Biomedical subjects

L D Solem

Publications and source records attributed to L D Solem.

46 records · Page 3Linked to original sources

PubMedDate not supplied

Initial dosage regimens of gentamicin in patients with burns.

For 95 patients with burns the gentamicin dosage regimen necessary to achieve optimal serum concentrations was determined. Individual elimination rates and distribution volumes for gentamicin were determined and correlated with renal function parameters and age. In patients with burns who had normal serum creatinine levels (less than 1.5 mg/dl), gentamicin clearance and thus dosage regimens can be stratified by age. Gentamicin's clearance decreased inversely with age. Initial dosage guidelines were calculated for different age groups of patients with normal levels of serum creatinine. The guidelines were developed to assist the clinician in attaining therapeutic concentrations with initial doses of gentamicin. Therapeutic serum concentrations were reached in most patients with burns dosed by these guidelines. Serum gentamicin concentrations should always be monitored during therapy, and dosages should be adjusted to ensure optimal concentrations during the course of therapy.

Adolescent↗

PubMedDate not supplied

Inaccuracy of nitrogen balance determinations in thermal injury with calculated total urinary nitrogen.

Many burn centers use nitrogen balance studies to estimate the adequacy of nutritional support. Nitrogen loss includes the sum of urinary urea nitrogen, nonurea urinary nitrogen, and losses from skin, wound, and stool. Urinary urea nitrogen is often used to calculate total urinary nitrogen by multiplying the urinary urea nitrogen by a factor of 1.25 to account for nonurea urinary nitrogen. This formula is appropriate when applied to a nonstressed individual who has fasted overnight but is not appropriate for patients who have undergone surgery or experienced trauma. We have undertaken this study to assess the predictability of this formula in patients with thermal injuries. Twenty-seven patients with major thermal injuries had random 24-hour urine collections, which were analyzed for both urinary urea nitrogen and total urinary nitrogen. In these patients with burns we found that urinary urea nitrogen represented approximately 65% of the directly measured total urinary nitrogen rather than 80% as assumed by the formula. This increase in the nonurea nitrogen loss is greater than that found after surgery or trauma. Individual measurements may underestimate losses by 20% to 60%. Directly measured total urinary nitrogen should replace calculated total urinary nitrogen as the index of urine nitrogen losses for nitrogen balance studies in patients with burns.

Burns↗

PubMedDate not supplied

Thermal injury, the inflammatory process, and wound dressing reduce human neutrophil chemotaxis to four attractants.

The purpose of this study was to assess the influence of thermal injury and the inflammatory process on chemotactic responses of neutrophils to four attractants (N-formyl-methionyl-leucyl-phenylalanine, the complement fragment C5a, interleukin-8, and leukotriene B4) under agarose, expression of Mac-1 (CD11b/CD18) adherence receptors on the cell surface, and polymerization of actin in the cell cytoplasm. Circulating neutrophils were isolated from peripheral blood, and exudate neutrophils from fluid collecting under two different wound dressings applied to abrasion sites of healthy subjects and to skin graft donor sites of patients with burns. Burn injury reduced the chemotactic responses of circulating neutrophils to all four attractants, suggesting a "global" defect in chemotactic function. Patient-exudate neutrophils collected under Tegaderm exhibited further decrements in all chemotactic responses, and patient-exudate neutrophils collected under Biobrane were nonmotile. The exudate neutrophils collected under Biobrane expressed high levels of Mac-1 receptors and irreversibly polymerized actin, which may contribute to the nonmotility of these exudate cells.

Actins↗

PubMedDate not supplied

Accelerated healing and reduced need for grafting in pediatric patients with burns treated with arginine-glycine-aspartic acid peptide matrix. RGD Study Group.

Arginine-glycine-aspartic acid (RGD) peptide matrix is designed to promote dermal healing by providing a molecular scaffold that facilitates cell ingrowth and establishment of normal tissue architecture. This study investigated the effectiveness and safety of RGD peptide matrix in the treatment of partial-thickness scald burns in pediatric patients. Either topical RGD peptide matrix or control treatment with silver sulfadiazine was applied to matched burn sites daily for up to 21 days. With RGD peptide matrix application under synthetic occlusive dressing, the incidence of healing was nearly threefold higher, average time to healing 2.5 days shorter (regression estimation), extent burn closure at all treated sites 37% greater, and number of needed grafting procedures fourfold lower compared with control treatment. All these differences were statistically significant. RGD peptide matrix was well tolerated. RGD peptide matrix promoted and accelerated healing in this study and thus may be able to reduce morbidity and treatment costs of partial-thickness burns in pediatric patients.

Administration, Topical↗

PubMedDate not supplied

Pulmonary failure in geriatric patients with burns: the need for a diagnosis-related group modifier.

One hundred eleven patients with burns who were age 60 years or older were treated from January 1984 through December 1992. Twenty-nine patients had pulmonary failure defined as 7 or more days of ventilatory support from the day of burn. The mortality rate for these patients was 41%; only four were discharged to home. The mortality rate for patients without pulmonary failure was 11%. Billing information was analyzed for 102 of the 111 patients. Charges for patients without pulmonary failure were two to three times greater than reimbursement. Charges for patients with pulmonary failure were 4 to 14 times greater than reimbursement. Reimbursement for elderly patients with burns is inadequate. Altering the Diagnosis-Related Group (DRG) definition of extensive burn to reflect the severity of injury in the geriatric population is one step toward reimbursement reform. Patients who require 7 or more days of ventilatory support after burn injury should be reimbursed under a separate DRG category or should have a DRG modifier.

Aged↗

PubMedDate not supplied

A multicenter clinical trial of a biosynthetic skin replacement, Dermagraft-TC, compared with cryopreserved human cadaver skin for temporary coverage of excised burn wounds.

This multicenter study compared the use of a biosynthetic human skin substitute with frozen human cadaver allograft for the temporary closure of excised burn wounds. Dermagraft-TC (Advanced Tissue Sciences, Inc.) (DG-TC) consists of a synthetic material onto which human neonatal fibroblasts are cultured. Burn wounds in 66 patients with a mean age of 36 years and a mean burn size of 44% total body surface area (28% total body surface area full-thickness) were surgically excised. Two comparable sites, each approximately 1% total body surface area in size, were randomized to receive either DG-TC or allograft. Both sites were then treated in the same manner. When clinically indicated (> 5 days after application) both skin replacements were removed, and the wound beds were evaluated and prepared for grafting. DG-TC was equivalent or superior to allograft with regard to autograft take at postautograft day 14. DG-TC was also easier to remove, had no epidermal slough, and resulted in less bleeding than did allograft while maintaining an adequate wound bed. Overall satisfaction was better with DG-TC.

Adult↗

PubMedDate not supplied

A biopsy of the use of the Baxter formula to resuscitate burns or do we do it like Charlie did it?

The Baxter formula is commonly used to calculate fluid requirements. Baxter reported that 12% of patients would require more than 4.3 mL/kg per percentage of total body surface area (%TBSA). We anecdotally observed that we frequently exceeded the predictions of the formula, and we wondered if this was unique to our practice. We studied our last 11 burn-related resuscitations and collected fluid resuscitation data from US burn centers. Twenty-eight centers were queried, and 6 centers shared data. We were therefore able to study the resuscitation data of 50 adult patients. For 29 patients (58%), 4.3 mL/kg/%TBSA was exceeded compared with the 12% reported by Baxter. These findings suggest that in actual practice, fluid volumes administered are larger than the Baxter formula predicts. This survey does not explain why. Possible reasons for the larger fluid volumes are as follows: (1) the sample is not representative; (2) the formula is used improperly; (3) burns have changed and require more fluids; (4) burn care has changed.

Adult↗

PubMedDate not supplied

Paraquat poisoning in a burn patient.

Paraquat is a bipyridyl compound widely used as a contact herbicide. Since its introduction in 1962, hundreds of deaths have occurred, usually after suicidal or accidental ingestion. Death after dermal absorption of paraquat is uncommon, but has occurred after either contact with undiluted paraquat, disruption of skin integrity, or prolonged exposure. It is the purpose of this case report to describe a patient who had fatal dermal paraquat absorption after a crop-dusting accident in which he sustained 37% TBSA burns. After 9.5 hours of cutaneous exposure, a paraquat level of 0.169 mg/ml was obtained at 20 hours, the standard lethal dose at 16 hours being 0.16 mg/ml. In light of the apparently irreversible pathophysiology of paraquat poisoning with plasma levels as low as 3 mg/L, prevention and early intervention are the best treatments. Our patient may have survived an otherwise routine thermal injury had his wounds been aggressively irrigated in the field.

Accidents, Occupational↗

PubMedDate not supplied

Gasoline burns: the preventable cause of thermal injury.

Gasoline related burns are a significant cause of thermal injuries each year in the United States. In this retrospective review of 1858 admissions to our Regional Burn Center from 1979 to 1988, 270 (14.5%) were persons with gasoline-related injuries. Natural gas and other distillates were excluded. Most victims were male (228 of 270); mean age was 27 years; mean burn size was 25% total body surface area. There were 299 skin grafts performed on 172 patients, and there were 16 deaths. The mean length of stay decreased from 38 to 17 days (p less than 0.001) between the first and second 5-year time periods, even though there was no significant change in age or mean burn size. The majority (59%) of gasoline-related burns were the result of inappropriate or unsupervised use of gasoline. The general public is largely unaware of the dangers of gasoline, and further education in this area is needed.

Adolescent↗

PubMedDate not supplied

Mechanisms of loss of human neutrophil chemotaxis following thermal injury.

The increased susceptibility to infection of patients with thermal injury is related to loss of host defense, which is reflected, in part, by the temporal loss of chemotactic function of leukocytic phagocytes. Our studies of patient neutrophils to define the mechanism of this phenomenon involved evaluation of both random and chemotactic migratory functions of patient neutrophils, measurement of receptors for chemotactic ligands, and measurement of receptors mediating substrate adherence of the cells. Measurements of migratory functions were made using the under-agarose technique and measurements of receptor expression were accomplished by flow cytometry using fluorescein-labeled ligand or receptor-specific antibody. We conclude that loss of chemotaxis in response to C5a/C5adesArg is the results of down-regulation of receptors for C5a and of reduced motility, and that loss of chemotaxis in response to the tripeptide FMLP is the result of reduced motility alone. Measurements of changes in the expression of "adherence" (iC3b) receptors revealed that up-regulation occurs early and can be sustained for weeks after injury. These results are taken to suggest that either hyper- or hypo-adherence could explain the loss of random migratory function observed for patient cells. Evidence of auto-oxidative alteration of cytoskeletal elements, to produce loss of random migratory function, also is reviewed. Considering the evidence for activation of the complement cascade after thermal injury C5a and C5adesArg are likely primary factors in effecting the down-regulation of C5a receptors, stimulation of secretion to mobilize iC3b receptors, and stimulation of respiration to auto-oxidize cell components. Such evidence of injury-mediated complement activation included data derived from application of a novel immunoassay for iC3b.

Burns↗