Nutrition Therapy in Burn-Injured Patients Robin Saucier, RD, CNSC 28 September 2010 Burn Incidence and Treatment In U.S. annually: • 1,000,000 burns receiving medical treatment • 4,000 fire and burn deaths – 75% occur at scene of incident or during transport • 40,000 admissions to hospital – 25,000 to hospital with specialized burn center • 94.4% survival rate when admitted to a specialized burn center – UCH is only ABA-verified burn center in Colorado Source: American Burn Association National Burn Repository (2005 report) Types of Burns • • • • Fire/flame (42%) Scald (31%) Hot object contact (9%) Electrical (4%) – can continue to burn for up to weeks after initial insult, organ failure without significant skin involvement • Chemical (3%) • Other – radiation, skin disease, or unspecified/unknown etiology (6%) Source: American Burn Association National Burn Repository (2010 report) Other conditions & considerations • Stevens-Johnson syndrome • Necrotizing fasciitis • Inhalation injury Pathophysiology of Burns Severity – %TBSA – Depth of skin injury • Superficial (1st degree) • Partial thickness (2nd degree) • Full-thickness (3rd/4th degree) – incl muscle • ≥3rd degree requires grafting Biphasic Metabolic Response • Ebb Phase Decrease in: cardiac output, oxygen • consumption, REE, body temp, tissue perfusion. Flow Phase – Acute response: Increase in: acute-phase proteins, catecholamines, cortisol, glucagon, cytokines, O2 consumption, REE, temp, tissue perfusion. – Adaptive response: Decrease in hypermetabolic rate, potential for restoration of body protein/LBM – can last for 9-12 months post-burn. • Fluid resuscitation: LR (per Parkland formula: • 4ml/kg/%TBSA over first 24h) – can gain 5-13L of fluid Metabolic rate peaks around 7-10 days post-burn. Importance of Nutrition Intervention in Burns Protein-energy malnutrition occurs rapidly in burns and causes: • Impaired wound healing • Muscle wasting • Immunocompetence for months after initial injury • Growth retardation in children Factors in Assessment • • • • • • • • • Severity (%TBSA/depth) Age Sex Ventilatory status Inhalation injury Concomitant injuries Medications/IV drips Co-morbidities/PMH Pre-burn nutritional status Nutrition Assessment: Calories • Use pre-burn or usual weight, if known (fluid resuscitation may alter admit weight; ICU body wts not accurate indicator of body cell mass). • Adjusted body weight is appropriate with obesity (>120% IBW) • Use actual body weight even if below 100% ideal Calculating Energy Requirements • Harris-Benedict equation x 1.5-2.0 • Ireton-Jones equation: EEE(v) = 1784 - 11(A) + 5(W) + 244 (S) + 239 (T) + 804 (B) EEE(s) = 629 - 11 (A) + 25 (W) - 609 (O) EEE=kcal/day: s=spontaneously breathing, v=ventilatordependent; A=age (yrs); W=body weight - (actual dry weight) (kg); S=sex (male=1, female=0); T = trauma, B= burn, O=obesity defined as BMI>27 (if present=1, absent=0). Calculating Energy Requirements • 25-45 kcal/kg • Curreri equation (be careful, often overestimates): 16-59yo: (25 x weight) + (40 x %TBSA) • Carlson equation REE for non-vented pt = BMR (0.89142 + 0.01335 × TBSA) × m² × 24 × activity factor of 1.25 Calculating Energy Requirements: Caveats • Energy surge reaches its peak around 7-10 days • • • post-burn Milner et al found that predictive equations most accurate in first 30 days post-burn Predictive equations may over-estimate with sedation, paralytics (paralytics may decrease EE as much as 30%). Indirect calorimetry most accurate but limitations. Utility of NICO? – NICO KCAL UTILIZATION: • VCO2 X 5.54 X 1440 = KCAL/Day Nutrition Assessment: Protein • Primary goal is healing, closure, LBM sparing: do • not reduce protein to preserve renal function. Significant protein loss via wound exudate despite nutrition support – Estimated 110g/d during first 10 days post-burn • Estimated protein needs (depending on TBSA): – – – – – 20-25% overall calories Superficial: 1.5-2.0 g/kg/d Partial thickness: 2.0-2.5g/kg/d Full thickness 2.5-3.0g/kg/d In some cases up to 4g/kg/d/d Nitrogen Balance • Nitrogen balance = N2 intake – (total UUN + fecal N2 loss + wound loss) – ≤10% TBSA open wound: 0.02g N2/kg/day – 11-30% TBSA open wound: 0.05g N2/kg/day – ≥30% TBSA open wound: 0.12g N2/kg/day Nutrition Assessment: Glutamine • Only if NOT enrolled in Re-ENERGIZE. – Defer to unit RD if unsure or patient may still be enrolled. • Recommended dosage: – 0.5g glutamine/kg/day • Dosage is in 10g increments, given as bolus via FT in water Glutamine Study • Based on the following hypotheses: – Enteral glutamine administration in adult subjects with severe thermal burn injuries decreases: • In-hospital mortality • Morbidity and length of care • The cost of care • Inclusion Criteria – ≥20% TBSA – Deep 2nd and/or 3rd degree burns requiring grafting – Age + TBSA = 60-119 Glutamine Study • Exclusion Criteria – ≥48 hours from admission to ICU to time of consent (if transferred may be enrolled up to 96 hrs post-burn at site investigator’s discretion) – Patients >80 yrs or <18 yrs of age – Liver cirrhosis – Child’s class C liver disease – Pregnancy – Associated multiple fractures or severe head trauma – Absolute contraindication for EN (intestinal occlusion or perforation, abdominal injury) – Patients with injuries from high voltage electrical shock – Patients who are moribund – Patients with BMI <18 or >50 – Enrollment in another industry-sponsored ICU intervention study Glutamine Study • Prescribed energy needs: – Indirect calorimetry • Measured energy expenditure x 1.0-1.3, OR – Ireton-Jones equation, OR – Basal energy expenditure using Harris-Benedict equation – If ≥50% TBSA, use BEE x 1.7-2.0 – If ≤50% TBSA, use BEE x 1.5-1.6 • Energy needs to be adjusted according to progression of wound healing. Glutamine Study • Prescribed Protein Needs – If ≥50% TBSA, use 2.0-3.0g/kg/d – If ≤50% TBSA, use 1.5-2.0(+) g/kg/d • Protein needs to be adjusted according to progression of wound healing & other biochemical markers. • Glutamine not included in protein allocation. Feeding Modalities • If <20% TBSA, can trial high kcal/prot diet • • with po supps, calorie count. 10-20% TBSA may still need enteral nutrition if po suboptimal. If ≥20% TBSA or <90% IBW, EN indicated. Usually started within first 24h of admission. TPN only indicated when EN fails, or in cases of abdominal compartment syndrome, significant pressor usage, etc. Enteral Nutrition • Feeding tubes placed within 4 hours of admission, EN • • • • • • started as soon as placement confirmed Osmolite 1.2/1.5 as standard formula If +inhalation injury, SIRS/sepsis, ALI, ARDS: consider Oxepa (caution with large burns – high fat, vitamin A content) If co-morbid conditions indicate (e.g., neuro trauma), can use Nutren 2.0 for lower carb, fluid content. Pt may become hypernatremic, TF’s may be changed to diluted (1:1, 1:2 with H2O) Prune juice often added as part of bowel regimen, especially with rectal tube. Include kcal given from Prostat in total kcals estimated/received Additional Supplementation • Daily MVI • 500mg Ascorbic Acid BID • 220mg Zinc (if not receiving IV trace • • • elements) – length of tx unknown (10-14 days?) ? 10,000 IU Vitamin A Oxandrolone (anabolic steroid to decrease loss of LBM, promote wound healing, counteract lysis during hypermetabolic state) IV Trace elements (copper, zinc, selenium) for >20% TBSA. Requires central access. – 14d course for 20-60% burn – 21d course for >60% burn Monitoring: Clinical Course • Review: Residuals, abd exam, stool output • • (rectal tube), I/O’s, significant changes in insulin gtt rates Surgical course: OR/grafting, wound healing (% open wound) – closure may not significantly decrease hypermetabolic response. Indirect calorimetry as indicated (appropriate with large burns when pt not responding to current nutrition therapy) Monitoring: Lab Values • Prealbumin & CRP • • • • checked Q Monday Sodium – loop diuretics, wound losses, fluid overload, hypertension Potassium – wound losses, diuretic therapy, renal failure Calcium – wound losses, chronic immobility Phosphorus – immobility, renal failure Adjusting Needs • Needs max around 7-10 days post-burn • May consider adjusting needs weekly until burns • • covered Predictive equations may not be reliable after 30 days post-burn Adjust needs for % open area: – Decreases needs: grafting, re-epithelialization – Increases needs: wound infection, graft loss, donor sites Long-term Follow-up • Cycling TF’s: Allow for improved appetite as po increases – 50-100% TF volume often delivered over 1216h if pt can tolerate volume until po >50% est needs. • Calorie count • High calorie/high protein diet • Oral supplementation Why we do it References • Gottschlich MM, Mayes T. Burns. In: Merritt R ed. The Aspen Nutr Support Practice Manual. 2nd ed. 2005:296-300. Silver Spring, MD: ASPEN. • Chan MM, Chan MM. Nutritional therapy for burns in children and adults. • • • • • Nutrition, March 2009 25(3): 261-9. Carlson DE et al. Resting energy expenditure in patients with thermal injuries. Surg Gynecol Obstet. 174(4):270-6. Milner EA et al. A longitudinal study of resting energy expenditure in thermally injured patients. J Trauma. 37(2):167-70. Cresci G, Gottschlich MM, Mayes T, Mueller C. Trauma, Surgery, and Burns. In: Gottschlich MM ed. Nutr Support Core Curriculum: A Case-Based Approach – the Adult Patient. 2007:455-476. Silver Spring, MD: ASPEN. Berger MM. Antioxidant micronutrients in major trauma and burns: evidence and practice. Nutr Clin Practice. 2006;21(5):438-446. Berger MM et al. Reduction of nosocomial pneumonia after major burns by trace element supplementation: aggregation of two randomised trials. Crit Care. 2006; 10:R153.