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Comments on the safety of outpatient dental anesthesia for children. Deaths from respiratory difficulties or cardiovascular collapse; Reference to a study by Michael Blayney et al in this issue; Assertion that practice guidelines for the administration of sedatives and anesthetics outside the operating room must be followed.

Implications: Significant neuromuscular block may be present in patients who have received vecuronium for days.

Purpose: To describe neuromuscular effects of rapacuronium in pediatric patients during N2O-halothane anesthesia and compare them with mivacurium in children., Methods: 103 pediatric patients, seven days -12 yr, received rapacuronium or mivacurium during N2O-halothane anesthesia. Onset and recovery of block were measured using EMG (Datex). Block was compared between groups based on drug treatment and age. Children < two years received 1 or 2 mg x kg(-1) rapacuronium: 2-12 yr received either 2 mg x kg(-1) or 3 mg x kg(-1) rapacuronium, or 0.2 mg x kg(-1) mivacurium., Results: There were no differences in onset (1.7+/-1.8 min) or maximum block (T1 2.4+/-8%) among neonates, infants, and toddlers after either dose of rapacuronium. There was no difference between 1 and 2 mg x kg(-1) of rapacuronium block at 60 sec. Train-of-four ratio (T4/T1) >0.7 occurred later after 2 mg x kg(-1) than 1 mg x kg(-1) in these patients (P<0.05). There was no difference in T25 among neonates, infants and toddlers for 1 mg x kg(-1) or 2 mg x kg(-1) doses. Rapacuronium, 3 mg x kg(-1), produced maximum block 1.5 min earlier than did mivacurium, 0.2 mg x kg(-1) (P<0.001). There was no difference in block at 60 sec, maximum block or time to maximum block between 2 and 3 mg x kg(-1) rapacuronium for children > two years of age. Maximum block occurred 1.0+/-0.5 min after 2 or 3 mg x kg(-1) when T1 was 0.2+/-1.1% of baseline. T25 and T4/T1 >0.7 occurred 10 to 11 min later after this dose of rapacuronium than after mivacurium., Conclusion: Rapacuronium produces block earlier than mivacurium. Recovery from rapacuronium block is dose related and slower than that following mivacurium during halothane anesthesia.

Background and Objectives: The performance of caudal injection (CI) has become a routine part of pediatric anesthesia. The intraoperative and immediate postoperative complications of CIs have been reported extensively. Although the long-term consequences of CI are unknown, they may include the development of epidermoid tumors in the spinal canal. Such tumors have been attributed to tissue coring (the process by which pieces of tissue are removed by a needle as it passes through the tissue) and the subdural deposition of such tissue., Methods: In this study, we examine the internal needle of 20-gauge i.v. cannulae from 50 CIs for evidence of tissue coring., Results: We found a total coring incidence of 54% (95% confidence interval = 40-68%). Epidermal tissue was present in 33% of the positive samples. Fat was present in 67% of the positive samples and bloody material in 26%. This study provides an estimate (with a 95% confidence interval) of the rate of coring during CI performed with hollow point needles., Conclusions: These findings suggest that technical modifications may improve patient safety. The results also have implications for long-term follow-up of caudal anesthetics. Techniques for reducing the incidence of tissue coring during the performance of CI are discussed.

Purpose: This study describes the effects of 0.3 mg.kg-1 mivacurium in 180 paediatric patients between the ages of one month and 13 yr., Methods: Alternate patients at each of two geographic sites received nitrous oxide-halothane or nitrous oxide-opioid anaesthesia. Neuromuscular blockade was monitored by electromyography (Datex NMT). Blood pressure and heart rate were recorded from an automated oscillometer. Tracheal intubation was performed 90 sec after administration of mivacurium and conditions were judged by the Krieg scale., Results: There was no difference in the time course of block between anaesthetics or geographic sites. The average time to 90% block and 25% recovery was 1.0 min and 8.0 min at one month vs 2.3 min and 9.8 min at 12.5 yr of age. Intubation conditions were better during opioid (excellent in 92%) than during halothane anaesthesia (excellent in 78%) (P = 0.03). Diaphragmatic movement was less frequent in younger patients (P < 0.001). Intubation conditions did not differ between the two geographic sites. In the first minute after mivacurium, systolic and diastolic blood pressures decreased (P < 0.001) to similar extents in all patients. A transient increase in the redness of the skin of the face, trunk, and/or arms was noted during both anaesthetics (28% of infants, and 61% of children over five yr of age)., Conclusion: The time course of block produced by mivacurium is more rapid in younger paediatric patients. The time course of mivacurium does not have the transatlantic variation which has been observed for vecuronium. Physiological changes suggestive of histamine release were frequent. Intubation conditions were very likely to be acceptable 90 sec after 0.3 mg.kg-1 mivacurium.

Study Objective: To distinguish among potential predictors of early, easy intubation in children, including apnea, neuromuscular block at two sites, and time, after administration of 0.3 mg/kg of mivacurium., Design: Prospective, randomized study., Setting: Operating rooms of Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania., Patients: 60 ASA physical status I and II children aged 2 through 7 years, scheduled for elective surgical procedures requiring endotracheal intubation., Interventions and Measurements: After premedication with midazolam, general anesthesia was induced with halothane and nitrous oxide, and patients were randomly assigned to one of four groups. Mivacurium 0.3 mg/kg was given and tracheal intubation was begun 45 seconds after its injection, or when apnea, block of the orbicularis oculi, (OO) or block of the adductor pollicis (AP) was noted. Intubation conditions were evaluated by an experienced endoscopist., Main Results: The first clinical event after administration of mivacurium 0.3 mg/kg was apnea at 43 seconds (median) (average 48 seconds, SEM 2 seconds) after injection. The difference in the time at which neuromuscular block occurred at the AP (median 75 seconds) (average 77 seconds, SEM 2 seconds) and the OO (median 63 seconds) (average 68 seconds, SEM 4 seconds) was statistically, but not clinically, significantly different. All nine intubations that were begun at least 90 seconds after administration of mivacurium resulted in good or excellent intubation conditions, as did 30 of the 51 intubations started earlier., Conclusions: In children, there is no advantage to monitoring neuromuscular function at the OO rather than the AP. After administration of 0.3 mg/kg of mivacurium, a 90-second interval before the start of intubation was a better predictor of good intubation conditions during halothane anesthesia (1% inspired) than were changes in evoked neuromuscular function.