Category Archives: Nutrition

ICU-acquired weakness: Impact on short- and long-term outcome

Greet Van den Berghe (Leuven, Belgium)

 

 

Complex pathophysiology with multiple mechanisms

MRC score requires cooperation of patient, does not distinguish between myopathy / neuropathy

Mostly non-volitional testing for pts who cannot cooperate; some differentiation between myopathy / neuropathy; direct muscle stimulation is NOT common in clinical practice

*Obesity is the only protective non-modifiable factor for weakness!

Modifiable risk factors that can be addressed: Avoid hyperglycaemia, avoid early Parenteral nutrition, aim to mobilise early

Short-term consequences include: ICU / hospital mortality, longer duration mech ventilation, extubation failure, swallowing disorders etc.

Long-term consequences include: post-ICU mortality, non-discharge to home, longer period of rehab, impaired functioning

Long term survival decreases with increasing severity of weakness

Longer ICU stay –> worsening weakness

 

Can we measure muscle wasting in the ICU using Ultrasound?

Zudin Puthucheary (London, UK)

US can track changes in muscle mass of critically ill pts

Rectus femoris cross-sectional area (RF CSA) validated against Fibre CSA (gold standard – muscle biopsy of vastus lateralis) and Ratio of Protein:DNA in myocyte (biochemical gold standard in muscle mass measurement; UNAFFECTED by hydration status)

RF CSA and Fibre CSA both underestimate muscle wasting compared to myocyte Protein:DNA

–>> muscle wasting visualised on Ultrasound is likely to also be an underestimate

 

US sensitively discerns muscle loss between pts with different severity of illness – significantly greater in pts with higher number of failed organs

 

US + Bx of muscle, repeated 10d later –> smaller, brighter RF = cellular infiltrate + myonecrosis (present in up to 40% of critically ill pts)  — US is a non-invasive tool to detect changes in Muscle QUALITY and has been used in the paediatric population for over a decade

Limitations with using US to measure Muscle MASS – How to assess?

 

Changes in RF CSA are associated with changes in muscle strength (MRC score)

This change is not seen in MLT i.e. MLT is not associated with muscle function in critical illness

MLT also does not correlate with muscle mass (measured on CT)

–> MLT is not a good indicator of muscle mass in critically ill population

Lack of standardisation in examination technique and reporting are greatest barriers to external validity

–> reliability, reproducibility, accuracy should not be assumed

Nestlé industry session: COVID-19 & Nutrition

COVID-19: The good, the bad and the ugly

Zudin Puthucheary  (London, UK)

 

THE UGLY:  CRIT-CON Pandemic Levels and their ethical risks

0 – Normal

1 – Preparatory

  • Drawbridge ethics: withholding certain services in hospital / community to protect ourselves
  • Moral panic: change in behaviour due to belief that we are at later stages of CRIT-CON than in reality

2 – Sustained surge (current state in the UK and many parts of Europe)

  • Magic number ethics : using untested / unvalidated scoring systems, thereby relinquishing responsibility of decision making
  • Moral blindness: taking on new concepts without rigour of evidence base
  • Paternalism: making decisions believing they are the right ones, without discussing with colleagues / patients

3 – Super surge

  • Moral confusion: making random decisions

4 – Code Red

  • Moral paralysis: nobody makes decisions
  • Hobbesian ethics: those who have loudest voices have most confidence in their views and therefore become dominant

 

Ethical risks in Nutritional care during COVID-19
  • First, do no harm – Remember best practice, consider actions with regards to CRIT-CON levels
  • Be aware of deviation from best practice

Example 1. Are HMB / probiotics / Vit C / Vit D justified just because of the pandemic?  – no evidence for these in normal critical care, let alone COVID-19

Example 2. Running out of feeding pumps – what to do, especially in pts proned for long duration

Systematic review: Administration of enteral nutrition in prone position  

  • sparse, limited quality data on Enteral feeding in prone pts
  • contradictory results re gastric residual volumes

Largest study of Enteral Nutrition in prone pts for ARDS

  • only 47 pts
  • apparently safe, BUT pts were not in prone position for long duration as seen in COVID-19 pts

==>> BDA provided guidance in response to these issues

  • Avoid bolus feeding in prone position (no evid of safety)
  • Consider gravity feeding if no pumps available

 

Effect of intermittent / continuous feeding on muscle wasting (Phase 2 clinical trial)

  • intermittent feeding safe, tolerable and feasible in supine pts (no prone pts)
  • but did not ameliorate acute skeletal muscle wasting

==>> BDA provided guidance on the basis of this trial

  • bolus feed ONLY if no pump available, NOT FOR prone / GI tract abnormalities / via jejunal tube
  • while safe, it is NOT standard of care

 

LESSONS:
  1. Do not get caught up in moral confusion – maintain best practice
  2. Refer to guidelines and updates, especially in evolving situation
  3. Leave unproven interventions to RCTs

 

THE BAD: Persistent critical illness

UK Length of stay (LOS) in ICU survivors – mean 4.7 days  (stable for past 5 years)

Internationally, LOS in COVID-19 survivors  – median 12 days (5-28d) = more than twice usual LOS

Day 9/10 –> transition to Persistent critical illness

  • antecedent characteristics e.g. age / pre-existing conditions more likely to kill than the illness itself (probably related to duration mech ventilation / muscle wasting)
  • only 16% pts stay longer than 9/10 days
  • COVID-19 pts (median LOS 12 days) are therefore all at risk of Persistent critical illness

  • Rapid recovery –> Basic ADLs at 1-year
  • Persistent critical illness –> no ADLs, not mobilising at 1-year

Muscle protein synthesis essential for rehabilitation from muscle wasting

Metabolic abnormalities likely limit energy and protein utilisation during persistent critical illness

Increased LOS / severity of illness = more severe muscle wasting

Muscle protein synthesis on Day 1 of critical illness is the same as Fasted controls (despite feeding) and has a variable recovery period

Muscle protein synthesis takes up to 30days to normalise 

Muscle protein synthesis is highly energy dependent

Critical illness (hypoxia + inflammation) reduces ATP generation from glucose and fatty acids

 

THE GOOD: Teamwork for rehabilitation

Mortality from COVID-19 is falling – more pts will survive

They WILL need nutrition, protein and energy for late phase of rehab

UK initiative to assess pts for post-ICU syndrome, initiate early rehabilitation, establish a framework to be used for both COVID and non-COVID pts

 

* Each coloured dot represents a specialist therapy

  • size of dots reflects extent of requirement for that therapy
  • lines indicate correlation; thickness of lines indicates strength of correlation

==>> In critical illness, there is an almost equal need for all classes of specialist therapy, with interlinkage between them and no single therapy more crucial than the others

 

Exercise ALONE is catabolic

Exercise must be combined with adequate protein intake

Older pts need more exercise, and have a narrower window for muscle synthesis post-exercise  –>> Quantity and Timing of feeding are both important

Before COVID-19: prevalence of  laryngeal pain (76%) and dysphagia (49%) in crit illness

COVID-19 likely to result in a ‘pandemic’ of SALT issues including dysphagia, preventing pts from successful oral feeding

* A ‘cheat sheet’ for ICU doctors, nurses and dieticians

Occupational Therapist: not available in all centres; roles expanding in COVID-19 – assessment / guidance on meal preparation, positioning, adaptive cutlery etc… Ask an Occupational Therapist to see how they can help!

Anxiety, depression and PTSD extremely common – 50% critically ill pts will have combination of these

  • ICD-10 criteria for anxiety: difficulty swallowing, nausea, abdo distress
  • ICD-10 criteria for depression: loss of interest / pleasure, alteration in appetite
  • Will impact on eating and nutrition

Deprivation = major reason for poor quality nutrition + protein intake – pts from deprived background unlikely to have good nutrition / good recovery

 

LESSONS:

  1. COVID-19 pts likely to have metabolic derangements of persistent critical illness
  2. Rehabilitation is a team game
  3. Be aware of deprivation as a significant barrier to rehab + recovery –> it will undo all the good work by healthcare team

What is new in Metabolic and Nutritional care?

Annika Blaser (Luzern, Switzerland)

Updates covered: ESPEN guidelines, GI Bleed prophylaxis, Future studies in GI dysfunction

ESPEN Guidelines

Recent evidence suggests Early Full nutrition (any route) is harmful

  • In health, glucose infusion suppresses endog. glucose production
  • NOT seen in crit illness e.g. burns, sepsis, trauma, pancreatitis etc –> ongoing endog. glucose production and energy expenditure. Early Full feeding results in OVERFEEDING

Autophagy: Evolutionary stress response which removes damaged organelles and degrades pathogens

  • In catabolic state, cells may be more effective at autophagy and more resilient to various stressors
  • Autophagy and catabolism likely inevitable in critical illness; nutrition suppresses autophagy   –>> Don’t be too afraid of catabolism in early phase of acute illness

All pts on ICU >48hrs with critical illness are at risk of malnutrition

* EN increases splanchnic blood flow and O2 demand, which may not be met early on in critical illness despite additional O2 delivery –> risk mesenteric ischaemia in early full EN (vs PN)

Summary:

a. No specific feeding recommendation for specific pt sub-groups

b. Focus on Not causing harm through overfeeding, refeeding, underfeeding or GI complications

c. Nutritional support cannot be individualised using only clinical diagnosis / pt demographics without considering changes and adaptation in metabolism (however no metabolic monitor available)

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GI Bleed Prophylaxis

BMJ rapid recommendations triggered by SUP-ICU trial showing no benefit of stress ulcer prophylaxis in pts at risk

Multitude of risk factors for GI bleed in ICU pts incl. mech ventilation, coagulopathy, shock sepsis, renal / hepatic failure etc… Enteral nutrition is the ONLY protective factor

Recommend:

a. Restrict acid suppression to pts with >4% GIB risk

b. PPI preferable, H2 antagonist also acceptable, NOT sucralfate

* Suggested mortality risk with PPI in severe illness – needs exploring, future SUP may be even further restricted

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GI Dysfunction in Critical Illness

Proposed 32 studies to facilitate overview of GI dysfunction and plan future research

Areas needing consensus:

  • EN intolerance
  • core set daily monitoring of GI function
  • core set outcomes
  • US protocol to assess GI function
  • descriptive definition of non-occlusive mesenteric ischaemia
  • reference methods to measure gastric emptying / nutrient absorption / barrier dysfunction