Port site electrosurgical (diathermy) burns during surgical laparoscopy

BACKGROUND: Direct and capacitive coupling of diathermy current have been reported as causes of occult injury during surgical laparoscopy. METHODS: In order to determine the incidence of electrosurgical injury adjacent to metal and plastic cannulas, skin biopsies at 19 port sites used for monopolar electrosurgery were analyzed for coagulative necrosis. Prior to surgery the cannulas were randomized to either metal or plastic. RESULTS: Coagulative necrosis was observed at nine electrosurgery port sites compared to only one control (chi2 = 4.872; df = 1; 0.05 > p > 0.02). Plastic cannulas afforded no greater protection from skin burns than metal cannulas. CONCLUSIONS: Burns may be the result of direct or capacitive coupling to metal cannulas or capacitive coupling to the skin edge across plastic cannulas. The potential exists for burns to other tissues also in close proximity to a cannula used for electrosurgery.     

Nitrogen metabolism of sheep and goats consuming Acacia brevispica and Sesbania sesban

We described the effects of two East African browses, Acacia brevispica and Sesbania sesban, on nitrogen metabolism of sheep and goats. The A. brevispica had a substantial amount of proanthocyanidins (condensed tannins); S. sesban did not. The browses were fed at three levels in combination with vetch (Vicia dasycarpa) and teff straw (Eragrostis abyssinica). Fecal N, N balance, and plasma urea N (PUN) were estimated with intact animals. Ruminal ammonia (RuA) and VFA concentrations were estimated with ruminally fistulated animals. Urinary N loss, PUN, RuA, and VFA concentrations were higher for S. sesban diets than for A. brevispica diets. Fecal N was highest with diets including A. brevispica due to high levels of fecal neutral-detergent insoluble N. Nitrogen retention was highest for diets including S. sesban. Nitrogen retention was adequate for A. brevispica diets because low urinary N compensated for high fecal N. Four hypotheses describe possible effects of tannins on N metabolism: 1) escape of protein from the rumen to the lower tract; 2) increased microbial yield; 3) increase in N-containing endogenous products; and 4) protein made indigestible in tannin-protein complexes. The effect of tannins in A. brevispica on N metabolism can best be described by the formation of indigestible tannin-protein complexes, although increased production of endogenous products is also possible.