J. Paul Waymack

Effects of fish oil on postburn metabolism and immunity

The metabolic effects and immune responses of different levels of fish oil in enteral formulas for postburn nutritional support were studied. Thirty-seven burned guinea pigs with previously placed gastrostomy feeding tubes were given diets containing 5, 15, 30, or 50% of nonprotein calories as fish oil. These diets were isonitrogenous, isocaloric, and contained identical amounts of vitamins and minerals. After 14 days of enteral feeding, there were no significant differences in resting metabolic expenditure, serum transferrin, and albumin levels. Weight loss was significantly greater in groups receiving 30 and 50% of fish oil compared to groups which received 5 and 15% of fish oil. Carcass weights and liver weights of animals in the two groups that received diets with higher lipid content were also significantly lower. Cell-mediated immunity, macrophage bactericidal indices, and opsonic indices were not different among the groups. This study confirms that diets containing lower levels of lipids are more effective for enteral nutritional support than those containing higher levels. In contrast to linoleic acid rich lipid sources, higher levels of fish oil did not show adverse effects on immunity possibly because it contained high concentrations of omega 3 fatty acids which are not precursors of immunosuppressive prostaglandin E2.

Effect of blood transfusion and anesthesia on resistance to bacterial peritonitis

Patients who undergo gastrointestinal operations and require prolonged anesthesia or blood transfusions have been reported to have a higher incidence of infectious complications. A rat peritonitis model was used to determine if the increased rate of infection was due to the severity of their underlying disease process or to possible immunosuppressive effects of transfusions and anesthesia. Four hundred adult Lewis rats were divided into four groups. Each group received either 0.5 ml of allogenic blood, 0.5 ml of syngeneic blood, metaphane anesthesia, or 1.5 ml of saline. They were challenged with either 1 X 10(8) or 1 X 10(7) Escherichia coli on the day of transfusion or 4 days after transfusion. Survival rates and mean survival times were determined. Syngeneic transfusions were found not to significantly impair survival. Anesthesia administration resulted in a moderate impairment in survival. Allogeneic blood transfusions caused the most severe impairment with a greater than 50% decrease in survival rates compared to controls in three of the four groups tested. Blood transfusions would thus appear to impair resistance to bacterial infections to an even greater degree than anesthesia. Unnecessary transfusions should therefore be avoided.

Effect of prostaglandin E in multiple experimental models. IV. Effect on resistance to endotoxin and tumor necrosis factor shock

Administration of a long-acting prostaglandin E, 16,16-dimethyl-PGE (dPGE), to rats improves their survival of bacterial peritonitis. We examined the mechanism of this protective effect with reference to its interaction with the release of cachectin (TNF). Sixty rats received saline, 20 micrograms/kg dPGE, or 80 micrograms/kg dPGE 12 hr prior to endotoxin and continuing for 48 hr. Survival rates for the saline, 20 micrograms/kg dPGE, and 80 micrograms/kg dPGE groups were 0, 40, and 85%, respectively. Forty rats received saline or 80 micrograms/kg dPGE, with the initial dose being 3 hr following endotoxin challenge and continuing for 48 hr. Survival rates for both groups were 0%. Sixty rats received saline or 80 micrograms/kg dPGE at 12 and 1 hr prior to endotoxin. Two hours after challenge, they were sacrificed and plasma TNF levels were assayed. The plasma TNF level in saline-treated rats was 22.72 +/- 0.83 ng/ml and in the dPGE-treated group, 16.03 +/- 1.13 ng/ml (P less than 0.001).

Early vascular grafting to prevent upper extremity necrosis after electrical burns Commentary on indications for surgery

Early vascular grafting is the only effective form of treatment for electrical burns of the wrist which are severe enough to impair blood flow to the hand. Failure to appreciate the significance of early changes in blood flow and to take prompt appropriate action may result in the irreversible loss of blood supply and subsequent amputation. This report analyses the problems encountered in six patients where the early signs of impaired blood flow were not appreciated and amputations were subsequently required.

The effect of ibuprofen on postburn metabolic and immunologic function

Patients suffering severe trauma, including thermal injuries, demonstrate both a hypermetabolic response and an immunosuppressed state following the injury. Biochemically, these patients produce extremely large amounts of cyclooxygenase products, including prostaglandin E. We have investigated the effect of a drug, ibuprofen, which blocks the synthesis of prostaglandins in a burned rat model. Ibuprofen at high doses was found to significantly diminish the hypermetabolic response to burn injury and sepsis. The same dosage of ibuprofen increased the mortality rate in the same burn sepsis model. Prostaglandin E may therefore exert some beneficial effects in traumatized patients by altering their metabolism.

Alterations in intracellular lymphocyte metabolism induced by infection and injury

The effects of burn injury and sepsis on intracellular lymphocyte metabolism were evaluated using a rat model. Adult Lewis rats were subjected to a sham burn, a 30% full-thickness burn, or a 30% full-thickness burn which was infected with Pseudomonas aeruginosa. One week later the animals were sacrificed, and the splenic lymphocytes were harvested and cultured for 24 hr with mitogen stimulation. Lymphocytes from the burned-infected rats were found to utilize more glucose and certain amino acids than did lymphocytes obtained from the other two groups. Lymphocytes obtained from the burned-infected group had lower levels of the immunologically important enzyme, adenosine deaminase, than did the lymphocytes obtained from the other two groups. In summary, sepsis appears to alter a number of intracellular lymphocyte metabolic processes. These alterations may be found to be predictive of early sepsis.

Renal calculi in the burned child

Fifteen burned children were noted to have developed renal calculi at our institution over the past 20 years. Primary risk factors appear to be immobilization and a high intake of dairy products and antacids. Presenting symptoms and physical signs include abdominal pain, haematuria, with transient leukocytosis and elevations of the blood urea nitrogen. Conservative therapy with increased fluid administration and urine acidification were successful in 13 of the patients. The remaining two patients required surgical extraction. There were no long-term renal sequelae in any of the patients.

Recent Advances in Burn Care

Over the past few decades, the mortality related to thermal injuries has been significantly reduced. This has been accomplished through an increased understanding and subsequent management of inhalation injury, the postburn hypermetabolic response, and immunocompromise. In addition, the prompt excision of the burn wound and early permanent closure has decreased the length of hospital stay and has facilitated timely social reintegration of the burned patient.

Hematuria in the burned child.

Hematuria is a frequent complication in burn patients, but its clinical significance has not been reported. The incidence, etiologies, treatment, and outcome of hematuria in 1,785 burn patients treated from 1964 to 1983, have been reviewed. Ninety-one patients had hematuria (>15 RBC/HPF with unspun urine). There were five main causes: urinary infections-(UTI), 50 cases; renal calculi (RC), 14 cases, including 3% and 5% total body surface area burn patients; catheter trauma, 7 cases; renal vein thrombosis (RVT), 5 cases; and acute renal failure (ATN), 4 cases. Ten patients died in the UTI group, five with Candida as the infecting organism. No RC patients died, but two required surgical extraction of their stones. This incidence of RC may be due to large intake of dairy products and antacids and to prolonged immobilization. The catheter trauma group had no deaths and was the youngest group. One RVT patient was diagnosed clinically and successfully treated surgically. The other three were diagnosed at necropsy. The ATN patients all developed renal failure late as part of multiple organ system failure and all died. We conclude hematuria is a serious finding in burn patients and prompt diagnosis of its etiology and treatment are essential for maintaining renal function and patient survival.

Immunostimulation by TP-5 in immunocompromised patients and animals-current status of investigation☆

TP-5 is a pentapeptide containing active site of the thymic hormone, thymopoietin. It has been shown to exert effects on multiple components of human and animal immune system both in vivo and in vitro. Initial studies demonstrated it to be necessary for T lymphocyte maturation. Its effects on other parts of the immune system are primarily immunostimulatory, and the drug can be used to correct immunodeficiencies resulting from several causes. TP-5 has been shown to improve survival rates in multiple animal studies where the animal has been rendered immunodeficient prior to septic challenge. It has also been successful in preventing and treating infections in a number of human studies. Evaluation of the exact mechanism by which the drug improves survival has demonstrated that it is of complex nature, involving interactions between various types of white blood cells.