Epidural catheter migration: a comparison of tunnelling against a new technique of catheter fixation.

We investigated the efficacy of a new technique of epidural catheter fixation that relies on a strip of adhesive foam transfixed by a securing suture. We compared this technique to a tunnelled technique in a prospective, randomized trial (n = 25 in each group). Epidural catheter depth was recorded at the time of insertion and at the time of removal. Clinically significant catheter movement was considered as > 2 cm outward movement or > 1 cm inward movement. The mean duration of epidural analgesia was five days for both groups. Clinically significant movement was noted in eight patients (32%) in the tunnelled group and seven patients (28%) in the sutured group (P = 0.75). Movement of the epidural catheter did not correlate with analgesic failure. The sutured technique provided similar protection against migration to tunnelling but any potential advantages were offset by concerns about a significantly higher incidence of erythema around the catheter exist site in the sutured group (1 vs 6 patients, P = 0.04).

Neuropsychological and pharmacokinetic assessment of hospice inpatients receiving morphine.

Eighteen inpatients receiving morphine for cancer pain in a palliative care unit were recruited to a study employing a range of neuropsychological tests to assess cognitive function. The tests employed were National Adult Reading Test, Williams Delayed Recall Test, Immediate Memory for Digits, Trailing Making Test, and the Digit Symbol Substitution Test. These data were correlated with biochemical tests of renal and hepatic function, morphine dose, route of administration, plasma morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) concentrations. Despite having no clinical evidence of impairment of cognitive function, the level of current intellectual functioning (Symbol Digit Substitution Test) was on average two standard deviations below normal. Immediate memory appeared to be well preserved, but Delayed Recall and Trailing Making Test scores were significantly above normal. There was no significant correlation between morphine dose, or plasma morphine and M3G and M6G concentrations, and the neuropsychological test results, although a weak correlation was found between plasma morphine concentration and digits forward (r = -0.47, p < 0.05) and Digit Symbol Substitution scores (r = -0.46, p < 0.05). Seven patients had some degree of nausea or vomiting, ascribed as an opioid adverse effect, and had higher serum creatinine concentrations, worse neuropsychological performance, and significantly higher plasma M3G concentrations (p < 0.05). These data provide some evidence to suggest that cognitive functioning in patients with advanced cancer receiving morphine may be significantly impaired despite apparent clinical normality. From these data it is not possible to determine what relative causal contribution the disease and the drug made to these observations, although renal function, plasma morphine, and M3G concentrations may be important. Future research should address a broad range of neuropsychological testing to assist in the modification of practices aimed at enhancement of quality of life, such as opioid substitution or rotation.

Effect of timing of ketorolac administration on patient-controlled opioid use.

In order to investigate the analgesic effect of timing of administration of ketorolac 10 mg i.v., we recorded patient-controlled use of diamorphine at 2, 4 and 12 h after abdominal hysterectomy. In a randomized, double-blind trial, 30 patients received ketorolac before skin incision and 28 after skin closure. A control group of 32 patients did not receive ketorolac. We measured operative blood loss and assessed nausea, vomiting and pruritus. After 2 h of patient-controlled analgesia, the median cumulative diamorphine dose in the group given ketorolac before operation was less than that of the control group (95% confidence interval 8-66 micrograms kg-1; P = 0.01). There were no other statistically significant differences in diamorphine consumption between the groups. The frequency of nausea and vomiting was similar in all groups Median blood loss in the group given ketorolac before operation exceeded that of the patients who did not receive ketorolac before operation (95% confidence interval 20-149 ml; P = 0.01). We conclude that the diamorphine-sparing effect of ketorolac attributable to timing of administration was small, conferred no clinical benefit and was accompanied by increased bleeding. No patient given ketorolac complained of pruritus.

Grading of direct laryngoscopy. A survey of current practice.

One hundred and twenty anaesthetists (30 of each grade), from three separate regions, were interviewed as to how they recorded the appearance of laryngeal structures at direct laryngoscopy and about their knowledge of the commonly used numerical grading system. About two-thirds of anaesthetists surveyed (69.2%) used the numerical grading system, but of these, over half could not identify a 'grade 2' laryngoscopic appearance correctly. Of anaesthetists who did not use the numerical method, over half could not correctly state the difference between a 'grade 2' and a 'grade 3' laryngoscopic appearance. Over 40% of anaesthetists stated incorrectly that the grading should be made on the initial view, even when laryngeal pressure had been needed. Junior anaesthetists were more likely to use the numerical method of recording. The results show that there is unacceptable uncertainty and inaccuracy in the use of the numerical grading system by users as well as non-users, which makes the current routine clinical use of the numerical grading system unsatisfactory.