- Email: [email protected]
Energy metabolism and dressings
Burns.8, 14 l-l 43
Printedin Great Britain
141
Abstracts CLINICAL
STUDIES
Vitamin A levels Serial estimations of serum vitamin A levels during both the acute and healing stages of burns showed that the observed decreased values were independent of age, sex, extent, depth or circumstances of the injury, and were closely related to the degree of wound healing. Vitamin A substitution did not affect the serum vitamin A levels whereas y-t_-glutamyltaurine administration successfully and steadily elevated the low serum vitamin A levels when wound healing was occurring at a satisfactory rate. When wound healing was only poor or non-existant y+glutamyltaurine was ineffective. It has been suggested that the low serum v,itamin A levels are not the result of vitamin A loss but due to a decreased rate of synthesis of retinal binding protein and to an increased need by healing tissue. Szebeni A., Negyesi G. and Feuer L. (1981) Vitamin A levels in the serum of burned patients. Burns I, 3 13. Candida infections Although Candida species were cultured from 452 01 1513 burned patients only 172 patients had bum wounds contaminated with this fungus and only 20.7 per cent of the patients subsequently developed invasive Candidal sepsis. The mortality of untreated Candida burn wound infection was 100 per cent, and with aggressive medical and surgical therapy 9 1.6 per cent. Candidaemia was found in 52 patients and 76.9 per cent of these died. The high mortality rate with. commonly, a failure to respond to treatment was considered to be due to the generalized collapse of defensive and homeostatic mechanisms characteristic of preterminal disease. Spebar M. J. and Pruitt B. A. (1981) Candidiasis in the burned patient. “1.Trauma 21,237. Coagulation and platelet changes There is a moderate decrease in coagulation factors soon after burning due partly to dilution by fluids given for resuscitation and partly to intravascular platelet aggregation, filtration and consumption in the injured tissue. All phases of coagulation return to normal by I week after injury and progress to a true hypercoagulable state between the second and fourth
weeks. Fibrin degradation products or later decreases in platelet content are correlated with septicaemia and are not part of the normal response to burns. Bartlett R. H., Fong S. W., Marrujo G. et al. (198 I) Coagulation and platelet changes after thermal injury in man. Burns 7,370. Carboxyhaemoglobin and cyanide levels in blood Blood carboxyhaemoglobin and cyanide levels were measured in 53 survivors of fires, 36 of whom had clinical evidence of smoke inhalation; the levels were only raised in patients who had inhaled smoke. Blood carboxyhaemoglobin levels can be used to confirm the diagnosis ofsevere smoke inhalation in patients, where the clinical data are inconclusive, provided the time between exposure to the smoke and the blood sample is known. A nomogram relating time, carboxyhaemoglobin levels and the known biological half life of carboxyhaemoglobin has been constructed. As there is no quick method of measuring blood cyanide levels the close relationship between cyanide and carboxyhaemoglobin levels suggests that the latter measurements, which are rapid and easy to perform, could be used to identify those patients who might benefit from treatment with antidotes to cyanide. Clark C. J., Campbell D. and Reid W. H. (1981) Blood carboxyhaemoglobin and cyanide levels in tire survivors. Lancrt 1, 1332. Energy metabolism and dressings Measurements of oxygen consumption. carbon dioxide production, rectal temperature. surface temperatures of the burn, normal skin and dressings. body heat content and evaporative water loss using sensitive scales were made in 23 children with burns covering about one-third of the body surface. After 24 hours in rooms kept at 28 *C and 40 per cent relative humidity base line measurements were made with the dressings in place and then after the dressings had been removed for up to 4 hours. Without dressings the patients showed heat losses of 27 W/m2 body surface area above the predicted normal value (a 50 per cent increase). Most of the increased heat loss was due to the latent heat of evaporation of water. Occlusive dressings reduced the heat loss to 12 W/m* body surface area above the predicted normal value. In contrast to the increased plasma catecholamine levels
Burns
142
at the time the bum was exposed, those observed in the dressed patients were not significantly different from the values for healed burned patients and did not correlate with the rate of heat production. It is concluded that the increased heat production of burned patients is a response to an increased rate of heat loss, not vice versa, and that application of occlusive dressing substantially reduces the patients’ energy production and therefore requirements. Caldwell F. T., Bowser B. H. and Crabtree J. H. (1981) The effect of occlusive dressings on the energy metabolism of severely burned children. Ann. Surg. 193,579. 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. 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. 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. 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
Vol. ~/NO.
2
three groups: group I received no treatment, group 11 received I7 ml saline per kg body weight intraperitoneally and group 111received the same volume of saline containing 25 mg of 5, 6 benzoalphapyrone. AAer 24 hours the burned and contralateral hind limbs were amputated, weighed, dried and reweighed. The burned limbs of the animals treated with benzopyrone had significantly less oedema than did the untreated or only saline-treated limbs. 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. 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 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. Levenson S. M., Gruber D. K., Gruber S. et al. (I 98 I) Burn sepsis: bacterial interference with Pseudomonas aeruginosa. J. Trauma 21,364. I
,
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 concentration 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. Hilton J. G. (1981) Effects of fluid resuscitation on total fluid loss following thermal injury. Surg. Gynecol. Obstet. 152,44 I. 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 indistinguishable 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
Printedin Great Britain
141
Abstracts CLINICAL
STUDIES
Vitamin A levels Serial estimations of serum vitamin A levels during both the acute and healing stages of burns showed that the observed decreased values were independent of age, sex, extent, depth or circumstances of the injury, and were closely related to the degree of wound healing. Vitamin A substitution did not affect the serum vitamin A levels whereas y-t_-glutamyltaurine administration successfully and steadily elevated the low serum vitamin A levels when wound healing was occurring at a satisfactory rate. When wound healing was only poor or non-existant y+glutamyltaurine was ineffective. It has been suggested that the low serum v,itamin A levels are not the result of vitamin A loss but due to a decreased rate of synthesis of retinal binding protein and to an increased need by healing tissue. Szebeni A., Negyesi G. and Feuer L. (1981) Vitamin A levels in the serum of burned patients. Burns I, 3 13. Candida infections Although Candida species were cultured from 452 01 1513 burned patients only 172 patients had bum wounds contaminated with this fungus and only 20.7 per cent of the patients subsequently developed invasive Candidal sepsis. The mortality of untreated Candida burn wound infection was 100 per cent, and with aggressive medical and surgical therapy 9 1.6 per cent. Candidaemia was found in 52 patients and 76.9 per cent of these died. The high mortality rate with. commonly, a failure to respond to treatment was considered to be due to the generalized collapse of defensive and homeostatic mechanisms characteristic of preterminal disease. Spebar M. J. and Pruitt B. A. (1981) Candidiasis in the burned patient. “1.Trauma 21,237. Coagulation and platelet changes There is a moderate decrease in coagulation factors soon after burning due partly to dilution by fluids given for resuscitation and partly to intravascular platelet aggregation, filtration and consumption in the injured tissue. All phases of coagulation return to normal by I week after injury and progress to a true hypercoagulable state between the second and fourth
weeks. Fibrin degradation products or later decreases in platelet content are correlated with septicaemia and are not part of the normal response to burns. Bartlett R. H., Fong S. W., Marrujo G. et al. (198 I) Coagulation and platelet changes after thermal injury in man. Burns 7,370. Carboxyhaemoglobin and cyanide levels in blood Blood carboxyhaemoglobin and cyanide levels were measured in 53 survivors of fires, 36 of whom had clinical evidence of smoke inhalation; the levels were only raised in patients who had inhaled smoke. Blood carboxyhaemoglobin levels can be used to confirm the diagnosis ofsevere smoke inhalation in patients, where the clinical data are inconclusive, provided the time between exposure to the smoke and the blood sample is known. A nomogram relating time, carboxyhaemoglobin levels and the known biological half life of carboxyhaemoglobin has been constructed. As there is no quick method of measuring blood cyanide levels the close relationship between cyanide and carboxyhaemoglobin levels suggests that the latter measurements, which are rapid and easy to perform, could be used to identify those patients who might benefit from treatment with antidotes to cyanide. Clark C. J., Campbell D. and Reid W. H. (1981) Blood carboxyhaemoglobin and cyanide levels in tire survivors. Lancrt 1, 1332. Energy metabolism and dressings Measurements of oxygen consumption. carbon dioxide production, rectal temperature. surface temperatures of the burn, normal skin and dressings. body heat content and evaporative water loss using sensitive scales were made in 23 children with burns covering about one-third of the body surface. After 24 hours in rooms kept at 28 *C and 40 per cent relative humidity base line measurements were made with the dressings in place and then after the dressings had been removed for up to 4 hours. Without dressings the patients showed heat losses of 27 W/m2 body surface area above the predicted normal value (a 50 per cent increase). Most of the increased heat loss was due to the latent heat of evaporation of water. Occlusive dressings reduced the heat loss to 12 W/m* body surface area above the predicted normal value. In contrast to the increased plasma catecholamine levels
Burns
142
at the time the bum was exposed, those observed in the dressed patients were not significantly different from the values for healed burned patients and did not correlate with the rate of heat production. It is concluded that the increased heat production of burned patients is a response to an increased rate of heat loss, not vice versa, and that application of occlusive dressing substantially reduces the patients’ energy production and therefore requirements. Caldwell F. T., Bowser B. H. and Crabtree J. H. (1981) The effect of occlusive dressings on the energy metabolism of severely burned children. Ann. Surg. 193,579. 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. 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. 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. 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
Vol. ~/NO.
2
three groups: group I received no treatment, group 11 received I7 ml saline per kg body weight intraperitoneally and group 111received the same volume of saline containing 25 mg of 5, 6 benzoalphapyrone. AAer 24 hours the burned and contralateral hind limbs were amputated, weighed, dried and reweighed. The burned limbs of the animals treated with benzopyrone had significantly less oedema than did the untreated or only saline-treated limbs. 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. 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 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. Levenson S. M., Gruber D. K., Gruber S. et al. (I 98 I) Burn sepsis: bacterial interference with Pseudomonas aeruginosa. J. Trauma 21,364. I
,
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 concentration 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. Hilton J. G. (1981) Effects of fluid resuscitation on total fluid loss following thermal injury. Surg. Gynecol. Obstet. 152,44 I. 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 indistinguishable 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