Nutrition in Sick Patients
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Why it is important?
What is the evidence?
How to treat and prevent malnutrition
Which route to choose
What sort of tubes are there?
Calculations and refeeding syndrome
‘A slender and restricted diet is
always dangerous in chronic and in
acute diseases’
Hippocrates 400 B.C.
‘Do not let your patients starve and when
you offer them nutrition support, do so by
the safest, simplest, most effective route.’
Dr Mike Stroud Feb 2006
Chair of NICE committee
Why is it important?
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McWhirter and Pennington 1994:
40% of hospital patients malnourished on
admission and nutritional state usually
deteriorates in hospital. Costs £3.8bn/yr
Critically ill are often malnourished:
admitted after major surgery, following
extended illness or hospital stay, high rate
of alcohol/drug misuse, poor self care,
elderly, co-existing disease etc
Effects of malnutrition
Effects of Undernutrition
Ventilation - loss of
muscle & hypoxic
responses
Psychology –
depression & apathy
Immunity – Increased risk
of infection
liver fatty change,
functional decline
necrosis, fibrosis
Decreased Cardiac output
Renal function - loss of
ability to excrete
Na & H2O
Impaired wound
healing
Hypothermia
Impaired gut
integrity and
immunity
Loss of strength
Anorexia
? Micronutrient deficiency
Nutritional State and Complications
HDU
25
20
15
10
5
0
Complications
Poor
No Complications
Intermediate
Good
Metabolic response to starvation
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Aims to minimize impact on vital organs
and conserve energy
Reduction in tissue metabolism
Decreased metabolic rate
Decreased temperature
Reduction in physical activity
Protein loss
Starvation
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Bobby Sands – lost 7 kg in first 17 days
Approx 0.5kg/day
Died at 65 days (9 weeks)
Not expending excess energy, not in ICU
ICU patients – often have increased
metabolic demands AND starvation
Complex metabolic changes
Critical illness: Metabolic demand
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sympathetic nervous system stimulation
acute phase response: cytokines
severe catabolism
organ failure, poor gut function
increased oxygen requirements
poor wound healing
insulin resistance: hyperglycaemia
Wasting
iatrogenic problems – drugs/HAI
Starvation and ICU
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Complex metabolic changes
Weight loss is high if sick patients are not
fed
But nutrients are not always adequately
absorbed or metabolised
Weight loss occurs despite feeding
Important to feed patients but with regard
to their individual needs and complexities.
ICU nutrition
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Used to be everything mixed up and given
via NG tube
Risk of infection
Now specialised feeds are used in sterile
packaging
What is the evidence in HDU?
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Early nutrition is important
Bowel function may recover within 12 hours
Use the gut if you can
Bowel sounds are not a good indication of bowel
function
Ileus is common
Giving pre-op sugary drinks can speed bowel
function (ERAS)
Use EN + TPN to achieve goals
How do we treat/prevent
malnutrition?
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Whose role is it?
How do we treat/prevent
malnutrition?
Think about it
 Identify it – history – weight loss, intake,
vomiting, diarrhoea, IBD, cancer etc:
doctors and nurses
 Weight- nurses
 Optimise intake –
oral/enteral/parenteral:
doctors/dietitians/nurses
Monitor – nurses/dietitians/doctors
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Organisation of Nutrition Support
Screen
Recognise
Treat
Oral
Enteral
Monitor & Review
3. NICE Guidelines for Nutrition Support in Adults 2006
Parenteral
Step 1: Screen
MUST Malnutrition Universal Screening Tool
from BAPEN
 BMI score,
 weight loss score,
 acute disease effect score together gives
low, medium and high risk of malnutrition:
if high, patient must be treated early
At risk of malnutrition
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Eaten little or nothing for 5 days and
unlikely to do so for at least next 5 days
Poor absorptive capacity and/or high
nutrient losses and/or increased
nutritional needs due to catabolism etc
Patient at risk
of becoming
malnourished
3. NICE Guidelines for Nutrition Support in Adults 2006
Malnourished
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BMI less than 18.5 Kg/m2
Weight loss > 10% within last 3-6
months
BMI < 20Kg/m2 and unintentional weight
loss > 5% in last 3-6 months
Patient already
malnourished
3. NICE Guidelines for Nutrition Support in Adults 2006
Weighing Patients
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Important for nutrition screening/dosage
Drug dosages
Cardiac output monitoring
Fluid balance
CT scanning
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Estimation?
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Routes: Enteral
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Preserves intestinal mucosal structure and
function
More physiological
Reduced risk of infectious complications
£6 vs £66
Routes
Of feeding
Naso-gastric Feeding
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Risk of aspiration in ICU: HOB 30 degrees
Don’t start feed at night
Risk of displacement
High aspirates and inadequate calories
common in ICU
PEG/gastrostomy feeding for long-term
Jejunal Feeding
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Jejunal feed: via a tube placed
Trans-nasally by endoscopy,
radiologically, at the bedside.
Into the jejunum either at laparotomy or
laparoscopy
May reduce incidence of aspiration
Often increases dose of EN given over NG
Why do we use TPN?
Parenteral Nutrition
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GI tract is not functional
GI tract cannot be accessed
Inadequate GI feeding:
Optimise enteral first if possible; if not
absorbing start TPN on day 3-7 depending
on nutritional state
TPN
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Doctors decide patient needs it
Dietitian sees patient
Decides best regime
Orders bag from pharmacy
Made up aseptically to requirements
Start low and build up
Monitor bloods
Access for PN
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Usually central line in ICU – keep a clean
port if PN may be needed. 5 lumen
Short term PN – can have PIC (need a
different formula) or PICC
Long-term TPN – tunnelled subclavian
catheter (Hickman) or subcutaneous port
is usually inserted – OBSERVE STRICT
ASEPSIS if handling these lines.
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Tubes and Lines
Complications
Constipation
 Diarrhoea – important points?
 Intolerance: ? Sepsis
Use pro-kinetics, NJ feeding, drugs
 Line sepsis
 Ileus – Avoid opioids, optimise fluid
balance and electrolytes, ?trickle of feed
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Overfeeding
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Lactic acidosis
Hyperglycaemia
Increased infections
Liver impairment (Alk phos, ALT, GGT,
acalculous cholecystitis)
Persistent pyrexia
How much to give – general
recommendations
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Prescription calculated by dietitian
Schofield equation e.g. for 60-74 year old
woman: BMR = (9.2x weight in kg) + 687,
(tables available)=requirement in Kcal/24hr
Add Activity factor and stress factor e.g. 10%
for bedbound + 20-60% for sepsis – burns
i.e for 65kg woman ventilated woman with
sepsis this works out as 1670 Kcal = approx 25
Kcal/kg/24hr
Rough guide to start: 25 Kcal/kg/day total
energy. Increase to 30 as patient improves
How much to give – general
recommendations
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1.25g/kg/day protein more just gets excreted
30ml fluid/kg/24 hours. Add 100-200ml/day for
each degree of temperature
Account for excess losses
Adequate electrolytes, micronutrients etc
Avoid overfeeding
Obesity: feed to BMR no stress factor unless
stress is severe e.g. burns/trauma
Refeeding Syndrome
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1944 conscientious objectors/concentration
camps – CCF when fed
Starvation 1st 24-72 hours – body uses glycogen
stores for gluconeogenesis, 72+ hours – FFA
oxidation to ketones, sparing protein.
Feeding – metabolism shifts back to glucose –
ATP and 2-3DPG produced. Phosphate drops
and K and Mg shift into cells due to anabolism
and insulin release.
Extra-cellular fluid expansion and thiamine B1
deficiency occur (co-factor in CH metabolism).
Refeeding Syndrome
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Unlikely to be a clear diagnosis
Contributes to fluid imbalances,
arrhythmias, muscle weakness, failure to
wean, cardiac failure
Awareness of the possibility is important:
nutritional history and electrolytes
Remember in HDU patients too – may not
be fed for a long time
Risk of re-feeding syndrome
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One or more of the following:
BMI less than 16 kg/m2
unintentional weight loss greater than
15% within the last 3-6 months
little or no nutritional intake for more
than 10 days
Very low levels of potassium, phosphate
or magnesium prior to feeding
NICE Guidelines for Nutrition
Support in Adults 2006
Risk of re-feeding syndrome
Two or more of the following:
 BMI less than 18.5 kg/m2
 unintentional weight loss greater than
10% within the last 3-6 months
 little or no nutritional intake for more than
5 days
 a history of alcohol abuse or drugs
including insulin, chemotherapy, antacids
or diuretics
Managing refeeding problems
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start nutrition support at 10 kcal/kg/day
maximum
increase levels slowly
restore circulatory volume and monitor
fluid balance and clinical status
provide multivitamin/trace element
supplementation: Pabrinex (B1,B2,C) o.d.
or thiamine B1 +Vigranon B before feed
provide extra Phosphate, K+ and Mg2+
NICE Guidelines for Nutrition
Support in Adults 2006
Complex nutrition: Monitoring
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U & Es, phosphate, calcium, magnesium
Glucose
LFTs
Fluid balance
Haematology
Weight
Trace elements if long-term
Conclusion
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Do not forget about feeding
Keep an eye on whether nutritional
targets are being met
Speak to the surgeons and dietitian
Remember refeeding syndrome
Do not be reluctant to start PN in a
supplemental capacity
Avoid hyperglycaemia
Nutrition is often neglected