What's new in general surgery: burns and metabolism

Immunonutrition as an adjuvant therapy for burns

BACKGROUND

With burn injuries involving a large total body surface area (TBSA), the body can enter a state of breakdown, resulting in a condition similar to that seen with severe lack of proper nutrition. In addition, destruction of the effective skin barrier leads to loss of normal body temperature regulation and increased risk of infection and fluid loss. Nutritional support is common in the management of severe burn injury, and the approach of altering immune system activity with specific nutrients is termed immunonutrition. Three potential targets have been identified for immunonutrition: mucosal barrier function, cellular defence and local or systemic inflammation. The nutrients most often used for immunonutrition are glutamine, arginine, branched-chain amino acids (BCAAs), omega-3 (n-3) fatty acids and nucleotides.

OBJECTIVES

To assess the effects of a diet with added immunonutrients (glutamine, arginine, BCAAs, n-3 fatty acids (fish oil), combined immunonutrients or precursors to known immunonutrients) versus an isonitrogenous diet (a diet wherein the overall protein content is held constant, but individual constituents may be changed) on clinical outcomes in patients with severe burn injury.

SEARCH METHODS

The search was run on 12 August 2012. We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library, MEDLINE (OvidSP), Embase (OvidSP), ISI WOS SCI-EXPANDED & CPCI-S and four other databases. We handsearched relevant journals and conference proceedings, screened reference lists and contacted pharmaceutical companies. We updated this search in October 2014, but the results of this updated search have not yet been incorporated.

SELECTION CRITERIA

Randomised controlled trials comparing the addition of immunonutrients to a standard nutritional regimen versus an isonitrogenated diet or another immunonutrient agent.

DATA COLLECTION AND ANALYSIS

Two review authors were responsible for handsearching, reviewing electronic search results and identifying potentially eligible studies. Three review authors retrieved and reviewed independently full reports of these studies for inclusion. They resolved differences by discussion. Two review authors independently extracted and entered data from the included studies. A third review author checked these data. Two review authors independently assessed the risk of bias of each included study and resolved disagreements through discussion or consultation with the third and fourth review authors. Outcome measures of interest were mortality, hospital length of stay, rate of burn wound infection and rate of non-wound infection (bacteraemia, pneumonia and urinary tract infection).

MAIN RESULTS

We identified 16 trials involving 678 people that met the inclusion criteria. A total of 16 trials contributed data to the analysis. Of note, most studies failed to report on randomisation methods and intention-to-treat principles; therefore study results should be interpreted with caution. Glutamine was the most common immunonutrient and was given in seven of the 16 included studies. Use of glutamine compared with an isonitrogenous control led to a reduction in length of hospital stay (mean stay -5.65 days, 95% confidence interval (CI) -8.09 to -3.22) and reduced mortality (pooled risk ratio (RR) 0.25, 95% CI 0.08 to 0.78). However, because of the small sample size, it is likely that these results reflect a false-positive effect. No study findings suggest that glutamine has an effect on burn wound infection or on non-wound infection. All other agents investigated showed no evidence of an effect on mortality, length of stay or burn wound infection or non-wound infection rates.

AUTHORS' CONCLUSIONS

Although we found evidence of an effect of glutamine on mortality reduction, this finding should be taken with care. The number of study participants analysed in this systematic review was not sufficient to permit conclusions that recommend or refute the use of glutamine. Glutamine may be effective in reducing mortality, but larger studies are needed to determine the overall effects of glutamine and other immunonutrition agents.

The Wittmann Patch s a temporary abdominal closure device after decompressive celiotomy for abdominal compartment syndrome following burn

BACKGROUND

Abdominal compartment syndrome is frequently the result of aggressive fluid resuscitation after burn. Management of the open abdomen following decompressive celiotomy is a major problem.

METHODS

From 2004 to mid-2005, six patients required decompressive celiotomy after developing abdominal compartment syndrome as a result of burn. A Wittmann Patch as used to close the abdominal wound. Patients were re-explored when clinical parameters improved and the abdomen was closed, with long-term follow-up for the abdominal wound.

RESULTS

Of the six patients, five had thermal injury and one had electrical injury. The mean total body surface area affected for thermal burn was 78% and for electrical burn was 37%. Diagnosis of abdominal compartment syndrome was based on elevated bladder pressure and organ dysfunction. The patients were treated with decompressive celiotomy and Wittmann Patch closure. Survivors subsequently underwent primary abdominal closure, with no evidence of ventral hernia at long-term follow-up.

CONCLUSION

In burn cases with abdominal compartment syndrome, a Wittmann Patch ay prove a helpful method of temporary abdominal closure, followed by primary closure with no complications.

Clinical experience with Alloderm: A one-staged composite dermal/epidermal replacement utilizing processed cadaver dermis and thin autografts

Alloderm has been advocated for the management of acute burns. However, few studies have demonstrated the feasibility of this technique.

METHODS

We reviewed the medical records of all patients treated in our burn center who received Alloderm since 1999.

RESULTS

Alloderm was used in 21 burn patients and 6 patients with traumatic skin loss. The average size of Alloderm used in the burn patients was 517+/-144 cm(2) (range 24-3000 cm(2)). The average Alloderm thickness used was 0.008 in. and autografts were harvested at an average of 0.007 in. Overall, Alloderm was used in a variety of locations including the face in 3 patients (2 burns, 1 traumatic skin loss) and hands in 7 patients (6 burns, 1 traumatic skin loss). Successful take was observed in 26/27 patients.

CONCLUSIONS

Alloderm can be used successfully in patients with acute burns requiring grafting.

Hospital Volume Outcome and Discharge Disposition of Burn Patients

BACKGROUND

The purpose of this investigation was to determine the impact of hospital clinical volume on patient outcomes (i.e., in-hospital mortality, length of stay) and discharge disposition of burn patients using a large nationally representative database.

METHODS

Patient data were obtained from the 1999-2001 National Inpatient Sample using burn diagnosis-related group codes 504 through 511. Hospitals were segregated into high-volume hospitals (treating more than 100 patients per year), medium-volume hospitals (treating 20 to 99 patients per year), and low-volume hospitals (treating fewer than 20 patients per year). Mortality, length of stay, and discharge disposition were catalogued for each diagnosis-related group code and hospital type.

RESULTS

In diagnosis-related group pair 504/505 (most severe), the mortality rate in patients admitted to high-volume hospitals (33.5 percent) was significantly higher than in patients admitted to both medium-volume hospitals (28.8 percent) and low-volume hospitals (11.5 percent) (p = 0.002). Within lower severity diagnosis-related groups, where the mortality rate was lower across all admissions, medium-volume hospitals and high-volume hospitals had a higher proportion of routine discharges to home, a lower need for home care, and a lower proportion of transfers compared with low-volume hospitals. Despite shorter length of stay, across most burn diagnosis-related groups, patients admitted to low-volume hospitals had lower rates of routine discharges and a higher proportion of admissions "with complications."

CONCLUSION

Higher-volume facilities, despite receiving the most severe burn patients, may provide better patient outcomes than lower-volume facilities. The patterns of discharges found at lower-volume facilities may result in higher diagnosis-related group reimbursement "capture" by lower-volume facilities and higher postdischarge resource use.

Defining the Ratio of Outcomes to Resources for Triage of Burn Patients in Mass Casualties

Management of a mass casualty involving burn patients that overwhelms local resources will likely require a triage process in which limited resources are devoted to the patients with the highest likelihood of survival. No objective criteria exist which define how patients could be categorized in such a situation. A table that classifies patients according to their anticipated survival from burn injury, and the resources required to achieve that survival, is presented here. The limitations and restrictions of applying such a guideline are discussed in detail.