Lit Review: New Evidence for Burn Resuscitation and Prognosis

These medical articles examine contemporary strategies for improving the clinical management and prognosis of severe burn injuries. Research into nutritional interventions reveals that supplemental enteral glutamine does not significantly reduce mortality or shorten hospital stays despite its common use. Fluid resuscitation studies highlight the ongoing debate between using crystalloids alone versus adding albumin, suggesting that while albumin may improve fluid balance, its impact on survival requires further randomized controlled testing. Beyond treatment protocols, the sources emphasize the importance of patient-specific risk factors, such as using the Modified Frailty Index to predict death more accurately than traditional age-based metrics. Finally, the evaluation of bronchoscopic scoring systems indicates that the Inhalation Injury Severity Score serves as a vital independent predictor of survival for patients with smoke-induced lung damage. Together, these findings aim to refine resuscitation standards and enhance the accuracy of prognostic tools in burn centers.   A Randomized Trial of Enteral Glutamine for Treatment of Burn Injuries. Heyland DK, Wibbenmeyer L, Pollack J, et al. N Engl J Med. 2022 Sep 15;387(11):1001-1010. Burn Resuscitation Practices in North America: Results of the Acute Burn ResUscitation Multicenter Prospective Trial (ABRUPT). Greenhalgh DG, Cartotto R, Taylor SL, et al. Ann Surg. 2023 Mar 1; 277(3):512-519. Modified Frailty Index is an Independent Predictor of Death in the Burn Population: A Secondary Analysis of the Transfusion Requirement in Burn Care Evaluation (TRIBE) Study. Sen S, Romanowski KS, Andre JA, Greenhalgh DG, Palmieri TL. J Burn Care Res. 2023 Mar 2;44(2):257-261. Inhalation Injury Severity Score on Admission Predicts Overall Survival in Burn Patients. Flinn AN, Bohan PM, Rauschendorfer C, Le TD, Rizzo JA. J Burn Care Res. 2023 Nov 2;44(6):1273-1277.   The Critical Edge is for educational and informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease, nor does it substitute for professional medical advice, diagnosis, or treatment from a qualified healthcare provider—always seek in-person evaluation and care from your physician or trauma team for any health concerns.   Comprehensive Study Guide: Critical Advances in Burn Resuscitation and Clinical Prognostication This study guide synthesizes key research findings regarding nutrition, resuscitation fluid choices, frailty assessment, and inhalation injury scoring in the management of severe burn injuries. I. Enteral Glutamine Supplementation: The RE-ENERGIZE Trial The RE-ENERGIZE trial addressed the clinical uncertainty regarding the benefits of glutamine supplementation for patients with severe burns, who experience significant inflammation and metabolic stress. Study Overview Purpose: To determine if enterally delivered glutamine reduces the time to discharge alive from the hospital or impacts mortality. Design: A multicenter, double-blind, randomized, placebo-controlled trial conducted across 54 burn centers in 14 countries. Participants: 1,200 patients with deep second- or third-degree burns (typically ≥10% to ≥20% Total Body Surface Area [TBSA] depending on age). Intervention: 0.5 g per kilogram of body weight per day of enteral glutamine versus a non-isonitrogenous placebo, administered every four hours via feeding tube or mouth. Duration: Treatment continued until seven days after the last skin grafting procedure, discharge from the acute care unit, or three months post-admission. Key Results Primary Outcome (Time to Discharge Alive): There was no significant difference between groups. The median time to discharge was 40 days for the glutamine group and 38 days for the placebo group. Mortality: Six-month mortality rates were similar, at 17.2% in the glutamine group and 16.2% in the placebo group. Tertiary Outcomes: No significant differences were found in in-hospital mortality, gram-negative bacteremia, or length of stay. Safety: While glutamine was associated with small increases in urea levels, it did not increase the incidence of acute kidney injury (AKI) or the need for renal replacement therapy. Serious adverse events were similar across both groups. Conclusion Supplemental enteral glutamine does not decrease mortality or reduce the time to discharge alive for patients sustaining severe burn injuries. II. Burn Resuscitation Practices: The ABRUPT Studies The Acute Burn ResUscitation Multicenter Prospective Trial (ABRUPT) examined the historical controversy regarding whether to use crystalloids alone or adjunctive colloids (specifically albumin) during the first 48 hours of burn shock. ABRUPT (Observational Study) Objective: To characterize current resuscitation practices in North America to design future randomized trials. Findings: Two-thirds of patients (253 of 379) were resuscitated with a combination of albumin and crystalloids; one-third (126) received crystalloids alone. The Albumin Group typically included older patients with larger, deeper burns, higher admission Sequential Organ Failure Assessment (SOFA) scores, and more frequent inhalation injuries. Albumin was generally initiated when crystalloid rates exceeded expected targets (often within the first 12 hours for the most severe injuries). The use of albumin was associated with an improvement in the in-to-out (I/O) ratio (the ratio of fluid intake to urine output). Resuscitation volumes in the first 24 hours generally met or exceeded the Parkland Formula estimate of 4 mL/kg/% TBSA. ABRUPT2 (Ongoing Randomized Trial) Following the observational phase, ABRUPT2 was launched as a multicenter randomized controlled trial. Hypothesis: Adjunctive albumin infusion initiated within 12 hours of injury will reduce fluid requirements and improve outcomes compared to Lactated Ringer’s (LR) alone. Target Population: Adults with ≥25% TBSA burns and a full-thickness component ≥20%. Primary Outcome: Total volume of fluid (mL/kg/% TBSA) at 24 and 48 hours. III. Prognostication via Frailty: The TRIBE Study Analysis While age and burn size are traditional predictors of mortality, recent research suggests that a patient's physiological reserve, or frailty, provides a more nuanced prognostic picture. The Modified Frailty Index (MFI) Researchers performed a secondary analysis of the Transfusion Requirement in Burn Care Evaluation (TRIBE) study data to evaluate two scoring systems: MFI-11: An 11-item index assessing functional status, diabetes, respiratory problems, cardiovascular disease, and neurocognitive issues. MFI-5: A condensed 5-item index that correlates strongly with the MFI-11. Clinical Implications Mortality Correlation: Both MFI-5 and MFI-11 were identified as independent predictors of in-hospital death, even after adjusting for age and TBSA. Risk Threshold: An MFI-11 score greater than 1 was independently associated with a nearly threefold increase in the risk of death. Comparison to Other Scores: Unlike the "Baux score" or "modified Baux score," which focus on age and injury size, the MFI accounts for an individual’s pre-injury physiological response and vulnerability. Intervention: There are currently no evidence-based interventions specifically for frail burn patients, but researchers suggest a combination of "pre-habilitation" and aggressive physical therapy may optimize outcomes. IV. Inhalation Injury Assessment and Scoring Inhalation injury significantly increases burn morbidity and mortality by inducing localized and systemic inflammatory responses. Fiberoptic bronchoscopy within 24 hours of admission remains the gold standard for diagnosis. Comparing Scoring Systems A prospective study evaluated 99 intubated patients using three different bronchoscopic grading systems: Abbreviated Injury Score (AIS) Inhalation Injury Severity Score (I-ISS) Bronchoscopic Mucosal Score (MS) Performance and Outcomes Correlation: There is a strong correlation (KA = 0.85) between the three systems in terms of how they grade injury at admission. Predicting Survival: After controlling for % TBSA, Injury Severity Score (ISS), and Glasgow Coma Scale (GCS), the I-ISS was the only scoring system independently associated with overall survival. Morbidity Prediction: Notably, none of the three scoring systems (AIS, I-ISS, or MS) were effective at predicting the development of pneumonia or Acute Respiratory Distress Syndrome (ARDS). Study Recommendations: Researchers suggest that because inhalation injury can progress after the initial assessment, repeated bronchoscopic evaluations may be necessary to identify high-risk patients more accurately. -------------------------------------------------------------------------------- Glossary of Key Terms Abbreviated Injury Score (AIS): A grading system used during bronchoscopy to assess the severity of inhalation injury based on visible mucosal damage. Crystalloids: Aqueous solutions of mineral salts or other water-soluble molecules (e.g., Lactated Ringer's) used as the primary fluid for burn resuscitation. Enteral Nutrition: The delivery of nutrients directly into the gastrointestinal tract, typically via a feeding tube or oral intake. Frailty: A state of decreased physiological reserve and increased vulnerability to stressors, such as severe burn injury. In-to-Out (I/O) Ratio: A clinical metric calculated by dividing the total fluid intake (mL/kg/% TBSA) by the total urine output (mL/kg); a higher ratio suggests fluid is being retained in the tissues rather than being processed by the kidneys. Inhalation Injury Severity Score (I-ISS): A bronchoscopic scoring system found to be an independent predictor of survival in burn patients. Modified Frailty Index (MFI): A tool used to assess frailty based on a patient's medical history and functional status; available in 11-item and 5-item versions. Parkland Formula: A standardized guideline for burn resuscitation that suggests providing 4 mL of fluid per kilogram of body weight per percentage of TBSA burned during the first 24 hours. Sequential Organ Failure Assessment (SOFA): A scoring system used to track a person's status during stay in an intensive care unit to determine the extent of organ function or rate of failure. Total Body Surface Area (TBSA): An assessment of the percentage of the body affected by burns, used to guide treatment and fluid resuscitation.