Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2000
Randomized Controlled Trial Comparative Study Clinical TrialRecovery of cognitive function after remifentanil-propofol anesthesia: a comparison with desflurane and sevoflurane anesthesia.
We compared the recovery characteristics of remifentanil, desflurane, and sevoflurane when used for anesthesia in elective operative procedures. Sixty ASA physical status I and II patients, aged 18-65 yr, were randomly assigned to receive remifentanil-propofol, desflurane-N2O, or sevoflurane-N2O anesthesia. Before the induction of anesthesia, the patients of the desflurane and sevoflurane groups received fentanyl 2 microg/kg. In all groups, anesthesia was induced with propofol and maintained either with remifentanil 0.25 microg x kg(-1) x min(-1), desflurane, or sevoflurane 0.85 MAC with 65% nitrous oxide in oxygen. Anesthetics were titrated to achieve an adequate level of surgical anesthesia and to maintain mean arterial pressure within 20% of baseline values. Early recovery times and a modified Aldrete Recovery Score > 9 were recorded. Trieger Dot Test and Digit Substitution Test (DSST) were performed the day before surgery and in the postanesthesia care unit to evaluate intermediate recovery. The remifentanil-propofol group had a significantly faster emergence than desflurane or sevoflurane, with no difference between both inhaled anesthetics. Thirty min after anesthesia administration, patients in the remifentanil-propofol and in the desflurane groups gave significantly more correct responses in the DSST compared with sevoflurane (remifentanil 87%, desflurane 83%, sevoflurane 56%), the impairment in the sevoflurane patients corresponding to the effects of a blood alcohol level of approximately 0.1% and, thus, being of clinical importance. Ninety minutes after anesthesia administration, no significant difference could be demonstrated among the groups in the DSST scores. Emergence and return of cognitive function was significantly faster after remifentanil-propofol compared with desflurane and sevoflurane up to 60 min after anesthesia administration. ⋯ We compared awakening and intermediate recovery times after remifentanil-propofol anesthesia to desflurane-N2O and sevoflurane-N2O anesthesia. Emergence and return of cognitive function was significantly faster after remifentanil-propofol compared with desflurane and sevoflurane up to 60 min after anesthesia administration.
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Anesthesia and analgesia · Jan 2000
Randomized Controlled Trial Clinical TrialThe effects of residual pain on oxygenation and breathing pattern during morphine analgesia.
To determine the influence of pain on opioid-induced respiratory depression, we studied oxygenation and breathing patterns in 40 patients scheduled for knee surgery during postoperative patient-controlled analgesia (PCA). After 1 h of morphine PCA, patients were randomized to receive either 20 mL of placebo or bupivacaine 0.25% through a crural nerve catheter and allowed to use PCA for one more hour. Abnormal breathing events were identified and characterized by using the Edentrace II device (Nellcor, Jouy-en-Josas, France). The Spo2 below which the patient spent 25% and 50% of a studied period was calculated (Spo2(25), Spo2(50)). Pain relief with regional analgesia increased the incidence of abnormal respiratory events associated with oxygen desaturation: during the second period, the pain score was lower in the bupivacaine group (0.7+/-1 vs 4.1+/-1.2), morphine consumption was larger in the placebo group (4.2+/-1.3 vs 0.7+/-1.4 mg), and there were more abnormal obstructive breathing events in the bupivacaine group (11+/-16 vs 3.7+/-4.3). Spo2(25) and Spo2(50) were lower in the bupivacaine than in placebo group (91.5%+/-2.8% vs 93.1%+/-2.1%, 92.9%+/-2.4% vs 94.2%+/-1.8%). ⋯ Pain relief with regional analgesia in patients previously treated with opioids increases the incidence of abnormal respiratory events associated with oxygen desaturation.
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Anesthesia and analgesia · Jan 2000
Randomized Controlled Trial Clinical TrialThe benefits of intraoperative small-dose ketamine on postoperative pain after anterior cruciate ligament repair.
In a randomized, double-blinded study with three parallel groups, we assessed the analgesic effect of intraoperative ketamine administration in 45 ASA physical status I or II patients undergoing elective arthroscopic anterior ligament repair under general anesthesia. The patients received either IV ketamine 0.15 mg/kg after the induction of anesthesia and before surgical incision and normal saline at the end of surgery (PRE group); normal saline after the induction of anesthesia and before surgical incision and IV ketamine at the end of surgery (POST group); or normal saline at the beginning and the end of surgery (CONT group). Anesthesia was performed with propofol (2 mg/kg for induction, 60-200 microg x kg(-1) x min(-1) for maintenance), sufentanil (0.2 microg/kg 10 min after surgical incision, followed by an infusion of 0.25 microg x kg(-1) x h(-1) stopped 30 min before skinclosure), vecuronium (0.1 mg/kg), and 60% N2O in O2 via a laryngeal mask airway. Postoperative analgesia was initially provided with IV morphine in the postanesthesia care unit, then with IV patient-controlled analgesia started before discharge from the postanesthesia care unit. Pain scores, morphine consumption, side effects, and degree of knee flexion were recorded over 48 h and during the first and second physiotherapy periods, performed on Days 1 and 2. Patients in the ketamine groups required significantly less morphine than those in the CONT group over 48 h postoperatively (CONT group 67.7+/-38.3 mg versus PRE group 34.3+/-23.2 mg and POST group 29.5+/-21.5 mg; P < 0.01). Better first knee flexion (CONT group 35+/-10 degrees versus PRE group 46+/-12 degrees and POST group 47+/-13 degrees; P < 0.05) and lower morphine consumption (CONT group 3.8+/-1.7 mg versus PRE group 1.2+/-0.4 mg and POST group 1.4+/-0.4 mg; P < 0.05) were noted at first knee mobilization. No differences were seen between the PRE and POST groups, except for an increase in morphine demand in the PRE versus the POST group (P < 0.05) in the second hour postoperatively. ⋯ We found that intraoperative small-dose ketamine reduced postoperative morphine requirements and improved mobilization 24 h after arthroscopic anterior ligament repair. No differences were observed in the timing of administration. Intraoperative small-dose ketamine may therefore be a useful adjuvant to perioperative analgesic management.
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Anesthesia and analgesia · Jan 2000
The anticonvulsant effects of volatile anesthetics on penicillin-induced status epilepticus in cats.
Volatile anesthetics may be used to treat status epilepticus when conventional drugs are ineffective. We studied 30 cats to compare the inhibitory effects of sevoflurane, isoflurane, and halothane on penicillin-induced status epilepticus. Anesthesia was induced and maintained with one of the three volatile anesthetics in oxygen. Penicillin G was injected into the cisterna magna, and the volatile anesthetic discontinued. Once status epilepticus was induced (convulsive period), the animal was reanesthetized with 0.6 minimum alveolar anesthetic concentration (MAC) of the volatile anesthetic for 30 min, then with 1.5 MAC for the next 30 min. Electroencephalogram and multiunit activity in the midbrain reticular formation were recorded. At 0.6 MAC, all anesthetics showed anticonvulsant effects. Isoflurane and halothane each abolished the repetitive spike phase in one cat; isoflurane reduced the occupancy of the repetitive spike phase (to 27%+/-22% of the convulsive period (mean +/- SD) significantly more than sevoflurane (60%+/-29%; P < 0.05) and halothane (61%+/-24%; P < 0.05), and the increase of midbrain reticular formation with repetitive spikes was reduced by all volatile anesthetics. The repetitive spikes were abolished by 1.5 MAC of the anesthetics: in 9 of 10 cats by sevoflurane, in 9 of 9 cats by isoflurane, and in 9 of 11 cats by halothane. In conclusion, isoflurane, sevoflurane, and halothane inhibited penicillin-induced status epilepticus, but isoflurane was the most potent. ⋯ Convulsive status epilepticus is an emergency state and requires immediate suppression of clinical and electrical seizures, but conventional drugs may be ineffective. In such cases, general anesthesia may be effective. In the present study, we suggest that isoflurane is preferable to halothane and sevoflurane to suppress sustained seizure.