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True allergies to local anesthetics are rare. It is common for practitioners to misdiagnose a serious adverse event to local anesthetics as an allergic reaction. The most likely causes for an allergic response are the preservative, antioxidant, or metabolites and not the anesthetic itself. This case report illustrates the need for practitioners to understand the many potential allergens in local anesthetics and to correctly diagnose patients that are truly allergic to the local anesthetic.

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Fifteen consecutive pediatric patients ranging from 3 to 5 years old were selected to receive one of three sedative/hypnotic techniques. Group 1 received oral chloral hydrate 50 mg/kg, and groups 2 and 3 received intramuscular ketamine 2 mg/kg and 3 mg/kg, respectively. In addition to ketamine, patients in groups 2 and 3 received transmucosal intramuscular injections of meperidine and promethazine into the masseter muscle. Sedation for the satisfactory completion of restorative dentistry was obtained for over 40 min on average in the chloral hydrate group, but completion of dental surgery longer than 40 min was achieved in groups 2 and 3 only by intravenous supplements of ketamine.

Two hundred geriatric patients ranging from age 65 to 92 yr (mean age 72 yr) were evaluated for office oral surgery and intravenous sedation. Surgical time ranged from 6 to 129 min. Monitored anesthesia care was utilized for the administration of fentanyl, midazolam or diazepam, and methohexital. No serious complications were seen and no patients were hospitalized.

Five hundred and fifty patients underwent general anesthesia with fentanyl, diazepam, and methohexital. Forty-seven (8.5%) developed signs of hypoventilation or airway obstruction. Arterial blood gas analysis revealed mild hypoxemia in three of the 47 cases and mild hypercarbia in six. Airway obstruction was more predictive of abnormal blood gas values than was hypoventilation.

During inhalation induction of the pediatric patient, laryngospasm can develop before intravenous access has been established. The intramuscular administration of succinylcholine is commonly used in such instances. This study was designed to determine if the injection of succinylcholine by an extraoral submental approach would be an acceptable method of terminating laryngospasm when compared to conventional intramuscular sites. Following induction with halothane and nitrous oxide in oxygen, a total of fifteen ASA 1 children were given 3.0 mg/kg intramuscular succinylcholine either intralingually by a submental approach, or using the upper leg musculature in order to electromyographically measure the time to maximum (or 90 percent depression from baseline) twitch depression. The intralingual submental injection had a mean twitch depression of 265 +/- 62.5 seconds compared to the quadriceps femoris at 295 +/- 42.6 seconds. A group with digital massage of the intralingual injection site produced a mean depression time of 133 +/- 11.9 seconds and was also the only group providing 100% success rate in reaching the desired twitch depression level. This may suggest that the operator should consider digital massage to produce a more predictable and desirable result.

Five patients requiring general anesthesia but presenting with compromised airways were successfully intubated by blind awake intubation with the aid of regional anesthesia and the use of appropriate sedation. Arterial blood gases were collected at three intervals: presedation, postsedation, and postintubation. Analysis of the blood gases revealed varying degrees of hypoxemia, hypercarbia, and acidosis following deep sedation before intubation. A decrease in oxygen saturation was also observed. Supplemental oxygen is suggested to avoid the effects of arterial desaturation during the sedation process. If oxygen is not administered, the risk of moderate hypoxia associated with blind awake intubation must be considered along with alternative problems including loss of protective reflexes or the inability to ventilate during induction and intubation via a direct technique.

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