Reuven Gurfinkel

Ketamine improves survival in burn injury followed by sepsis in rats

Ketamine was reported to decrease cytokine production and improve survival after Escherichia coli-induced sepsis. We examined whether ketamine decreased interleukin (IL)-6 production and improved survival after 1) burn injury or 2) burn injury combined with sepsis (E. coli) at 24 h. Ketamine (10 mg/kg) or saline was given at 1 h after burn injury (G 1, 2, 5, 6), 24 h after burn injury (G 3, 4), or at E. coli inoculation (G 7, 8). Mortality was recorded for 7 days and IL-6 was measured in serum at 6 h after burn (G 1–2), 30 h after burn (G 3–4), or 6 h after sepsis (30 h after burn) (G 5–8). Burn injury only: Ketamine given immediately (1 h) after burn injury but not 24 h after, decreased the burn-induced increase of IL-6 but did not improve survival. Burn injury + sepsis: Ketamine given immediately after burn injury did not significantly decrease the sepsis-induced increase of IL-6 or improve survival. In contrast, ketamine given immediately after sepsis significantly improved survival (46.1% versus 13.3%, P = 0.008) and decreased IL-6 production (72,640 ± 40,990 vs 332,300 ± 32,300 pg/mL, P = 0.008). We conclude that ketamine therapy improves survival in burn injury followed by sepsis. This beneficial effect is probably achieved through interference with the inflammatory cascade, as evidenced by attenuation of the proinflammatory marker IL-6.

Histological assessment of tangentially excised burn eschars

BACKGROUND The burn eschar serves as a medium for bacterial growth and a source of local and systemic infection. To prevent or minimize these complications, it is important to debride the eschar as early as possible. OBJECTIVE To identify the presence of viable skin within the excisions by examining tangentially excised burn eschars. METHODS A total of 146 samples of burned human tissue were removed during 54 routine sharp tangential excision procedures (using dermatomes). The samples were histologically examined to identify the relative thickness of the dead, intermediate and viable layers. RESULTS The mean (± SD) thickness of the excised samples was 1.7±1.1 mm. The sacrificed viable tissue (mean thickness 0.7±0.8 mm) occupied 41.2% of the entire thickness of the excision. In 32 biopsies (21.8%; 95% CI 16.0 to 29.3), the excision did not reach viable skin. Only eight biopsies (5.4%; 95% CI 2.8 to 10.1) contained all of the necrotic tissue without removing viable tissue. CONCLUSIONS The thickness of a single tangentially excised layer of eschar is not much greater than the actual thickness of the entire skin and often contains viable tissue. Because surgical debridement is insufficiently selective, more selective means of debriding burn eschars should be explored.

Development of a Novel Animal Burn Model Using Radiant Heat in Rats and Swine

OBJECTIVES The objective was to develop a novel animal model of burns in rats and pigs. METHODS The model uses heat that is delivered via a radiant heater with an opening of 5 cm by 5 cm, set at 400 degrees C, for 20 seconds. An advantage of this model is that the heating source does not come into direct contact with the animal, and the heat dispersion surrounding its center is very constant. The device was evaluated in 40 rats and seven pigs. With rats, three to four burns were created on each rat, resulting in a burn covering a total body surface area of 30% to 50%. In pigs, 16 burns were created on each animal. RESULTS In rats, infliction of burns resulted in mortality rates of 0%-50% depending on the size of the burns and the rats. In pigs, the burns reepithelialized within approximately 3 weeks and resulted in hourglass contracted scars in two of three burns within 1 month. CONCLUSIONS The authors describe a novel animal burn model that utilizes radiant heat to create consistent burns that maximizes safety to the investigators and animals.

Pediatric Burns in the Bedouin Population in Southern Israel

Burn trauma is an important public health concern, with increased risk for burns in children. A cross-sectional study was performed to describe the epidemiological characteristics and risk factors for burns in hospitalized Bedouin children in Soroka University Medical Center during the years 2001–2002. In a population of 558 hospitalized burn-injured patients, 282 Bedouin children were identified. Two hundred and sixty five patients (94.0%) had burns involving less than 20% of the body surface area. Cause of the burns was scald in 190 patients (67.4%), fire in 80 patients (28.4%), chemical in 8 patients (2.8%), and explosion in 2 patients (0.7%). Two female patients (0.7%) aged 11 and 17 years died of their burns that were caused by fire. The mean length of hospitalization was 9.8 days. Pediatric burn injury has become a significant public health problem in the Bedouin population of the Negev. To reduce the burden of burn injury, it is necessary to increase current efforts in prevention of burns.

Comparison of purified olive oil and silver sulfadiazine in the treatment of partial thickness porcine burns

INTRODUCTION Burns are widespread in the developed world, and expensive burn dressings are not universally available. Most burn patients suffer from a partial thickness burn that can be treated conservatively. Nevertheless, the ideal dressing for the burn wound has not been identified. We performed an animal experiment to compare the healing of partial thickness burns treated with silver sulfadiazine (SSD) and olive oil. METHODS A randomized controlled animal experiment was conducted on 3 anesthetized domestic pigs in which 51 partial thickness burns were created using a metal bar heated to 400°C and applied to the dorsum of the animals for 20 seconds. The burns were treated every other day with SSD cream (n = 16), purified olive oil (n = 20), or no topical therapy at all (n = 15). Assessment of wound healing was done by drawing and scanning the margins of the wound at the endpoint of the experiment. The remaining open wound area was then calculated using Scion Image version beta 4.0.2 (Scion, Frederick, Md), and the results were analyzed using a 1-way ANOVA test. RESULTS Burns treated with SSD healed faster than control burns (P < .05). There were no differences in the healing rates of wounds treated with olive oil versus controls or SSD. There were no wound infections in any of the 3 study groups. CONCLUSIONS Treatment of partial thickness burns with purified olive oil did not result in faster healing when compared with SSD or dry gauze in a porcine model.

Combined ultrasonic and enzymatic debridement of necrotic eschars in an animal model.

Several methods are used to debride burn eschars, however, most are ineffective for ischemic eschars. We investigated a novel combination of enzymatic and ultrasonic debridement for ischemic eschars. A previously described ischemic flap model in rats was used to compare the time to flap debridement or perforation of enzymatic (Debrase™, a derivative of bromelain), ultrasonic, or combined debridement (Hybrid Debridement Technology). We also evaluated the effects of ultrasonic intensity, probe size, probe housing, and operation mode (pulsatile vs. continuous) on the time to full eschar perforation. Ultrasonic and enzymatic debridement alone did not result in flap perforation even after 15 minutes. Combined ultrasonic and enzymatic debridement resulted in flap perforation within 2 to 5 minutes in the four flap zones (P < 0.001 for all four flap zones compared with ultrasound alone). The most rapid debridement was observed with an ultrasonic intensity of 3.2 W/cm2, applied using a 4.9 cm2 probe. The temperature elevation associated with ultrasonication was controlled by perfusion of fresh Debrase™ solution and alternating the ultrasound energy. Combination of ultrasonic and enzymatic debridement of ischemic flap eschars in rats with Debrase™ is more rapid and effective than either method alone.

Idiopathic distal radioulnar synostosis

Abstract Radioulnar synostosis is rare, and exists in two forms: congenital and post-traumatic. The congenital form presents only in the proximal forearm, and the post-traumatic form may present anywhere along the radius and ulna. The only known aetiology for distal radioulnar synostosis is post-traumatic. We present a rare case of distal radioulnar synostosis with no previous history of trauma.