Effect of intra-operative end-tidal carbon dioxide partial pressure on tissue oxygenation.

Postsurgical infection risk is correlated with subcutaneous tissue oxygenation. Mild hypercapnia augments cutaneous perfusion. We tested the hypothesis that peripheral tissue oxygenation increases as a function of arterial PCO2 in surgical patients. Twenty patients were randomly assigned to intra-operative end tidal PCO2 of 3.99 (control) or 5.99 kPa (hypercapnia). All other anaesthetic management was per protocol. Tissue oxygen partial pressure, transcutaneous oxygen tension, cerebral oxygen saturation, and cardiac output were measured. Mean (SD) subcutaneous tissue oxygen tension was 8.39 (1.86) kPa in control and 11.84 (2.53) kPa hypercapnia patients (p = 0.014). Cerebral oxygen saturation was 55 (4)% for control vs. 68 (9)% for hypercapnia (p = 0.004). Neither cardiac index nor transcutaneous tissue oxygen tension differed significantly between the groups. Mild intra-operative hypercapnia increased subcutaneous and cerebral oxygenation. Increases in subcutaneous tissue oxygen partial pressure similar to those observed in patients assigned to hypercapnia are associated with substantial reductions in wound infection risk.

A case of gelastic seizures in Harare, Zimbabwe.

We describe a very rare case of a frontal lobe epilepsy that presented with gelastic seizures. It occurred in a 19 year old male and the gelastic seizures were controlled by carbamazepine 400 mg/day.

The cause and treatment of postvagotomy diarrhoea.

Six patients with watery postvagotomy diarrhoea and 4 patients with intractable diabetic diarrhoea were treated with cholestyramine. The diarrhoea responded completely to therapy, during which the stool content of water, sodium, postassium and magnesium fell. Two of the patients, while receiving cholestyramine, had a rise in faecal fat, but this was not accompanied by diarrhoea, the stools being well formed. Evidence is presented which suggests that the mechanism of diarrhoea is similar in both disorders and is due to division or neuropathy of the hepatic fibres of the vagus nerve. This results is distension of the gallbladder, contraction of which expels increased quantities of bile salts, which swamp the reabsorptive capacity of the small intestine and induce diarrhoea by direct action on the colon. If this theory is valid, cholecystectomy, by preventing large quantities of concentrated bile salts from suddenly entering the gut, may result in improvement of postvagotomy and diabetic diarrhoea.