High protein intake and nitrogen balance in patients receiving venovenous extracorporeal membrane oxygenation: A descriptive cohort study.

BACKGROUND: This retrospective cohort study sought to describe the ability of high protein regimens to achieve nitrogen equilibrium in patients receiving venovenous extracorporeal membrane oxygenation (VV ECMO). METHODS: Patients aged ≥18 years with a documented nitrogen balance study (NB) on VV ECMO between February 2018 and December 2021 were included. Studies with incomplete 24-h urine collections or changes in blood urea nitrogen ≥10 mg/dl were excluded. Data were summarized, correlation between first NB and potentially contributing variables was assessed with Kendall tau. Subanalysis described findings after stratifying for weight class (obese vs nonobese) and duration of VV ECMO at the time of NB. RESULTS: A total of 68 NBs in 30 patients were included; 47% of the cohort had obesity. The number of NBs per patient was 2.2 ± 1.1, which were completed on a median of 31.5 (interquartile range: 16, 53.8) days receiving ECMO. Nitrogen equilibrium or positive balance was achieved in 72% of studies despite elevated nitrogen excretion. Patients received 87.9 ± 16.8% of prescribed protein on NB days for average intakes of 2.4 ± 0.4 g/kg of actual weight per day and 2.4 ± 0.5 g/kg of ideal weight per day in patients without and with obesity. Median NB in patients without obesity was -1.46 (-8.96, 2.98) g/day and -0.21 (-10.58, 4.04) g/day in patients with obesity. A difference in median NB after stratification for timing was observed (P = 0.029). CONCLUSION: Nitrogen equilibrium can be achieved with high protein intake in adults receiving VV ECMO. NB monitoring is one tool to individualize protein prescriptions throughout the course of VV ECMO.

Measured vs Predicted Energy Expenditure in Mechanically Ventilated Adults With Acute, Traumatic Spinal Cord Injuries.

BACKGROUND: Research regarding the impact of acute spinal cord injury (aSCI) on energy expenditure is limited. Patients with aSCI are prone to complications of both over- and under-feeding, making appropriate nutrition support pivotal to patient care. The purpose of this study was to describe energy expenditure and assess the performance of predictive equations in mechanically ventilated adults with aSCI. METHODS: Adult patients admitted to a single trauma center from March 2017 through June 2018 with aSCI and a documented indirect calorimetry (IC) within 6 weeks of injury were included for analysis. Predictive equations evaluated included Penn State 2003b (PS 2003b), the derived Weir equation, 25 kcal/kg and 30 kcal/kg. Sub-set analysis was performed for patients with and without obesity, isolated aSCI, and concomitant traumatic injuries. RESULTS: On hundres fifteen IC studies in 51 patients were included for analysis. Median energy expenditure was 1747 kcal/day (interquartile range [IQR], 1492-2099 kcal/day), or 22.7 kcal/kg (IQR, 19.3-25.9 kcal/kg). When stratified by hospital day, energy expenditure ranged from 20 to 25 kcal/kg. PS 2003b and the derived Weir equation had similar correlation coefficients (r = 0.81 and 0.82, respectively). The 25 and 30 kcal/kg performed unacceptably (r = 0.61). PS 2003b predicted within 10% of measured energy expenditure most frequently. All equations were biased towards overfeeding, except for PS 2003b in the obese subset. CONCLUSION: In the absence of IC, PS 2003b or the derived Weir equation may be acceptable predictive equations in this population. However, bedside clinicians should monitor carefully for signs and symptoms of overfeeding.

Oxandrolone in Patients on Venovenous Extracorporeal Membrane Oxygenation: A Case Series.

Venovenous extracorporeal membrane oxygenation (VV ECMO) induces a systemic inflammatory response, which may progress to persistent inflammation, immunosuppression, and catabolism syndrome (PICS). The anabolic steroid oxandrolone may improve the metabolic aberrations of PICS. We report our experience with 3 patients on VV ECMO who received oxandrolone after demonstrating refractory catabolism on serial nitrogen balance (NB) studies or persistent weakness. Patients in cases 1 and 3 were started on oxandrolone on VV ECMO days 45 and 29, respectively, for negative NB despite nutrition optimization. The case 2 patient started oxandrolone for persistent weakness 68 days after cannulation. All patients demonstrated improvements in NB results. One patient developed mild transaminitis while on oxandrolone, which did not alter his medication course and resolved after the medication was discontinued. The impact of oxandrolone on functional capacity varied between patients. Oxandrolone may be beneficial in persistently catabolic VV ECMO patients to improve NB results. In some patients, this may support functional recovery. Additional research is needed to identify optimal patients for therapy and to investigate the impact of oxandrolone in this population.

Are Current Protein Recommendations for the Critically Ill Adequate for Patients on VV ECMO: Experience From a High-Volume Center.

BACKGROUND: The nutrition needs of patients requiring extracorporeal membrane oxygenation (ECMO) have not been established in the literature. The purpose of this study is to investigate if current protein recommendations are adequate to achieve nitrogen equilibrium in patients on venovenous ECMO (VV ECMO). METHODS: Patients aged ≥18 years on VV ECMO admitted November 2016 through January 2018 with a documented nitrogen balance (NB) study were included. Patients were stratified by body mass index (BMI) into obese (BMI ≥ 30 kg/m2 ) and nonobese (BMI < 30 kg/m2 ) categories for analysis. RESULTS: After exclusions, 55 NB studies in 29 patients were analyzed. Twelve nonobese patients received a median of 2.1 g protein/kg actual body weight (ABW) (interquartile range [IQR]: 1.7-2.5), and median NB was -2.2 g/d (IQR: -7.4 to 2.8). In 17 obese patients, median protein delivery of 2 g protein/kg ideal body weight (IBW) (IQR: 1.7-2.5) achieved a median NB of -7.3 g/d (IQR: -12.6 to -2.8). Obese patients exhibited greater urinary urea nitrogen excretion than nonobese patients did (24.6 vs 17.6 g/d, P < 0.0001). CONCLUSIONS: Obese and nonobese patients undergoing VV ECMO may require more protein than is currently recommended for critical illness. Monitoring nutrition delivery and serial NB to assess prescription adequacy should be incorporated into routine patient care. Further research is needed to confirm these findings and create specific guidelines for patients on VV ECMO.