Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2004
Randomized Controlled Trial Comparative Study Clinical TrialSevoflurane decreases bispectral index values more than does halothane at equal MAC multiples.
At the minimum alveolar concentration (MAC) of inhaled anesthetics, 50% of subjects move in response to noxious stimulation. Similarly, at MAC-awake, 50% of subjects respond appropriately to command. The bispectral index (BIS) nominally measures the effect of anesthetics on wakefulness or consciousness. ⋯ BIS values in awake patients did not differ between the sevoflurane and halothane groups (96 +/- 2 and 96 +/- 2, mean +/- sd, respectively). At 1 MAC without and with neuromuscular blockade and at 1.5 MAC, BIS values for patients anesthetized with halothane (54 +/- 7, 56 +/- 7, and 49 +/- 7, respectively) exceeded those for patients anesthetized with sevoflurane (34 +/- 6, 34 +/- 6, and 29 +/- 5, respectively) (P < 0.0001). This finding adds to other evidence indicating that BIS is drug specific.
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Anesthesia and analgesia · Dec 2004
Randomized Controlled Trial Clinical TrialParamedian lumbar epidural catheter insertion with patients in the sitting position is equally successful in the flexed and unflexed spine.
Positioning for placement of an epidural catheter can be quite painful for patients with lower limb injuries. We randomly allocated 50 patients scheduled for surgery after lower limb injuries for placement of a lumbar epidural catheter in the sitting position with the back in the neutral unflexed position by either the midline or paramedian approach. If the approach failed after two attempts, patients were placed in a flexed-spine position, and the procedure was attempted again. ⋯ The incidences of resistance to catheter insertion (eight versus one), paresthesia (seven versus zero), and appearance of blood in the catheter (six versus zero) were significantly more frequent in the midline compared with the paramedian approach. The midline group also experienced more discomfort than the paramedian group. We conclude that, with the patient sitting with an unflexed spine, it is usually possible to insert an epidural catheter with the paramedian approach.
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Anesthesia and analgesia · Dec 2004
Randomized Controlled Trial Clinical TrialSingle-injection paravertebral block before general anesthesia enhances analgesia after breast cancer surgery with and without associated lymph node biopsy.
Paravertebral block (PVB) seems to decrease postoperative pain and postoperative nausea and vomiting (PONV) after breast surgery, but the studies have not been placebo controlled. We studied 60 patients scheduled for breast cancer surgery randomly given single-injection PVB at T3 with bupivacaine 5 mg/mL (1.5 mg/kg) or saline before general anesthesia. The patient and attending investigators were blinded; the PVB or the sham block was performed behind a curtain by an anesthesiologist not involved in the study. ⋯ The average peak bupivacaine plasma concentration was 750 ng/mL. One patient had bilateral convulsions immediately after bupivacaine injection. We conclude that PVB before general anesthesia for breast cancer surgery reduced postoperative pain, opioid consumption, and occurrence of PONV and improved recovery from anesthesia.
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Anesthesia and analgesia · Dec 2004
Randomized Controlled Trial Comparative Study Clinical TrialThe postoperative blood-sparing efficacy of oral versus intravenous tranexamic acid after total knee replacement.
To assess the blood-sparing efficacy of tranexamic acid (TA) administered orally or via a variable IV infusion, 80 healthy patients undergoing elective total knee replacement were studied according to a prospective, controlled, randomized, single-blinded study design. Patients were allocated to one of four treatment groups. In group TA-long, 30 min before deflation of the limb tourniquet, an IV bolus dose of TA 15 mg/kg was administered over 30 min. ⋯ In the control group, TA was not administered. At patient discharge, postoperative allogeneic blood administration was significantly more in group Control when compared with each of the three TA treatment groups. Because oral drug administration is simple and does not require specific infusion equipment, the authors suggest that oral TA is a superior blood-sparing strategy compared with IV drug administration.