Comparison of Measured Resting Energy Expenditure Versus Predictive Equations in Pediatric Burn Patients

A methodological and clinical approach to measured energy expenditure in the critically ill pediatric patient

The metabolic response to injury and stress is characterized initially by a decreased energy expenditure (Ebb phase) followed by an increased metabolic expenditure (Flow phase). Indirect calorimetry is a methodology utilized to measure energy expenditure and substrate utilization by measuring gas exchange in exhaled air and urinary nitrogen. The use of indirect calorimetry in critically ill patients requires precise equipment to obtain accurate measurements. The most recent guidelines suggested that measured energy expenditure by indirect calorimetry be used to determine energy requirements. This article reviews the methodological and clinical use of indirect calorimetry in critically ill pediatric patients.

Interrupted Nutrition Support in Patients With Burn Injuries: A Single-Centre Observational Study

Background

Enteral nutrition (EN) is essential to meet the increased metabolic requirements of burn-injured patients. However, feeds are often suspended for care. This study examines the interruptions in EN (IEN).

Objective

To determine the frequency and duration of IEN and whether these interruptions are predictable or unpredictable.

Design

This retrospective chart review of 27 adult burn patients examined age, sex, body mass index, percentage of total body surface area, length of hospital stay, predicted energy requirements from equations and indirect calorimetry, EN start time, time EN reached goal rate, and interruptions to EN.

Results

Predictable interruptions accounted for 74.5% (frequency) and 81.6% (duration) of total interruptions. The most frequent and time-consuming interruptions were perioperative period, extubation, and tests/procedures (predictable) versus high gastric residual volume, emesis/nausea, and feeding tube displacement (unpredictable).

Conclusions

Most IEN were due to predictable events. Based on these findings, compensating for predictable interruptions to meet nutritional requirements in burn patients is recommended.

Establishment and assessment of new formulas for energy consumption estimation in adult burn patients

OBJECTIVE

An accurate knowledge of energy consumption in burn patients is a prerequisite for rational nutrition therapy. This study sought to create a formula that accounts for the metabolic characteristics of adult burn patients to accurately estimate energy consumption of patients with different areas and extents of burn and at different times after injury.

METHODS

Resting energy expenditure (REE) data on 66 burn patients, with total body surface area (TBSA) of burns ranging from 4% to 96%, were evaluated at different times after injury. REE values were determined in patients using indirect calorimetry at days 1, 2, 3, 7, 14, 21, and 28 after injury. We then constructed a mathematical model of REE changes post-burn. Next, established two new formulas (one non-linear and the other linear) for energy consumption estimation using model-based analytical solution and regression analysis. The new formulas were compared with measured REE and commonly used formulas including those of Carlson, Xie, Curreri, and Milner to determine accuracy and reliability.

RESULTS

Comparative analysis showed that the new formulas offered significantly higher accuracy and reliability than the Milner formula, which is considered the most accurate of commonly used burn energy consumption estimate formulas. The accuracy of the new nonlinear formula (94.29%) and that of the linear formula (91.43%) were significantly higher than that of Milner formula (72.86%) when compared to measured REE (χ2  =  11.706, P  =  0.001; χ2  =  8.230, P  =  0.004, respectively). The reliabilities of the new estimation formulas were both 100% and that of Milner formula was 74.24% (χ2  =  19.513, P  =  0.000).

CONCLUSION

The new formulas constructed in this study provide reliable simulation of the impact of the degree of burn and post-burn days on energy consumption and offer notably higher accuracy and reliability than other formulas. These formulas will help determine nutritional needs of burn patients.

TRIAL REGISTRATION

The study was registered on Chinese Clinical Trial Registry as ChiCTR-TRC-13003806.

Burn management

PURPOSE OF REVIEW

To update critical care practitioners on the recent advancements in burn care.

RECENT FINDINGS

Particular topics discussed include airway management, acute resuscitation, issues within the intensive care unit, nutrition, and wound management.

SUMMARY

This is a concise review of the recent burn literature tailored to the critical care practitioner. Criteria for extubation of burn patients are examined, as is the need for cuffed endotracheal tubes in pediatric burn patients. Strategies to avoid over-resuscitation are discussed, including use of colloid, as well as nurse-driven and computer-guided resuscitation protocols. New data regarding common ICU issues such as insulin therapy, delirium, and preferred intravenous access are reviewed. The importance of nutrition in the burn patient is emphasized, particularly early initiation of enteral nutrition, continuation of nutrition during surgical procedures, and use of adjuncts such as immunonutrition and beta blockade. Finally, both short-term and long-term wound issues are addressed via sections on laser Doppler assessment of burns and pressure garment therapy to prevent long-term scarring.

Nutrition in burns: Galveston contributions

Aggressive nutrition support is recommended following severe burn injury. Initially, such injury results in a prolonged and persistent hypermetabolic response mediated by a 10- to 20-fold elevation in plasma catecholamines, cortisol, and inflammatory mediators. This response leads to twice-normal metabolic rates, whole-body catabolism, muscle wasting, and severe cachexia. Thus, it is relevant to review the literature on nutrition in burns to adjust/update treatment. Failure to meet the increased substrate requirements may result in impaired wound healing, multiorgan dysfunction, increased susceptibility to infection, and death. Therefore, aggressive nutrition support is essential to ensure adequate burn care, attenuate the hypermetabolic response, optimize wound healing, minimize devastating catabolism, and reduce morbidity and mortality. Here, the authors provide nutrition recommendations gained from prospective trials, retrospective analyses, and expert opinions based on the authors' practices in Galveston, Texas, and Vienna, Austria.