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Cardiac muscle function studies
300
Printed
Burns, 9,300-301
in Great Britain
Abstracts CLINICAL
STUDIES
Burns
Pregnancy
and
An analysis of 50 patients with bums in pregnancy has shown that patients in the second or third trimester of pregnancy with bums covering 50 per cent or more of the body surface should be delivered as soon as possible since maternal death is likely and foetal survival rate is not improved by waiting. Vaginal delivery has always proved possible even in the presence of perineal burns but Caesarean section should be considered and may be preferred. Patients in the first trimester may survive with more extensive burns. Pregnancy testing on admission should be mandatory in burned women of reproductive age. In patients with burns of less than 40 per cent of the body surface area in the second and third trimesters, spasmolytics should be used to suppress spontaneous labour and to cover operations, thus allowing greater foetal maturity without worsening maternal prognosis. Matthews R. N. (1982) Obstetric implications of burns in pregnancy. Br. J. Obst. Gynec. 89,603. lodinated
PVP
and Thyroid
Function
Topical treatment of the burn wound with iodinated PVP did not induce hyperthyroidism in 12 patients with burns covering between 10 and 70 per cent of the body surface area. Early loss of plasma proteins accounted for the initial decrease of thyroxine binding globulin (TBG). There was the usual decrease in T, to TBG ratio and increase in rT, to TBG ratio. The decrease in T, to TBG ratio was attributed to inhibition of thyroid hormone release. The PVP iodine treatment induced a minor but significant increase in the basal TSH level showing an intact regulation of thyroid function by the pituitary gland. Habermann J., Pickardt C. R., Scriba P. C. et al (1982) Thyroid function during treatment of burn injuries with polyvinylpyrrolidone iodine complex. Unfallheilkunde, 85,253. Changes
in Oxygen
Metabolism
Changes in oxygen metabolism were measured in 23 patients with burns covering between 13 and 87 per cent of the body surface area. Only IO of the patients survived. Daily measurements were made of the partial pressure of haemoglobin at 50 per cent oxygen saturation (P,,), 2-3 diphosphoglycerate (DPG), inorganic phosphorus (Pi), ATP and blood gases. On
admission P,, values were high. In non-survivors P,, started to decline one week after burning. Values of P,, Corrected to pH 7.4 were correlated with values of DPG, In survivors P,, tended to correlate with the values of inorganic phosphorus but in nonsurvivors at the septic or terminal stage, the values of P,, did not correlate with Pi or ATP, Low values of P,, predicted the poor outcome of severely burned patients. During convalescence P,, and DPG values were higher than normal and often remained elevated for weeks. Nishimura N and Fukuda M (1982) P,, in burn injury. Crit. Care. Med. 10, 384. Factors Affecting
Mortality
Probability
Data from 854 burned patients have been analysed for the effect of factors other than age and extent of bum on mortality probability using multiple logistic regression analysis. The following variables also had a significant effect on mortality probability when incorporated into a predictive model with age, size of partial skin thickness burn and size ofa full thickness skin loss burn; the admission white blood cell count, admission serum osmolality, the involvement of inflammable liquids in the injury, the presence of pre-existing mental disorders and circulatory and digestive diseases. Berry C. C., Wachtel T. L. and Frank H. A. (1982) An analysis of factors which predict mortality in hospitalized burn patients. Burns 9, 38 Polyethylene
Glycol Poisoning
Three patients with burns covering between 20 and 56 per cent of the body surface were treated with Furacin soluble dressing and died with unexplained increases in the anion gap and serum osmolality. Ethylene glycol was found in the circulation. ALI 3 patients were acidotic and died with acute renal failure. There was an increase in serum bound calcium and a corresponding decrease in the ionized calcium. The cause of the high ‘calcium gap’ appeared to be binding of calcium by dicarboxylic acid metabolites of polyethylene glycol. Bruns D. E., Herold D. A., Rodeheaver G. T. et al (1982) Polyethylene glycol intoxication in burn patients. Burns 9, 49. ANIMAL STUDIES Cardiac muscle function
studies
Atria1 muscle was isolated 16-18 hours after guineapigs received either a sham burn or scalds covering 16
Abstracts
301
per cent of the body surface. Isometric contractile tension and its maximal rate of increase were not significantly altered by the injury however, the maximal rate of relaxation was uniformly less in muscle from the burned group at all times up to 4 hours after in vitro contractile responses were elicited. Similarly the relaxation responses to increased stimulation frequency and calcium concentration were generally less in the burned group. Adams H. R., Baxter C. R. and Parker J. L. (1982) Contractile function of heart muscle from burned guinea-pigs. Circ. Shock. 9, 63. Benefits of Early Wound Closure Early excision and wound closure on the first day after burning in guinea-pigs reduced the catabolic response and immunological depression. Compared with scalded but not excised animals early wound closure was followed by weight gains and thymic DNA synthesis which returned to normal by the sixth day after burning. Supranormal plasma and thymic free cortisol levels returned to normal by day 6 in the excised group but remained markedly elevated in the burned but not excised animals. Echinard C. E., Sajdel-Sulkowska E., Burke P. A. et al (1982) The beneficial effect of early excision on clinical response and thymic activity after burn injury. J. Trauma. 22, 560. Patterns
of Vascular
Damage
Angiographic studies in rabbits showed the patterns of vascular damage induced by electrical burns and by frostbite. Frostbite caused a progressive increase in arterial and venous thrombosis after initial spasm over the period between I5 minutes and 48 hours. The electrical injury had caused serious vascular damage by 15 minutes after injury and there was only a slight deterioration over the following 47 hours. Anticoagulation and medical sympathectomy delayed the appearance of vascular injury but did not affect the ultimate vascular or tissue damage. Lazarus H. M. and Hutto W. (1982) Electric burns and frostbite patterns of vascular injury. J. Trauma. 22, 58 I.
Burn Shock in Guinea-pigs
Circulatory function was assessed in guinea-pigs with scalds covering either zero, 15.7,24.6 or 43.4 per cent of the body surface at I, 2, 4, 6, 8 and 24 hours after injury. In contrast to the unchanging values in the control, zeroburn, animals the haemodynamic functions of the scalded animals were abnormal and both the magnitude and duration of dysfunction generally depended upon the size of injury. Burn shock was characterized by haemoconcentration, hypothermia, tachycardia (bradycardia in the most severely injured) minimal adjustments in systemic blood pressure, hyperkalaemia, normonatraemia (hyponatraemia in the most severely injured), arterial acidaemia and decreased respiratory rate. Circulatory functions of animals in the two less severe injuries groups returned towards control levels during the. first 8 hours after injury. Severe shock persisted in the most severely injured animals with a 70 per cent mortality by 24 hours after injury. Adams H. R., Baxter C. R., Parker J. L. et al (198Ii Development of acute burn shock in unresuscitated guinea-pigs. Circ. Shock. 8, 6 13.
LABORATORY STUDIES Watch out for High Serum
Potassium
Levels
Ten batches of fresh frozen plasma stored with citrate phosphate dextrose were found to have a mean potassium concentration of 13.14 mmol/l (SE= 1.74) and a mean inorganic phosphate level of IO.73 mg per 100 ml (SE=0.48). Both these mean values are approximately three times the values found in normal plasma. When large volumes of fresh frozen plasma with these potassium concentrations are given quickly soon after burning when renal function may be impaired toxic levels of potassium may occur. In contrast the high levels of phosphate may be of benefit to those patients showing hypophosphataemia. Hauben D. J. and Mahler D. (1982) Hiah levels of potassium and inorganic phosphate in flesh frozen plasma stored with citrate phosphate dextrose. Bums. 9,68.
Printed
Burns, 9,300-301
in Great Britain
Abstracts CLINICAL
STUDIES
Burns
Pregnancy
and
An analysis of 50 patients with bums in pregnancy has shown that patients in the second or third trimester of pregnancy with bums covering 50 per cent or more of the body surface should be delivered as soon as possible since maternal death is likely and foetal survival rate is not improved by waiting. Vaginal delivery has always proved possible even in the presence of perineal burns but Caesarean section should be considered and may be preferred. Patients in the first trimester may survive with more extensive burns. Pregnancy testing on admission should be mandatory in burned women of reproductive age. In patients with burns of less than 40 per cent of the body surface area in the second and third trimesters, spasmolytics should be used to suppress spontaneous labour and to cover operations, thus allowing greater foetal maturity without worsening maternal prognosis. Matthews R. N. (1982) Obstetric implications of burns in pregnancy. Br. J. Obst. Gynec. 89,603. lodinated
PVP
and Thyroid
Function
Topical treatment of the burn wound with iodinated PVP did not induce hyperthyroidism in 12 patients with burns covering between 10 and 70 per cent of the body surface area. Early loss of plasma proteins accounted for the initial decrease of thyroxine binding globulin (TBG). There was the usual decrease in T, to TBG ratio and increase in rT, to TBG ratio. The decrease in T, to TBG ratio was attributed to inhibition of thyroid hormone release. The PVP iodine treatment induced a minor but significant increase in the basal TSH level showing an intact regulation of thyroid function by the pituitary gland. Habermann J., Pickardt C. R., Scriba P. C. et al (1982) Thyroid function during treatment of burn injuries with polyvinylpyrrolidone iodine complex. Unfallheilkunde, 85,253. Changes
in Oxygen
Metabolism
Changes in oxygen metabolism were measured in 23 patients with burns covering between 13 and 87 per cent of the body surface area. Only IO of the patients survived. Daily measurements were made of the partial pressure of haemoglobin at 50 per cent oxygen saturation (P,,), 2-3 diphosphoglycerate (DPG), inorganic phosphorus (Pi), ATP and blood gases. On
admission P,, values were high. In non-survivors P,, started to decline one week after burning. Values of P,, Corrected to pH 7.4 were correlated with values of DPG, In survivors P,, tended to correlate with the values of inorganic phosphorus but in nonsurvivors at the septic or terminal stage, the values of P,, did not correlate with Pi or ATP, Low values of P,, predicted the poor outcome of severely burned patients. During convalescence P,, and DPG values were higher than normal and often remained elevated for weeks. Nishimura N and Fukuda M (1982) P,, in burn injury. Crit. Care. Med. 10, 384. Factors Affecting
Mortality
Probability
Data from 854 burned patients have been analysed for the effect of factors other than age and extent of bum on mortality probability using multiple logistic regression analysis. The following variables also had a significant effect on mortality probability when incorporated into a predictive model with age, size of partial skin thickness burn and size ofa full thickness skin loss burn; the admission white blood cell count, admission serum osmolality, the involvement of inflammable liquids in the injury, the presence of pre-existing mental disorders and circulatory and digestive diseases. Berry C. C., Wachtel T. L. and Frank H. A. (1982) An analysis of factors which predict mortality in hospitalized burn patients. Burns 9, 38 Polyethylene
Glycol Poisoning
Three patients with burns covering between 20 and 56 per cent of the body surface were treated with Furacin soluble dressing and died with unexplained increases in the anion gap and serum osmolality. Ethylene glycol was found in the circulation. ALI 3 patients were acidotic and died with acute renal failure. There was an increase in serum bound calcium and a corresponding decrease in the ionized calcium. The cause of the high ‘calcium gap’ appeared to be binding of calcium by dicarboxylic acid metabolites of polyethylene glycol. Bruns D. E., Herold D. A., Rodeheaver G. T. et al (1982) Polyethylene glycol intoxication in burn patients. Burns 9, 49. ANIMAL STUDIES Cardiac muscle function
studies
Atria1 muscle was isolated 16-18 hours after guineapigs received either a sham burn or scalds covering 16
Abstracts
301
per cent of the body surface. Isometric contractile tension and its maximal rate of increase were not significantly altered by the injury however, the maximal rate of relaxation was uniformly less in muscle from the burned group at all times up to 4 hours after in vitro contractile responses were elicited. Similarly the relaxation responses to increased stimulation frequency and calcium concentration were generally less in the burned group. Adams H. R., Baxter C. R. and Parker J. L. (1982) Contractile function of heart muscle from burned guinea-pigs. Circ. Shock. 9, 63. Benefits of Early Wound Closure Early excision and wound closure on the first day after burning in guinea-pigs reduced the catabolic response and immunological depression. Compared with scalded but not excised animals early wound closure was followed by weight gains and thymic DNA synthesis which returned to normal by the sixth day after burning. Supranormal plasma and thymic free cortisol levels returned to normal by day 6 in the excised group but remained markedly elevated in the burned but not excised animals. Echinard C. E., Sajdel-Sulkowska E., Burke P. A. et al (1982) The beneficial effect of early excision on clinical response and thymic activity after burn injury. J. Trauma. 22, 560. Patterns
of Vascular
Damage
Angiographic studies in rabbits showed the patterns of vascular damage induced by electrical burns and by frostbite. Frostbite caused a progressive increase in arterial and venous thrombosis after initial spasm over the period between I5 minutes and 48 hours. The electrical injury had caused serious vascular damage by 15 minutes after injury and there was only a slight deterioration over the following 47 hours. Anticoagulation and medical sympathectomy delayed the appearance of vascular injury but did not affect the ultimate vascular or tissue damage. Lazarus H. M. and Hutto W. (1982) Electric burns and frostbite patterns of vascular injury. J. Trauma. 22, 58 I.
Burn Shock in Guinea-pigs
Circulatory function was assessed in guinea-pigs with scalds covering either zero, 15.7,24.6 or 43.4 per cent of the body surface at I, 2, 4, 6, 8 and 24 hours after injury. In contrast to the unchanging values in the control, zeroburn, animals the haemodynamic functions of the scalded animals were abnormal and both the magnitude and duration of dysfunction generally depended upon the size of injury. Burn shock was characterized by haemoconcentration, hypothermia, tachycardia (bradycardia in the most severely injured) minimal adjustments in systemic blood pressure, hyperkalaemia, normonatraemia (hyponatraemia in the most severely injured), arterial acidaemia and decreased respiratory rate. Circulatory functions of animals in the two less severe injuries groups returned towards control levels during the. first 8 hours after injury. Severe shock persisted in the most severely injured animals with a 70 per cent mortality by 24 hours after injury. Adams H. R., Baxter C. R., Parker J. L. et al (198Ii Development of acute burn shock in unresuscitated guinea-pigs. Circ. Shock. 8, 6 13.
LABORATORY STUDIES Watch out for High Serum
Potassium
Levels
Ten batches of fresh frozen plasma stored with citrate phosphate dextrose were found to have a mean potassium concentration of 13.14 mmol/l (SE= 1.74) and a mean inorganic phosphate level of IO.73 mg per 100 ml (SE=0.48). Both these mean values are approximately three times the values found in normal plasma. When large volumes of fresh frozen plasma with these potassium concentrations are given quickly soon after burning when renal function may be impaired toxic levels of potassium may occur. In contrast the high levels of phosphate may be of benefit to those patients showing hypophosphataemia. Hauben D. J. and Mahler D. (1982) Hiah levels of potassium and inorganic phosphate in flesh frozen plasma stored with citrate phosphate dextrose. Bums. 9,68.