142 Burns Vol. ~/NO. 2

at the time the bum was exposed, those observed in the three groups: group I received no treatment, group 11 dressed patients were not significantly different from received I7 ml saline per kg body weight intra- the values for healed burned patients and did not peritoneally and group 111 received the same volume of correlate with the rate of heat production. It is saline containing 25 mg of 5, 6 benzoalphapyrone. concluded that the increased heat production of AAer 24 hours the burned and contralateral hind limbs burned patients is a response to an increased rate of were amputated, weighed, dried and reweighed. heat loss, not vice versa, and that application of The burned limbs of the animals treated with occlusive dressing substantially reduces the patients’ benzopyrone had significantly less oedema than did energy production and therefore requirements. the untreated or only saline-treated limbs.

Caldwell F. T., Bowser B. H. and Crabtree J. H. (198 1) The effect of occlusive dressings on the energy metabolism of severely burned children. Ann. Surg. 193,579.

Miller S. H., Abell M., Buck D. et al. (1981) Effects of 5,6 benzoalphapyrone on traumatic edema due to crush and bum injury. J. Trauma 21,372.

Prediction of Gram-negative septicaemia Two models have been developed to attempt the early diagnosis of septicaemia. Thrice daily measurements of clinical state including degree of mental clarity, gastrointestinal tract symptoms, appearance of the wound or grafts, respiratory rate, temperature, systolic blood pressure and urine volume were related to biochemical and bacteriological measurements of white blood cell count, platelet count, Pa 02, arterial blood pH, blood and urine cultures, endotoxin assay, skin biopsy cultures, disseminated intravascular coagulation and chest x-ray. Multiple regression and discriminant analysis of all these variables produced two models which would have predicted the diagnosis of sepsis 83 and 86 per cent of the time one day before diagnosis was made using only conventional methods of assessment. False positive predictions were found on only 7 and 3 per cent of occasions, respectively.

Bacterial antagonism In rats with deep bums covering 20 per cent of the body surface the topical application of a low virulence strain of Ps. aeruginosa (JB-77) within I hour of burning protected the rats from the lethal effect of subsequent (48 hour) topical contamination of the bum by a highly virulent strain of Ps. aeruginosa (VA 134) (PC 0.00 1). Similar orotection was observed

I ,

in burned, initially-germ-free rats. No protection was found if only 24 hours was allowed between the seeding of the bum with the low and then high virulence strains. Similarly oral administration of the low virulence organisms was not effective. The mechanism of this apparent antagonism between low and high virulence strains of Ps. aeruginosa has not yet been determined.

Carvajal H. F., Feinstein R., Traber D. L. et al. (198 I) An objective method for early diagnosis of Gram-negative septicaemia in burned children. J. Trauma 7,22 I.

Levenson S. M., Gruber D. K., Gruber S. et al. (I 98 I) Burn sepsis: bacterial interference with Pseudomonas aeruginosa. J. Trauma 21,364.

Colloid in fluid resuscitation Studies in dogs with deep bums covering I5 per cent of the body surface have shown that the efficacy of resuscitation is dependent upon the albumin content of the administered fluid. Compared with the results in untreated burned dogs and in those receiving only Ringers lactate solution it was found that although the total fluid loss from the vascular bed increased as a result of fluid resuscitation the quantity of fluid lost was inversely proportional to the albumin concen- tration of the fluid therapy. The highest albumin concentration used was associated with the least fluid loss, the fastest restoration of cardiac output to normal and least abnormal haematocrit values.

ANIMALSTUDIES Cooling the burned area The burned area of guinea pigs covering IO per cent of the body surface was immersed in water at O-3 “C for 30 minutes at IO. 20. 30 or 60 minutes after scaldine. India ink perfusion indicated the patency of dermil vessels at 2,4, 8, 24, 72 and 96 hours after injury. By 96 hours, significant differences could be seen between untreated animals and those cooled IO, 20 or 30 minutes after injury. Those not cooled until 60 minutes after scalding had dermal perfusion that was essentially the same as that in control animals. Dermal washout studies using i]rXe performed at 8 and 24 hours confirmed the india ink studies. Grossly, burn wounds cooled by 30 minutes after scalding had markedly better healing than control animals and animals cooled 60 minutes after scalding.

Raine T. J., Heggers J. P., Robson M. C. et al. (I 98 I) Cooling the burn wound to maintain microcirculation. J. Trauma 21,394.

LABORATORY STUDIES

Exudate under plastic film dressings The exudate under an adhesive polyurethane film dressing (Op-Site) contains cell types and numbers of cells that are typical of an inflammatory response and the protein content of the exudate is virtually indis- tinguishable from that of plasma. The neutroohils present in exudate killed strains of Staph. aureus at a rate similar to that of normal whole blood, suggesting

Benzopyrones reduce oedema One hind limb of 34 rats was immersed for 30 seconds in water at 55 ‘C and the animals were divided into

Hilton J. G. (1981) Effects of fluid resuscitation on total fluid loss following thermal injury. Surg. Gynecol. Obstet. 152,44 I.