Anaesthetic breathing systems in the accident and emergency department.

We report two cases where patients with an acute head injury developed hypercapnia as a result of the inappropriate use of the Magill breathing circuit. The Magill circuit is inefficient when used for controlled ventilation because the patient is ventilated with his own expired gas and develops hypercapnia. The suitability of alternative breathing systems are discussed.

Effect of i.v. metoclopramide on gastric emptying after opioid premedication.

Metoclopramide was given i.m. or i.v. to patients who had been given an opioid premedication, and the effects on gastric emptying assessed. Forty patients were allocated randomly to one of four treatment groups: group 1, oral diazepam 10 mg; group 2, i.m. morphine 10 mg; group 3, i.m. morphine 10 mg and i.v. metoclopramide 10 mg; group 4, i.m. morphine 10 mg and i.m. metoclopramide 10 mg. Gastric emptying was estimated from the absorption of oral paracetamol. I.v. metoclopramide antagonized the reduction in paracetamol absorption caused by morphine, whereas i.m. metoclopramide did not. This finding may be of importance in anaesthesia for emergencies.

Use of regional anaesthesia in a patient with acute porphyria.

The porphyrias are inherited disorders of haem metabolism, acute attacks of which may be precipitated by anaesthesia, surgery and pregnancy. The principal clinical feature of the disease is an acute neuropathy. A patient with acute intermittent porphyria was given bupivacaine as part of a regional anaesthetic for Caesarean section. The course of anaesthesia was uneventful.

Cannulation of the epidural space. A comparison of 18- and 16-gauge needles.

A group of 685 obstetric patients were randomly allocated to have their epidural block performed using either a 16-gauge or an 18-gauge Tuohy needle. Bleeding was noted from needle or catheter trauma in 18% of patients and it proved impossible to insert the catheter in 3%. The majority of mothers experienced little discomfort during the procedure but 2% found insertion to be very uncomfortable. There was no significant difference in the complication rate, ease of use, or patient discomfort between the 18- or 16-gauge needles. Epidural analgesia, although safe, is not without hazard. It may be difficult to perform and may, rarely, cause considerable discomfort.

The effect of head turn on auditory asymmetry.

In two experiments, right-handed men and women were tested for ear differences in report of dichotically presented digits, with their heads straight ahead, turned 90 degrees to the left, and turned 90 degrees to the right. In Experiment 1, head turn was controlled simply by asking the subjects to fixate an appropriately located point; a right-ear advantage occurred under all conditions of head turn among the men, but only in the head-straight condition among the women. In Experiment 2, head turn was controlled by having the subjects direct a flashlight attached to their heads toward the fixation point. This eliminated the right-ear advantage under all head conditions for the men, but for the women the right-ear advantage was, if anything, more pronounced when their heads were turned than when straight. These results suggest that auditory asymmetry depends in part on whether space is perceived as divided into left and right sides, and in part of the balance between spatial and verbal requirements. Both factors, and the asymmetry itself, may interact with sex.