisher's exact test were used for analyses. Adverse perioperative events or complications occurred in 45 of 143 patients (31.5%; exact 95% confidence interval, 24.0% to 39.8%). Of these 45 patients, 41 experienced one or more adverse intraoperative events. The most common adverse event was sustained hypertension (36 patients). There were no perioperative deaths, myocardial infarctions, or cerebrovascular events. Preoperative factors univariately associated with adverse perioperative events included larger tumor size (P: = 0.007), prolonged duration of anesthesia (P: = 0.015), and increased levels of preoperative urinary catecholamines and catecholamine metabolites: vanillylmandelic acid (P: = 0.019), metanephrines (P: = 0.004), norepinephrine (P: = 0. 014), and epinephrine (P: = 0.004). Despite premedication of most patients with phenoxybenzamine and a beta-adrenergic blocker, varying degrees of intraoperative hemodynamic lability occurred. ⋯ Few patients who had pheochromocytoma or paraganglioma resection experienced significant perioperative morbidity and none died in the largest retrospective study on this topic to date. This study confirms the very good perioperative outcomes demonstrated in smaller studies on this high-risk population, and identifies several risk factors for adverse outcomes.
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Anesthesia and analgesia · Nov 2000
Comparative Study Clinical TrialThromboelastography as a perioperative measure of anticoagulation resulting from low molecular weight heparin: a comparison with anti-Xa concentrations.
Low molecular weight heparin (LMWH) is commonly used to prevent postoperative thromboembolism. Currently, there is no convenient test to measure the degree of anticoagulation from LMWH. This prospective study examines the relationship of thromboelastography and serum anti-Xa concentration in patients treated with enoxaparin. Twenty-four adult patients scheduled for orthopedic surgery using epidural anesthesia were enrolled. Epidural catheters were removed the morning after surgery before the commencement of subcutaneous enoxaparin 30 mg twice daily. Venous blood samples were obtained at 1) the induction of anesthesia (baseline), 2) immediately before the third dose of enoxaparin postoperatively (Day 2-trough), 3) 4 h after the third dose postoperatively (Day 2-peak), and 4) immediately before the fifth dose postoperatively (Day 3-trough). Whole blood samples were obtained for thromboelastography, activated clotting time, and anti-Xa level analyses at each of the four time intervals. At the four sample intervals, the r time (mean +/- SEM). (20 +/- 1, 25 +/- 2, 51 +/- 6, 31 +/- 3 mm) and the k time (9 +/- 0. 7, 12 +/- 1, 27 +/- 5, 14 +/- 2 mm) of the thromboelastograph were significantly correlated with the expected peak and trough levels of LMWH and serum anti-Xa levels (P: < 0.05). At the Day 3-trough, thromboelastograph r times exceeded the normal range in 6 of 25 patients (25%). Prolongation of r time and k time on postoperative Day 3 may indicate an exaggerated response to LMWH. Thromboelastography is a test that could potentially correlate with the degree of anticoagulation produced by low molecular weight heparin. ⋯ Thromboelastography is a test that could potentially correlate with the degree of anticoagulation produced by low molecular weight heparin. The r time from the thromboelastogram correlates with serum anti-Xa concentration.
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Anesthesia and analgesia · Nov 2000
Comparative StudyVentricular arrhythmias with or without programmed electrical stimulation after incremental overdosage with lidocaine, bupivacaine, levobupivacaine, and ropivacaine.
It is unclear whether the mechanism of death from local anesthetic (LA) intoxication is primarily a consequence of cardiac arrhythmias or myocardial contractile depression, and whether LAs might differ in this susceptibility to these two mechanisms. By using programmable electrical stimulation (PES) protocols in anesthetized, ventilated dogs, we compared the arrhythmogenic potential of bupivacaine (BUP), ropivacaine (ROP), levobupivacaine (LBUP), and lidocaine (LIDO). Open-chest dogs were randomized to receive escalating incremental infusions of the four local anesthetics until cardiovascular collapse. We assumed a concentration relationship of 4:1 for LIDO/BUP, LBUP, and ROP. The effective refractory period did not change significantly until the dose increment corresponding to target concentrations of 8 and 32 microg/mL for BUP, LBUP, ROP, and LIDO, respectively. Thirty percent to 50% increases in effective refractory period occurred in surviving dogs at this dose. The incidence of spontaneous or PES-induced ventricular tachycardia and ventricular fibrillation did not differ among groups. Compared with LIDO, the incidence of PES-induced extrasystoles was more frequent for BUP- and LBUP-treated dogs (P: < 0.05). ROP-treated dogs did not differ from LIDO-treated dogs with respect to PES-induced extrasystoles. At the dose increment preceding cardiovascular collapse, all LAs produced significant increases in heart rate and reductions in blood pressure compared with their respective baseline values. The incidence of programmable electrical stimulation-induced ventricular tachycardia and fibrillation with BUP does not differ from the incidence that occurs with the single S:(-) enantiomers LBUP and ROP, providing further evidence against stereoselective arrhythmogenesis as a primary component of local anesthetic-induced cardiotoxicity. ⋯ Progressive bupivacaine intoxication in anesthetized, ventilated dogs does not produce early arrhythmogenic events. The incidence of programmable electrical stimulation-induced ventricular tachycardia and fibrillation with bupivacaine does not differ from the incidence that occurs with the single S:(-) enantiomers levobupivacaine and ropivacaine, providing further evidence against stereoselective arrhythmogenesis as a primary component of local anesthetic-induced cardiotoxicity.