摘要:

Biobrane (Woodrufff Manufacturing, Santa Ana, CA) is a new synthetic skin substitute consisting of a silicone rubber membrane and a flexible nylon fabric bonded with peptides derived from dermal collagen. In a previous study from our laboratory we found Biobrane alone was unable to lower the bacterial counts of experimentally infected burn wounds. This study was designed to determine the ability of topical antimicrobials to penetrate the surface of Biobrane and reach the infected burn wound.The experiment was performed in two parts. In the first portion of the experiment 20 agar plates withBacillus subtilisimpregnated into the agar were divided into thirds. One third of the agar's surface was covered with a 3-cm square of Biobrane, one third was left uncovered, and one third was covered with a 3-cm square of Biobrane plus a topical antimicrobial applied to its surface. A small plastic cap was filled with approximately 0.3 cc of silver sulfadiazine or mafenide acetate and applied to the surface of the Biobrane. The plates were incubated for 24 hours at 37°C. The zones of inhibition were compared to the zones of inhibition obtained from standard agar well diffusion plates tested for silver sulfadiazine alone and mafenide acetate alone againstB. subtilis.In the second part of the experiment 20 male Sprague-Dawley rats weighing between 280 and 320 gm were burned using a modified Walker burn model. The burns were inoculated with 108Pseudomonas aeruginosaand at 5 days postburn the animals underwent burn escharectomy. The escharectomized wound was biopsied for quantitative bacteriology and divided into two equal parts. One half of the wound was covered with Biobrane; the other half served as an untreated control. In ten animals silver sulfadiazine was applied to the surface of the Biobrane and in the other ten animals mafenide acetate was applied every 12 hours to Biobrane's surface. The Biobrane was changed at 48 and 96 hours and quantitative biopsies were taken from the control wound and from the wound surface covered by the Biobrane plus the topical antimicrobial.In part one of the experiment the zone of inhibition on the Biobrane topically applied silver sulfadiazine plates averaged 29 mm with a range of 25–32 mm, while on the Biobrane plus topically applied mafenide acetate plates the zones of inhibition averaged 33.6 mm with a range of 29–37 mm. In part two of the experiment, the animals treated with silver sulfadiazine topically applied to Biobrane's surface had reduced the bacterial counts to < 105organisms/gm of tissue in 8/10 animals, whereas the mafenide acetate topically applied to Biobrane had lowered the bacterial counts to < 105in 2/10 animals.Both silver sulfadiazine and mafenide acetate demonstrated excellent in vitro penetrability of Biobrane when plated onB. subtilis-impregnated agar. The combined use of Biobrane plus antimicrobials applied to its surface can effectively lower infected wound bacterial counts, providing temporary coverage of the escharectomized infected burn wound. This new application may extend the utility of the newer synthetic burn wound dressings.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Endocrine responses to trauma are often inferred from responses seen after a single injury or elective surgery. However, major trauma frequently is followed by emergent surgery, necessitating evaluation of responses to repeated stimuli. We used sequential hemorrhage to study such responses. Splenectomized dogs anesthetized with pentobarbital (25 mg/kg) were hemorrhaged 7.5 ml/kg, 2 days following adrenal vein cannulation. Secretion rates of cortisol and catecholamines were determined in timed adrenal samples by HPLC. The bled volume was reinfused after 1 hour; the procedure was repeated 24 hours later. A significant response in adrenal secretion of cortisol was seen following hemorrhage each day (p<0.001), but the response on day 2 was 40% greater (p<0.05). Secretion rates of epinephrine and of norepinephrine did not change after hemorrhage on day 1 (p<0.20) However, each hormone showed a dramatic response on day 2 increasing to 14× control levels (p<0.005). There were no differences in any cardiovascular variable during control period or after hemorrhage on the 2 days. The results demonstrate dramatic potentiation of the response to a second insult that persists for at least 24 hours after the first, and suggest that the endocrine response to traumatic injury with emergent surgery cannot be evaluated by studying responses either to isolated insults or to elective surgery.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Rats were serially exchange transfused to hematocrits less than 2% (50-cc exchange) with either Krebs-Henseleit-albumin (KHA) solution or Fluosol-43 (F-43). Reflectance spectrophotometry was employed to monitor cerebral cytochrome c oxidase redox states. Determinations of mean arterial pressure (MAP), arterial and venous oxygen content difference (A-VO2), and cerebral cortical ATP and lactate concentrations were also made. As hemodilution progressed, neither solution provided normal quantities of oxygen as evaluated by the cytochrome c oxidase redox state and a decrease in A-VO2difference, although F-43 was significantly (p< 0.01) better than KHA in terms of cytochrome c oxidase redox state as well as maintenance of MAP. There was no significant difference between the two test solutions in terms of cortical ATP and lactate.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

We have sequentially measured the daily extravascular lung water (EVLW) changes in 16 severely traumatized patients to better define the principal etiologic factors causing post-traumatic interstitial fluid accumulation and subsequent respiratory failure.We found that severe hemorrhagic shock (mean initial BP = 40 mm Hg), massive transfusion (12.7 liters of blood), and crystalloid resuscitation with resulting hemodilution of plasma colloid osmotic pressure (PCOP) (PCOP ≤ 15 mmHg) do not cause EVLW accumulation. Post-traumatic elevations in EVLW were seen after lung contusion (average EVLW = 15.3 ± 2.5 ml/kg), sepsis (average EVLW = 17.1 ± 2.9 ml/kg) and cardiac failure (EVLW = 15.3 ± 0.3 ml/kg).Severe hemorrhagic shock, massive transfusion, and crystalloid resuscitation with resulting hemodilution of plasma colloid oncotic pressure do not cause EVLW accumulation. Post-traumatic elevations in EVLW are seen after lung contusion, sepsis, and cardiac failure. We conclude that after trauma elevations in capillary hydrostatic pressure and capillary permeability alterations resulting from lung contusion or sepsis are the primary determinants of interstitial fluid accumulation.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Retrospective analysis of 115 patients with venous injuries managed at Lincoln Hospital in a 7-year period disclosed a total mortality of 15%. Retrohepatic caval injury was uniformly fatal; infrarenal caval injury was not. Fifty-six per cent of victims of truncal venoarterial injuries died. Isolated venous injury of the extremity was never lethal. Ligation of injured veins of the neck and upper extremities was well tolerated. Ligation of external iliac, or common femoral, or superficial femoral veins resulted in edema in 50% of the patients compared to 7% after repair (p< 0.05). Venoarterial injuries of iliac or femoral-level veins resulted in 37% incidence of compartment syndrome against 5% in isolated arterial injuries (p< 0.01). Therapeutic fasciotomy after the onset of clinically evident compartment syndrome did not prevent foot drop in any patient. We advocate that all major veins of the lower extremities be repaired with the same care as arterial injuries. Prophylactic fasciotomy for all patients with iliac or femoral venoarterial injuries should be considered as strongly as with popliteal venoarterial injuries. The caliber and patency of repaired veins must be assessed by venography at operation, and again before discharge from the hospital.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

There has been increasing recognition in recent literature that immunoregulatory factors can often be detected in the serum of patients with thermal and traumatic injuries. We, too, have shown that a significant number of patients with severe thermal injuries are profoundly immunosuppressed. This immunosuppression was mediated by substances which circulate in the serum which could be easily detected using in vitro lymphocyte assays. The suppressive material was not present in normal serum, and exerted its effects through the activity of a specific (suppressor) subpopulation of lymphocytes. In this study, we have analyzed serum samples obtained from burn patients by plasmapheresis for suppressive activity, then fractionated each using Sephadex G-200. Individual fractions were tested for suppressive activity in mixed lymphocyte cultures, and approximate molecular weights established for suppressive peaks by means of chromatography calibration standards. Evidence linking suppressive activity of the sera to the presence of endotoxin, prostaglandin E, interferon, and 'cutaneous burn toxin' is discussed.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The role of glucocorticoids and androgens in postburn augmentation of skeletal muscle proteolysis was investigated following a 3-second single hindlimb scald (6 to 7% body surface area) in the rat. Soleus muscles and calf muscles from the burned and unburned hindlimbs were excised 3 days postburn and compared to age-matched controls to evaluate both the local and systemic effects of burn injury. Free tyrosine content in soleus and calf muscles of the burned limb was 30% and 58%, respectively, higher than in corresponding control muscles. Net proteolysis in burned limb soleus muscles, as measured by tyrosine 'production' in vitro, was more than doubled as compared to controls. In contrast, tyrosine content and production by muscles from the unburned limb of burned rats did not differ from controls. Specific binding of the glucocorticoid dexamethasone in cytosols of burned limb soleus and calf muscles was more than 80% below control level. Soleus muscles from the unburned limb of burned rats showed a 60% decrease in dexamethasone binding but that of the unburned limb calf muscles did not differ from controls. The latter difference and the observation in control rats of a relatively lower dexamethasone binding in calf muscles as compared to soleus muscles suggest that the glucocorticoid binding could be influenced by the type of fibers comprising the muscle. Unlike the glucocorticoid binding, neither the thermal injury nor the muscle fiber type had a significant effect on specific cytosolic binding of the androgen methyltrienolone by the muscle tissues studied. It is concluded that thermal injury restricted to one hindlimb leads to regional differences in skeletal muscle proteolysis and glucocorticoid binding. Muscles of the burned region exhibit stimulation of proteolysis and virtual disappearance of cytosolic glucocorticoid receptors. Muscles from the unburned region appear to have a normal rate of proteolysis and either normal or decreased glucocorticoid binding. It remains to be elucidated whether the decrease in cytosolic glucocorticoid receptors is due to changes in receptor synthesis and degradation, or to accelerated translocation of the receptors into the nucleus.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Guinea pigs subjected to a full-thickness 30% body surface flame burn significantly reduced food intake and lost body weight for 5 days thereafter. Comparison of brain monoamine changes in burned, pair-fed control, and freely feeding control groups revealed normal levels of norepinephrine and elevated concentrations of dopamine in burned animals compared to the pairfed control group. Levels of the serotonin precursor, tryptophan, and metabolite, 5-hydroxyindoleacetic acid, were also increased in burned compared to pair-fed animals, suggesting increased activity of indoleamine neurons. Although brain catecholamine levels were not correlated with food intake, significant negative correlations between food consumption and tryptophan, serotonin, and 5-hydroxyindoleacetic acid were observed. These data suggest that aberrations in indoleamine and possible catecholamine neurotransmitter systems may be involved in the mediation of burn-induced anorexia.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Following a 3-second subxiphoid immersion of shaved, unresuscitated guinea pigs in 100°C water, cardiac output (CO), mean systemic blood pressure (BP), total peripheral resistance (TPR), hematocrit (HCT), serum histamine (SH), and serum lactate (SL) were measured in untreated and cold-water treated animals up to 24 hours after injury. Animals receiving cold-water treatment (CWT) were immersed in 15°C water for 15 minutes immediately after scald injury. CWT significantly (p< 0.05) reduced SH and SL for up to 8 and 24 hours, respectively, after injury compared to untreated injured animals. HCT of CWT animals remained significantly lower than that of untreated animals for the first 8 hours after injury. However, CWT-animal HCT was not significantly different from control-animal HCT for this same period. CWT-animal BP was significantly greater than untreated-animal BP for the first 8 hours after injury. CWT- and untreated-animal TPR progressively rose after injury; however, at 24 hours after injury CWT-animal TPR was significantly reduced to 87% ± 18.0 of preinjury values while untreated-animal TPR was maximally elevated to 170% ± 10.0 of preinjury values. At 4 hours after injury CO of both untreated and SWT animals was significantly depressed at 56% ± 3.0 and 50% ± 10.0 of preinjury values, respectively. However, by 24 hours after injury untreated-animal CO remained depressed at 52% ± 3.0 while CWT-animal CO was significantly improved at 92% ± 19.0 of preinjury values. These studies document a beneficial hemodynamic response of severely burned animals after CWT and further verify the phenomenon of cold inhibition of burn wound tissue histamine release after severe scald injury. A correlation between decreased serum histamine and lactate levels and improved cardiovascular function following severe scald injury and CWT is also suggested.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

A period of aggressive surgical treatment and early identification of fungal infection of the burn wound was compared with the previous 5 years' experience with patients suffering from fungal infection of burn wounds. The portion of those patients withCandidainfections diagnosed and treated premortem increased from 48.0% to 63.6% and of patients with noncandidal infections from 40.8% to 67.0% in the more recent period. The mortality of patients withCandidainfections in 1973 to 1977 was 83.3% and in 1978 was 87.5%. The mortality of noncandidal infections, 87.4% in 1973 to 1977, was 25.0% in 1978. Local surgical control of the infected portion of burn wounds is an effective way of improving the survival in noncandidal burn wound infections. Surgical excision of burn wounds does not alter the poor prognosis of patients withCandidainvasion of the burn wound.

ISSN:0022-5282    

出版商:OVID    

年代:1982

数据来源: OVID