William F. McManus

Hypermetabolic Low Triiodothyronine Syndrome of Burn Injury

The free tetraiodothyronine index (FT4I) and free triiodothyronine index (FT3I) in burn patients represented the serum levels of free (dialyzable) T4 and free T3, respectively. FT4I and FT3I were lower with greater burn size and were lower in nonsurvivors than expected for the burn size. There was no compensatory elevation of basal or releasing hormone-stimulated thyrotrophin (TSH) concentrations. Reverse T3 was higher with greater burn size. T3 treatment restored FT3I but did not affect mortality or resting metabolic rate (MR) measured in survivors, compared with placebo therapy. Whereas the hypermetabolic response to burn injury appeared to be independent of thyroid hormones, MR was correlated positively with burn size and with elevated plasma nor-epinephrine and epinephrine concentrations for several weeks after injury. Lack of augmented TSH concentrations, absence of low plasma reverse T3, and presence of hypermetabolism suggest that the reduced plasma free T3 does not indicate functional hypothyroidism, but may represent an adaptation to the assumption of metabolic control by the sympathetic nervous system.

Prospective Study of Burn Wound Excision of the Hands

To examine the role of early excision and grafting in the preservation of maximal function of hands with deep dermal burns, we prospectively evaluated 164 burned hands in consecutively admitted patients (mean age, 29 years; mean burn size, 37% of body surface). All hands with burn depths of second degree, deep second degree, or third degree above the level of the tendons and joint capsules were assessed preoperatively, intraoperatively, and at discharge from the hospital. Patients were treated by excision and grafting in the first or second postburn week, by delayed grafting alone, or by allowing primary healing. Total active range of motion measurements were made on the day of discharge (mean, 64th postoperative day). Mean operative blood loss per hand was 1,270 ml. When all (alive and dead) patients undergoing early excision and grafting were examined by a binomial probability model, early surgery was shown to produce no adverse affect on survival. Excision and grafting of hands with deep dermal burns, whether early or late, offered no advantage over physical therapy and primary healing in maintaining hand function. Likewise, hands with more superficial burns responded equally to operative and nonoperative treatment. While early excision and grafting of hands with third-degree burns tended to produce poorer results than did initial nonoperative care and late grafting, the differences are just outside the range of significance. Early excision and grafting of selected third-degree injuries of the hands may be indicated in patients with small total body surface burns in order to shorten hospital stay. However, early surgical intervention in patients with massive burns should be directed toward area coverage, not toward hand excision.

An effective prehospital emergency system.

An Emergency Medical Services (EMS) system with the capabilities of rapid response, patient extrication, basic life support, advanced life support, radio communication, and transportation provides appropriate care for a wide spectrum of injured and acutely ill patients. The validity of the selective dual response system in demonstrated by: 1) rapid provision of basic life support, 2) appropriate availability of advanced life support, 3) conservation of educational and fiscal resources, and 4) the enchancement of knowledge and manipulative skill expertise of relatively few, but busy, EMT-paramedics who are provided close medical supervision and support.

Replacement therapy with modified immunoglobulin G in burn patients: Preliminary kinetic studies

Suppression of serum immunoglobulin G for periods ranging from days to weeks following thermal injury may enhance the risk of infection in burn patients. In an initial trial, we attempted to determine whether intravenous pulses of Immunoglobulin G (IgG) will establish and maintain normal serum IgG concentrations in this interval. The levels of endogeneous serum IgG in eight control patients, mean total burn size 45 percent body surface area (no IgG infusions), were measured by radial immunodiffusion on various postburn days. Commercially available reduced alkylated IgG (5 percent Gamimune, Cutter Biological, Berkeley, California) was infused in doses of 500 mg/kg twice per week in four patients (total burn size 32 percent) and once per week in five patients (total burn size 47 percent), beginning during the first postburn week. Circulating IgG was measured prior to each infusion and at three postinfusion times: (1) 15 minutes (peak), (2) one day, and (3) either day 3, 4, or 6. Surgery or blood transfusions prior to one of these time points invalidated kinetic analysis of some infusions. Exponential two-point decay constants for total serum IgG after each of 24 infusions were calculated separately for early (day 0-1) and later (day 1-3 or 1-4) postinfusion intervals and assessed by stepwise regression analysis to determine sources of variation in decay. Early decay was seen to be faster with larger burn size after accounting for variation of decay with preinfusion and peak IgG values. Later decay was not related to burn size. Maltose, a constituent of the IgG preparation, was detectable in serum for only four to eight hours after each infusion and may have contributed to a 20 percent increase in total serum glucose between four and eight hours postinfusion. Mean serum IgG in patients given infusions twice weekly was in the normal range after one infusion, about a week earlier than in untreated patients. Such infusions maintained normal IgG levels.

Experimental inhalation injury in the goat.

Inhalation injuries are usually produced by inhalation of gaseous or particulate products of incomplete combustion and are rarely due to heat per se unless steam is inhaled. The clinical and anatomic characteristics of an appropriate animal model should mimic the disease encountered clinically. A model of inhalation injury has been produced in anesthetized goats through the use of a modified bee smoker. The smoke is delivered at a low temperature and contains byproducts of incomplete combustion. This reproducible injury produces necrotic tracheobronchitis and bronchiolitis with pseudomembrane and cast formation in association with mild multifocal atelectasis and bronchopneumonia. These lesions spontaneously resolve within 3 weeks without supportive therapy. The upper trachea, protected from smoke injury by the inflated cuff of the endotracheal tube, showed no evidence of injury. This nonlethal injury is proposed as an appropriate model for evaluation of the pathophysiology and treatment of inhalation injury.

Lightning injury with survival in five patients

Of a total of 4,153 admissions, five patients with lightning-associated injuries were admitted to a burn center during a 15-year period, 1969 through 1983. In these patients, the burned portion of the total body surface ranged from 3% to 29% (average, 16%), and all survived. The associated injuries and complications in these lightning-strike victims and a review of treatment guidelines are presented.

Superior Mesenteric Artery Syndrome in a Burn Patient

Weight loss resulting from the hypermetabolic response to burn injury is not unusual and is often unavoidable. The loss of retroperitoneal fat has been postulated as a major factor in the cause of the uncommon complication of superior mesenteric artery syndrome. This syndrome is frequently treated nonoperatively with aggressive nutrition support. Nasojejunal feeding past the point of obstruction should be considered as the primary method of nutrition support. Alternatively, total parenteral nutrition or a combination of enteral and parenteral feeding may be necessary to meet nutritional needs until the duodenal obstruction resolves. This case study describes the nutrition management of a burn patient who developed superior mesenteric artery syndrome.

Subeschar Antibiotic Infusion in the Treatment of Burn Wound Infection

In a reproducible infected rat burn model, subeschar infusion of antibiotics failed to protect the animals from death via burn wound invasion excepting those animals receiving carbenicillin. Subcutaneous injection of maximal doses of carbenicillin at a distance from the burn wound protected these animals equally well. Some advantage was defined for the subeschar route of administration with suboptimal doses of carbenicillin. More important is the fact that propective selection of an effective antibiotic could not be made on the basis of in vitro antibiotic sensitivity tests.

Inappropriate Vasopressin Secretion (SIADH) in Burned Patients

To determine if concentration of plasma arginine vasopressin (AVP) is inappropriate for the plasma Na+ concentration in hyponatremic burned patients, we obtained 32 plasma samples from 20 patients with total burn size (TBS) 15 to 80% of body surface on or after postburn day (PBD) 4 in the morning following all-night recumbency. In the 25 samples (17 patients) with hyponatremia, AVP was elevated, 1.6 to 14.3 (normal less than 0.5) pg/ml. Most patients with normal serum Na+ had normal AVP values. Out of the total, nine patients (12 samples) without renal failure or sepsis, selected also for hyponatremia and urinary Na+ greater than or equal to 20 mEq/L, were considered separately. BUN of 11.7 +/- 1.8 mg/dl and plasma glucose of 130 +/- 5.6 mg/dl, Na+ of 130 +/- 1.1 mEq/L, calculated osmolality of 272 +/- 1.6 mosm/kg, and cortisol of 20.4 +/- 1.6 micrograms/dl were associated with a 24-hour fluid intake of 4.3 +/- 0.26 L and urinary output of 2.7 +/- 0.33 L, Na+ of 80 +/- 14 mEq/L, and osmolality of 520 +/- 73 mosm/kg (mean +/- SE). In all of the plasma samples, AVP was markedly elevated (6.9 +/- 1.1 pg/ml). In another study, four hyponatremic burned patients were given a standard water load. Excretion of the water was delayed, and further dilution of the initially hypotonic plasma resulted in a fall of urinary osmolality and plasma AVP. Cutaneous thermal injury can cause resetting of the mechanism linking plasma tonicity and AVP secretion resulting in dilutional hyponatremia. This syndrome occurs in the absence of gross physiologic perturbations such as volume depletion or adrenal insufficiency.

A Rapid Section Technique for Burn Wound Biopsy

Abstract : At the US Army Institute of Surgical Research, histologic diagnosis of infection using burn wound biopsies has proved superior to quantitative culture methods and is considered the most accurate method for distinguishing between microbial colonization and invasive infection of burn wounds. Although the frozen section technique is faster and is often useful, rapid section technique is the method of choice for histologic evaluation of burn wound biopsies. This technique takes about four hours to complete, yields permanent sections, and can be accomplished in any conventional histology laboratory. (Reprints).