Anesthesia and analgesia
-
Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Multicenter Study Clinical TrialThe safety and efficacy of a fentanyl patient-controlled transdermal system for acute postoperative analgesia: a multicenter, placebo-controlled trial.
A noninvasive method of delivery of parenteral opioids for management of acute pain may offer logistic advantages for patients and nursing staff. A patient-controlled transdermal system (PCTS) under development consists of a preprogrammed, self-contained drug-delivery system that uses electrotransport technology (E-TRANS, ALZA Corp, Mountain View, CA) to deliver 40 micro g of fentanyl HCl over 10 min per on-demand dose for patient-controlled analgesia (PCA). In this randomized, double-blinded, placebo-controlled trial we compared the efficacy and safety of on-demand fentanyl HCl PCTS 40 microg against placebo for postoperative pain up to 24 h after major abdominal, orthopedic, or thoracic surgery in 205 patients. The primary efficacy measurement was the percentage of patients withdrawn from the study because of inadequate analgesia after completing at least 3 h of treatment. Secondary efficacy measures included mean pain intensity (using visual analog scales), patient global assessments, and investigator global assessments. Of 189 patients considered evaluable for efficacy, 25% of patients in the fentanyl HCl PCTS 40 microg group withdrew because of inadequate analgesia, compared with 40.4% of the placebo group (P < 0.05). Use of fentanyl HCl PCTS 40 micro g was associated with lower VAS scores and higher mean patient and investigator global assessment scores compared with placebo. No patient experienced clinically relevant respiratory depression. This study showed that a fentanyl HCl PCTS 40 microg for PCA was superior to placebo and well tolerated for the control of moderate to severe postoperative pain for up to 24 h after major surgery. ⋯ This multicenter, randomized, double-blinded, placebo-controlled trial showed that an on-demand fentanyl HCl patient-controlled transdermal system (PCTS) was superior to placebo and well tolerated for the control of moderate to severe postoperative pain for up to 24 h after major surgery. This fentanyl HCl PCTS is a preprogrammed, needle free, self-contained drug-delivery system that uses electrotransport technology (iontophoresis) to deliver 40 microg of fentanyl per on-demand dose.
-
Anesthesia and analgesia · Feb 2004
Case ReportsGrand mal convulsion after an accidental intravenous injection of ropivacaine.
A 36-yr old, ASA physical status I patient scheduled for hip arthroplasty under regional anesthesia received at the end of surgery an i.v. injection of approximately 200 mL of a 0.15% ropivacaine solution (300 mg = 4.6 mg/kg) in approximately 5 min. The bag prepared for postoperative epidural infusion was accidentally connected to a peripheral i.v. line. The patient developed grand mal convulsions, hypotension, and respiratory arrest. No arrhythmias were observed. Twenty minutes after the event, the arterial plasma concentration of ropivacaine was 3.10 microg/mL. Using a pharmacokinetic model, the peak plasma concentration at the time of the accidental administration was estimated at 17.04 microg/mL. The patient recovered uneventfully. ⋯ An accidental i.v. injection of approximately 300 mg of ropivacaine was followed by seizures without any arrhythmia. The patient recovered uneventfully.
-
Anesthesia and analgesia · Feb 2004
Meloxicam, a specific COX-2 inhibitor, does not enhance the isoflurane minimum alveolar concentration reduction produced by morphine in the rat.
A synergistic effect of nonselective cyclooxygenase (COX) inhibitors on morphine-induced decrease of isoflurane minimum alveolar concentration (MAC(ISO)) has been observed in the rat. We studied the influence of specific COX-2 inhibitors on this decrease of MAC. Sixty-four female rats were anesthetized with isoflurane in oxygen. The animals were grouped into saline solution, aspirin (30 mg/kg), morphine (1 mg/kg), morphine (1 mg/kg) + aspirin (30 mg/kg), meloxicam (1 and 3 mg/kg), and morphine (1 mg/kg) + meloxicam (1 and 3 mg/kg). Then the MAC(ISO) was determined from alveolar gas samples at the time of tail clamp. The groups treated with saline solution, aspirin, and 1 and 3 mg/kg meloxicam did not express any statistically relevant changes among them. The administration of morphine + meloxicam 1 or 3 mg/kg significantly reduced the MAC(ISO) just as in the group where only morphine was administered (morphine 1.35% +/- 0.07%, morphine + 1 mg/kg meloxicam 1.36% +/- 0.04%, and morphine + 3 mg/kg meloxicam 1.37% +/- 0.08%). The greatest reduction of MAC(ISO) was after administration of morphine + aspirin (1.19% +/- 0.05%). The administration of meloxicam does not potentiate the morphine-induced decrease of MAC(ISO) in the rat. ⋯ A synergistic effect between morphine and aspirin on isoflurane minimum alveolar concentration has been observed in the rat--an effect that does not occur between morphine and meloxicam.