Biomedical subjects
Publications and source records attributed to A Mowbray.
Diabetic ketoacidosis (DKA) can result in neuropathic abnormalities of the somatic and the autonomous nervous systems. We report the case of a 50-year-old man with Type 1 diabetes of 20-year duration who after severe DKA lost vision in his right eye and only retain partial vision in his left. This case demonstrates that optic neural tissue is vulnerable to haemodynamic and metabolic complications of DKA.
This study compared the spread of 3 ml of a solution of bupivacaine-methylene blue in the intercostal space of patients and cadavers. There were 51 successful injections in each group which demonstrated in 86% of patient injections and 84% of cadaver injections that spread was confined to one intercostal space. Spread was more extensive in cadavers, probably as a result of autolysis. It would therefore still appear necessary, when low volumes of local anaesthetic are used, to block each intercostal nerve individually.
The effect of radial artery cannulation on local tissue oxygenation and acid-base balance was studied in 20 patients. Using capillary samples drawn from each thumb, a significant difference was observed between capillary PO2 on each side (p less than 0.001), with the higher PO2 on the cannulated side. There were no significant differences between sides in terms of [H+] or PCO2. It is considered that the differences in capillary PO2 were due to local tissue vasodilatation. The presence of chlorbutol in the sodium heparin flushing solution is implicated as the causative factor. Further study of 20 patients using preservative-free heparin demonstrated no significant differences between cannulated and non-cannulated sides in terms of capillary PO2, PCO2 or [H+]. Sodium heparin with chlorbutol appears to improve local tissue oxygenation and is recommended for use in flushing solutions for invasive arterial monitoring.
Twenty-one patients scheduled to undergo thoracotomy or median sternotomy had intercostal catheters inserted pre-operatively. During thoracotomy, under direct vision, the spread of 20 ml of a solution containing bupivacaine and methylene blue was followed. In most cases the spread involved one or two intercostal spaces. However, in all but one patient, dye spread medially to the paravertebral space where it then spread in both caudad and cephalad directions to reach between two and five vertebrae. In three cases, dye was seen crossing the anterior surface of the vertebrae to reach the contralateral aspect. It is concluded that a major component of dermatomal block during intercostal catheterisations may be secondary to paravertebral spread.
Ten first-year medical students were taught basic cardiopulmonary resuscitation (CPR) according to the guidelines laid down by the American Heart Association. Following a 7.5-hour instruction period they, in turn, taught 40 secondary school pupils. On formal assessment using models, all the school children were able to perform basic CPR.
Fifty-three urban general practitioners were questioned about alcoholism. They mostly had reasonably good, if sometimes muddled knowledge of the condition, when to suspect it, and how to confirm its presence. Social harms were seen as predominant over somatic ones. The majority had had postgraduate instruction supplemented by reading. Most were prepared to treat alcoholics, and revealed tolerant and sympathetic attitudes towards them and their families. The survey negates the general impression of unwillingness by general practitioners to engage with alcoholism.
Thirty patients took part in a double-blind trial to compare morphine 10 mg i.m. with morphine 5 mg into the extradural space for pain relief following Caesarean section. With the extradural route the mean time to first analgesia was 7.95 h compared with 4.75 h for the i.m. route. The mean number of further doses of diamorphine 7.5 mg required for pain relief in the first 24 h was 1.93 (+/- 0.30) in the i.m. group and 1.46 (+/- 0.31) in the extradural group. There was a small but definite advantage in the use of the extradural route for the initial dose of morphine. No serious side-effects were noted in either group.