Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2000
Randomized Controlled Trial Clinical TrialKetorolac suppresses postoperative bladder spasms after pediatric ureteral reimplantation.
We evaluated the efficacy of ketorolac in suppressing postoperative bladder spasms after ureteroneocystostomy (ureteral reimplantation). Twenty-four pediatric patients undergoing intravesical ureteroneocystostomy were enrolled prospectively to receive either ketorolac or placebo via double-blinded randomization. Twelve patients in each group shared similar preoperative characteristics. All were maintained on an epidural infusion of bupivacaine (0.1%) with fentanyl (2 microg/mL) throughout the study. Patients were given either ketorolac (0.5 mg. kg(-1). dose(-1)) or placebo (equivalent volume saline) IV after surgery and every 6 h thereafter for 48 h. Parents were instructed to record bladder spasm episodes prospectively by using a standardized time-flow diary. Three patients (25%) in the ketorolac group experienced bladder spasms, compared with 10 patients (83%) in the placebo group (two-sided P < 0.05). The median severity score for the ketorolac group was 1.2 (mild = 1.0, severe = 3.0), compared with 2.6 for the placebo group (P = 0.003). We conclude that IV ketorolac reduces the frequency and severity of postoperative bladder spasms after intravesical ureteroneocystostomy. ⋯ We studied the efficacy of ketorolac, a prostaglandin synthesis inhibitor, in the treatment of bladder spasm after ureteroneocystostomy (antireflux operation). Patients were randomized in a double-blinded manner to receive either ketorolac or placebo after the surgery. We demonstrate that ketorolac reduces the frequency and severity of postoperative bladder spasm.
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Anesthesia and analgesia · Jul 2000
Randomized Controlled Trial Comparative Study Clinical TrialCaruncle single injection episcleral (Sub-tenon) anesthesia for cataract surgery: mepivacaine versus a lidocaine-bupivacaine mixture.
We compared the quality of anesthesia provided by mepivacaine 2% or a mixture of lidocaine 2%-bupivacaine 0.5%, both with hyaluronidase, in caruncle single-injection episcleral (sub-Tenon) anesthesia. Sixty patients undergoing cataract surgery were included in this randomized, double-blinded study. The time to the onset of blockade, maximal akinesia, need for supplemental injection, and time to recovery were recorded. With mepivacaine, the time to onset was slightly shorter, and the akinesia score higher, than with the mixture. Although statistically significant, these differences are small. With mepivacaine, the time to recovery was shorter. We conclude that the reproducible short duration of the block may be an advantage in outpatient surgery. ⋯ We compared the classic mixture of lidocaine 2% plus bupivacaine 0.5% to mepivacaine 2% for caruncle episcleral (sub-Tenon) anesthesia for cataract surgery. Mepivacaine provided a more efficient block with a quicker onset and a quicker recovery. However, these differences were very small and were of little clinical interest.
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Anesthesia and analgesia · Jul 2000
Evidence for GABA(A) receptor agonistic properties of ketamine: convulsive and anesthetic behavioral models in mice.
We examined the potentiation by ketamine of the gamma-aminobutyric acid(A) (GABA(A)) receptor function using convulsive and anesthetic behavioral models in adult male ddY mice. General anesthetic potencies were evaluated by a rating scale, which provided the data for anesthetic scores, loss of righting reflex, duration, and recovery time. All drugs were administered intraperitoneally. Small subanesthetic doses of ketamine did inhibit tonic seizures induced by a large dose of the GABA(A) receptor antagonist bicuculline (8 mg/kg). The 50% effective dose value was 15 (95% confidence limits 10-22) mg/kg. Even large anesthetic doses (100-150 mg/kg) did not suppress clonic seizures in 50% of the animals. The GABA(A) receptor agonist, muscimol (0.32-1.12 mg/kg), potentiated ketamine-induced anesthesia in a dose-dependent fashion (P < 0.05). Similarly, the benzodiazepine receptor agonist, diazepam (1-3 mg/kg), augmented ketamine anesthesia in a dose-dependent manner (P < 0.05). Bicuculline (2-5 mg/kg) dose-dependently antagonized ketamine-induced anesthesia (P < 0.05). Neither the benzodiazepine receptor antagonist, flumazenil (2-20 mg/kg), nor the GABA synthesis inhibitor, L-allylglycine (200 mg/kg), affected the anesthetic action of ketamine. These results suggest that ketamine has GABA(A) receptor agonistic properties and that ketamine-induced anesthesia is mediated, at least in part, by GABA(A) receptors. ⋯ We examined the potentiation by ketamine of the gamma-aminobutyric acid(A) receptor function using convulsive and anesthetic behavioral models in mice. Subanesthetic doses of ketamine-inhibited tonic convulsions induced by the gamma-aminobutyric acid(A) receptor antagonist bicuculline. The gamma-aminobutyric acid(A) receptor agonist, muscimol, potentiated ketamine-induced anesthesia. Bicuculline antagonized ketamine anesthesia, but the benzodiazepine receptor antagonist, flumazenil, and the gamma-aminobutyric acid synthesis inhibitor, L-allyglycine, did not. The effects of ketamine on the gamma-aminobutyric acid(A) receptors appear to correlate with its anesthetic actions.
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Anesthesia and analgesia · Jul 2000
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialA comparison of remifentanil and fentanyl in patients undergoing surgery for intracranial mass lesions.
We compared the effects of remifentanil versus fentanyl during surgery for intracranial space-occupying lesions. Patients were randomly assigned to receive either remifentanil (0.5 microg. kg(-1). min(-1) IV during the induction of anesthesia reduced to 0.25 microg. kg(-1). min(-1) after endotracheal intubation; n = 49) or fentanyl (dose per usual practice of the anesthesiologist; n = 54). Anesthesia maintenance doses of isoflurane, nitrous oxide, and opioid were at the anesthesiologist's discretion for both groups. There were no differences between opioid groups for the frequency of responses (hemodynamic, movement, and tearing) to intubation, pinhead holder placement, skin incision, or closure of the surgical wound. Adverse event frequencies were similar between groups. Times to follow verbal commands (P < 0.001) and tracheal extubation (P = 0. 04) were more rapid for remifentanil. The percentage of patients with a normal recovery score (were alert or arousable to quiet voice, were oriented, were able to follow commands, had motor function unchanged from their preoperative evaluation, were not agitated, and had modified Aldrete Scores of 9-10) at 10 min after surgery was more for remifentanil (45% vs 18%; P = 0.005). By 20 min, no difference between groups existed (P = 0.27). Anesthesiologists used more isoflurane in the fentanyl group (4.22 vs 1.93 minimum alveolar anesthetic concentration hours). Neurosurgeons, blinded to treatment group, favored the use of remifentanil. Similar frequencies of light anesthesia responses and other adverse events suggest that intraoperative depths of anesthesia were similar in the two groups. Under these conditions, emergence was more rapid with remifentanil. This is consistent with the necessity for less isoflurane use in the remifentanil group and the intrinsic rapid clearance of this opioid. ⋯ Patients given remifentanil-based anesthesia for craniotomy had faster recovery times from anesthesia than did those given fentanyl-based anesthesia.
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Anesthesia and analgesia · Jul 2000
Randomized Controlled Trial Comparative Study Clinical TrialThe recovery of cognitive function after remifentanil-nitrous oxide anesthesia is faster than after an isoflurane-nitrous oxide-fentanyl combination in elderly patients.
We tested the hypothesis that remifentanil-nitrous oxide (N(2)O) anesthesia shortens postoperative emergence and recovery compared with an isoflurane-N(2)O-fentanyl combination in elderly patients undergoing spinal surgery. A total of 60 patients (>65 yr old) were randomly assigned to one of two groups for maintenance of anesthesia. After the induction with 3.6 +/- 1.2 mg/kg IV thiopental and endotracheal intubation facilitated with 1.4 +/- 0.5 mg/kg succinylcholine, patients were maintained with either 0.5%-1.5% isoflurane, 70% N(2)O, and up to 7 microg/kg fentanyl (iso/fent group) or 48 +/- 11 microg/kg remifentanil and 70% N(2)O (remi group). A mini-mental status examination was used to assess cognitive ability preoperatively, at 15, 30, and 60 min after arrival at the postanesthesia care unit and again 12-24 h postoperatively. The time from the conclusion of anesthesia to spontaneous respiration was similar in both groups. Times to eye opening (4.8 +/- 2.6 vs 2.3 +/- 1.1 min), extubation (6.8 +/- 3.8 vs 3.2 +/- 2.1 min), and verbalization (9.9 +/- 6.2 vs 3.9 +/- 2.6 min) were significantly shorter for the remi group (P < 0.05). Postoperative mini-mental status examination scores were significantly lower in the iso/fent group at 15 (16.3 +/- 5.8 vs 23. 7 +/- 3.3), 30 (20.2 +/- 5.2 vs 26.3 +/- 2.7), and 60 min (23.5 +/- 4.4 vs 27.5 +/- 2.0) (P < 0.001); however, the scores equalized after 12 h. Requirements for postoperative analgesics were similar in the two groups. More patients in the remi group were treated with antiemetics (21 vs 7, P = 0.06). Use of remifentanil-N(2)O for maintenance did not shorten the overall length of stay in the postanesthesia care unit; a stay is often related to multiple administrative issues, rather than cognitive recovery. ⋯ Maintenance of anesthesia with remifentanil-nitrous oxide (N(2)O), compared with isoflurane-N(2)O-fentanyl, can safely shorten postoperative recovery of cognitive function in a geriatric population. Earlier recovery may facilitate postoperative neurological assessment. Use of remifentanil-N(2)O for maintenance did not shorten the overall length of stay in the postanesthesia care unit, a stay often related to multiple administrative issues, rather than cognitive recovery.