The development of a performance indicator to objectively monitor the quality of care provided by an acute pain team.

Quality assurance procedures are essential in the maintenance of clinical standards in medicine. Conventional analysis techniques have difficulty in detecting gradual changes over time. Cumulative sum techniques monitor the frequency with which an event occurs and can detect changes in its frequency as soon as they become statistically significant. This study explores the use of cumulative sum techniques to monitor the performance of an acute pain team in a teaching hospital. It shows that periods of suboptimal performance can be readily identified. The prospective use of these techniques in clinical audit may allow the earlier identification and correction of technical or organisational problems. These should lead to improvements in patient care and satisfaction.

Electronic data collection by trainee anaesthetists using palm top computers.

The Royal College of Anaesthetist requires that trainees wishing to specialise in Anaesthesia register with the College and keep a logbook documenting their experience and training in clinical anaesthesia. There are a number of advantages if such logbooks are kept in an electronic format. For the first time in the United Kingdom, we have evaluated the usefulness in a district general hospital of introducing a computerized system of record keeping based on a portable palm top computer. This has enabled the careful analysis of the individual work load of each trainee in the department by means of a specific program designed to generate a comprehensive report after the information from each individual has been downloaded on to a standard desk top computer. We have found a number of interesting and unexpected results and have highlighted ways in which the system may be improved.

Multiple-choice examinations: adopting an evidence-based approach to exam technique.

Negatively marked multiple-choice questions (MCQs) are part of the assessment process in both the Primary and Final examinations for the fellowship of the Royal College of Anaesthetists. It is said that candidates who guess will lose marks in the MCQ paper. We studied candidates attending a pre-examination revision course and have shown that an evaluation of examination technique is an important part of an individual's preparation. All candidates benefited substantially from backing their educated guesses while only 3 out of 27 lost marks from backing their wild guesses. Failure to appreciate the relationship between knowledge and technique may significantly affect a candidate's performance in the examination.

Peripartum cardiomyopathy presenting as a cardiac arrest at induction of anaesthesia for emergency caesarean section.

Peripartum cardiomyopathy is defined as the onset of acute heart failure without demonstrable cause in the last trimester of pregnancy or within the first 6 months after delivery. It occurs in about 1 in 4000 deliveries and is often unrecognized as symptoms of normal pregnancy commonly mimic those of mild heart failure. We describe a previously asymptomatic patient who presented with a cardiac arrest at induction of general anaesthesia for emergency Caesarean section and subsequently developed acute heart failure. This case is unique both in its mode of presentation and the total absence of antecedent symptoms or signs of cardiac disease.

Effects of vagus nerve stimulation on amino acids and other metabolites in the CSF of patients with partial seizures.

Electrical stimulation of the vagus nerve (VNS) is a new method for the treatment of patients with medically intractable epilepsy. Sixteen patients, ten of whom participated in a larger multicenter double-blind trial on the efficacy of VNS in epilepsy, and six who participated in pilot studies, consented to participate in the present study. Ten patients received HIGH stimulation and six patients LOW stimulation for the 3-month trial. Cerebrospinal fluid (CSF) samples (16 ml) were collected both before and after 3 months of VNS. Amino acid and neurotransmitter metabolites were analyzed. Four patients responded to VS with more than a 25% seizure reduction after 3 months. Mean and median concentrations of phosphoethanolamine (PEA) increased in responders and decreased in nonresponders. Free GABA increased in both groups but more so in the nonresponders. After 9 months of VS (6-9 months on HIGH stimulation) 4 of 15 patients had more than 40% seizure reduction. There were significant correlations between seizure reduction and increases in asparagine, phenylalanine, PEA, alanine and tryptophan concentrations. Comparison between patients with HIGH or LOW stimulation showed a significant increase in ethanolamine (EA) in the HIGH group and a decrease in glutamine in the LOW group. All patients regardless of response or stimulation intensity showed significantly increased total and free GABA levels. A decrease in CSF aspartate was marginally significant. Other trends were decreases in glutamate and increases in 5-hydroxyindoleacetic acid. Chronic VNS appears to have an effect on various amino acids pools in the brain.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of epilepsy by stimulation of the vagus nerve.

We treated 14 patients with medically refractory partial seizures by stimulation of the vagus nerve in two single-blind pilot studies. Patients received stimulation through an implantable, programmable NeuroCybernetic Prosthesis, consisting of a pulse generator and a lead-electrode assembly. The mean reduction in seizure frequency after 14 to 35 months of vagal stimulation was 46.6%. Of the 14 patients, five (35.7%) had a 50% or greater reduction in seizure frequency. Two patients, one of whom had had 10 to 100 seizures per day before stimulation, have been seizure-free for over 1 year. Adverse events were primarily limited to initial hoarseness and a tingling sensation at the electrode site in the neck when the device was activated. Most patients tolerated the device and stimulation well. There were no permanent adverse events. Some cases of medically refractory partial seizures are improved by vagal stimulation.

Electrophysiological studies of cervical vagus nerve stimulation in humans: I. EEG effects.

Evidence from studies of experimental animals indicates that electrical stimulation of the vagus nerve alters EEGs under certain stimulus parameters. We report EEG effects of electrical stimulation of the vagus nerve in 9 patients with medically intractable seizures as part of a clinical trial of chronic vagal stimulation for control of epilepsy. The mechanism of action of the vagal antiepileptic effect is unknown, and we believed that analysis of electrophysiologic effects of vagal nerve stimulation would help elucidate the brain areas affected. The left vagus nerve in the neck was stimulated with a programmable implanted stimulator. Stimulation at various stimulus frequencies and amplitudes had no noticeable effect on EEG activity whether the patient was under general anesthesia, awake, or asleep, but vagus nerve stimulation may interrupt ongoing ictal EEG activity.

Electrophysiologic studies of cervical vagus nerve stimulation in humans: II. Evoked potentials.

Evidence from studies of experimental animals indicates that electrical stimulation of the vagus nerve not only can alter the EEG but evokes activity in specific brain areas. We report effects of electrical stimulation of the vagus nerve in 9 patients with medically intractable seizures as part of a clinical trial of chronic vagal stimulation for control of epilepsy. The left vagus nerve in the neck was stimulated with a programmable implanted stimulator. Effects of stimulus amplitude, duration, and rate were studied. Noncephalic reference recording of the vagus nerve evoked potential showed some unusual properties: a scalp negative component occurred with a latency of 12 ms, very high amplitude (< or = 60 microV), and widespread scalp distribution. Field distribution studies indicated that this potential was myogenic in origin and generated in the region of the stimulating electrodes in the neck area. Chemically induced muscle paralysis confirmed this observation. Bipolar scalp recording showed several small-amplitude topographically distinct potentials occurring in 30 ms. No effect, either acute or chronic, could be detected on pattern-reversal evoked potentials, auditory brainstem evoked potentials, auditory 40-Hz potentials, or cognitive evoked potentials.