Protein and Calorie Requirements Associated With the Presence of Obesity

A Comparison of High and Usual Protein Dosing in Critically Ill Patients With Obesity: A Post Hoc Analysis of an International, Pragmatic, Single-Blinded, Randomized Clinical Trial

OBJECTIVES

Across guidelines, protein dosing for critically ill patients with obesity varies considerably. The objective of this analysis was to evaluate whether this population would benefit from higher doses of protein.

DESIGN

A post hoc subgroup analysis of the effect of higher protein dosing in critically ill patients with high nutritional risk (EFFORT Protein): an international, multicenter, pragmatic, registry-based randomized trial.

SETTING

Eighty-five adult ICUs across 16 countries.

PATIENTS

Patients with obesity defined as a body mass index (BMI) greater than or equal to 30 kg/m 2 ( n = 425).

INTERVENTIONS

In the primary study, patients were randomized into a high-dose (≥ 2.2 g/kg/d) or usual-dose protein group (≤ 1.2 g/kg/d).

MEASUREMENTS AND MAIN RESULTS

Protein intake was monitored for up to 28 days, and outcomes (time to discharge alive [TTDA], 60-d mortality, days of mechanical ventilation [MV], hospital, and ICU length of stay [LOS]) were recorded until 60 days post-randomization. Of the 1301 patients in the primary study, 425 had a BMI greater than or equal to 30 kg/m 2 . After adjusting for sites and covariates, we observed a nonsignificant slower rate of TTDA with higher protein that ruled out a clinically important benefit (hazard ratio, 0.78; 95% CI, 0.58-1.05; p = 0.10). We found no evidence of difference in TTDA between protein groups when subgroups with different classes of obesity or patients with and without various nutritional and frailty risk variables were examined, even after the removal of patients with baseline acute kidney injury. Overall, 60-day mortality rates were 31.5% and 28.2% in the high protein and usual protein groups, respectively (risk difference, 3.3%; 95% CI, -5.4 to 12.1; p = 0.46). Duration of MV and LOS in hospital and ICU were not significantly different between groups.

CONCLUSIONS

In critically ill patients with obesity, higher protein doses did not improve clinical outcomes, including those with higher nutritional and frailty risk.

In critically ill adult patients with COVID-19, lower energy and higher protein intake are associated with fewer mechanical ventilation and antibiotic days but not with ICU length of stay

BACKGROUND

Coronavirus disease 2019 (COVID-19) nutrition management guidelines recommend hypocaloric, high-protein feeding in the acute phase of critical illness. This study aimed to determine, among critically ill adults with COVID-19, whether nutrition support affects outcomes in nonobese patients when providing a mean energy intake of ≥20 kcal/kg/day vs <20 kcal/kg/day and protein intake of ≥1.2 g/kg/day vs <1.2 g/kg/day, using actual body weight, and in patients with obesity when providing ≥20 kcal/kg/day vs <20 kcal/kg/day and a protein intake of ≥2 g/kg/day vs <2 g/kg/day using ideal body weight.

METHODS

This retrospective study included adults with COVID-19 on mechanical ventilation (MV) admitted to the intensive care unit (ICU) from 2020 to 2021. Clinical and nutrition parameters were recorded the first 14 days of ICU stay.

RESULTS

One hundred four patients were included: 79 (75.96%) were male and had a median age of 51 years and body mass index of 29.65 kg/m2 . ICU length of stay (LOS) was not affected by nutrition intake, but patients receiving <20 kcal/kg/day had fewer MV days (P = 0.029). In a subgroup analysis, MV days were lower in the nonobese group receiving <20 kcal/kg/day (P = 0.012). In the obese group, those receiving higher protein intake had fewer antibiotic days (P = 0.013).

CONCLUSION

In critically ill patients with COVID-19, lower energy and higher protein intake were respectively associated with fewer MV days and, in patients with obesity, fewer antibiotic days, but they had no effect on ICU LOS.

ESPEN practical and partially revised guideline: Clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous 2019 guideline to provide best medical nutritional therapy to critically ill patients has been shortened and partially revised. Following this update, we propose this publication as a practical guideline based on the published scientific guideline, but shortened and illustrated by flow charts. The main goal of this practical guideline is to increase understanding and allow the practitioner to implement the Nutrition in the ICU guidelines. All the items discussed in the previous guidelines are included as well as special conditions.

The Effects of Graded Protein Intake in Conjunction with Progressive Resistance Training on Skeletal Muscle Outcomes in Older Adults: A Preliminary Trial

Many studies have evaluated the effects of resistance training (RT) and protein intake to attenuate the age-related loss of skeletal muscle. However, the effects of graded protein intake with conjunctive RT in older adults are unclear. Older adults (n = 18) performed 10 weeks of whole-body RT with progressions to intensity and volume while consuming either a constant protein (CP) diet (0.8−1.0 g/kg/d) with no protein supplement or a graded protein (GP) diet progressing from 0.8 g/kg/d at week 1 to 2.2 g/kg/d at week 10 with a whey protein supplement. Data were collected prior to commencement of the RT protocol (PRE), after week 5 (MID), and after week 10 (POST). Dual Energy X-ray Absorptiometry derived lean/soft tissue mass, ultrasonography derived muscle thickness, and a proxy of muscle quality were taken at PRE and POST, while isokinetic dynamometry derived peak torque were taken at PRE, MID, and POST. This study demonstrated the feasibility of the RT protocol (attendance = 96%), and protein intake protocol (CP in range all weeks; GP deviation from prescribed = 7%). Peak torque, muscle quality scores, and appendicular lean/soft tissue mass demonstrated the main effects of time (p < 0.05) while no other main effects of time or group * time interactions were seen for any measure. In conclusion, RT improved appendicular lean/soft tissue mass, peak torque, and muscle quality, with no differential effects of graded or constant protein intake.

Nitrogen balance in mechanically ventilated obese patients

ABSTRACT Objective This study aimed to evaluate if the protein intake recommendations for obese critically ill requiring mechanical ventilation are sufficient to promote a positive or neutral nitrogen balance. Methods Cross-sectional study that included 25 obese, ≥18 years old, undergoing mechanical ventilation and who were target to receive high-protein enteral nutrition therapy (2.0-2.5g/kg ideal body weight). Clinical, nutritional and biochemical variables were analyzed. Nitrogen balance was performed when patient was receiving full enteral nutrition therapy and was classified: positive when intake was greater than excretion; negative when excretion was greater than intake; neutral when both were equal. Results The characteristics of patients evaluated were 64.1±9.4 years old, clinical treatment 88%, body mass index 36.5±5.1kg/m2, nitrogen balance 0.3g/day (-5.3 to 4.8g/day), protein intake 2.1g/day (2.0-2.3g/kg) ideal body weight. Of individuals analyzed, 52% showed positive or neutral nitrogen balance with median of 4.23g/day 2.41 to 6.40g/day) in comparison to negative group with median of -5.27g/day (-10.38 to -3.86g/day). Adults had higher ratio of negative nitrogen balance (57.1%) than elderly (44.4%), with protein intake of 2.0 versus 2.1g/day, respectively. No correlation was found between nitrogen balance and variables assessed. Conclusion High-protein enteral nutrition therapy contributed to positive or neutral nitrogen balance for approximately half of obese ventilated individuals. With similar protein intake, elderly showed a higher proportion of positive or neutral nitrogen balance. Nitrogen balance can be influenced by various factors, so further studies are required to identify different protein needs in obese critically.

Protein Requirements during Hypocaloric Nutrition for the Older Patient With Critical Illness and Obesity: An Approach to Clinical Practice

Current guidelines recommend a hypocaloric, high protein nutrition regimen for patients with obesity and critical illness. The impact of advancing age presents with unique challenges in which a greater protein intake is required to overcome the anabolic resistance associated with aging in the face of presumed decreased renal function. The primary objective of this review is to provide an overview of the impact of obesity and advancing age on protein requirements for patients with critical illness and review the scientific evidence supporting the rationale for hypocaloric, high protein nutrition for this subpopulation, as well as provide some practical suggestions for their clinical management.

Protein metabolism and requirements in the ICU

The critically ill patient is highly catabolic, loosing significant amounts of protein and muscle. This proteolysis may induce a loss of 20% of the muscle mass in 10 days of hospitalization. Muscle loss may be assessed measuring urinary nitrogen excretion, muscle mass by ultrasound, bioimpedance, computerized tomography or MRI. To reduce the negative nitrogen balance, protein can be administrated enterally, or parenterally through amino acids as a part of parenteral nutrition. ESPEN guidelines recommend to administer 1.3 g/kg/day of protein to critically ill patients but this recommendation should be adapted according to clinical conditions. Elderly, obese, trauma, burn, acute kidney injury patients should receive larger amount of protein.

Impact of the Time to Initiation of Parenteral Nutrition on Patient Outcomes in Critically Ill Adults

Background:

The optimal time to initiate parenteral nutrition (PN) in critically ill adults in whom enteral nutrition is not feasible is controversial.

Objective:

The objectives were to compare in-hospital mortality and hospital length of stay in patients initiated on PN within 7 days or after 7 days of poor nutrient intake.

Methods:

This single-center, retrospective study included critically ill adult patients who received at least 2 consecutive days of PN during hospitalization from May 2014 to July 2016.

Results:

The median duration of PN (interquartile range) was 8 (5-13) days. In total, 110 patients received PN within 7 days of poor nutrient intake while 49 patients received PN after 7 days of poor nutrient intake. There was no statistically significant difference in in-hospital mortality between groups (29.09% vs 18.37%, P = .1535). Patients initiated within 7 days had a significantly shorter median hospital length of stay than patients initiated after 7 days (20 days vs 27 days, P = .0013). There were 69 patients who were classified as obese. Obese patients initiated within 7 days had a significantly shorter median hospital length of stay than obese patients initiated after 7 days (17 days vs 33 days, P = .0007).

Conclusions:

Time to initiation of PN did not impact in-hospital mortality. However, there was an association between early initiation of PN and a shorter hospital length of stay that was most pronounced among obese patients.

Dietary Management of Blood Glucose in Medical Critically Ill Overweight and Obese Patients: An Open-Label Randomized Trial

BACKGROUND

Enteral nutrition (EN) increases hyperglycemia due to high carbohydrate concentrations while providing insufficient protein. The study tested whether an EN formula with very high-protein- and low-carbohydrate-facilitated glucose control delivered higher protein concentrations within a hypocaloric protocol.

METHODS

This was a multicenter, randomized, open-label clinical trial with parallel design in overweight/obese mechanically ventilated critically ill patients prescribed 1.5 g protein/kg ideal body weight/day. Patients received either an experimental very high-protein (37%) and low-carbohydrate (29%) or control high-protein (25%) and conventional-carbohydrate (45%) EN formula.

RESULTS

A prespecified interim analysis was performed after enrollment of 105 patients (52 experimental, 53 control). Protein and energy delivery for controls and experimental groups on days 1-5 were 1.2 ± 0.4 and 1.1 ± 0.3 g/kg ideal body weight/day (P = .83), and 18.2 ± 6.0 and 12.5 ± 3.7 kcals/kg ideal body weight/day (P < .0001), respectively. The combined rate of glucose events outside the range of >110 and ≤150 mg/dL were not different (P = .54, primary endpoint); thereby the trial was terminated. The mean blood glucose for the control and the experimental groups were 138 (-SD 108, +SD 177) and 126 (-SD 99, +SD 160) mg/dL (P = .004), respectively. Mean rate of glucose events >150 mg/dL decreased (Δ = -13%, P = .015), whereas that of 80-110 mg/dL increased (Δ = 14%, P = .0007). Insulin administration decreased 10.9% (95% CI, -22% to 0.1%; P = .048) in the experimental group relative to the controls. Glycemic events ≤80 mg/dL and rescue dextrose use were not different (P = .23 and P = .53).

CONCLUSIONS

A very high-protein and low-carbohydrate EN formula in a hypocaloric protocol reduces hyperglycemic events and insulin requirements while increasing glycemic events between 80-110 mg/dL.

Energy balance in obese, mechanically ventilated intensive care unit patients

OBJECTIVES

The aims of this study were, first, to compare the predicted (calculated) energy requirements based on standard equations with target energy requirement based on indirect calorimetry (IC) in critically ill, obese mechanically ventilated patients; and second, to compare actual energy intake to target energy requirements.

METHODS

We conducted a prospective cohort study of mechanically ventilated critically ill patients with body mass index ≥30.0 kg/m² for whom enteral feeding was planned. Clinical and demographic data were prospectively collected. Resting energy expenditure was measured by open-circuit IC. American Society of Parenteral and Enteral Nutrition (APSPEN)/Society of Critical Care Medicine (SCCM) 2016 equations were used to determine predicted (calculated) energy requirements. Target energy requirements were set at 65% to 70% of measured resting energy expenditure as recommended by ASPEN/SCCM. Nitrogen balance was determined via simultaneous measurement of 24-h urinary nitrogen concentration and protein intake.

RESULTS

Twenty-five patients (mean age: 64.5 ± 11.8 y, mean body mass index: 35.2 ± 3.6 kg/m²) underwent IC. The mean predicted energy requirement was 1227 kcal/d compared with mean measured target energy requirement of 1691 kcal/d. Predicted (calculated) energy requirements derived from ASPEN/SCCM equations were less than the target energy requirements in most cases. Actual energy intake from enteral nutrition met 57% of target energy requirements. Protein intake met 25% of target protein requirement and the mean nitrogen balance was -2.3 ± 5.1 g/d.

CONCLUSIONS

Predictive equations underestimated target energy needs in this population. Further, we found that feeding to goal was often delayed resulting in failure to meet both protein and energy intake goals.

Protein Provision in Critically Ill Adults Requiring Enteral Nutrition: Are Guidelines Being Met?

BACKGROUND

In a previous audit, 81% of enteral protein prescriptions failed to meet protein guidelines. To address this, a very high-protein enteral formula and protein supplements were introduced, and protein prescriptions were adjusted to account for nonnutrition energy sources displacing enteral formula. This follow-up audit compared protein provision in critically ill adults requiring exclusive enteral nutrition (EN), first, with local and international guidelines, and second, after changes to practice, with the previous audit in the same intensive care unit (ICU).

METHODS

Data were collected from 106 adults consecutively admitted to the ICU of a U.K. tertiary hospital and requiring exclusive EN ≥3 days. Protein targets based on local guidelines (1.25, 1.5, or 2.0 g/kg/d), nutrition prescription, and delivery were recorded for 24 hours between days 1-3, 5-7, 8-10, and 18-20 post-ICU admission.

RESULTS

The proportion of day 1-3 protein prescriptions meeting protein targets increased from 19% in 2015 to 69% in 2017 (P < .0005, φ = 0.50). The median percentage of protein target delivered was lower than prescribed (79% vs 103%; (P < .0005; r = 0.53) and EN delivery only met the target of 22% of patients. The proportion of protein prescriptions meeting protein targets was similar for days 1-3 (69%), 5-7 (71%), and 8-10 (68%), but increased slightly by days 18-20 (74%). The proportion of patients for which EN delivery met protein targets increased with the number of days post-ICU admission (22%, 26%, 37%, and 53% for days 1-3, 5-7, 8-10, and 18-20, respectively).

CONCLUSION

The proportion of protein prescriptions meeting guideline targets was higher after changes to practice.

ESPEN guideline on clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous guidelines to provide best medical nutritional therapy to critically ill patients have been updated. These guidelines define who are the patients at risk, how to assess nutritional status of an ICU patient, how to define the amount of energy to provide, the route to choose and how to adapt according to various clinical conditions. When to start and how to progress in the administration of adequate provision of nutrients is also described. The best determination of amount and nature of carbohydrates, fat and protein are suggested. Special attention is given to glutamine and omega-3 fatty acids. Particular conditions frequently observed in intensive care such as patients with dysphagia, frail patients, multiple trauma patients, abdominal surgery, sepsis, and obesity are discussed to guide the practitioner toward the best evidence based therapy. Monitoring of this nutritional therapy is discussed in a separate document.

Current perspective for tube feeding in the elderly: from identifying malnutrition to providing of enteral nutrition

With the number of individuals older than 65 years expected to rise significantly over the next few decades, dramatic changes to our society and health care system will need to take place to meet their needs. Age-related changes in muscle mass and body composition along with medical comorbidities including stroke, dementia, and depression place elderly adults at high risk for developing malnutrition and frailty. This loss of function and decline in muscle mass (ie, sarcopenia) can be associated with reduced mobility and ability to perform the task of daily living, placing the elderly at an increased risk for falls, fractures, and subsequent institutionalization, leading to a decline in the quality of life and increased mortality. There are a number of modifiable factors that can mitigate some of the muscle loss elderly experience especially when hospitalized. Due to this, it is paramount for providers to understand the pathophysiology behind malnutrition and sarcopenia, be able to assess risk factors for malnutrition, and provide appropriate nutrition support. The present review describes the pathophysiology of malnutrition, identifies contributing factors to this condition, discusses tools to assess nutritional status, and proposes key strategies for optimizing enteral nutrition therapy for the elderly.

Metabolic support challenges with obesity during critical illness

Adiposity-based chronic disease, critical illness, and nutrition therapy increase the risk for overfeeding and worsened nutritional and clinical outcomes. Hypocaloric, high-protein nutrition therapy provides critically ill obese patients the opportunity to achieve net protein anabolism with a reduced risk for overfeeding-related complications. The intent of this review is to discuss the impact of obesity on clinical outcomes, describe the consequences of obesity that increase complications associated with nutrition therapy, provide the framework to develop a hypocaloric, high-protein regimen, review the scientific evidence to support this mode of therapy, and discuss its limitations. Practical suggestions for patient monitoring are also provided.

High-Protein Hypocaloric Nutrition for Non-Obese Critically Ill Patients

High-protein hypocaloric nutrition, tailored to each patient's muscle mass, protein-catabolic severity, and exogenous energy tolerance, is the most plausible nutrition therapy in protein-catabolic critical illness. Sufficient protein provision could mitigate the rapid muscle atrophy characteristic of this disease while providing urgently needed amino acids to the central protein compartment and sites of tissue injury. The protein dose may range from 1.5 to 2.5 g protein (1.8-3.0 g free amino acids)/kg dry body weight per day. Nutrition should be low in energy (≈70% of energy expenditure or ≈15 kcal/kg dry body weight per day) because efforts to match energy provision to energy expenditure are physiologically irrational, risk toxic energy overfeeding, and have repeatedly failed in large clinical trials to demonstrate clinical benefit. The American Society for Parenteral and Enteral Nutrition currently suggests high-protein hypocaloric nutrition for obese critically ill patients. Short-term high-protein hypocaloric nutrition is physiologically and clinically sensible for most protein-catabolic critically ill patients, whether obese or not.