Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialTramadol added to 1.5% mepivacaine for axillary brachial plexus block improves postoperative analgesia dose-dependently.
Adjuncts to local anesthetics for peripheral plexus blockade may enhance the quality and duration of anesthesia and postoperative analgesia. The analgesic, tramadol, has a unique mechanism of action that suggests efficacy as such an adjunct. It displays a central analgesic and peripheral local anesthetic effect. We designed a prospective, randomized, controlled and double-blind clinical trial to assess the effect of tramadol added to brachial plexus anesthesia. One-hundred patients scheduled for carpal tunnel release surgery under brachial plexus anesthesia were randomized into four groups. All patients received 1.5% mepivacaine 40 mL plus a study solution containing either isotonic sodium chloride (Group P, n = 17), tramadol 40 mg (Group T(40), n = 22), tramadol 100 mg (Group T(100), n = 20) or tramadol 200 mg (Group T(200), n = 20). We evaluated the time of onset of anesthesia, duration of sensory and motor blockade, duration and quality of postoperative analgesia, and occurrence of adverse effects. Onset and duration of sensory and motor blocks were not different among groups. The number of patients requesting analgesia in the postoperative period was significantly less in the 3 tramadol groups compared with the placebo group (P = 0.02); this was also noted with the placebo and T(40) groups compared with the T(200) group. No statistical significance was demonstrated between the placebo and the T(40) group or the T(100) group and the T(200) group. Furthermore, there was a significant trend effect among groups applying the Cochran-Armitage tendency test (P = 0.003), suggesting a dose-dependent decrease for additional postoperative analgesia requirements when tramadol was added. Side effects did not differ among groups, although they were more frequently recorded in the T groups. Our study suggests that tramadol added to 1.5% mepivacaine for brachial plexus block enhances in a dose-dependent manner the duration of analgesia with acceptable side effects. However, the safety of tramadol has to be investigated before allowing its use in clinical practice. ⋯ Tramadol's unique mechanism of action suggests efficacy as a local anesthetic adjunct for peripheral plexus blockade. Our study demonstrates that tramadol, added to mepivacaine for brachial plexus anesthesia, extends the duration and improves the quality of postoperative analgesia in a dose dependent fashion with acceptable side effects.
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialPreoperative oral rofecoxib reduces postoperative pain and tramadol consumption in patients after abdominal hysterectomy.
We designed this study to determine whether the administration of a preoperative dose of rofecoxib to patients undergoing abdominal hysterectomy would decrease patient-controlled analgesia (PCA) tramadol use or enhance analgesia. Sixty patients were randomized to receive either oral placebo or rofecoxib 50 mg 1 h before surgery. All patients received a standard anesthetic protocol. Intraoperative blood loss was determined. At the end of surgery, all patients received tramadol IV via a PCA-device. Pain scores, sedation scores, mean arterial blood pressure, heart rate, and peripheral oxygen saturation were assessed at 1, 2, 4, 6, 8, 12, and 24 h after surgery. Total and incremental tramadol consumption at the same times was recorded from the PCA-device. Antiemetic requirements and adverse effects were noted during the first postoperative 24 h. Duration of hospital stay was also recorded. The pain scores were significantly lower in the rofecoxib group compared with the placebo group at 6 times during the first 12 postoperative h (P < 0.05). The total consumption of tramadol (627 +/- 69 mg versus 535 +/- 45 mg; P < 0.05) and the incremental doses at 1, 2, 4, 6, 8, and 12 h after surgery were significantly more in the placebo group than in the rofecoxib group. There were no differences between groups in intraoperative blood loss, sedation scores, hemodynamic variables, peripheral oxygen saturation, antiemetic requirements, or adverse effects after surgery. The length of hospital stay was also similar in the groups. We conclude that the preoperative administration of oral rofecoxib provided a significant analgesic benefit and decreased the opioid requirements in patients undergoing abdominal hysterectomy. ⋯ This study was designed to determine whether the administration of a preoperative dose of rofecoxib to patients undergoing abdominal hysterectomy would decrease patient-controlled analgesia tramadol use or enhance analgesia. We conclude that the preoperative administration of oral rofecoxib provided a significant analgesic benefit and decreased the opioid requirements in patients undergoing abdominal hysterectomy.
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Comparative Study Clinical TrialThe comparative effects of desflurane and isoflurane on lumbar cerebrospinal fluid pressure in patients undergoing craniotomy for supratentorial tumors.
We compared the effects of desflurane and isoflurane on cerebral perfusion pressure (CPP), lumbar cerebrospinal fluid pressure (LCSFP), and mean arterial blood pressure (MAP) in patients anesthetized with desflurane or isoflurane undergoing craniotomy for supratentorial mass lesions. Additionally, emergence from anesthesia was examined to determine if neurologic function could be assessed earlier after isoflurane or desflurane anesthesia. Thirty-six patients were randomized to receive either desflurane or isoflurane for maintenance of anesthesia at 1.2 minimum alveolar concentration (MAC). Patients were hyperventilated (PaCO(2), 30 +/- 2 mm Hg) after baseline LCSFP was obtained via the subarachnoid catheter. At a MAC of 1.2, mean LCSFP was not statistically different between the two study groups either before or after hyperventilation. Additionally, CPP was not significantly different between the two groups. Finally, patient's time to respond to commands was 50% shorter in the desflurane group (30 +/- 36 min) (mean +/- SD) when compared with the isoflurane group (72 +/- 126 min); however, this was not significant (P = 0.17). In patients undergoing craniotomy for supratentorial mass lesions, desflurane and isoflurane have similar effects on CPP and MAP. Additionally, desflurane in the setting of hyperventilation does not cause significant changes in LCSFP. ⋯ This is the largest study to date comparing the effects of desflurane and isoflurane on patients undergoing craniotomy for supratentorial mass lesion with evidence of midline shift or edema. Neither desflurane nor isoflurane significantly altered lumbar cerebrospinal fluid pressure when moderate hypocapnia was maintained.
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Anesthesia and analgesia · Apr 2004
Clinical TrialContinuous assessment of cerebral autoregulation in subarachnoid hemorrhage.
Cerebral vasospasm remains a leading cause of morbidity and mortality after subarachnoid hemorrhage (SAH). Cerebral ischemia may ensue when autoregulation fails to compensate for spasm. We examined how autoregulation is affected by vasospasm by using transcranial Doppler. The moving correlation coefficient between slow changes of arterial blood pressure and mean or systolic flow velocity (FV), termed "Mx" and "Sx," respectively, was used to characterize cerebral autoregulation. Vasospasm was declared when the mean FV increased to more than 120 cm/s and the Lindegaard ratio was more than 3. This occurred in 15 of 32 SAH patients. On the basis of the bilateral transcranial Doppler recordings of the middle cerebral artery in vasospastic patients, Mx and Sx were calculated for baseline and vasospasm. Mx increased during vasospasm (0.46 +/- 0.32; mean +/- SD) and was significantly higher (P = 0.021) than at baseline (0.21 +/- 0.24). Sx was also increased (0.22 +/- 0.26 vs 0.05 +/- 0.21 at baseline; P = 0.03). Mx correlated with mean FV (r = 0.577; P = 0.025) and the Lindegaard ratio (r = 0.672; P < 0.006). Mx (P = 0.006) and Sx (P = 0.044) were higher on the vasospastic side (Mx, 0.44 +/- 0.27; Sx, 0.24 +/- 0.23) when compared with the contralateral side (Mx, 0.34 +/- 0.29; Sx, 0.16 +/- 0.25). The increased Mx and Sx during cerebral vasospasm demonstrate impaired cerebral autoregulation. Mx and Sx provide additional information on changes in autoregulation in SAH patients. ⋯ The moving correlation coefficients between slow changes of arterial blood pressure and mean or systolic flow velocity, termed "Mx" and "Sx," respectively, characterize cerebral autoregulation but have not been applied to subarachnoid hemorrhage. A study in 15 patients revealed that Mx and Sx were significantly increased, indicating impaired autoregulation during vasospasm as compared with baseline, as well as on the side of vasospasm in comparison with the contralateral side.
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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.