Pharmacologic reduction of the risk of aspiration.

Parameters for significant risk of aspiration have been defined as a gastric pH less than 2.5 and/or a volume greater than 25 ml. We investigated the effects of metoclopramide and cimetidine, alone and in combination, on the pH and volume of gastric contents of patients taking nothing by mouth before general anesthesia. We divided 40 young women having gynecologic surgery into four groups: control subjects (group 1), those given metoclopramide (group 2), those given cimetidine (group 3), and those given both drugs (group 4). Injections were given 45 to 90 minutes before induction of general anesthesia, and no other premedicant was allowed. When the mean pH and volume of gastric contents were measured, the patients given both drugs had a mean pH of 6.9 and a mean volume of 2.0 ml. The control group showed significant risk for aspiration in terms of both volume and pH. Use of metoclopramide alone reduced the risk related to volume, and cimetidine alone reduced the risk related to pH. The most striking effects were achieved by the combination of the two agents, which produced a relatively narrow range of "safe" pH and volume.

Predictors of success in an anesthesiology residency.

The selection of residents in medical specialty programs is a difficult task facing all selection committees. The present authors examined factors that contribute to successful residency performance by 26 anesthesiology residents in order to assist the program's selection committee in developing selection criteria. The best predictor of a resident's academic average in the anesthesiology program was the number of years the resident had spent in other specialties. Comparison of the residents' scores on the Anesthesiology In-Training Examination (ITE) and their scores on Part I of the examinations of the National Board of Medical Examiners (NBME) showed a statistically significant negative correlation. The higher that residents scored on the NBME Part I examination, the lower they scored on the ITE. No significant correlations were found between the residents' ITE scores and undergraduate grade-point average or nonacademic variables such as the residents' age or parents' level of education. The residents' composite grade-point average (GPA) for the residency and their interview scores had a strong positive relationship significant at the 0.06 level.

Inhibition of catecholamine biosynthesis by carbidopa and metyrosine in neuroblastoma.

In three patients with neuroblastoma and high circulating levels of dopamine and dopa, we interfered pharmacologically with catecholamine biosynthesis either at the tyrosine hydroxylase or dopa decarboxylase step in an attempt to 1) improve the efficacy of antitumor therapy and 2) avoid the potential arrythmogenic interaction between elevated circulating catecholamines and an halogenated hydrocarbon anesthetic during surgery. Biochemical evidence indicated that inhibition of catecholamine biosynthesis had occurred but there was no associated significant change in clinical status or response to other therapy.

Assessment of neuromuscular function in infants.

This study was conducted to measure neuromuscular transmission in newborn infants. Age-dependent differences in neuromuscular transmission and the effect of nitrous oxide anesthesia upon neuromuscular function were assessed in pediatric surgical patients following induction of anesthesia with methohexital by the use of the frequency sweep electromyogram (FS-EMG). Children older than 12 weeks' chronologic age usually had FS-EMG responses similar to those of adults, whereas infants less than 12 weeks old had significantly less pronounced FS-EMG responses at high stimulation frequencies (>50 Hz). Administration of 70 per cent nitrous oxide induced 11-38 per cent reductions in the amplitudes of the FS-EMG responses at all frequencies of stimulation in the younger group. A positive correlation was found between inability to sustain a tetanic contracture (FS-EMG fade) in the 50-100-Hz region of stimulation and percentage depression of the FS-EMG response induced by nitrous oxide.

Complications of airway intrusion in 100 consecutive cases in a pediatric ICU.

One-hundred consecutive patients who underwent orotracheal intubation (OT), nasotracheal intubation (NT), or tracheostomy in the pediatric ICU were evaluated for complications of these airway invasions. Twelve patients had major complications as a result of airway intervention. The mortality for patients requiring mechanical ventilation was 17% as compared with a total overall mortality of 8.3% for patients in the pediatric ICU. Major complications occurred in 10% of patients who had orotracheal intubation, in 11% of patients who had nasotracheal intubations, and in 26% of patients subjected to tracheostomy. Laryngotracheobronchitis (croup) was the primary diagnosis associated with the highest rate of complications. An association was found between the occurrence of seizures or hypoperfusion state (shock) while intubated and the occurrence of major complications of airway intrusion. Acquired infections of the respiratory tract with Hemophilus influenzae, Pseudomonas, Klebsiella, and Candida albicans were also associated with a high rate of complications.

Infant tracheostomy. A new look with a solution to the difficult cannulation problem.

Although most infant airway and ventilatory problems will be best solved by the use of endotracheal tubes, clear-cut indications for tracheostomy exist. Past reticence to use tracheostomy for infants has been due mainly to the fear of decannulation problems. Recognition of obstructive airway lesions, particularly the lumen-narrowing tracheal stomal granuloma, has been facilitated by the routine use of the newer infant bronchoscopes with optical telescopes. Successful decannulation begins with proper tracheostomy technique, and continues through tracheostomy management and a well-conceived decannulation program. Decannulation should include evaluation of the structure and function of the airway endoscopically and it may include translaryngeal endoscopic resection or formal surgical removal of any obstructing lesions. Experienced nursing personnel are essential to the entire program.

A preplanned treatment for malignant hyperpyrexia.

Although a rare complication of general anesthesia, unanticipated malignant hyperpyrexia requires a rapid, organized treatment plan. With the aid of a treatment protocol sheet and a compact drug and cooling package, treatment can be implemented quickly in each operating room.

Alterations in ventricular fluid pressure during ketamine anesthesia in hydrocephalic children.

We studies ventricular fluid pressure changes in 26 hydrocephalic children following administration of ketamine. The increase in VFP previously found with intravenously administered ketamine was compared with changes after ketamine given intramuscularly, and the possible alteration of this increase with sedative premedicants was studies. Changing the route of administration did not change the time to peak VFP changes or the duration of pressure elevation. There was no demonstrable alteration of the increase in VFP by premedication with secobarbital, dorperidol, or diazepam in clinical dosage. We feel that acute rises of VFP may affect areas of marginal cerebral blood flow and may increase the risk of herniation of brain tissue.