Applied nutritional investigationProspective randomized trial to assess caloric and protein needs of critically Ill, anuric, ventilated patients requiring continuous renal replacement therapy☆
Introduction
In our previous work,1 we demonstrated a markedly abnormal amino acid profile in our critically ill, ventilated patients requiring continuous renal replacement therapy (CRRT) for renal failure. Between 14% and 57% of measured amino acids were below the lower limit of normal when protein loads smaller than 2.5g · kg−1 · d−1 were administered. With a protein intake of 2.5 g · kg−1 · d−1, all the measured amino acids were within the normal range.
urther, we showed that the amino acid balance became increasingly positive as protein input was increased. We postulate that increasing protein inputs to 2.5 g · kg−1 · d−1 will also result in an improved nitrogen balance, and that this will positively affect patient mortality or morbidity.
Section snippets
Patients
Fifty sequential, critically ill, ventilated patients were entered into this study on commencement of CRRT for renal failure (Table I). The mean age was 53.3 ± 17.4 y, and 62% were male. Illness severity was assessed with the Second Acute Physiology and Chronic Health Evaluation (APACHE II) scores, which are based on the degree of derangement of acute physiology, age, and chronic health evaluation. Mean APACHE II score was 26.0 ± 8.0, with a predicted risk of death (ROD) of 50.0 ± 25.0%. The
Baseline data
There were no significant differences in baseline data between the trial and control groups (Table I).
Actual feeding and predicted and expended energy
In 68% of cases, a metabolic cart could be used to measure EE. In the remaining 32% of cases, analysis of the exhaled gases could not be performed due to the use of nitric oxide for severe lung injury or the requirement for 100% fraction of inspired oxygen, making the measurement of oxygen consumption inaccurate.7
At study entry, the mean predicted (Schofield) caloric requirement was 2101 ± 410.
Discussion
This study demonstrated successful nutrition support, with patients receiving 99% of predicted and 89% of measured EEs.
We found a previously unreported relation between predicted and actual energy requirements, with the Schofield formula underestimating requirements for predictions of less than 2500 calories and overestimating requirements for predictions of greater than 2500 calories (Fig. 1; P = 0.025). The mean EE increased throughout the period of the study by 56 cal/d (P < 0.0001; Fig. 4).
Conclusions
This study involving early feeding with full provision of energy in 50 sequential, critically ill, ventilated patients requiring CRRT for renal failure has demonstrated the benefits of using a metabolic cart to avoid the errors of under- and overestimating EE common with the predictive formulae. It has shown that EE increases over at least the first week of critical illness. It has demonstrated that nitrogen balance is positively related to protein intake, more likely to be attained with
References (41)
- et al.
The effects of varying energy, and nitrogen intake on nitrogen balance, body composition, and metabolic rate
Clin Chest Med
(1986) - et al.
Energy metabolism, nitrogen balance, and substrate utilization in critically ill children
Am J Clin Nutr
(2001) - et al.
Comparison of indirect calorimetry, the Fick method, and prediction equations in estimating the energy requirements of critically ill patients
Am J Clin Nutr
(1999) - et al.
A reappraisal of caloric requirements in healthy women
Am J Clin Nutr
(1986) - et al.
A reappraisal of the caloric requirements of men
Am J Clin Nutr
(1987) - et al.
Human energy requirementsoverestimation by widely used prediction equation
Am J Clin Nutr
(1985) Nutritional management of the critically ill neurologic patient
Crit Care Clin
(1997)- et al.
Nutritional support of the septic patient
Crit Care Clin
(1995) Nutritional support of the burn patient
Crit Care Clin
(1995)Implications of critical illness, injury, and sepsis on lean body mass, and nutritional needs
Nutrition
(1998)
Nutritional support of the elderly patient in an intensive care unit
Clin Geriatr Med
Nutritional management of acute renal failure
Am J Kidney Dis
Nutritional assessment in the critically ill
Crit Care Clin
Determination of caloric and protein requirements for critically ill patients
Mayo Clin Proc
Nitrogen balance as related to caloric and protein intake in active young men
Am J Clin Nutr
Changing concepts of nutrient requirements in diseaseimplications for artificial nutritional support
Lancet
Plasma glucose turnover and oxidation during hemodialysisnutritional effect of dialysis fluid
Am J Clin Nutr
Metabolic aspects of continuous renal replacement therapies
Kidney Int
Theories and assumptions on energy expenditure
Crit Care Clin
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2022, Australian Critical CareCitation Excerpt :In the ESPEN guidelines, no specific recommendations for patients receiving renal therapy are provided,7 while in the ASPEN guidelines, it is recommended that patients on frequent haemodialysis or CRRT receive protein doses of up to 2.5 g/kg/day owing to the significant amino acid loss associated with CRRT.8 This higher dose is predominantly based on protein catabolism studies in which doses of up to 2.5 g/kg/day are required to negate the observed negative nitrogen balance.27,28 Most respondents reported achieving 61–80% of protein prescriptions in practice.
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This project was funded by an Alfred Hospital Small Projects Grant.