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Biomedical subjects

B A Pruitt

Publications and source records attributed to B A Pruitt.

At least 91 records · Page 5Linked to original sources
PubMed1992

Resting energy expenditure in patients with thermal injuries.

Resting energy expenditures (REE) were measured using indirect calorimetric techniques in 62 patients with burn injuries admitted during 1987 to 1989 and compared with similar measurements made during 1972 to 1973. Energy requirements were related to burn size in both populations, but were greater in the earlier population. In the present study, data from some patients were obtained using a canopy system and from others during mechanical ventilation and were analyzed separately. The regression of REE on burn size was linear for the canopy measurements (r = 0.724) and for the ventilator measurements (r = 0.579). REE data were corrected for the expected basal metabolic rate (BMR) for each patient, with appropriate adjustment for age and sex. The regression of REE per BMR on burn size was linear (r = 0.724), differing from the curvilinear relationship found during 1972 to 1973. These data suggest a change in postburn energy requirements, probably related to differences in patient management. Predictive equations based on older data can be expected to overestimate energy requirements in patients receiving modern burn therapy.

Adolescent↗
PubMed1991

Fungal burn wound infection. A 10-year experience.

To evaluate our experience with fungal burn wound infection, we performed a 10-year review for comparison with our experience with bacterial burn wound infection. During the study period, a marked decline occurred in bacterial wound infection but not in fungal wound infection. Patients with either bacterial or fungal burn wound infection had massive injury, with burn size averaging greater than 50% of the total body surface area. Factors that appear to have markedly reduced bacterial burn wound infection, including patient isolation, topical chemotherapeutic agents, and burn wound excision, do not appear to have had a similar effect on fungal wound infection. The mechanism of spread and colonization of fungi, and the lack of effective topical chemotherapeutic antifungal agents, may explain in part our findings.

Adult↗
PubMed1991

Alterations in host defense associated with anesthesia and blood transfusions. II. Effect on response to endotoxin.

The effect of blood transfusions and anesthesia on host response to endotoxin was evaluated in multiple Lewis rat models. The rats were randomized to receive A'Sogaloff Cancer Institute rat blood, pentobarbital sodium, or lactated Ringer's solution and, at either 2 or 7 days following administration of these agents, were challenged with intravenous endotoxin. Neither blood transfusions nor anesthesia altered mortality when administered 2 days before endotoxin challenge. However, blood transfusions administered 7 days before endotoxin challenge were found to prolong survival, to prevent endotoxin-induced alterations in T-lymphocyte subsets, and to decrease plasma tumor necrosis factor levels. In conclusion, blood transfusions appear to depress immune function in a beneficial manner in endotoxin shock.

Anesthesia, General↗
PubMed1991

Effects of granulocyte-macrophage colony-stimulating factor in burn patients.

We studied the effects of granulocyte-macrophage colony-stimulating factor in burn patients. Serial measurements of granulocyte oxidative function were obtained in treated patients and in a group of controls matched for age and total burn size. The administration of granulocyte-macrophage colony-stimulating factor resulted in a 50% increase in mean leukocyte counts. Both groups showed significant baseline increases in granulocytic cytosolic oxidative function. Treated patients showed normal stimulated cytosolic oxidative function, which was significantly depressed compared with that of untreated patients. Myeloperoxidase activity was increased in treated patients during the first postburn week but then declined to normal levels. Untreated patients had a significant increase in myeloperoxidase activity for the first 3 weeks following injury. Untreated patients exhibited a significant decrease in superoxide activity during the second 3 weeks following injury. Treated patients demonstrated normal superoxide activity.

Acridines↗
PubMed1991

Effect of prostaglandin E in multiple experimental models. VIII. Effect on host response to metastatic tumor.

Prostaglandin E (PGE) is produced by certain tumors and is reported to decrease primary tumor growth. We evaluated its effect in multiple tumor models utilizing a 1 week course of the long acting PGE derivative dimethyl-PGE (dPGE) at a dosage of 100 micrograms/kg/day vs. a lactated Ringers control. For all tumor models, a suspension of 1 x 10(6) colon carcinoma cells were injected into Wistar-Furth rats. When the suspension was injected subcutaneously and the drug was begun at the time of tumor challenge, there was no effect on survival. When the tumor was injected intraperitoneally or intravenously and the drug begun at the time of tumor challenge, dPGE decreased survival time. When the tumor was administered intravenously but dPGE was delayed for 5 days, there was no effect on survival time. When rats were given a 1 week course of dPGE or saline, dPGE was found not to alter natural killer (NK) cell cytotoxicity, macrophage cytotoxicity, spontaneous lymphocyte blastogenesis, or mitogen stimulated blastogenesis. dPGE failed to alter lymphocyte metabolism of glucose in nonstimulated lymphocytes, but decreased the rate of glucose metabolism and adenosine deaminase activity in mitogen stimulated lymphocytes. In conclusion, PGE appears to enhance metastatic growth of tumor lines where it does not alter primary tumor growth. This effect does not appear immunologically mediated.

Animals↗
PubMed1991

Prophylactic use of high-frequency percussive ventilation in patients with inhalation injury.

Death and the incidence of pneumonia are significantly increased in burn patients with inhalation injury, despite application of conventional ventilatory support techniques. The effect of high-frequency percussive ventilation on mortality rate, incidence of pulmonary infection, and barotrauma were studied in 54 burn patients with documented inhalation injury admitted between March 1987 and September 1990 as compared to an historic cohort treated between 1980 and 1984. All patients satisfied clinical criteria for mechanical ventilation. High-frequency percussive ventilation was initiated within 24 hours of intubation. The patients' mean age and burn size were 32.2 years and 47.8%, respectively (ranges, 15 to 88 years; 0% to 90%). The mean number of ventilator days was 15.3 +/- 16.7 (range, 1 to 150 days), with 26% of patients ventilated for more than 2 weeks. Fourteen patients (25.9%) developed pneumonia compared to an historic frequency of 45.8% (p less than 0.005). Mortality rate was 18.5% (10 patients) with an expected historic number of deaths of 23 (95% confidence limits of 17 to 28 deaths). The documented improvement in survival rate and decrease in the incidence of pneumonia in patients treated with prophylactic high-frequency ventilation (HFV), as compared to a cohort of patients treated in the 7 years before the trial, indicates the importance of small airway patency in the pathogenesis of inhalation injury sequelae and supports further use and evaluation of HFV.

Adolescent↗
PubMed1991

Dissociation of blood volume and flow in regulation of salt and water balance in burn patients.

The relationship between effective blood volume and related hormones in burn patients following resuscitation is not well understood. Previous reports have suggested that hormone secretion is altered by a resetting of neural control mechanisms. Serum and urine sodium, plasma renin activity, serum ADH, cardiac index, effective renal plasma flow, and total blood volume were measured in seven burn patients (mean age, total burn size, and postburn day: 32 years, 56%, and 9 days, respectively). The same values (with the exception of cardiac index and blood volume) were measured in 10 control patients (mean age, 24 years). The blood volume of patients was measured by 51chromium red blood cell (RBC) labeling and compared to normal predicted values based on body surface area and sex. Mean serum sodium and osmolality were 138 mmol/L (millimolar) and 286 mosm/kg, respectively, in both patients and control subjects. Mean +/- standard error of the mean total blood volume in the patients was low, 81% +/- 4% of predicted values. Cardiac index and renal plasma flow were significantly elevated. Plasma renin activity and antidiuretic hormone (ADH) levels were elevated and altered in the direction expected from blood volume measurements despite the findings of increased blood flow. Dissociation of organ flow and hormonal response suggests that simultaneous direct blood volume measurements are necessary to elucidate factors other than altered neural control settings to explain hormonal changes in the flow phase of injury. Depressed total blood volume appears to promote elevated ADH levels in burn patients following resuscitation. Whether there is an additional role of altered neural control settings remains to be established.

Adrenocorticotropic Hormone↗
PubMed1991

The morphology of smoke inhalation injury in sheep.

Pulmonary injury resulting from inhalation of chemical and particulate products of incomplete combustion is one of the principal determinants of mortality following burn injury. In this study, the histopathology of inhalation injury was examined in sheep. Mild, moderate, or severe smoke injury was produced in anesthetized sheep by insufflation with various doses of ambient temperature smoke, generated by burning polyethylene, wood pulp, and nonwoven cellulose pads. A total of 64 sheep were exposed and evaluated at times ranging from 15 minutes to 4 weeks after exposure. Morphologic changes in the lungs were studied using light microscopy and both transmission and scanning electron microscopy. The primary, dose-responsive injury observed was acute cell membrane damage in the trachea and bronchi leading to edema, progressive necrotic tracheobronchitis with pseudomembrane formation, and airway obstruction. These inflammatory and occlusive effects were followed by congestion, alveolar space edema, atelectasis, and bronchopneumonia. Morphologic changes occurring in the alveolar epithelium following high smoke dosage included intracellular edema in type-I cells, changes in the membrane-bound vacuoles of type-II cells, and septal thickening caused by interstitial edema. No capillary endothelial changes were observed.

Animals↗
PubMed1990

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).

Animals↗
PubMed1990

Bashkirian train-gas pipeline disaster: the American military response.

The United States Army Institute of Surgical Research was asked to provide burn care assistance in June 1989 following the explosion of leaking methane/propane gas in the Central Soviet Union, which destroyed two passenger trains and injured 800 passengers. A 17-member burn team flew from San Antonio, Texas, to Ufa, USSR and assisted in the management of 150 burn patients in a general medical-surgical hospital. Early problems included heavily colonized burn wounds, with a microbial flora that demonstrated broad antibiotic resistance. As wound complications were controlled, 28 operative procedures were performed to excise and graft the burn wounds. The recommendations for burn disaster management, based on our experience in Ufa, should be of assistance to other groups that may be asked to provide similar assistance in the future.

Bashkiria↗
PubMed1990

Effect of prostaglandin E in multiple experimental models. VII. Effect on resistance to sepsis.

The immunosuppression seen following burn injury has frequently been attributed to elevated prostaglandin E levels. We evaluated the contribution of elevated prostaglandin E levels on susceptibility to infectious complications utilizing multiple mouse models. The administration of 100 micrograms/kg of the long-acting derivative of prostaglandin E, 16,16-dimethyl-prostaglandin E, was found to improve survival in C3/HEN mice challenged with 1 x 10(8) Escherichia coli organisms intraperitoneally. The administration of indomethacin was found to decrease survival in the same model. With C3/HEJ (endotoxin-resistant) mice, indomethacin was found to increase mortality rates in animals challenged with 1 x 10(8), 1 x 10(9) or 1 x 10(10) Escherichia coli organisms. These findings suggest that elevated prostaglandin E levels seen in burn patients may not be responsible for the postburn increased susceptibility to infectious complications.

Animals↗
PubMed1990

Smoke inhalation injury and the effect of carbon monoxide in the sheep model.

The role of carbon monoxide (CO) in causing the physiologic and anatomic changes characteristic of smoke inhalation injury was evaluated in 34 sheep. The smoke-exposed group received a dose of smoke known to produce mild inhalation injury. The CO group received a pure gas mixture that contained concentrations of oxygen, carbon dioxide, and CO similar to those in the smoke. Cardiopulmonary function was measured immediately after exposure, and 24 and 72 hours after exposure. The CO group showed a transient increase in cardiac output, but the smoke group showed no such response. The CO group maintained normal PaO2 levels during the 72-hour study period; the smoke group gradually developed hypoxemia. The lungs of the CO exposed animals had no discernible histologic changes; lungs of the smoke group showed progressive inflammatory changes. These results indicate that CO per se is not the primary etiologic agent of smoke inhalation injury.

Animals↗
PubMed1990

Multiple graft harvestings from deep partial-thickness scald wounds healed under the influence of weak direct current.

The time required for wound healing, contraction, and hypertrophic scarring often limit the use of deep partial-thickness burn wounds as donor sites for split-thickness grafts. We have examined the effects of weak direct current and silver nylon dressings on the healing of partial-thickness scald burns, split-thickness grafts taken from these wounds when healed, and the resulting donor sites in a guinea pig model. Dorsal scald wounds treated with weak direct current reepithealized by 12 days postinjury. Split-thickness grafts taken from healed scald wounds showed more rapid revascularization with direct current treatment than did control grafts. Grafts and donor sites treated with direct current showed more rapid reepithelialization, decreased contraction, improved hair survival, and decreased dermal fibrosis when compared to controls not treated with direct current. Only donor wounds treated with weak direct current were reusable as donor sites.

Animals↗
PubMed1990

Evaluation and management of patients with inhalation injury.

Inhalation injury, present in approximately one third of burned patients treated at burn centers, increases mortality by a maximum of 20% in relation to age and extent of burn. The development of animal models of inhalation injury has made possible the identification of both the airway and vascular responses evoked by smoke inhalation. Inflammatory occlusion of terminal bronchioles and necrosis of the endobronchial mucosa render the airway and pulmonary parenchyma susceptible to infection and the resulting pneumonitis further increases mortality. Early diagnosis, best achieved by endoscopic bronchoscopy and 133xeon ventilation perfusion scan, permits timely application of high-frequency ventilation that appears to reduce the incidence of pneumonia and to decrease mortality. Pharmacologic agents give promise of ameliorating the deleterious changes of the vasculature. The recent advances in understanding inhalation injury have identified the research needed to further improve patient salvage.

Animals↗
PubMed1990

The effect of transfusions on the incidence of bacterial infection.

The use of blood transfusions has been a art of medical practice for over half a century. The efficacy of blood and blood products in patients in hypovolemic shock from trauma or operative procedures has been well established. During the past quarter century, it has been demonstrated that blood transfusions administered prior to transplantation decrease the frequency and severity of allograft rejection. More recent work has indicated that this beneficial effect is the result of the transfusion inducing a state of immunosuppression in the recipient. A number of reports have suggested that this posttransfusion immunosuppression may result in an increased susceptibility to bacterial infections.

Animals↗
PubMed1990

Effect of blood transfusions on immune function. Part VI. Effect on immunologic response to tumor.

Transfusions are reported to increase the incidence of tumor metastasis in clinical studies and primary tumor growth in animal studies. We evaluated the effect of transfusions on immunologic response to primary and metastatic tumors in multiple rat models. One half of the animals were administered lactated Ringer's solution and one half ACI rat blood at the time of tumor challenge. In 80 rats a slow-growing colon tumor was implanted subcutaneously. At 4 months there were no significant differences in tumor size or leukocyte infiltration of the tumor. Similar results were obtained with a rapidly growing colon cancer. Analysis of T-lymphocyte subpopulations in both groups showed no differences. Rats transfused at the time of intravenous challenge with a suspension of 1 x 10(6) tumor cells had a mean survival time of 38.3 +/- 0.8 days and the control group had a mean survival time of 41.1 +/- 0.8 days (p = 0.016). One week after transfusion, natural killer cell lysis of tumor cells at a 100:1 effector/target cell ratio was 18.0% +/- 1.8% in the transfusion group and 23.0% +/- 1.3% in the control group (p = 0.034). In conclusion, transfusions in multiple rat cancer models did not affect primary tumor growth or the host's immunologic response to it but did significantly impair natural killer cell function and survival with tumor metastases.

Adenocarcinoma↗