Hypermetabolism and burn excision
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Abstracts 139 Macrophage activity and smoke/burn injury Chemiluminescence and morphological appearance of broncho- alveolar lavage cells were assessed in 10 patients who had only inhaled smoke, in 15 patients with only cutaneous bums and in 17 patients who had a combined injury. Compared with controls the combined injury group showed significant increases in the num- bers of polymorphonuclear leucocytes and macrophages and had significantly greater spontaneous chemiluminescence. Both increases were greater than expected from the individual injuries. Chemiluminescence response to stimulation by opsonized bacteria was significantly higher in the combined injury group than con- trols, but significantly lower than in the smoke inhalation only group. Clark C. J., Pollock A. J. Reid W. H. et al. (1988) Role of pulmonary alveolar macrophage activation in acute lung injury after bums and smoke inhalation. Lmcet ii, 872-874. ANIMAL STUDIES Dressing-induced epithelialization The rate of epithelialization of a partial skin thickness wound in guinea-pigs was studied under a water-impermeable Opsite dress- ing, under a polyether urethane (PEU) high vapour permeability dressing and in an air-exposed wound. The percentage of re- epithelialization on day 2 was 85 per cent in PEU-covered wounds, 66 per cent in the Opsite-covered wounds and 35 per cent in the air-exposed wounds. The epidermal thickness did not differ among the three types of treatment, however the eschar had maximal thickness in the air-exposed wound. Beneath the PEU dressing a thick layer of fibrinogen/fibrin was found. Jonkman M. F., Bruin P., Hoeksma E. A. et al. (1988) A clot inducing wound covering with high vapour permeability: enhanc- ing effects on epidennal wound healing in partial thickness wounds in guinea pigs. Surgery 104, (3), 537-545. Hepatic, renal and intestinal blood flow Hepatic, gastric, small intestinal and renal blood flows were measured in rats with scalds covering 20 per cent of the body surface area. These rats had also received plasma volume replace- ment resuscitation prior to the measurements using ZO1thallium and a ‘Z5iodine-labelled fatty acid. The uptake of these labelled compounds by the GI tissues was not significantly different from that found in unburned animals at 0.25 h, 18 h and 72 h after injury. However, 201thallium uptake by the kidney was significantly reduced at 0.25 h after injury. This lack of change in GI tract blood flow suggests that the GI tract dysfunction observed soon after burning is not simply the result of hypovolaemia, with concomi- tant reductions in mesenteric and renal blood flows: some tissue- derived factor may also be involved. Carter E. A., Tompkins R. G. and Burke J. F. (1988) Hepatic and intestinal blood flow following thermal injury. 1. Bum Care R&&l. 9, (4) 347-350. Macrophage function and wound healing Topical application or i.v. infusions of glucan, a macrophage stim- ulant, increased the breaking strength of healing wounds in rats on both days 4 and 7 after injury. Although formalin fixation signifi- cantly enhanced breaking strength in fresh control wound tissue, no increase occurred in wound tissues treated with glucan indica- ting that maximal cross-linking of collagen had already occurred. Studies with labelled proline indicated no change in the rate of collagen synthesis by glucan administration. Topical or i.v. infu- sion of supematants from glucan-activated macrophages also increased the wound breaking strength 4 days after injury. Browder W., Williams D., Lucore P. et al. (1988) Effect of enhanced macrophage function on early wound healing. Surgery 104, (2). 224-230. Hypermetabolism and bum excision Sheep with a burn covering 25 per cent of the body surface area had an oxygen consumption that was 72 per cent above normal 3 days after injury. This increase was the result of an increased cardiac index since the AVO, difference remained relatively con- stant. Body temperature was not significantly increased. Plasma and burn lymph thromboxane B, levels were significantly increased. When almost two-thirds of the burned area were excised and grafted the oxygen consumption was subnormal during the period of anaesthesia and then returned to and per- sisted for at least 48 h at the hypermetabolic values observed preoperatively. The wound was not grossly infected and blood cultures were sterile. Thus postbum hypermetabolism once stimulated may be per- petuated by a smaller bum. Partial excision of eschar does not appear to reduce the hypermetabolic state if a substantial non- infected inflammatory wound remains. Demling R. H. and Lalonde C. (1988) Effect of partial burn excision and closure on postbum oxygen consumption. Surgery 104, (5) 846-852. Sterile inflammation and metabolism Whole-body oxygen consumption and plasma and lymph inflammatory mediators were measured for 7 days in sheep after the insertion of sterile gauze beneath the skin and then for a further 5 days after the gauze had been removed. The gauze induced transient early increases in both plasma and lymph contents of thromboxane B, and 6-keto PGFlaj+. The body temperature increased by l”C, the cardiac index increased by 30 per cent whereas oxygen consumption was not increased. However, after the gauze had been in place for 5 days the wound lymph monocyte count had increased to 15 per cent of the total cell count, the VO, and cardiac index had increased by 50 per cent and the systemic vascular resistance had decreased. There was no further increase in body temperature. Post-mortem examina- tion 5 days after removal of the gauze showed a sterile wound with a marked monocyte macrophage infiltration in lungs and liver. Lung water content was normal. Lung and liver lipid peroxi- dation was increased three times and doubled over control values respectively. Lalonde C., Demling R. H. and Pecquet-Goad M. E. (1988) Tissue inflammation without bacteria produces increased oxygen consumption and distant organ lipid peroxidation. Surgery 104, (I), 49-56. PGE and immune function The role of PGE in immunosuppression following bum injury was studied in rats with bums covering 30 per cent of the body surface area using 16,16-dimethyl PGE. This PGE derivative did not modify bum sepsis mortality but improved mean survival times in an E. co/i peritonitis model. The derivative also impaired neutrophil migration into bum wounds at lower dosages, however, when given parenterally it failed to impair cell-mediated immunity at any dosage yet improved lymphocyte function at certain dosages. It appears that PGE may not be as immunosuppressive in vivo as it is in vitro studies. Waymack J. P. and Yurt R. W. (1988) Effect of prostaglandin E on immune function in multiple animal models. Arch. Surg. 123, (111 1429-1432.
Transcript of Hypermetabolism and burn excision
Abstracts 139
Macrophage activity and smoke/burn injury Chemiluminescence and morphological appearance of broncho- alveolar lavage cells were assessed in 10 patients who had only inhaled smoke, in 15 patients with only cutaneous bums and in 17 patients who had a combined injury. Compared with controls the combined injury group showed significant increases in the num- bers of polymorphonuclear leucocytes and macrophages and had significantly greater spontaneous chemiluminescence. Both increases were greater than expected from the individual injuries. Chemiluminescence response to stimulation by opsonized bacteria was significantly higher in the combined injury group than con- trols, but significantly lower than in the smoke inhalation only group.
Clark C. J., Pollock A. J. Reid W. H. et al. (1988) Role of pulmonary alveolar macrophage activation in acute lung injury after bums and smoke inhalation. Lmcet ii, 872-874.
ANIMAL STUDIES
Dressing-induced epithelialization The rate of epithelialization of a partial skin thickness wound in guinea-pigs was studied under a water-impermeable Opsite dress- ing, under a polyether urethane (PEU) high vapour permeability dressing and in an air-exposed wound. The percentage of re- epithelialization on day 2 was 85 per cent in PEU-covered wounds, 66 per cent in the Opsite-covered wounds and 35 per cent in the air-exposed wounds. The epidermal thickness did not differ among the three types of treatment, however the eschar had maximal thickness in the air-exposed wound. Beneath the PEU dressing a thick layer of fibrinogen/fibrin was found.
Jonkman M. F., Bruin P., Hoeksma E. A. et al. (1988) A clot inducing wound covering with high vapour permeability: enhanc- ing effects on epidennal wound healing in partial thickness wounds in guinea pigs. Surgery 104, (3), 537-545.
Hepatic, renal and intestinal blood flow Hepatic, gastric, small intestinal and renal blood flows were measured in rats with scalds covering 20 per cent of the body surface area. These rats had also received plasma volume replace- ment resuscitation prior to the measurements using ZO1thallium and a ‘Z5iodine-labelled fatty acid. The uptake of these labelled compounds by the GI tissues was not significantly different from that found in unburned animals at 0.25 h, 18 h and 72 h after injury. However, 201thallium uptake by the kidney was significantly reduced at 0.25 h after injury. This lack of change in GI tract blood flow suggests that the GI tract dysfunction observed soon after burning is not simply the result of hypovolaemia, with concomi- tant reductions in mesenteric and renal blood flows: some tissue- derived factor may also be involved.
Carter E. A., Tompkins R. G. and Burke J. F. (1988) Hepatic and intestinal blood flow following thermal injury. 1. Bum Care R&&l. 9, (4) 347-350.
Macrophage function and wound healing Topical application or i.v. infusions of glucan, a macrophage stim- ulant, increased the breaking strength of healing wounds in rats on both days 4 and 7 after injury. Although formalin fixation signifi- cantly enhanced breaking strength in fresh control wound tissue, no increase occurred in wound tissues treated with glucan indica- ting that maximal cross-linking of collagen had already occurred. Studies with labelled proline indicated no change in the rate of collagen synthesis by glucan administration. Topical or i.v. infu-
sion of supematants from glucan-activated macrophages also increased the wound breaking strength 4 days after injury.
Browder W., Williams D., Lucore P. et al. (1988) Effect of enhanced macrophage function on early wound healing. Surgery 104, (2). 224-230.
Hypermetabolism and bum excision Sheep with a burn covering 25 per cent of the body surface area had an oxygen consumption that was 72 per cent above normal 3 days after injury. This increase was the result of an increased cardiac index since the AVO, difference remained relatively con- stant. Body temperature was not significantly increased. Plasma and burn lymph thromboxane B, levels were significantly increased. When almost two-thirds of the burned area were excised and grafted the oxygen consumption was subnormal during the period of anaesthesia and then returned to and per- sisted for at least 48 h at the hypermetabolic values observed preoperatively. The wound was not grossly infected and blood cultures were sterile.
Thus postbum hypermetabolism once stimulated may be per- petuated by a smaller bum. Partial excision of eschar does not appear to reduce the hypermetabolic state if a substantial non- infected inflammatory wound remains.
Demling R. H. and Lalonde C. (1988) Effect of partial burn excision and closure on postbum oxygen consumption. Surgery 104, (5) 846-852.
Sterile inflammation and metabolism Whole-body oxygen consumption and plasma and lymph inflammatory mediators were measured for 7 days in sheep after the insertion of sterile gauze beneath the skin and then for a further 5 days after the gauze had been removed. The gauze induced transient early increases in both plasma and lymph contents of thromboxane B, and 6-keto PGFlaj+. The body temperature increased by l”C, the cardiac index increased by 30 per cent whereas oxygen consumption was not increased.
However, after the gauze had been in place for 5 days the wound lymph monocyte count had increased to 15 per cent of the total cell count, the VO, and cardiac index had increased by 50 per cent and the systemic vascular resistance had decreased. There was no further increase in body temperature. Post-mortem examina- tion 5 days after removal of the gauze showed a sterile wound with a marked monocyte macrophage infiltration in lungs and liver. Lung water content was normal. Lung and liver lipid peroxi- dation was increased three times and doubled over control values respectively.
Lalonde C., Demling R. H. and Pecquet-Goad M. E. (1988) Tissue inflammation without bacteria produces increased oxygen consumption and distant organ lipid peroxidation. Surgery 104, (I), 49-56.
PGE and immune function The role of PGE in immunosuppression following bum injury was studied in rats with bums covering 30 per cent of the body surface area using 16,16-dimethyl PGE. This PGE derivative did not modify bum sepsis mortality but improved mean survival times in an E. co/i peritonitis model. The derivative also impaired neutrophil migration into bum wounds at lower dosages, however, when given parenterally it failed to impair cell-mediated immunity at any dosage yet improved lymphocyte function at certain dosages. It appears that PGE may not be as immunosuppressive in vivo as it is in vitro studies.
Waymack J. P. and Yurt R. W. (1988) Effect of prostaglandin E on immune function in multiple animal models. Arch. Surg. 123, (111 1429-1432.
