Protein prescription and delivery practices in critically ill adults: A survey of Australian and New Zealand intensive care dietitians.

BACKGROUND: Protein provision is thought to be integral to attenuating muscle wasting in critical illness, yet patients receive half of that prescribed. As international guidelines lack definitive evidence to support recommendations, understanding clinicians' views relating to protein practices is of importance. OBJECTIVES: The objective of this study was to describe Australia and New Zealand intensive care unit (ICU) dietitians' protein prescription and perceived delivery practices in critically ill adults, including common barriers and associations between ICU clinical experience and protein prescriptions for different clinical conditions. METHODS: A 42-item descriptive quantitative survey of Australian and New Zealand intensive care dietitians was disseminated through nutrition and ICU society e-mailing lists. Data were collected on respondent demographics and reported protein practices including questions related to a multitrauma case study. Data were analysed using descriptive and content analysis and reported as n (%). Fisher's exact tests were used to compare experience and protein prescriptions. RESULTS: Of the 67 responses received (one excluded due to >50% missing data), more than 80% of respondents stated they would prescribe 1.2-1.5 g protein/kg bodyweight/day for most critically ill patients, most commonly using European Society of Clinical Nutrition and Metabolism (ESPEN) guidelines to support prescriptions (n = 61/66, 92%). Most respondents (n = 49/66, 74%) thought their practice achieved 61-80% of protein prescriptions, with frequently reported barriers including fasting periods (n = 59/66, 89%), avoiding energy overfeeding (n = 50/66, 76%), and gastrointestinal intolerance (n = 47/66, 71%). No associations between years of ICU experience and protein prescriptions for 14 of the 15 predefined clinical conditions were present. CONCLUSIONS: Australian and New Zealand ICU dietitians use international guidelines to inform protein prescriptions of 1.2-1.5 g/kg/day for most clinical conditions, and protein prescriptions do not appear to be influenced by years of ICU experience. Key perceived barriers to protein delivery including avoidance of energy overfeeding and gastrointestinal intolerance could be explored to improve protein adequacy.

How does muscularity assessed by bedside methods compare to computed tomography muscle area at intensive care unit admission? A pilot prospective cross-sectional study.

BACKGROUND: Low muscularity and malnutrition at intensive care unit (ICU) admission have been associated with negative clinical outcomes. There are limited data available evaluating the validity of bedside techniques to measure muscle mass in critically ill adults. We aimed to compare bedside methods for muscle mass assessment [bioimpedance spectroscopy (BIS), arm anthropometry and subjective physical assessment] against reference technology [computed tomography (CT)] at ICU admission. METHODS: Adults who had CT scanning at the third lumbar area <72 h after ICU admission were prospectively recruited. Bedside methods were performed within 48 h of the CT scan. Pearson's correlation compared CT muscle area with BIS-derived fat-free mass (FFM) (kg) and FFM-Chamney (kg) (adjusted for overhydration), mid-upper arm circumference (cm) and mid-arm muscle circumference (cm). Depleted muscle stores were determined using published thresholds for each method. Cohen's kappa (κ) was used to evaluate the agreement between bedside and CT assessment of muscularity status (normal or low). RESULTS: Fifty participants were enrolled. There were strong correlations between CT muscle area and FFM values and mid-arm muscle circumference (P < 0.001). Using FFM-Chamney, all six (100%) participants with low CT muscle area were detected (κ = 0.723). FFM-BIS, arm anthropometry and subjective physical assessment methods detected 28%-38% of participants with low CT muscle area. CONCLUSIONS: BIS-derived FFM using an adjustment algorithm for overhydration was correlated with CT muscle area and had good agreement with muscularity status assessed by CT image analysis. Arm anthropometry and subjective physical assessment techniques were not able to reliably detect participants with low CT muscle area.