Epidural fentanyl is not effective for analgesia for extracorporeal lithotripsy (ESWL)
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Biomedical subjects
Publications and source records attributed to S K Pandit.
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We conducted a placebo-controlled double-blind investigation in 15 normal volunteers to study the time course of amnesia to auditory stimulation produced by lorazepam. We also studied the relationship between auditory amnesia and auditory evoked potentials to determine if long-latency auditory evoked potentials (LLAEPs) could be utilized as electrophysiologic predictors of memory. Amnesia was produced by administration of 0.05 mg/kg lorazepam intravenously. To separate the changes in LLAEPs due to generalized sedation from those associated with amnestic properties of a drug, a third group of subjects given 1.5 mg/kg secobarbital was included. Observed frequency and duration of amnesia to auditory stimulation after lorazepam was 58% and 3 hours, respectively (mean values), with marked diminuition of antirecall effect at 120 minutes. Administration of lorazepam increased the latency and decreased the amplitude of N1 and P3 components of LLAEPs. These changes appeared to be a result of generalized sedation rather than the amnestic properties of the drug. We failed to find a definite relationship between amnesia and changes in LLAEPs. We conclude that P3 component of LLAEPs cannot be utilized as an electrophysiologic predictor of amnesia in humans.
Equianalgesic doses of butorphanol (40 micrograms X kg-1) and fentanyl (2.0 micrograms X kg-1) were compared as supplements to balanced general anaesthesia for outpatient laparoscopic procedures. Thirty-six adult female patients (ASA physical status I or II) participated in the study. The study drugs (butorphanol or fentanyl) were given just prior to induction of anaesthesia in a double-blind fashion. Following induction with a standard dose of thiopentone and tracheal intubation using succinylcholine, nitrous oxide in oxygen and a succinylcholine infusion were used for maintenance of anaesthesia. Seventeen of the 18 patients in the butorphanol group and 14 of the 18 patients in the fentanyl group showed signs of light anaesthesia and required supplementation with isoflurane. Induction, maintenance and recovery characteristics were not different in the two groups except that the post-intubation arterial pressure and heart rate in the fentanyl group were significantly higher than the base line values and the patients receiving butorphanol were more drowsy and also more pain-free in the postoperative period. The incidence of nausea and vomiting was high in both groups. Overall, butorphanol (40 micrograms X kg-1) used as part of a standard balanced general anaesthetic for a standard outpatient procedure was not superior to fentanyl (2 micrograms X kg-1) used in the same fashion.
The chemistry, pharmacology, pharmacokinetics, clinical efficacy, adverse effects, drug interactions, dosage, and cost and availability of midazolam hydrochloride are reviewed. The anxiolytic, sedative, hypnotic, anticonvulsant, muscle-relaxant, and amnesic properties of midazolam are similar to those of other injectable benzodiazepines. Midazolam is approximately two to four times as potent as diazepam. Midazolam hydrochloride is water soluble (resulting in fewer local adverse reactions after injection), has a rapid onset and short duration of action, and causes relatively mild cardiovascular and respiratory effects. The drug generally is well tolerated. Midazolam is a good premedicant for general or regional anesthesia. Its greatest use will probably be for conscious sedation during surgical or diagnostic procedures performed under local or regional anesthesia. Induction of anesthesia with midazolam alone is somewhat unpredictable; opiate pretreatment makes induction more consistent. Midazolam is a less reliable induction agent than thiopental, but because it produces fewer adverse cardiovascular and respiratory effects than thiopental, midazolam appears to be a safer induction agent for elderly patients or patients with cardiovascular disease. The recommended dose of midazolam for preoperative sedation is 0.07-0.1 mg/kg given by intramuscular injection one hour before surgery. For conscious sedation, 0.1-0.15 mg/kg intravenously in divided doses is usually adequate. Lower doses of midazolam are recommended for elderly or debilitated patients and patients who have severe liver disease. The costs of equipotent doses of midazolam and injectable diazepam are similar. An oral dosage form is under investigation in the United States. Midazolam's pharmacologic and pharmacokinetic profile makes it an attractive alternative to other injectable benzodiazepines used in anesthesia.
Dezocine, a new mixed agonist-antagonist opioid analgesic, and morphine were compared in a double-blind study in 206 patients with postoperative pain. The analgesic efficacy of single intravenous injections of dezocine (2.5, 5.0, and 10.0 mg), morphine (5.0 mg), and placebo was assessed by verbal and visual scales at regular intervals for six hours after administration. All active treatments provided greater pain relief than placebo. Pain relief with dezocine 5 and 10 mg was significantly greater (P less than .05) than with placebo for up to four and five hours, respectively, and with morphine up to one hour. Pain relief scores were significantly higher (P less than .05) with morphine than with placebo at all observations except that of the fifth hour, and higher with dezocine 2.5 mg than with placebo for the first 30 minutes. Doses of 5 and 10 mg of dezocine produced approximately the same peak analgesic effect, with the larger dose having a longer duration of effect. All active treatments produced mild to moderate sedation. Side effects were few and mild or moderate with all of the treatments. The physician's and the patients' evaluations favored dezocine in a dose-dependent order, with morphine 5 mg rated lower than dezocine 5 mg and higher than dezocine 2.5 mg.
Vecuronium 0.1 mg/kg, pancuronium 0.1 mg/kg, vecuronium 0.075 mg/kg + pancuronium 0.025 mg/kg, vecuronium + pancuronium 0.05 mg/kg each and vecuronium 0.025 mg/kg + pancuronium 0.075 mg/kg were compared with respect to time taken to onset of effect, duration of clinical relaxation and intubation conditions in five groups of 20 patients each. The time to onset and intubating conditions were similar in all the groups, indicating that the combinations have no advantage over the individual drugs. The duration of clinical relaxation was 25 minutes with vecuronium, and increased as the proportion of pancuronium in the mixture increased, being 56 minutes with pancuronium 0.1 mg/kg.
A randomised, double-blind, placebo-controlled parallel study was conducted in adult females to evaluate the efficacy and safety of a combination of cimetidine 300 mg orally and metoclopramide 10 or 20 mg intravenously in reducing pre-operative residual gastric volume and raising gastric pH. The effect of preoperative metoclopramide on postoperative nausea and vomiting was also investigated. Oral cimetidine was given approximately 2-2.5 hours before, and intravenous metoclopramide either 15 or 30 minutes prior to induction of anaesthesia. The study showed that placebo-treated patients undergoing outpatient operations have an increased risk of acid aspiration because of high residual gastric volume and low pH and increased risk of serious pulmonary injury should acid aspiration occur. Metoclopramide 10 or 20 mg intravenously prior to induction of anaesthesia was effective in reducing the residual gastric volume significantly, but not in raising pH. The combination of cimetidine and metoclopramide, as well as cimetidine alone, reduced the risk factors of acid aspiration by raising gastric pH and reducing residual volume. No anti-emetic effect of metoclopramide was observed. Higher doses of metoclopramide (20 mg) produced significant side effects (flushing, dizziness, extrapyramidal side effects), but were only marginally more effective than 10 mg doses in reducing residual gastric volume.
Dezocine, a new mixed agonist-antagonist-type opioid analgesic, was compared in a double-blind trial with placebo and 10 mg of morphine in 190 patients with acute postoperative pain. The medications were given intramuscularly. Dezocine was administered at three dose levels (5, 10, and 15 mg). Pain relief scores, sedation, and side effects were recorded at 15, 30, 60, 120 and 240 min after injection. Significantly higher pain relief scores (p less than 0.05) were reported for the groups receiving dezocine 10 and 15 mg than the placebo group at all observation times, except for dezocine 15 mg at four hours. Morphine produced significantly better pain relief than placebo only between the second and fourth hour after administration. Significantly better pain relief was obtained with dezocine (10 and 15 mg) than with morphine during the first hour. The mean four-hour cumulative pain relief scores (TOTPAR) were significantly (p less than 0.05) higher than placebo for all active treatment groups. Side effects were few with no significant differences between the treatment groups. Seventy-nine per cent of the patients in the dezocine 15 mg group, and 73, 68, 58 and 50 per cent respectively, of the patients in the dezocine 10 mg, dezocine 5 mg, morphine 10 mg and placebo group had a satisfactory clinical response. Significantly (p less than 0.05) more patients in the groups receiving dezocine 10 and 15 mg than in the placebo group had a satisfactory clinical response; the difference was not significant for the dezocine 5 mg and morphine 10 mg groups.(ABSTRACT TRUNCATED AT 250 WORDS)
In a randomised double-blind trial carried out on fit, unpremedicated patients undergoing standard minor operations with early postoperative mobility, using a standard form of anaesthesia, pretreatment with diazepam 0.15 mg/kg or midazolam 0.1 mg/kg failed to reduce significantly the incidence of postoperative muscle pains following suxamethonium 1 mg/kg. By contrast, tubocurarine 0.05 mg/kg proved to be effective as a pretreatment. Neither benzodiazepine influenced the incidence or severity of fasciculations seen with suxamethonium or the duration of neuromuscular block. Tubocurarine virtually abolished visible fasciculation and, in the dose used, reduced the intensity and duration of the neuromuscular block. There were no clinically significant changes in serum potassium, creatinine phosphokinase or aldolase after suxamethonium, although 5 out of 47 showed an atypical rise in creatinine phosphokinase.
The effect of halothane and enflurane on changes in heart rate during reversal of neuromuscular blockade was compared in 48 patients. Premedication and anaesthetic technique was standardized. Either halothane or enflurane was used as the primary anaesthetic. Neuromuscular block was reversed by injection of glycopyrrolate and neostigmine, given either separately or simultaneously. Heart rate changes were significantly different between the halothane and enflurane subgroups. Patients anaesthetized with enflurane showed less fluctuations in heart rate. Simultaneous injection of glycopyrrolate and neostigmine minimized the tachycardia in the halothane subgroups only.
Pancuronium, vecuronium and a combination of these were administered in an incremental fashion to study any potentiation of effect with the combination of the two relaxants. The ED95 (dose producing a 95% block) of the combination was 29 micrograms kg-1 for each component in comparison to 57 micrograms kg-1 for vecuronium and 59 micrograms kg-1 for pancuronium. The dose-response curves for the three groups did not differ from each other and no potentiation was demonstrated.
A combination of pancuronium and d-tubocurarine is associated with potentiation of the neuromuscular blocking effects of each drug used singly. The time to onset of maximum block and the time to 25% recovery after administration of equipotent (ED95) doses of pancuronium (0.07 mg/kg) alone, d-tubocurarine (0.51 mg/kg) alone, and pancuronium (0.024 mg/kg) in combination with d-tubocurarine (0.144 mg/kg) were studied in three groups of 10 patients each. The time to onset of maximum block was slightly but not significantly shorter with the combination (3.5 min) than with pancuronium (4.78 min) or d-tubocurarine (4.88 min). The time to 25% recovery with the pancuronium-d-tubocurarine combination (39.7 min) was significantly shorter than it was after d-tubocurarine (57.6 min) but not significantly different from pancuronium (54.4 min). The combination of pancuronium and d-tubocurarine also was associated with greater cardiovascular stability.
The effect of halothane and enflurane on changes in heart rate during reversal of neuromuscular block was compared in 48 adult patients. Premedication and anaesthetic technique were standardized. Either halothane or enflurane was the primary anaesthetic while pancuronium was used in all patients to achieve muscle relaxation. Ventilation was mechanically controlled and PaCO2 was between 30-40 mmHg. The neuromuscular block was reversed by an intravenous injection of atropine 1.2 mg and neostigmine 2.5 mg, given either separately or simultaneously, in different patient subgroups. Heart rate changes were significantly different between the halothane and enflurane groups. In general, reversal of neuromuscular block was accompanied by less fluctuations in heart rate after enflurane as compared to halothane anaesthesia. Simultaneous injection of atropine and neostigmine modified the tachycardiac response in the halothane sub-group only. Our observations suggest that use of enflurane offers an advantage over halothane in those patients in whom rapid fluctuations in heart rate during reversal of neuromuscular block may be dangerous.
The study on which this article is based evaluated the effect of a clerkship in anesthesiology on medical students' attitudes toward anesthesiology as a specialty, the role of anesthesiologists as physicians, career choice, and the usefulness of this experience in their learning. Eighty-four participating students filled out questionnaires on the first and the last day of a four-week clerkship. Responses to common questions in the questionnaires administered before and after the clerkship were compared by paired t-test to determine statistical significance. The results suggest that the clerkship (a) significantly improved graduating students' attitudes toward anesthesiologists as physicians and (b) provided a worthwhile clinical experience.
Physostigmine salicylate (2.0 mg) or 0.9% NaCl (2.0 ml) was administered intravenously in a double-blind fashion to adult volunteers in an attempt to reverse the effects of a 0.05-mg/kg dose of lorazepam given intravenously 30 min earlier. No other medication affecting the central nervous system was given. No differences were observed between the two groups with regard to the frequency of amnesia, psychomotor impairment, or EEG changes during a period of 4 h. The only significant difference in the level of sedation between the two groups was observed 60 min into the study. This difference is attributed to the high incidence of nausea and vomiting that occurred at that time exclusively in one group. Time to complete recovery was the same in both groups. However, physostigmine, not saline, was associated with a high incidence of muscarinic and sympathetic stimulating effects. The results obtained indicate that at the dose used, physostigmine is of no clinical value in treating sedation induced by lorazepam.
Entrainment of air following exploration of posterior cranial fossa in the sitting position was studied in five patients. Intracranial pressure was monitored through a ventriculostomy catheter after closure of the dura. In three patients nitrous oxide was added to the breathing mixture only after the baseline intracranial pressure had stabilised following closure of the dura. A marked rise in intracranial pressure was observed immediately. A rapid decrease in intracranial pressure occurred when nitrous oxide administration was stopped. Two patients were nitrous oxide from the beginning. No change in intracranial pressure was noted. Computerised tomogram on the first postoperative day revealed a significant amount of air in eight cases.
The time course of antirecall effect and grades of sedation after the oral administration of diazepam and lorazepam were determined in 120 patients. Three standard doses of each drug were employed. Grades of sedation following oral diazepam were dose related, with a latency of 30-60 min and duration of 120-150 min. All three doses of lorazepam produced significantly more sedation with a similar latency (30-60 min) but longer duration (more than 240 min). Peak frequencies of the antirecall effects of diazepam 10, 15, and 20 mg were 5, 20, and 30 per cent, respectively. The duration was about two hours. Peak frequencies of the antirecall effect after lorazepam 2, 3, and 4 mg were 30, 45, and 72 per cent, respectively. Latency of peak action was about 60-90 min for all the doses, but the duration, especially with 3 and 4 mg doses, was long (4 h).
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