Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialAcetylsalicylic acid, diclofenac, and lornoxicam, but not rofecoxib, affect platelet CD 62 expression.
Nonsteroidal antiinflammatory drugs are routinely administered in the perioperative period. Because of the absence of cyclooxygenase-2 in platelets, cyclooxygenase-2-selective drugs are thought not to cause platelet inhibition. Because platelets play an important role in the coagulation process, the absence of platelet function inhibition may lead to fewer bleeding complications after surgery. We studied the influence of aspirin, diclofenac, lornoxicam, and rofecoxib on arachidonic acid and collagen-induced CD 62 P (P selectin) expression by using flow cytometry. Blood from 68 volunteers was obtained before and 1, 3, and 12 h after the oral ingestion of 1 of the randomly assigned study medications. Aspirin, diclofenac, and lornoxicam had a significant effect on arachidonic acid and collagen-induced CD 62 P expression in platelets, whereas rofecoxib did not show this effect. We conclude that rofecoxib is safe to use perioperatively with respect to inhibition of platelet function. ⋯ We compared the effect of rofecoxib and three nonselective nonsteroidal antiinflammatory drugs on platelet function, measured by CD 62 P expression. Platelet function was not altered by rofecoxib, but it was inhibited by aspirin, diclofenac, and lornoxicam. Rofecoxib may be safer than classic NSAIDs with respect to platelet function during the perioperative period.
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialPreoperative oral dextromethorphan attenuated tourniquet-induced arterial blood pressure and heart rate increases in knee cruciate ligament reconstruction patients under general anesthesia.
The precise mechanism of tourniquet-induced arterial blood pressure increase is unknown. We determined the effect of preoperative oral dextromethorphan (DM) on arterial blood pressure and heart rate changes during tourniquet inflation in knee cruciate ligament reconstruction patients under general anesthesia. Patients in the DM group (n = 38) received oral DM 30 mg, and patients in the control group (n = 38) received oral placebo 2 h before the induction of anesthesia. Anesthesia was maintained with sevoflurane 2.0% and N(2)O in 33% oxygen, and the trachea was intubated until the end of surgery. Arterial blood pressure and heart rate were measured at 0, 30, and 60 min after the start of tourniquet inflation. Systolic arterial blood pressure and heart rate at 60 min in the control group were significantly more than those in the DM group (131.1 +/- 15.8 mm Hg versus 123.6 +/- 15.9 mm Hg [P < 0.05] and 74.1 +/- 11.3 bpm versus 67.8 +/- 8.5 bpm [P < 0.01], respectively). The percentage increase in systolic arterial blood pressure and heart rate in the DM group was also attenuated when compared with that in the control group (P < 0.05). In conclusion, preoperative oral DM 30 mg significantly attenuated arterial blood pressure and heart rate increases during tourniquet inflation under general anesthesia. ⋯ We demonstrated that preoperative oral dextromethorphan 30 mg significantly attenuated arterial blood pressure and heart rate increases at 60 min during tourniquet inflation in patients undergoing knee cruciate ligament reconstruction under general anesthesia.
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Anesthesia and analgesia · Apr 2004
Comparative StudyThe effects of pretreatment with lidocaine or bupivacaine on the spatial and temporal expression of c-Fos protein in the spinal cord caused by plantar incision in the rat.
We investigated the spatial and temporal patterns of c-Fos protein (Fos) expression in the dorsal horn of the spinal cord caused by plantar incision in the rat and the effects of pretreatment with local anesthetics. Bupivacaine (0.5%), lidocaine (2%), or saline for control was injected for nerve block and local infiltration before the plantar incision was made under anesthesia. Pain behavior and Fos expression in the L4-L5 segments of the spinal cord were assessed at 1, 3, 6, 24, 48, 72, and 120 h after the incision. The withdrawal threshold to mechanical stimulation decreased significantly at 1 h until 120 h (1-72 h, P < 0.01;120 h, P < 0.05), and pretreatment with local anesthetics increased the threshold significantly at 1 h (both groups: P < 0.01), 3 h (both groups: P < 0.01), and 6 h (bupivacaine, P < 0.01; lidocaine, P < 0.05) in comparison with that in the saline group. In the saline group, Fos expression was detected predominantly in laminae I-II and V-VI, and the total Fos expression was maximal at 1 h and then decreased gradually. Pretreatment with local anesthetics suppressed Fos expression significantly in all layers, and this suppression continued for several days. This study provides evidence of spatial and temporal changes in Fos expression induced by plantar incision. Our results indicate that although pretreatment with local anesthetics suppresses Fos expression for several days in the postoperative period, the analgesic effect is observed only for the expected duration of the local anesthetic used. ⋯ Prevention of early pain by pretreatment with local anesthetics provides little benefit for postoperative pain relief in the plantar incision model, although c-Fos expression is suppressed. The number of c-Fos-expressing neurons is not necessarily correlated with pain behavior.
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Anesthesia and analgesia · Apr 2004
Bispectral index as an indicator of seizure inducibility in electroconvulsive therapy under thiopental anesthesia.
The prediction of seizure thresholds in electroconvulsive therapy (ECT) remains problematic. We examined the relationship between bispectral index (BIS) score and seizure duration in ECT performed under thiopental anesthesia in patients receiving their usual regimen of antidepressant medication for its potential as a predictor of seizure inducibility. One-hundred ECT treatments were evaluated in 16 adult patients diagnosed with depression. BIS scores were recorded at the preanesthetic and preictal periods and at recovery from ECT. Seizure duration was defined as the duration of the electroencephalogram seizure pattern. The relationships between preanesthetic and preictal BIS scores and seizure duration were evaluated. Effective seizure threshold was determined by receiver operator characteristic analysis, and the area under the curve (AUC) was calculated for seizure durations of more than 10 s, more than 20 s, and more than 30 s. The relationship between seizure duration and thiopental estimated effect-site and plasma concentrations was analyzed as well. Preictal BIS scores for seizures lasting longer than 30 s were significantly higher than those for seizures lasting <30 s. A preictal BIS score of 55 or more represents a strongly determinant condition for achieving seizures that last longer than 30 s (AUC, 0.937; receiver operator characteristic), as well as for briefer seizures that last more than 20 or 10 s (AUC: 0.938 and 0.959, respectively). There was no significant correlation between seizure duration and the estimated thiopental effect-site or plasma concentration. We conclude that during thiopental anesthesia, the minimum threshold for inducing seizures of any duration correlates with a preictal BIS score of 55. This threshold was independent of antidepressant regimen and thiopental dosage. We suggest that the preictal BIS score is useful in predicting the ictogenic threshold in ECT. ⋯ We found that the bispectral index (BIS) score serves as an indicator of seizure inducibility in electroconvulsive therapy (ECT) under thiopental anesthesia and that the relationship between BIS score and seizure duration was not linear, suggesting that the pharmacological mechanisms by which thiopental and propofol suppress ECT seizure activity are different.
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Anesthesia and analgesia · Apr 2004
The effect of erythropoietin on allogeneic blood requirement in patients undergoing elective liver resection: a model simulation.
We investigated whether recombinant human erythropoietin (rHuEPO) administration would reduce red blood cell (RBC) transfusion requirements in patients undergoing elective liver resection. We retrospectively investigated 200 patients undergoing elective liver resection. Factors likely to predict perioperative RBC transfusion were studied using a logistic regression analysis. A mathematical model was used to simulate RBC transfusion requirements if (a). transfusion thresholds had been predefined at a hemoglobin concentration of 7-8 g/dL, (b). preoperative hemoglobin concentrations had been increased to 15 g/dL by rHuEPO administration in patients with preoperative hemoglobin concentration in the range 10-13 g/dL, and (c). both interventions had been used. A cost/benefit evaluation of rHuEPO administration formed part of this simulation. RBC transfusion was correlated with major and median liver resection, total liver vascular exclusion, and a combined nonhepatic abdominal surgery but was not correlated with a preoperative hemoglobin concentration in the range 10-13 g/dL. Adherence to a small transfusion threshold or rHuEPO administration alone would have resulted in a slight reduction in transfusion requirements and transfusion rates for the whole population. However, the two interventions in combination would have significantly reduced both variables. One-hundred-eighteen patients undergoing median and major liver resection received 92% of RBC transfused. Sixty-six of these 118 patients had preoperative hemoglobin concentrations in the range 10-13 g/dL and could have received rHuEPO before surgery. rHuEPO alone would have avoided the transfusion of 63 RBC packs of 203 in this subgroup and 12 transfused patients of 31 (P = 0.02). rHuEPO administration to these 66 patients would have cost 186000 Euro. The 63 RBC saved would have cost 10,710 Euro. ⋯ A mathematical model simulation suggests that the routine preoperative administration of erythropoietin to patients scheduled for major and median liver resection presenting with a preoperative hemoglobin concentration in the range 10-13 g/dL could reduce blood transfusion requirements. However, the cost/benefit ratio warrants consideration.