Nutri&on)support)in)the)cri&cally)ill)pa&ent)

Brian)K.)Gehlbach,)MD)Division)of)Pulmonary,)Cri&cal)Care,)&)

)))Occupa&onal)Medicine)University)of)Iowa)

!!

Disclosures)None!

Objec&ves)1.  Cite!evidence.based!strategies!for!the!

provision!of!enteral!nutri9on!in!the!ICU.!2.  Describe!the!clinical!manifesta9ons!and!

preven9on!of!the!refeeding!syndrome.!3.  Cite!the!differen9al!diagnosis!for!diarrhea!

in!the!cri9cally!ill!pa9ent.!

Cri&cal)illness)is)metabolically)costly)

Long!CL!et!al.!JPEN!1979.

Changes)in)res&ng)metabolic)

expenditure)with)&me)

The)intes&nal)microflora)is)altered)during)cri&cal)illness)

Adapted!from!Alverdy!JC!et!al.!J!Leukoc!Biol!2008.!

Use)of)vasoac&ve)drugs)=!!intes9nal!ischemia,!Δ!in!mucosal!pH,!CO2!and!O2!!!

Highly)processed)enteral)nutri&on)±)parenteral)nutri&on!=!distal!bowel!nutrient!deficiency!

Mul&ple)an&bio&c)use)=!predominance!of!virulent!&!resistant!organisms!

Long)term)opiate)use)=!intes9nal!iner9a!±!bacterial!overgrowth.organisms!trapped—cannot!jump!to!new!host!

Yet,)most)studies)of)specific)nutri&onal)strategies)have)been)nega&ve,)and)some)show)harm.))

Why?)•  The!studies!aren’t!big!enough,!or!!

!good!enough?!•  The!pa9ents!are!too!heterogeneous?!•  Nutri9on!doesn’t!ma[er?!•  We!don’t!know!enough!(yet)?!

–  Ex.!nutri9on!&!autophagy!!

A)55)year)old)male)presents)with)pneumonia)and)ARDS.)Which)of)the)following)nutri&onal)strategies)is)best)supported)by)the)evidence?))A.  Targe9ng!a!blood!glucose!level!of!81!to!108!mg/dl.!!B.  The!administra9on!of!enteral!omega.3!fa[y!acid,!γ.

linolenic!acid,!and!an9oxidant!supplements.!C.  The!provision!of!enteral!nutri9on!plus!early!

supplemental!parenteral!nutri9on!as!needed!to!meet!caloric!goals.!!

D.  The!provision!of!trophic!enteral!feeds!for!the!first!6!days.!!

E.  Holding!enteral!feeds!for!gastric!residual!volumes!>!300!ml.!!

NEJM 2009. •  6104!medical!pts!expected!to!require!ICU!tx!for!≥!3!days!

!•  Intensive!(81!to!108)!vs!conven9onal!(≤!180)!control!

!•  Lower!mortality!with!conven9onal!glucose!control!

•  272!adults!with!ALI!•  No!benefit,!&!sugges9on!of!harm!!

Heyland!et!al.!NEJM!2013.!

•  Background:↓!glutamine!levels!associated!with!↑!mortality;!evidence!of!oxida9ve!stress!in!cri9cal!illness!

•  Result:!No!effect!of!an9oxidants;!glutamine!↑’d!mortality!

Rice!et!al.!ARDS!Network.!NEJM!2011.!

•  PN!ini9ated!on!Day!3!as!needed!to!achieve!caloric!goal!(EN!+!PN!=!Calculated!caloric!goal)!&!adjusted!daily!

•  Study!conducted!in!European!ICUs!following!European!guidelines.!Therefore,!“late!PN”!was!the!ac9ve!interven9on.!

•  BG!target!80.110.!Casaer!et!al.!NEJM!2011.!

The)Early)group)received)far)more)energy)than)the)Late)group…)

Casaer!et!al.!NEJM!2011.!

Total)Ene

rgy)

(kcal/kg/day))

Total)Ene

rgy)

%)of)target)

…but)there)were)be\er)outcomes)with)delayed)PN)

•  More!likely!to!be!“discharged!alive!earlier”!!

•  ↓!ICU!infec9ons!&!cholestasis!

•  ↓!MV!&!RRT!

Survival

Casaer!et!al.!NEJM!2011.!

In!a!post%hoc(analysis,!the!greatest!difference!occurred!in!pts!for!whom!early!EN!was!surgically!contraindicated!!(

Enteral)feeding)preserves)structure)&)func&on)of)GI)tract)

•  Prevents!atrophy!of!small!intes9nal!villi!

•  Maintains!gut!barrier!func9on!

•  Preserves!IgA!secre9on!

Ohta!Am!J!Surgery!2003.!

Ini&al)trophic)vs)full)enteral)feeding)in)pts)with)ALI:)the)EDEN)trial)•  Trophic!vs!full!enteral!

feeding!for!the!first!6!days!

•  No)difference!in!ven9lator.free!days,!60.day!mortality,!or!infec9ous!complica9ons!

•  Trophic!feeding!group!had!less!GI!intolerance!!

ARDSNetwork.!JAMA!2012.!

1000)adults)

Full)feeding)protocol)

Also)well)tolerated)!>)85%)of)pts)ini&ally)fed)using)a)gastric)tube)

ARDSNetwork.!JAMA!2012.!

“Doctor,)the)residual)is)(250,%300,%___,%etc)…should)we)hold)the)tube)feeds?)

•  Mul9center!RCT!of!no!gastric!residual!volume!monitoring!vs!250!ml!trigger!

•  Clinical!intolerance!=!regurgita9on!+/.!vomi9ng!

•  No)differences)in)VAP)rates)or)outcomes)

Development)of)VAP)

Reignier!et!al.!NEJM!2013.!

The)clinical)bo\om)line)for)monitoring)tolerance)of)enteral)feeding)

It!is!reasonable!to!rely!on!clinical!signs!for!evidence!of!feeding!intolerance.!At!a!

minimum,!a!higher!gastric!residual!volume!trigger—say,!400!cc–is!

warranted!

A)43)year)old)male)with)severe)obesity)(BMI)45))presents)with)respiratory)failure)requiring)intuba&on)&)MV.)Which)of)the)following)is)true)regarding)his)nutri&onal)support?)A.  Feeding!should!be!withheld!for!the!first!week.!!B.  The!presence!of!increased!nutrient!reserves!in!obesity!

will!confer!protec9on!against!the!loss!of!lean!body!mass.!

C.  He!should!receive!parenteral!nutri9on!in!order!to!reduce!the!risk!of!aspira9on.!

D.  The!use!of!a!hypocaloric!regimen!(60.70%!target!energy!requirements)!may!improve!insulin!sensi9vity.!

E.  His!dietary!plan!should!include!protein!restric9on!(e.g.!≤!1.5!g/kg!IBW/day).!

Considera&ons)for)the)cri&cally)ill)obese)pa&ent)•  The!“obesity!paradox”:!mild!to!moderate!obesity!(class!I!

and!II)!may!be!somewhat!protec9ve!in!CI!

•  Controlled!hypocaloric!regimens!may!reduce!fat!stores,!preserve!lean!body!mass,!and!increase!insulin!sensi9vity.!(ASPEN!guidelines).!–  60.70%!target!energy!requirements,!or!22.25!kcal/kg!ideal!body!weight/day.!

•  A[en9on!to!protein!!!–  BMI!30.40:!≥!2!g/kg!IBW/day!–  BMI!≥!40:!≥!2.5!g/kg!IBW/day!! McClave!JPEN!2011.!

A)65)year)old)homeless)man)with)a)history)of)alcohol)abuse,)chronic)pancrea&&s,)weight)loss,)and)severe)COPD)is)intubated)for)respiratory)failure.)A)feeding)tube)is)placed)and)full)enteral)feeding)is)ini&ated.))

Which)of)the)following)is)true?)A.  In!the!short!term,!full!enteral!feeding!may!impair!efforts!

at!discon9nuing!mechanical!ven9latory!support.!!B.  The!pa9ent!is!at!risk!for!volume!deple9on!caused!by!

hyperinsulinemia,!which!increases!the!renal!excre9on!of!Na.!

C.  The!pa9ent!is!at!risk!for!hyperkalemia!caused!by!transcellular!shiy!of!potassium.!

D.  Diarrhea!may!occur!as!the!result!of!longstanding!mucosal!hypertrophy.!

E.  The!presence!of!a!prolonged!PR!interval!may!indicate!the!presence!of!magnesium!deficiency.!

The)refeeding)syndrome)At)risk)Alcoholism!Ac9ve!cancer!+/.!tx!Malabsorp9on!!Poorly!controlled!diabetes!Chronic!liver!disease!COPD!AIDS!Ea9ng!disorders!Food!insecurity!!!!!

Manifesta&ons)•  Onset!usually!within!

several!days!of!↑!feeding!•  ↑!!insulin!&!synthesis!of!

glycogen,!protein,!&!fat!leading!to!↓!potassium,!phosphorus,!magnesium!

•  Cardiac!arrhythmias!&!CHF!•  Respiratory!muscle!

weakness!•  Convulsions!!

Preven&on:)Recognize)atkrisk)scenarios,)ini&ate)feeding)at)50%)of)energy)requirements)(permissive)underfeeding),)&)monitor)electrolytes)closely)

Malnutrii&on)warning)signs)•  Uninten9onal!weight!loss!>!10%!within!1.3!months!!•  Prolonged!fas9ng!or!NPO!status!>!7.10!days!•  Inadequate!nutri9onal!intake!>!10!days!•  <!70.80%!ideal!body!weight!•  Muscle!was9ng!•  Chronic!dysphagia!•  Persistent!N/V/D!!!Byrnes.!Curr!Opin!Clin!Nutr!Metab!Care!2011.!

Approach)to)diarrhea)Differen&al)diagnosis)

–  C.(difficile(–  Hyperosmolar!agents!(hypertonic!elixirs,!sorbitol.containing!meds)!

–  An9bio9cs,!other!medica9ons!– Mucosal!atrophy!!

Can)try)•  con9nuous!instead!of!bolus!feeding!•  a!formula!with!lower!osmolality!•  soluble!fiber.containing!formula9ons!(avoid!if!at!high!risk!for!

bowel!ischemia!or!severe!dysmo9lity)!

Summary)•  Use!the!gut!(the!corollary:!Avoid!TPN)!•  Use!“regular”!feeding!tubes!in!most!instances!•  The!op9mal!dose!of!nutri9on!is!not!known.!!•  Monitoring!of!enteral!feeding!should!be!based!primarily!on!clinical!criteria!

•  Iden9fy!pa9ents!at!risk!for!refeeding!syndrome!•  Diarrhea!can!be!from!C.(difficile,!meds,!mucosal!atrophy,!formula9on!