A Comprehensive Assessment of Nutritional Status and Factors Impacting Nutrition Recovery in Hospitalized, Critically Ill Patients Following Liberation from Mechanical Ventilation

Disease related malnutrition is a concern for the critically ill, however there is a paucity of research examining nutrition recovery in survivors of critical illness. Prior to the development of nutrition interventions to enhance recovery from critical illness, a more comprehensive understanding of the nutrition recovery trajectory and factors influencing the early stages of ward-based recovery is required. Thus, the overarching purpose of this thesis was to produce a comprehensive body of work that enhances our understanding of various facets of nutrition recovery in the hospitalized, critically ill patient following liberation from mechanical ventilation (LMV). To explore and characterize nutrition recovery, I first evaluated: 1) the feasibility of performing common measures of nutritional status during the first seven days following LMV, 2) nutrition intake following LMV, and 3) meal and food intake patterns of patients prescribed non-modified oral diets following LMV. The compilation of these findings illustrated some of the factors that contribute to compromised nutrition recovery in patients following LMV. To better understand nutrition following LMV, feasibility of performing common measures to assess nutritional status was evaluated. Recruitment and retention into the study were also assessed to evaluate the capacity to investigate nutrition recovery. As part of this study, critically ill adults (>18 years) who received mechanical ventilation (MV) for at least 72 hours were recruited. Over a 6-month recruiting period, 538 patients were screened, and of the patients identified as meeting the study eligibility criteria (n=65), 35% consented to participate (n=23). Of the patients who participated (n=19, 42% male, aged 35-85 years), 32% were lost to follow-up prior to the seventh day following LMV. Common methods to assess body composition (weight, mid-upper arm circumference, and bioelectrical impedance analysis to calculate phase angle) and physical function (hand-grip dynamometry) were obtained on greater than 70% of occasions they were to be measured, however, use of standardized and previously validated protocols to obtain these measures was not practical in this patient population. Protocol deviations occurred for 94%, 45%, and 44% of occasions that mid-arm circumference, bioelectrical impedance, and hand-grip strength were measured, respectively. Primarily, the disposition of recovering critically ill patients (decreased level of alertness, muscular weakness, discomfort and pain) precluded proper acquisition of these measurements. Nutrition intake was measured using weighed food records during the first 7 days following LMV. Of the 227 meals served over 125 study days, energy and nutrient intake was successfully measured for 92% of meals. For all days patients were receiving enteral nutrition (EN), the volume of EN formula delivered could be extracted from the chart. Large variations in daily protein (range: 0-151 g/d) and energy (range: 0-2306 kcal/d) intake were observed across all study days. For patients receiving nutrition exclusively via EN (n=48 days), protein and calorie intake was >75% of prescribed on 77% and 88% of occasions, respectively. In contrast, for days that patients received an oral diet as their sole source of nutrition (n=54 days), protein intake was never >75% of prescribed and energy intake was >75% of prescribed on only 24% of occasions. Meal and food intake patterns were examined in a subgroup of 9 patients who had been prescribed a regular (non-texture or fluid modified) diet for at least one day over the study duration. Only 55% and 56% of the total amount of protein and calories provided, respectively were consumed. Although there were no significant differences between the amounts of calories and protein consumed between main meals (195, 255, and 231 kcal and 9, 11, and 9 g protein for breakfast, lunch, and dinner, respectively) considerable individual variation in eating patterns between the patients was observed with respect to the amount of protein and calories consumed at meals and which meals (breakfast, lunch or dinner) the most was consumed. To further characterize dietary prescription practices and use of EN following LMV, a retrospective chart review (n=134, 55% male, mean age 61 years) was conducted. We observed 16% of patients who received EN while ventilated had it discontinued concomitantly with LMV. However, considerable variation in the use of EN therapy and type of oral diet prescriptions in patients prior to hospital discharge was observed. Only 55% of patients who survived the hospital admission ever received a regular, non-modified diet without supplementary EN at the time of hospital discharge, and one in five patients were still receiving EN at the time of hospital discharge. Collectively, these results advance our insight into nutrition recovery following critical illness from a Canadian perspective. Feasible and validated tools to properly assess nutritional status in this unique group of patients are required, as is the need for the development of interventions to enhance protein and energy intake in recovery. Due to the heterogeneity of the patients observed, nutrition interventions delivered by practicing clinicians should be as individualized as much as possible to achieve optimal outcomes

Adequacy of Protein and Energy Intake in Critically Ill Adults Following Liberation From Mechanical Ventilation Is Dependent on Route of Nutrition Delivery

This is the peer reviewed version of the following article: Moisey, L. L., Pikul, J., Keller, H., Yeung, C. Y., Rahman, A., Heyland, D. K., & Mourtzakis, M. (2020). Adequacy of protein and energy intake in critically ill adults following liberation from mechanical ventilation is dependent on route of Nutrition Delivery. Nutrition in Clinical Practice, 36(1), 201–212, which has been published in final form at https://doi.org/10.1002/ncp.10558. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Background: Studies examining nutrition intake of critically ill patients following liberation from mechanical ventilation (LMV) are scarce. The objectives of this prospective, observational feasibility study were to quantify and assess protein and energy intake in hospitalized, critically ill patients following LMV, to determine barriers to optimal intake, and to report on the feasibility of recruiting and retaining patients into this study. Methods: Adult patients requiring MV for >72 hours in a medical/surgical intensive care unit (ICU) were recruited. Protein and energy intakes were quantified up to 14 days following LMV. Patients also identified barriers to eating. Results: Nineteen patients (mean age, 60 years [SD, 12 years]) were studied over 125 days. Over all study days, the median amounts of protein and energy consumed in comparison with amounts prescribed by dietitians were 46% (interquartile range [IQR], 26-100) and 71% (IQR, 38-100), respectively. When stratified by route of nutrition delivery, on days (n = 54) when patients consumed an oral diet as the sole nutrition source, median amounts of protein and energy consumed in comparison with those prescribed were only 27% (IQR, 15-41) and 47% (IQR, 29-66), respectively. The most frequently reported barriers to eating were poor appetite, early satiety, and taste changes. Conclusions: Protein and calorie intake is below prescribed amounts for patients whose enteral nutrition is discontinued and an oral diet prescribed as sole nutrition source following LMV. Acceptable strategies to enhance nutrition intake in post-ICU patients during the recovery stages of critical illness are needed.This research was funded by a research grant from the Canadian Foundation for Dietetic Research. L.L. Moisey was supported by a Canadian Institutes for Health Research Doctoral Research Award

Clinically Practical Approach for Screening of Low Muscularity Using Electronic Linear Measures on Computed Tomography Images in Critically Ill Patients

This is the peer reviewed version of the following article: Avrutin, E., Moisey, L. L., Zhang, R., Khattab, J., Todd, E., Premji, T., Kozar, R., Heyland, D. K., &amp; Mourtzakis, M. (2017). Clinically practical approach for screening of low muscularity using electronic linear measures on computed tomography images in critically ill patients. Journal of Parenteral and Enteral Nutrition, 42(5), 885–891, which has been published in final form at https://doi.org/10.1002/jpen.1019. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Background: Computed tomography (CT) scans performed during routine hospital care offer the opportunity to quantify skeletal muscle and predict mortality and morbidity in intensive care unit (ICU) patients. Existing methods of muscle cross-sectional area (CSA) quantification require specialized software, training, and time commitment that may not be feasible in a clinical setting. In this article, we explore a new screening method to identify patients with low muscle mass. Methods: We analyzed 145 scans of elderly ICU patients (≥65 years old) using a combination of measures obtained with a digital ruler, commonly found on hospital radiological software. The psoas and paraspinal muscle groups at the level of the third lumbar vertebra (L3) were evaluated by using 2 linear measures each and compared with an established method of CT image analysis of total muscle CSA in the L3 region. Results: There was a strong association between linear measures of psoas and paraspinal muscle groups and total L3 muscle CSA (R2 = 0.745, P < 0.001). Linear measures, age, and sex were included as covariates in a multiple logistic regression to predict those with low muscle mass; receiver operating characteristic (ROC) area under the curve (AUC) of the combined psoas and paraspinal linear index model was 0.920. Intraclass correlation coefficients (ICCs) were used to evaluate intrarater and interrater reliability, resulting in scores of 0.979 (95% CI: 0.940-0.992) and 0.937 (95% CI: 0.828-0.978), respectively. Conclusions: A digital ruler can reliably predict L3 muscle CSA, and these linear measures may be used to identify critically ill patients with low muscularity who are at risk for worse clinical outcomes