Continuing Professional Education Session

 

Nutrition in patients with CRRT

(Pierre Singer)

 

AKI – metabolic modifications, hypercatabolism, hyperglycaemia

Nutrients and solutes levels affected by haemodialysis/haemofiltration

Equations to calculate energy expenditure (EE) can be misleading in CRRT, likely to result in overfeeding – measure EE by indirect calorimetry after 6 hours stabilisation

 

Pts use more fat than carbohydrates, therefore give 50% fat + 50% carbs

 

Amino acids lost through convection and ultrafiltration: 8g/day, total loss including catabolism: 10-15g/day, therefore give at least 1.3g/kg/day protein and more to compensate for losses

 

Loss of micronutrients in effluent: Selenium, Copper, Zinc –replace with trace element solutions

 

Hypophosphataemia in AKI treated with haemodialysis is associated with adverse events

 

Nutrition of obese patients

(Mette Berger)

 

BMI poor indicator of body composition / obesity, doesn’t account for muscle loss in ageing and disease, and does not detect sarcopenia (measured on cross sectional CT imaging at Lumbar L3 level)

 

Obesity associated with increased all-cause mortality in hospitalised pts (increased prevalence of hypertension, Type 2 DM, hypercholesterolaemia)

 

High rates of central obesity and sarcopenia in CKD irrespective of RRT

 

Obesity and trauma:

• Relative block on lipolysis and fat oxidation
• Shift to preferential use of proteins and carbohydrates
• Resultant catabolism

 

Glucose handling in obesity:

• Relative insulin resistance and risk of Type 2 DM
• Sepsis/trauma induces post-receptor insulin resistance
• Significant risk of hyperglycaemia (conventional feeds use carbohydrates as predominant energy source)

 

Obesity can co-occur with malnutrition – MDT approach to handle various aspects of obesity

 

How much to feed obese pts?

• Penn State Equations: 80% validity in predicting resting metabolic rate in critically ill pts at extremes of BMI

(Prediction of resting metabolic rate in critically ill patients at the extremes of body mass index.)

 

Simple guide:

• Assess nutritional need and develop plan within 48hrs of ICU admission (pt usually has little reserves)
• Will need Indirect Calorimetry or Penn State Equations for more accurate calculation of energy expenditure
• Feeding should not be hypocaloric, but rather Aim for Iso-caloric for lean mass
• Ideal body weight used to calculate protein needs (2-2.5 g/kg)
• Careful attention to micronutrients, B12, Cu, Fe to avoid anaemia / neurological problems
• Convert to Enteral feeding as soon as pt is stabilised

 

 

Nutrition during non-invasive ventilation

(Steffen Weber-Carstens)

 

Reasons NOT to feed enterally during NIV:

• Potential need for intubation
• NGT presence may cause air leakage, compromising effectiveness of NIV
• Gastric distension associated diaphragmatic splinting
• Removal of mask to consume oral diet may cause deterioration

 

In this group of pts, TPN is in fact preferred to EN – no increase in mortality / gastrointestinal infection rate with TPN compared to EN; EN associated with significantly more GI infections

Enteral versus parenteral early nutrition in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2).

 

Nutrition in necrotising pancreatitis

(Valentin Fuhrmann)

 

Severe acute pancreatitis

• shock, respiratory failure, AKI, delirium, abdominal compartment syndrome
• mortality 20%
• Early enteral nutrition (EN) important in the multimodal therapy

 

Recommendations:

Mild- oral feed once pain / vomiting resolved

Severe- Early EN – ESPEN 2018; Parenteral nutrition only when EN route not available / not tolerated / not meeting energy requirements (ACG 2013)

 

NG tube feeding safe and well-tolerated compared to NJ feeding

Nasogastric or nasojejunal feeding in predicted severe acute pancreatitis: a meta-analysis

 

Feeding intolerance is common in acute pancreatitis (nausea, vomiting, ileus, diarrhoea)

Early versus on-demand nasoenteric tube feeding in acute pancreatitis.

 

Managing feeding intolerance:

• Start EN early to avoid extended ileus
• Re-assess GI function early
• Slow start, do not aim for full energy needs
• Prokinetics
• Post-pyloric feeding is an option if prokinetics not helping
• Diagnose and manage of intraabdominal hypertension
• Consider parenteral route

 

 

ESICM guidelines:  DELAY enteral feeding in cases of

• Uncontrolled shock
• Uncontrolled hypoxia / hypercapnoea / acidosis
• Abdominal compartment syndrome
• Gastric aspirates > 500mls / 6hrs

 

 

 

Nutrition in elderly frail patients

(Jean-Charles Preiser)

Nutritional management in frailty:

• Acute phase: refeeding risk
• Recovery phase: Need adequate calories, high protein intake, exercise, selected pharmaconutrients

 

ESPEN Recommendations for refeeding hypophosphataemia

• Measure electrolytes 2-3x/day, supplement if needed
• Restrict energy supply for 48hrs then gradually increase

 

Positive energy balance is associated with accelerated muscle atrophy (Positive energy balance is associated with accelerated muscle atrophy and increased erythrocyte glutathione turnover during 5 wk of bed rest)

 

Burden of critical illness in frail pts lasts for long period after d/c from ICU and hospital

• huge task of rebuilding
• Vit D deficiency associated with muscle loss (type 2 myocytes), supplementation increases muscle protein synthesis in non-critically ill
• Selected amino acids, in particular leucine, can stimulate muscle protein synthesis
• Combination of increased protein intake, amino acid supplementation and exercise

 

 

Nutrition in malnourished patients

(Michael Hiesmayr)

 

Risk factors for malnutrition include:

• Unintentional weight loss >5% in 1 month
• Starvation >7days
• Prolonged hypocaloric feeding / chronic swallowing difficulties
• Idiosyncratic diets (qualitative malnutrition)
• Nutrient losses / reduced absorption e.g. GI condition, chronic pancreatitis, chronic antacid use (by binding minerals), chronic high-dose diuretics, post bariatric surgery

 

Malnourished pts do not always look thin (e.g. bariatric surgery); low BMI does not mean malnourishment (e.g. endurance sports)

 

Those who tend to eat less in hospital are either the elderly or pts <39 yrs of age: ? related to unusual situation of being hospitalised at this age / history of chronic illness

 

Measurements:

• BMI – fluctuates with fluid resuscitation
• Muscle mass – visualisation by CT / Ultrasound (degree of subjectivity)
• Muscle function – MRC grading of strength, Dynamometer
• Bioimpedance

 

Muscle layer thickness is dynamic and fluid-sensitive

• up to 15% apparent increase in muscle mass after 8-hr surgical procedure
• reflects lean tissue, but also fluid, impaired venous return and inflammation

 

 

Nutrition risk assessment:

 

Estimate body weight if unknown

Investigate nutrition history

• history from pt / family
• If malnourished, start slow feed and increase progressively
• Prophylactic thiamine
• Supplement K+, Mg++, PO4- (measure)

Observe pt for GI tolerance, cardio/pulmonary tolerance

 

Sensible take home messages:

• Due to loss of autonomy, ICU pts are often dependent on nutrition care
• Always consider malnutrition once the pt has been on ICU >7 days even if body size appears fine
• Look at the patient, not just the numbers – muscle bulk, hands, overall appearance
• NO reason not to feed early once condition stabilised
• If the pt is ‘eating independently’ on ICU, always monitor intake to avoid false reassurances of adequate nutrition
• Aim to retrain pt to eat while on ICU + swallowing test before discharge to the ward, where there is less direct nursing care and risk of further malnutrition

Energy Needs and Nutritional Status

Heleen Ondemans-Van Straaten (The Netherlands)

Assess nutritional status

• Hx unintended weight loss / decreased physical performance before admission
• Physical exam
• Body Composition
  • Bio-impedance analysis 
  • Phase angle calculation 

• Ultrasound / CT manual measurement of muscle diameter / circumference 

Low muscle mass and low phase angle = increased risk of mortality 

BMI does not reflect nutritional status – obese patient can be malnourished

Assess energy needs

Energy needs vary with time, phase of illness

• ESPEN guidelines recommend Hypocaloric nutrition no more than 70% energy expenditure in acute phase   

Early overfeeding definitely not beneficial, likely harmful

GI Dysfunction

Annika Reintam Blaser (Estonia)

No tool or marker to measure GI function in critically ill; GI dysfunction not usually obvious early on

Motility can be assessed, but does not reflect digestion / absorption

Sometimes the best early indicator comes from asking the surgeon about condition of the bowel during surgery!

Terminology: Acute GI injury (AGI) with grading of severity, to guide enteral feeding 

Feeding Intolerance can be at level of stomach (obvious: vomiting, large volume aspirates) and also small bowel / colon (less easy to monitor: distension / diarrhoea)

Use of Enteral feeding and pro kinetics

• Start Slow
• Review daily for response
• Clear plan of action as if managing drug prescription

How to Monitor Nutrition

Jan Wernerman (Sweden)

Assess calorie and protein intake

• hourly record of intake and GI losses
• identify non-nutrition calories, non-nutrition proteins
• consider GI response to previous day’s feeding plan

Indirect Calorimetry early and reliable in mechanical ventilation, more difficult in spontaneous breathing

• measures energy expenditure (different from energy requirement)
• guides feeding decisions but EE changes with time, therefore needs repeat measurement

Protein:

• how much to give? Do sick pts need more?
• no hard evidence
• practicality of measuring urinary urea
• difficulty of interpreting Nitrogen balance data
•  high protein dose early on in illness is better retained than higher protein dose given late

Triglycerides:

• stay with recommended limits
• upper reference 2mmol/L
• limited evidence of harm in humans when TGs 5-10mmol/L over a few days, but in practice, the response is usually to decrease fat intake
• is pt on prolonged propofol infusion? Known to raise TGs
• some pts will have raised TGs regardless of what we do

Glucose: ESPEN (2018) recommends monitoring at least 4-hourly, using insulin when BM > 10mmol/L

Phosphate:

• may decrease in response to feeding
• ESPEN (2018) recommends restricting caloric intake but limited evidence for duration of restriction

Specific nutrients: Trace elements, vitamins, Selenium, Glutamine, Growth hormone, Thyroxine

• difficult to advise on measurements
• even if levels known, controversial as to relation to illness
• no clear guidelines on when to supplement 
• prudent to look at overall clinical picture

Advantages of Enteral Nutrition vs Parenteral Nutrition in critical illness

Arthur RH van Zanten (The Netherlands)

Early Enteral Nutrition (EEN): initiated within 24-48 hours of admission, trauma, injury

• aim to maintain condition of gut (microvilli health, intestinal barrier, intestinal mucosal immunity)
• provide nutrients to deal with metabolic stress
• reduce morbidity compared with parenteral nutrition
• reduce cost compared with parenteral nutrition

Usual post-operative organ recovery time

• Stomach 24-48hrs
• Small intestine 12-24hrs (recovers most quickly, consider post-pyloric feeding with prokinetics)
• Colon 48-120hrs (therefore do not wait for bowel sounds before commencing feeding)

Fewer post-op complications with EEN in major upper GI resection

• the anastomosis needs Oxygen, Blood flow and Nutrition to heal

Early EN vs delayed EN: no difference in mortality, but significantly reduced risk of infection

Few situations where EN should be delayed

• unstable shock
• acute GI bleed
• bowel ischaemia
• abdominal compartment syndrome

** use of vasopressors not a contraindication unless harm-dynamically unstable

EN has limited risk of overfeeding compared to parenteral feeding, however EN is also less likely to achieve feeding targets due to interruption in feeding times