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Biomedical subjects

M D Peck

Publications and source records attributed to M D Peck.

At least 37 records · Page 2Linked to original sources
PubMed1989

Low protein diets improve survival from peritonitis in guinea pigs.

Enteral diets with different protein content were tested to determine their effect on outcome in a model of protracted bacterial peritonitis. Hartley guinea pigs were provided with gastrostomies, and 1 week later, osmotic pumps were implanted into the peritoneal cavity to allow for continuous release of live bacteria over the course of 1 week. Three days after pump implantation, the animals began receiving isocaloric enteral diets that contained 5%, 10%, 15%, or 20% of total calories as protein. After 2 weeks of observation, the survivors were killed. All animals lost weight during the 2-weeks period, but there was no difference in weight lost. Nitrogen balance correlated with dietary protein. The mortality rate was significantly higher in the groups that received 15% and 20% of total calories compared with the group that received 5% (p less than 0.05). Although dietary protein in the 5% group was insufficient for meeting the nutritional needs of the animal, survival was best in this group. Possible explanations are that protein restriction in this model may either augment host defence or impair bacterial virulence.

Animals↗
PubMed1987

Role of surgical treatment in the management of complications of the gastrointestinal tract in patients with leukemia.

The clinical course of patients with leukemia, specifically after treatment, is complicated by opportunistic infections, often derived from the gastrointestinal tract. Four hundred and thirty-eight patients with leukemia were treated at the Arizona Health Sciences Center from 1976 to 1985. Fifty-five (13 per cent) had 60 major gastrointestinal complications develop. Thirty-seven were treated medically with a mortality rate of 51 per cent, while 18 who were treated surgically had a 17 per cent mortality rate. These infections usually occur during induction or consolidation chemotherapy. Positive blood cultures and white blood cell counts of less than 2,500 per millimeter are a frequent occurrence. The most common complications of the gastrointestinal tract are enterocolitis, perirectal sepsis and bleeding. Because of the combined defects in phagocytosis (neutropenia), antibody production and cell mediated immunity, opportunistic infections (such as viral, fungal, parasitic or bacterial) are frequent and often lethal, despite routine antibiotic coverage. A protocol to identify a subset of patients with septic leukemia who may require emergency surgical treatment is vital since death in this group is most commonly from undiagnosed sepsis or progression of hematologic defects. This protocol should include repeated physical examinations, daily roentgenograms of the abdomen, liberal use of endoscopy, contrast roentgenography and computed tomography (CT) or ultrasound. Extensive surgical procedures can be safely carried out in patients with leukemia. The diagnosis of leukemia should not be a deterrent to emergency surgical exploration.

Adolescent↗
PubMedDate not supplied

Occupation-related burn injuries.

Unlike household burn injuries, the characteristics of burn injuries in the workplace have not been well described. In an effort to understand the causes and effects of occupation-related burn injuries and to aid in prevention, we sought to describe work-related burn injuries by frequency, burn type, age of the patients, body parts burned, and occupation of the patients. This was a statewide, cross-sectional study of all burns that occurred in the workplace during 1994. Data on fatal injuries were obtained from the National Census of Fatal Occupational Injuries. Survey data from the North Carolina Department of Labor were used for nonfatal injuries. Burns caused 34 deaths (15.3%) and 1720 injuries in the workplace in 1994. Of the nonfatal injuries, 1363 (79.2%) were caused by exposure to caustic substances or hot objects or substances. The head and upper extremities were the most frequently injured body parts (936 injuries; 57.6%). The average age of those burned was 30.7 years; most of the patients ranged from 25 to 35 years old. High-risk occupations included vehicle and equipment cleaners, food service personnel, and millwrights (11.3%, 5.3%, and 5.2% of burn injuries, respectively). Unlike the flame burns that occur in homes, exposure to caustics and hot objects and substances caused the majority of on-the-job burn injuries. Protective gear for the head and upper extremities may prevent a significant number of burns. Education and prevention programs may best be directed at workers with high-risk occupations and workers in the 25- to 35-year age range.

Accidents, Occupational↗
PubMedDate not supplied

The management of burns to the perineum and genitals.

A review of 1987 patients treated during the years 1981 to 1986 was conducted to answer the following questions about perineal burns: (1) Are Foley catheters necessary for all patients? (2) Is there any advantage to early excision of the perineal burn wound? (3) What are the complications of perineal wounds? One hundred three patients with perineal burns were identified; mean burn size was 36% of total body surface area. There were 29 deaths in this group but none were related to the perineal burns. Of the 74 survivors 36 (49%) needed Foley catheters. However, the catheters were in place for the period of resuscitation only. There were no urethral complications associated with catheterization. Only three patients required surgery: one had a urethral meatotomy and two had split-thickness skin grafts. In conclusion, we found no genitourinary complications associated with perineal burns. Almost all perineal and genital burns were managed without indwelling catheters. Early excision of the perineal burn wound is not necessary, and most of these wounds will heal satisfactorily without grafting.

Burns↗
PubMedDate not supplied

Fungal translocation is associated with increased mortality after thermal injury in guinea pigs.

Thermal injury increases the rate of translocation of Candida albicans in guinea pigs, but early enteral feeding can significantly decrease this rate. We studied the combined effects of C. albicans translocation and early feeding on outcome of thermal injury in guinea pigs. Eighty guinea pigs were subjected to a flame burn covering 50% total body surface area. One hour before burn injury, half of the animals underwent gavage with 3 x 10(10) viable C. albicans, a dosage that in previous studies was associated with greater than 90% incidence of yeast translocation to the mesenteric lymph nodes. The other half underwent gavage with an equal volume of saline. After injury, half of each group were randomly selected to receive guinea pig feed ad libitum and the other half were starved for 72 hours. All were allowed access to water ad libitum. Mortality rate was recorded at 3 3 days. The group that underwent gavage with C. albicans and subsequent starvation after burn injury had a significantly higher mortality rate than had any of the other groups. We conclude that induced translocation of C. albicans in guinea pigs increases mortality after burn injury. Moreover, early enteral feeding has a protective effect, presumably by decreasing translocation rates has been shown in previous studies.

Animals↗
PubMedDate not supplied

Vitamin E supplementation does not improve survival from infection in mice when given after burn injury.

Previous studies have shown that vitamin E acetate given by gavage to mice before thermal injury can improve survival from subsequent infection. We tested the efficacy of aqueous vitamin E given parenterally after burn injury. Female BALB/c mice (n = 120) were given 15% total body surface area full-thickness flame burns. Three groups of mice were randomized to receive water-miscible vitamin E with the resuscitation fluid in doses of 0.5 mg per mouse, 0.167 mg per mouse, or 0.056 mg per mouse. These doses represented approximately nine, three, and one times the murine recommended daily allowance for vitamin E, respectively. Control mice were given saline only. The next day the mice were challenged with 2.5 x 10(5) Pseudomonas aeruginosa beneath the eschar. Administration of vitamin E was continued on a daily basis for a total of three doses and ending the day after bacterial challenge. Mortality rates were observed for 1 week and were not statistically different among the four groups. We conclude that vitamin E supplementation started after thermal injury in mice does not improve outcome from subsequent challenge with Pseudomonas aeruginosa.

Animals↗
PubMedDate not supplied

Dietary fat and infection in burned animals.

Dietary lipids can influence the immune response, chiefly through modulation of eicosanoid synthesis. Previous studies showed that diets high in linoleic or oleic acid significantly improved survival rates, compared with diets high in either saturated fats or omega-3 fatty acids, when fed to mice for 2 to 3 weeks before burn injury. These experiments suggest that neutrophil function in rats is not altered by diets high in either fish or safflower oil before burn injury. Serum opsonization is marginally improved by safflower oil diets for 2 weeks before burn injury but not for 6 weeks before burn injury.

Animals↗
PubMedDate not supplied

Comparison of length of hospital stay to mortality rate in a regional burn center.

Data were collected prospectively from 196 patients admitted to our regional burn center during a 10-month period. Fifteen patients died during hospitalization, for a mortality rate of 7.7%. The mean hospital stay of the 181 patients who survived was 13.9 days (+/- 13.7 SD), ranging from 2 to 89 days. The mean burn size was 9.2% (+/- 11% SD), ranging from 0.5% to 60% total body surface area. One hundred ten patients received at least 1 day of antibiotic treatment, and 22 patients required ventilatory support during hospitalization. Hospital stay was longer for those requiring antibiotics (18.6 days vs 7 days) or ventilatory support (34.4 days vs 11.2 days). When these and other variables were entered into a linear regression model, the most powerful predictors of hospital stay were burn size and duration of antibiotic use (p = 0.0001), followed next by the presence of other traumatic injuries (p = 0.047).

Adolescent↗
PubMedDate not supplied

Chemical dependency in patients with burn injuries: a fortress of denial.

Chemical dependency is frequently encountered in patients admitted to burn centers. We were interested in the prevalence of chemical dependency among our patients, as well as the rate at which those patients sought further treatment after discharge. Blood and urine specimens were collected within 24 hours of admission from 843 patients more than 18 years of age admitted with acute injuries. Many patients admitted to substance abuse during routine psychosocial evaluation; others admitted only when confronted by the counselor with positive toxicology test results. Of 51 patients counseled, 12 denied a history of chemical dependency. Of the other 39, 21 admitted to a history of chemical dependency, and 31 tested positive for either alcohol or drugs in toxicology screening. Every patient identified with chemical dependency was informed of existing substance abuse programs and given the opportunity to be referred to any of these programs. Only half of the patients who were offered rehabilitation therapy accepted treatment.

Adolescent↗
PubMedDate not supplied

Surveillance of burn wound infections: a proposal for definitions.

The diagnosis of burn wound infections is a subjective art, with no recent attempts to standardize or validate the definitions of terms used to discuss such infections. The Centers for Disease Control included definitions of types of burn wound infections in its definitions for nosocomial infections in 1988. Although the other Centers for Disease Control criteria for nosocomial infections have epidemiological applications, its criteria for burn wound infections have neither clinical nor epidemiological value to burn centers and their health care providers. With the approval of the Board of Trustees of the American Burn Association, the authors of this article formed a working subcommittee of the Committee on the Organization and Delivery of Burn Care. Definitions of burn wound infections are presented for consideration for application in either of 2 areas: (1) surveillance of burn wound infections in burn centers and (2) standardized criteria for multicenter clinical trials or national registries.

Burn Units↗
PubMedDate not supplied

A multicenter review of toxic epidermal necrolysis treated in U.S. burn centers at the end of the twentieth century.

Toxic epidermal necrolysis (TEN) is a potentially fatal disorder that involves large areas of skin desquamation. Patients with TEN are often referred to burn centers for expert wound management and comprehensive care. The purpose of this study was to define the presenting characteristics and treatment of TEN before and after admission to regional burn centers and to evaluate the efficacy of burn center treatment for this disorder. A retrospective multicenter chart review was completed for patients admitted with TEN to 15 burn centers from 1995 to 2000. Charts were reviewed for patient characteristics, non-burn hospital and burn center treatment, and outcome. A total of 199 patients were admitted. Patients had a mean age of 47 years, mean 67.7% total body surface area skin slough, and mean Acute Physiology and Chronic Health Evaluation (APACHE II) score of 10. Sixty-four patients died, for a mortality rate of 32%. Mortality increased to 51% for patients transferred to a burn center more than one week after onset of disease. Burn centers and non-burn hospitals differed in their use of enteral nutrition (70 vs 12%, respectively, P < 0.05), prophylactic antibiotics (22 vs 37.9%, P < 0.05), corticosteroid use (22 vs 51%, P < 0.05), and wound management. Age, body surface area involvement, APACHE II score, complications, and parenteral nutrition before transfer correlated with increased mortality. The treatment of TEN differs markedly between burn centers and non-burn centers. Early transport to a burn unit is warranted to improve patient outcome.

APACHE↗
PubMedDate not supplied

Arginine supplementation and its effect on established peritonitis in guinea pigs.

To evaluate the efficacy of supplemental arginine with nutritional support in the presence of sepsis, eighty-eight gastrostomized female Hartley guinea pigs were implanted with osmotic pumps effusing an Eschericia coli/Staphylococcus aureus mixture. Animals were randomized and infused for two weeks with isocaloric and isovolumetric diets containing 0%, 2%, 4%, or 6% supplemental arginine as arginine hydrochloride. Survival was 12/22 (54%) in 0%, 9/22 (41%) in 2% and 4%, and 2/22 (9%) in 6%. Analysis by chi-square test of independence was significant (p = 0.0141) with 6% survival lower than the others. Median survival was 11 days in 0%, 8 days in 2% and 6%, and 9 days in 4%. Median survival was longer in 0% than in 2% or 6% (Kruskal-Wallis ANOVA: p = 0.02). Nitrogen balance was significantly lower in 6% compared to 0% on days 2 through 10, and lower than 2% and 4% on days 6 and 9. Nitrogen balance was higher in 0% than in 2% on days 4, 6, 10, and 13. Serum albumin and C3 were lower in all experimental groups than normal controls (ANOVA: p = 0.01). Comparison of liver, spleen, adrenals, gastrocnemius, and carcass weights, cell-mediated immunity as determined by contact sensitivity to DNFB, and transferrin showed no significant differences. There was a positive dose-response effect seen amongst the experimental groups for the amino acids arginine, ornithine, and citrulline in relation to the amount of supplemental arginine. This study suggests that dietary arginine supplementation does not enhance survival in a guinea pig model of established peritonitis.

Animals↗
PubMedDate not supplied

Short-term dietary protein manipulation does not affect survival from intraperitoneal pseudomonas infection in mice.

Manipulation of dietary protein has a variable effect on immune function and outcome from infections. In this study we investigated the role of different sources of protein at different levels on the susceptibility of mice to infection with Pseudomonas aeruginosa. CF1 mice were pair-fed diets with 5%, 20%, and 40% protein by weight. At the end of two weeks feeding of the experimental diets, mice were challenged with Ps. aeruginosa intraperitoneally and mortality was recorded over one week. No significant differences in survival among groups fed different levels of protein were seen. Similarly, type of protein used did not affect outcome. We conclude that overall two-week manipulation of dietary protein did not significantly affect outcome from infection in this model.

Animals↗
PubMedDate not supplied

Survival in septic guinea pigs is influenced by vitamin E, but not by vitamin C in enteral diets.

Oxygen-free radicals are produced during sepsis, and may contribute to cell injury and dysfunction. We studied the effect of different levels of vitamins E and C in the diet fed enterally to septic guinea pigs. Sixty-four female guinea pigs were provided with gastrostomies and allowed to recover. Intraperitoneal osmotic pumps were then implanted that provided effusion of Escherichia coli and Staphylococcus aureus for the next 7 days. Three days after pump implantations, the animals were started on one of nine diets. The diets were isocaloric and isonitrogenous, and differed only in the amounts of vitamins E and C. Three levels of each vitamin were used, based on the Recommended Daily Allowance (RDA). The feedings were continued for 2 weeks, during which time mortality was observed. The amount of vitamin C had no effect on outcome, with mortality rates of 68% (15/22) in the 1 x RDA group, 73% (16/22) in the 5 x RDA group, and 65% (13/20) in the 25 x RDA group. However, vitamin E altered outcome significantly, with mortality rates of 86% (18/21) in the 1 x RDA group, 45% (10/22) in the 3 x RDA group, and 76% (16/21) in the 9 x RDA group. Mortality in the 3 x RDA group was significantly lower than that in the 1 x RDA group and in the 9 x RDA group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗