Kevin Sittig

Clinical Evaluation of an Acellular Allograft Dermal Matrix in Full-Thickness Burns

A multicenter clinical study assessed the ability of an acellular allograft dermal matrix to function as a permanent dermal transplant in full-thickness and deep partial-thickness burns. The study consisted of a pilot phase (24 patients) to identify the optimum protocol and a study phase (43 patients) to evaluate graft performance. Each patient had both a test and a mirror-image or contiguous control site. At the test site, the dermal matrix was grafted to the excised wound base and a split-thickness autograft was simultaneously applied over it. The control site was grafted with a split-thickness autograft alone. Fourteen-day take rates of the dermal matrix were statistically equivalent to the control autografts. Histology of the dermal matrix showed fibroblast infiltration, neovascularization, and neoepithelialization without evidence of rejection. Wound assessment over time showed that thin split-thickness autografts plus allograft dermal matrix were equivalent to thicker split-thickness autografts.

Obstructive jaundice promotes bacterial translocation from the gut

Experiments were performed to determine if obstructive jaundice promotes the translocation of bacteria from the gastrointestinal tract to visceral organs. Three groups of mice were studied: control (n = 20), sham ligated (n = 28), and bile duct ligated (n = 33). The sham-ligated group underwent laparotomy and manipulation of the portal region, whereas the ligated group had their common bile ducts ligated. Seven days later, the mice were killed, their organs cultured, and the gastrointestinal tract examined histologically. The bilirubin levels of the ligated group (18.7 mg/dL) were elevated compared with the other groups (0.5 mg/dL) (p less than 0.05). The incidence of bacterial translocation was higher in the ligated (33%) than in the control (5%) or sham-ligated (7%) groups (p less than 0.05). Since bile is important in binding endotoxin and maintaining a normal intestinal microflora, cecal bacterial populations were quantitated. The cecal levels of gram-negative, enteric bacilli were 100-fold higher in the bile duct-ligated mice in which bacterial translocation occurred (p less than 0.05), indicating that intestinal bacterial overgrowth was a major factor responsible for bacterial translocation. The mucosal appearance of the intestines from the control and sham-ligated groups was normal. In contrast, subepithelial edema involving the ileal villi was present in the ligated group. In conclusion, the absence of bile within the gastrointestinal tract allows intestinal overgrowth with enteric bacilli and the combination of bacterial overgrowth and mucosal injury appears to promote bacterial translocation.

A serial study of the erythropoietic response to thermal injury.

OBJECTIVE Since controversy exists over whether erythropoietin levels are increased or decreased after thermal injury, a prospective study was performed to answer this question as well as to characterize the erythropoietic response to thermal injury. SUMMARY BACKGROUND DATA The concept of using erythropoietin to reduce the need for blood transfusions after thermal injury is attractive. However, since the etiology of burn anemia is both unclear and multifocal, prior to initiating a trial of erythropoietin therapy, it will be necessary to better define the erythropoietic response to thermal injury. METHODS Twenty-four burn patients with a mean burn size of 31 +/- 18% had serial measurements of serum iron, total iron binding capacity (TIBC), ferritin, erythropoietin, transferrin saturation, hemoglobin, and reticulocyte counts performed on burn days 1, 3, 5, 7, 10, 14, and then weekly. RESULTS The erythropoietic response was characterized by a decrease in hemoglobin levels as well as serum iron, TIBC, and transferrin saturation (p < 0.05). Ferritin and erythropoietin levels increased as did the reticulocyte count. The erythropoietin response to anemia appeared to be at least grossly intact, since there was an appropriate inverse relationship between the degree of anemia and the magnitude of the erythropoietin response (r2 = .61, p < 0.00001). CONCLUSIONS Since the erythropoietin levels of these anemic burn victims reached supranormal levels and they manifested a moderate reticulocytosis, the role of replacement erythropoietin therapy after thermal injury requires further study.

Blood transfusions: for the thermally injured or for the doctor?

BACKGROUND Because of the inherent risks of blood transfusions, including the transmission of viral and other infectious diseases, it is important to re-evaluate blood transfusion policies. METHODS The present study compared the results of a new selective transfusion policy in which patients were not transfused unless their hemoglobin levels went below 6-6.5 g/dL versus our previous routine transfusion policy in which the hemoglobin levels were routinely maintained at 10 g/dL. The selectively transfused group consisted of 14 patients with a mean +/- SD burn size of 28% +/- 11%, while the routinely transfused group consisted of 38 clinically comparable patients with a mean burn size of 26% +/- 12%. RESULTS The patients managed by selective transfusion received fewer transfusions (2.1 +/- 1.7 units) during their hospital stay than patients transfused routinely (7.4 +/- 7.6 units) (p < 0.007) and were less likely to receive maintenance transfusions (4 of 29 total units versus 116 of 282 total units) (p < 0.004). No adverse hemodynamic or other adverse effects related to limiting blood transfusions in the selectively transfused group was noted. CONCLUSION Routinely transfused patients, on average, received over 5 units more blood than the selective group without any apparent clinical benefit. Thus, the results of this pilot study support a policy of selective blood transfusions in burn patients.

Recent Advances in the Management of Gallstones

Demands for less invasive, more cost-effective therapy have revolutionized the management of gallstones over the past 10 years. There are no reliable methods of permanently reversing the pathophysiologic defects that cause gallstones. Open cholecystectomy (OC), the gold standard for managing symptomatic cholelithiasis, has been largely replaced by laparoscopic cholecystectomy (LC), which has the advantages of a minimal hospital stay and quicker return to work. Other adjunctive therapies, limited in applicability to selected patients, include oral bile acid therapy (BAT), dissolutional agents, and extracorporeal shock wave lithotripsy. Choledocholithiasis (CDL), formerly managed exclusively with surgical common duct exploration, is increasingly treated with therapeutic biliary endoscopy. Methods of laparoscopic common bile duct exploration are being developed. Optimal algorithms for applying these techniques to patients undergoing LC are evolving. In a sense, the solution to all, or certainly most, gallstones now can be seen through a scope.

Results of a Multicenter Outpatient Burn Study on the Safety and Efficacy of Dimac-ssd, a New Delivery System for Silver Sulfadiazine

Dimac with silver sulfadiazine (Dimac-SSD), a new silver sulfadiazine delivery system, was evaluated prospectively in a multicenter study for the treatment of outpatient burn injuries. The goal of this study was to evaluate the effect of Dimac-SSD on the microbiology of the burn wounds and to quantitate its clinical safety and efficacy. A total of 197 patients were evaluated. Eight (4%) of these patients did not complete the study. Six patients withdrew because of local discomfort caused by the Dimac-SSD and two patients were terminated because of technical problems. The mean +/- SD duration of treatment with Dimac-SSD was 12 +/- 8.5 days, during which time the mean number of dressing changes was 2.9 per patient. During treatment with Dimac-SSD, the burn wound bacterial flora remained stable and overgrowth with Pseudomonas species or Gram-negative bacilli did not occur. Only four (2%) patients developed clinical infections; thus the Dimac-SSD appeared to have good antimicrobial effectiveness. This dressing was not associated with any organ system or metabolic side-effects and patient discomfort during application and removal was minimal. Thus this new delivery system for silver sulfadiazine was associated with excellent wound healing, a low incidence of wound infections, reduced frequency for dressing changes, and excellent patient compliance.

Suspected biliary complications after laparoscopic and open cholecystectomy leading to endoscopic cholangiography : a retrospective comparison

To study how suspected postoperative biliarycomplications are influenced by surgical technique, wecompared clinical profiles of 63 patients referred forERCP after open (OC) and laparoscopic cholecystectomy (LC) over a four-year period. ERCP was notperformed for postoperative pain alone and only six(9.5%) studies were normal. Referrals after LC wereyounger (mean 39.1 vs 53.6 years, P < 0.001) and ERCP was requested earlier (mean 71.6 vs 2360 days,P < 0.001) in the postoperative course.Choledocholithiasis (CDL) alone, the most commonfinding, was successfully managed with a single ERCP in97.2% of cases. CDL after LC occurred in youngerpatients (35.5 vs 58.9 years, P < 0.01) who presentedearlier (mean 98.6 days vs 5.1 years, P < 0.01),without biliary ductal dilatation (P < 0.01).Although CDL after LC was associated with higher ALT andbilirubin levels than after OC, the difference was notstatistically significant. Cystic duct leaks (LC: sixpatients, OC: four patients) were typically associated with CDL after OC and 90% resolved withendoscopic therapy. Biliary ligation (four cases) wasmanaged successfully with choledochojejunostomy. Weconclude that findings at ERCP for suspected biliaryobstruction or injury after OC or LC are similar andusually can be endoscopically managed. After LC,referrals currently are younger, present much earlier,and retained stones are less likely to be associatedwith ductal dilatation than after OC.