Hugo F. Carvajal

Effect of antihistamine-antiserotonin and ganglionic blocking agents upon increased capillary permeability following burn trauma.

: Tiny (0.2% TBS), partial thickness, non-contact radiant heat burns in guinea pigs resulted, within 3 hours, in significant edema formation and protein leakage at the site of the injury. Areas of skin distant to the burn also showed an increase in water content but no protein leakage. Pretreatment of the animals with either chlorisondamine hydrochloride or a mixture of methysergide and chlorpheniramine significantly decreased postburn edema formation and protein leakage. Liquid emulsion autoradiography revealed that leakage of protein occurs primarily in the areas of skin adjacent to the panniculus carnosus. The studies suggest that: the increase in vascular permeability that occurs as a consequence of burn injuries is humorally mediated; albumin leakage is limited to the injured tissues; and histamine, serotonin, and presumably catecholamines play significant roles in the development of this phenomenon.

Burn edema and protein leakage in the rat. I. Relationship to time of injury.

Abstract Studies to determine the relationship between increased vascular permeability (water content and protein leakage) and time postinjury were performed in rats. Three small, thermal burns were inflicted to the left of the spine. Animals were sacrificed at the following time intervals postinjury: 0.5, 1.5, 3, 6, 12, 18, 24, 36, and 48 hr. Radio-iodinated human serum albumin (131I-RISA), 200 μCi/kg body weight, was given iv 30 min prior to sacrifice. Segments of skin were obtained, weighed, counted (scintillation counting), dried (60° for 96 hr), and reweighed. Autoradiographic studies were also performed. Water content was maximal at 3 h postburn and was no longer demonstrable by 24 hr. Albumin leakage was maximal at 30 min and disappeared by 12 hr postinjury. In another set of experiments in which 131I-RISA was injected at the time of the burn, high tissue counts persisted for as long as 48 hr. These studies have shown that abnormal albumin extravasation occurs only during the first 6 to 12 hr postinjury. Once in the interstitium, however, albumin may remain trapped for up to 48 hr.

Management of Burns

An overview of the management of the acutely burned patient has been described. Adherence to the sound principles of early resuscitation, appropriate nutrition, wound management, and rehabilitation can provide hope for many of the victims of this tragic injury. Complications encountered throughout the burn illness present unique and perplexing problems for the physician, who must utilize all the clinical wisdom and facility available in the management of such complex problems.

Caloric Requirements in Burned Children: A Simple Formula to Estimate Daily Caloric Requirements

The present study evaluated the efficacy of a surface area formula in estimating the daily caloric requirements of 52 severely burned children who were consecutively admitted to the Shriners Burns Institute in Galveston and who survived their injuries. Their ages ranged from 2 weeks to 15 years (X 6.3 years); their burns ranged from 20% to 82% (X 39%); and their hospital stay ranged from 20 to 120 days (X 55 days). Caloric requirements were calculated according to a standard formula (1,800 Kcalper square meter of body surface per day plus 2,200 Kcal per square meter of body surface area burned per day). Most of the calories were suplied in the form of homogenized milk plus a regular house diet.Using the weight on the 14th day postburn as baseline (dry weight), the patients were divided into two groups. Patients in group 1 (40 patients) received calories as recommended by the formula, gained weight, and appeared well nourished. Patients in group 2 (12 patients) failed to receive the number of calories recommended by the formula and lost weight. On the basis of this study, we propose that the formula is accurate and can be used routinely to estimate the minimum caloric requirements of burned children.

Effect of burn depth upon oedema formation and albumin extravasation in rats

Abstract Studies to determine the influence of burn depth upon albumin extravasation and oedema formation were conducted in 90 Sprague-Dawley rats. Oedema formation and protein leakage were studied at 30 min, 3 h and 12 h after injury. The burns were induced with a constant temperature heating element designed to produce tiny (02 per cent) non-contact radiant heat burns (Fig. 1). The depth of the burn was controlled by varying the exposure time (8, 12, 16 and 24 s). Oedema occurred rapidly and was of similar magnitude for all burn depths at 30 min and 3 h after injury but it was more marked in the deeper burns at 12 h ( P 131 1 extravasation was more prominent in the 24-s than in the 8-s burn at 30 min after injury ( P 131 I leakage occurred in areas distant to the burn. On the basis of these studies it seems unimportant for the purpose of fluid resuscitation and protein replacement in burned victims, to differentiate between partial- and full-thickness injuries.

Pediatric trauma care is cost effective: a comparison of pediatric and adult trauma care reimbursement.

Trauma causes staggering losses: in 1987, Hermann Hospital lost

Effect of inhibiting prostaglandin synthesis on edema formation and albumin leakage during thermal trauma in the rat.

8 million to uncompensated trauma care. To demonstrate the survivability of pediatric trauma care delivery we examined reimbursement profiles for adult and pediatric trauma patients. We retrospectively reviewed the records of 3445 patients with serious trauma from October 1987 through March 1992. The group was divided into adult (> or = 17 years) and pediatric patients (< 17 years). We compared reimbursement profiles based on hospital costs generated, reimbursement, financial class, demographics, discharge diagnostic codes, and outcome. Significance was assessed by t test and Chi-square. We found a decreased length of stay (LOS) and a lower association with under-reimbursement or zero reimbursement in pediatric patients. A significantly lower percentage of pediatric patients paid none of their bill (17.1%) compared with the adults (23.2%). Pediatric reimbursement exceeded hospital costs (110.0%) compared with adult reimbursement (90.3%). This suggests that pediatric trauma care can survive in an atmosphere of shrinking resources.

An objective method for early diagnosis of gram-negative septicemia in burned children.

Prostaglandins (PGs) participate in the inflammatory response, but the contribution of endogenously synthesized PGs to edema formation and increased vascular permeability is not known. Using a 10% scald burn in the rat, we measured water content (as percent, wet minus dry/wet weight) and 131I-RISA leakage (counts/g dry tissue) in scalded and normal skin at 30 minutes and 3 hr post injury. Four groups (10 rats/group) in each time period studied: control; scald; scald, 5 mg/kg indomethacin; scald, 10 mg/kg indomethacin. Indomethacin was administered intravenously 30 minutes before the scald; RISA was injected intravenously 30 min before termination of the study. In all indomethacin-treated groups immunoreactive plasma PGA was significantly lower (p less than 0.05) than in scalded, untreated groups. All scalded groups showed significantly higher RISA counts and water content than did the control group (p less than 0.01). At 30 min post-injury the indomethacin -treated groups did not differ from the untreated scald group (p greater than 0.20). In the 3 hour study all scalded groups had significantly higher content and RISA counts than control (p less than 0.01). Thus PGs produced during thermal trauma do not greatly contribute to the edema formation and increase in vascular permeability.

Optimal composition of burn resuscitation fluids

The present investigation was undertaken to standardize the early diagnosis of Gram-negative septicemia in burned children. Data were collected by means of a matrix which encompassed eight clinical variables routinely monitored by nursing personnel. These variables were evaluated according to their severity using a numerical scale of 0 to 3. A sepsis score was thus calculated for each of 243 burned patients, three times a day throughout their entire hospitalization. Eighty patients with suspiciously high scores (controls) were subjected to a battery of ten laboratory tests aimed at confirming the presence or absence of septicemia. During the 26 months of the study 16 patients (22 episodes) had clinical and laboratory evidence of Gram-negative septicemia. Multiple regression and discriminant analysis techniques were then used to develop statistical models for early diagnosis of septicemia. The two most practical and reliable of these are reported herein. Model I and II would have predicted the diagnosis of sepsis, 83% and 86% of the time, respectively, 1 day before the diagnosis was made using conventional methods. The false positive rates of Models I and II were 7% and 3%, respectively. On the basis of this information it seems possible and rewarding to utilize decision-making charts for monitoring and diagnosis of septicemia.

Effect of nicotinic acid on vascular permeability after thermal trauma in the rat.

The hemodynamic, renal, and hematologic responses to fluid resuscitation with four different hydrating solutions (lactated Ringers and hypertonic salt solutions, with and without albumin) administered in equal quantities were compared in an ovine burn model. Forty-five animals, including a sham group, were studied. The burn (40%, flame) was inflicted under anesthesia, but the animals were then studied while in the awakened state. Fluid resuscitation was begun one hour after the burn. While all animals survived the burn and disclosed reasonable hemodynamic stability throughout the experiment, those that received lactated Ringers with albumin (LRA) restored their cardiac output to preburn values, by 24 h postinjury demonstrated higher serum albumin and colloid osmotic pressure levels, experienced no electrolyte or acid-base imbalances, and maintained serum osmolality within normal limits. In contrast to the other solutions, LRA did not induce edema in unburned tissues, and seemed optimal for burn resuscitation.