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The Young Patient Who Collapses

229

What are the main clinical concerns and where

would you like Belle to be managed?



Severe electrolyte disturbance.



Clinical presentation and ultrasound evidence which could be consis-

tent with cardiac failure and associated pulmonary oedema.



Long QTc interval on ECG.



Dehydration and renal impairment (even modestly increased levels

could suggest signicant renal injury in patients with extremely low

body weight).



Possible starvation ketosis.



Low body mass index (BMI) and possible psychiatric disorder.

Belle should be admitted to a high-

dependency facility where she can be

carefully monitored and managed.

Which other healthcare professionals should you

involve in Belle’s care?



Cardiologist



Dietitian



Psychiatrist



General physician



The full critical care MDT

What is anorexia?

Anorexia means loss of appetite and is seen in organic disorders (e.g. cancer)

and psychological problems (e.g. depression).

Anorexia nervosa is a specic psychiatric diagnosis according to the ICD-

11 (International Statistical Classication of Diseases and Related Health

Problems version 11) and DSM- 5 (Diagnostic and Statistical Manual of

Mental Disorders). Signs and symptoms include a distorted perception

of body shape or weight, behavioural issues regarding food and control

of calorie intake, as well as other psychological and physical issues, most

notably low BMI.

Diagnosis involves the following (as per ICD-11):

BMI <18.5 kg/m

or rapid weight loss more than 20% total body weight

in 6 months

2. Restriction of calorie intake and extreme fear of weight gain often asso-

ciated with the following behaviours:

You ask the liaison psychiatrist to review Belle urgently. They attend to

review her in the resuscitation department, and, after thorough review, they

tell you that their working diagnosis is anorexia nervosa or anorexia nervosa

with bulimic subtype. She has not taken an overdose on this occasion, but

the psychiatrist believes that Belle is at risk of harm to herself if she were

to be allowed to go home now.

https://t.me/medicina_free

Clinical Cases in Critical Care

230



Purging



Vomiting



Excessive exercise



Use of appetite suppressants, diuretics or laxatives

Distorted body image and/or excessive pre-occupation with body

weight or shape.

There may be amenorrhoea and/or loss of libido in adults.

What are the cardiovascular complications

anorexia and starvation?



Bradycardia and long QTc interval.



Severe autonomic dysfunction leading to tachycardia.



Orthostatic hypotension secondary to severe dehydration.



Hypotension, even in sitting position.



Adaptive vagal hyperactivity in chronic states.



Loss of cardiac muscle mass over time (up to 50% decrease in LV mass)

which can lead to overall decrease in cardiac output.



Mitral valve prolapse, pericardial eusions and cardiomyopathies have

been documented.

The precise pathophysiology of cardiac failure in anorexia and starvation

is not clearly elucidated. There is a risk of cardiac failure with aggressive

correction of dehydration.

How do you proceed?

This is a difficult situation. Proceeding to admit to critical care depends on

whether Belle has capacity or not (see Case 19). Persuading her to stay is the ideal

option. Belle has just been treated for a life-

threatening arrhythmia which could

re- develop at any time. She has a metabolic acidosis secondary to starvation ketosis

and severely deranged electrolytes as a result of malnutrition. In addition, the

psychiatrist believes she would be a risk to herself if she were allowed to go home.

Given her malnutrition and unstable clinical state, it is likely that she does

not possess the capacity to make this decision. Best interests principles outlined

in the Mental Capacity Act 2005 and DoLS (Deprivation of Liberty Safeguards)

may be required to treat her life- threatening medical problems (including

treatment for malnutrition). A compulsory treatment order using section2 of

the Mental Health Act 2007 (England) allows assessment and treatment for

up to 28 days (the law varies in dierent parts of the UK and throughout the

world). Consider discussing whether a patient should be treated against their

will with the hospital’s legal team.

Belle should be encouraged at every opportunity to engage with her

treatment as she is likely to require medical and psychiatric support for many

months/years.

You explain your findings to Belle. You tell her that she is very unwell

and that you would like to move her to the critical care unit for ongoing

management. She refuses.

https://t.me/medicina_free

The Young Patient Who Collapses

231

Do you know any guidelines for the management

of critically unwell patients with anorexia?

MEED (Medical Emergencies in Eating Disorders) was published in 2022. This doc-

ument replaces MARSIPAN and Junior MARSIPAN for those aged under 18

years

(Management of Really Sick Patients with Anorexia Nervosa). This extensive

document includes advice on nutritional, psychiatric and medical management.

It provides a risk assessment framework using a ‘trac lights’ system.

NICE also publishes guidelines on managing patients with eating disorders

(NG69, updated 2020).

What is Belle’s BMI?

BMI (kg/m

) is used as a rough guide to measure whether a person is a

‘healthy weight’.

Weight in kg

Height in m

The NHS recommended range for most adults is 18.5–24.9 kg/m

Criticisms of BMI calculation include the fact it does not reect percentage

body fat or muscle mass. A falsely high BMI will be recorded in the presence

of oedema or uid overload. Recommended healthy ranges consider neither

ethnic variability regarding risk of diabetes nor the true nutritional status of

the patient. However, BMI can be useful as a quick guide to whether the patient

is under-

or overweight.

Belle’s calculation:

178

12 9

A healthy weight range for an 18- year- old woman of this height would be

58.6–78.9 kg.

According to MEED, patients over 18 years old with BMI <13 have high

impending risk to life (BMI > 15 have a low impending risk to life).

What other features can be used to categorise risk

in patients with anorexia nervosa?

Physical examination



Reduced muscle power



Low score on sit- up- squat- stand test (two or less)



Postural hypotension



Hypothermia (<35 °C)

Fortunately, after discussion with her parents, Belle agrees to be admitted to the

HDU. She tolerates the insertion of invasive monitoring, a nasogastric tube and

a urinary catheter. Her weight is measured as 41

kg and her height is 178 cm.

https://t.me/medicina_free

Clinical Cases in Critical Care

232

Blood tests



Hyponatraemia (<130 mmol/l)



Hypokalaemia (<3.0 mmol/l)



Raised transaminases



Hypoglycaemia (<3 mmol/l)



Raised urea or creatinine outside the typical range

ECG



Bradycardia (<40 bpm)



Prolonged QTc interval (>450 ms)



Non- specic T- wave changes



Signs of hypokalaemia

What are the stages of starvation?

Starvation is an adaptive state where the human body eventually becomes

hypometabolic to preserve glucose for brain use (Table18.1). It is worth noting

that the brain is also adept at using ketones as a source of energy.

Table 18.1: Phases of starvation.

Phase Comments

Phase 1

(up to 6 h)

Increase in catecholamines and cortisol.

Decrease in insulin.

Hepatic glycogenolysis and gluconeogenesis.

Blood glucose levels are maintained.

Phase 2

(6–72 h,

but may

be up to

weeks)

Once glycogen stores depleted gluconeogenesis continues using

lactate, with glutamine and alanine from body proteins.

Glutamine derived almost entirely from gut protein content.

Lipolysis releases glycerol, the carbon from which can be used with

carbon from muscle protein hydrolysis for de novo glucose synthesis.

Proteolysis in skeletal muscle releases amino acids.

Phase 3

(72 h to

2 wks)

Increased hepatic synthesis of ketone bodies by day 3 attempts to

minimise loss of body protein.

Body attempts to conserve proteins but with prolonged fasting,

amino acids from skeletal muscle are used in gluconeogenesis.

Brain uses ketones metabolised from free fatty acids (acetoacetate

and beta- hydroxybutyrate). By 4 days into starvation, 70% of the

brain’s energy is derived from ketones.

Cardiac muscle can use ketones as a fuel source.

Note that in the presence of sepsis, ketone production is impaired,

resulting in signicantly greater loss of lean body mass in the rst

week as proteins are mobilised and specic amino acids released

are utilised for gluconeogenesis.

Phase 4

(beyond

2 wks)

Fat stores depleted.

Proteolysis becomes only means of generating energy.

Loss of lean body mass and organ tissue reduces resting energy

expenditure.

Eventually, chronically reduced basal metabolic rate (BMR) with

reduced body weight.

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The Young Patient Who Collapses

233

Do you start full nasogastric feed immediately?

Justify your answer.

No. From the history and physical examination, there is suspicion that Belle is

in a state of starvation. Care must be taken to avoid inducing potentially fatal

refeeding syndrome.

Belle’s basal metabolic rate (BMR) will probably have reduced by up to

25% and her body has adapted to utilising fat and protein for energy rather

than carbohydrate. Her brain will have switched to using ketones as its main

energy source.

What is refeeding syndrome?

Prolonged starvation reduces overall cell mass, along with intracellular mineral

content (serum levels may well be maintained). When sugars are reintroduced

suddenly, glycaemia leads to increased insulin and decreased glucagon levels.

This stimulates synthesis of proteins, fats and glycogen. These synthetic processes

would consume Belle’s modest plasma stores of intracellular ions (potassium,

phosphate and magnesium). Provision of carbohydrate generates a specic

demand for B group vitamins involved in metabolism, specically thiamine.

Refeeding syndrome results in massive uid shifts and mineral depletion,

particularly hypophosphataemia. Other clinical features include hypokalae-

mia, hypomagnesaemia, hyperglycaemia, arrhythmias, pulmonary oedema

and cardiac failure.

Which other patients are particularly at risk

of refeeding syndrome?

NICE Guidance was published in 2006 (CG32) to help identify those at risk.

Refeeding syndrome should be considered a risk where the patient has one

or more of these factors:



BMI <16kg/m



Unintentional weight loss >15% during preceding 3–6 months



Minimal nutritional intake for >10 days



Low levels of potassium, phosphate or magnesium before commence-

ment of feeding

Or two or more of the following:



BMI <18.5 kg/m



Unintentional weight loss >10% during preceding 3–6 months



Minimal nutritional intake for >5days



History of alcohol or drug misuse

Belle meets the rst criteria with her BMI <16 kg/m

. From the collateral

history, she has probably also had minimal nutritional intake for more than

10 days. She already has low potassium, magnesium and phosphate.

Other patient groups who should be assessed for risk of refeeding syndrome

include the following:

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Clinical Cases in Critical Care

234



Patients with cancer.



Those with malabsorption or maldigestion, e.g. inammatory bowel dis-

ease, pancreatitis, short bowel syndrome, etc. Note that food provision

will not increase the risk of refeeding in this group if feed is not absorbed.

Review feed options with the dietitian, e.g. hydrolysed NG formula or

parenteral nutrition.



Frail patients.



Uncontrolled diabetes mellitus.



Postoperative patients– particularly those undergoing bowel surgery

or surgery for conditions which reduce the ability to eat, e.g. head and

neck cancers, etc.



Chronic alcoholism.



Morbidly obese patients.



Those with increased losses– potassium and magnesium losses with

loop diuretics, magnesium losses with high-

output ileostomies.



Patients with substantial conrmed weight loss commencing enteral or

parenteral nutrition.

How will you manage Belle to avoid refeeding

syndrome?

This strategy is best undertaken with the advice of a dietitian and based on

NICE guidance.



Identify Belle as being at risk.



Check her potassium, calcium, phosphate and magnesium.



Administer thiamine 200–300 mg orally, high- potency vitamin B tab-

lets three times daily, and a trace element supplement once daily before

feeding commences, as per NICE guidance. Check with the ICU phar-

macist as to whether typical doses need adjustment for low body weight.



Start feed at a low rate and slowly increase over the following week.



Rehydrate carefully with electrolyte supplements, monitoring fluid

balance closely and physical symptoms of uid overload.



Closely monitor and replace electrolytes as required for the rst 2weeks

in conjunction with advancing nutritional intake.



If oral/enteral phosphate and magnesium fail to correct levels, mea-

sure vitamin D and PTH status. Vitamin D deciency can compromise

calcium, phosphate and magnesium uptake. If vitamin D levels are low,

supplement carefully to avoid hypervitaminosis D due to lack of adipose

tissue and liver mass to store excess.

Would you use parenteral nutrition to feed Belle?

There is no indication in Belle’s case for parenteral nutrition since there is no

evidence of gut failure, although gut morphology will have adapted due to

the absence of food and glutamine provision for gluconeogenesis. There are

multiple complications secondary to parenteral nutrition, so it is to be avoided

where possible in favour of the enteral route.

https://t.me/medicina_free

The Young Patient Who Collapses

235

What are the risks associated with parenteral

nutrition?



Risks associated with insertion or presence of the intravenous catheter

 Infection

 Vascular injury

 Air embolus

 Bleeding

 Extravasation

 Thrombosis



Risks associated with TPN (total parenteral nutrition)

 Electrolyte imbalance

 Hyper/hypoglycaemia

 Micronutrient deficiencies

 Liver dysfunction/hyperammonaemia

 Volume overload

 Cholecystitis

 Metabolic bone disease can develop with long term use

What are Belle’s daily nutritional requirements?

There are various methods of calculating a patient’s nutritional

requirements.

The Harris–Benedict formula calculates BMR using height, weight, sex, age

and general level of activity. The calculation is best applied to healthy individ-

uals. BMR is increased in fever (by 10% per 1 °C above 37 °C), and in burns,

sepsis and surgery to varying degrees.

Belle’s case is extremely challenging due to her chronic malnutrition and

will require frequent liaison with an experienced dietitian.

Nutrition provides macronutrients and micronutrients and the following is

a rough estimate for established enteral feeding but which would be calculated

and adjusted for each individual.

Current enteral feeds provide a full prole of vitamins, minerals and trace

elements. After the rst week or two of stabilisation, the goal for weight gain

is 0.5–1.0

kg per week. This is achieved by gradual increase in enteral nutri-

tion provision. It is not uncommon for those with a high- risk BMI to require

50–90 kcal/kg/d of actual body weight before weight gain becomes consistent

(Table18.2).

Zinc deciency can manifest as skin rash typical of the condition acroder-

matitis enteropathica. Once hydration and nutrition are established, consider

empirical zinc supplement for 3 days. Note that zinc excess competitively

inhibits iron, calcium and magnesium uptake across the gut.

You ask the critical care dietitian to design a nutritional plan for Belle.

You notice Belle has an erythematous rash. The dietitian suggests this could

be due to zinc deciency.

https://t.me/medicina_free

Clinical Cases in Critical Care

236

What are the non- cardiac complications of severe

malnutrition?



Anaemia is common– related to iron deciency and vitamin B12/folate

deciency.



Immune suppression.



Oedema in the lower limbs and abdomen.



Flaky skin.



Apathy.



Listlessness.



Eventually, marasmus (more usually in infants) and kwashiorkor (more

usual in children) may develop.

Table 18.2: Nutritional requirements for adults.

Energy 25–35 kcal/kg/d is usual approximate requirement for healthy

adult.

No absolute recommendation.

kcal/kg/d is a good starting point for younger adults

Intake should be increased 200

kcal/d until weight gain of 0.5–

1.0

kg/wk is achieved.

If hypophosphataemia occurs, this should be corrected before

feed is advanced further.

Protein 1.5

g/kg/d

Fats Approximately a third of daily calorie intake should come from

fats. Standard enteral feed is approximately 55% carbohydrate

and 35% fat

Carbohydrates 2–7 g/kg/d (depending on health and exercise)

Water 25–35

ml/kg/d

Sodium 0.9–1.2

mmol/kg/d

Potassium 1–2

mmol/kg/d

Calcium 0.25

mmol/kg/d

Phosphate 0.3–0.6

mmol/kg/d

Magnesium 0.2–0.4

mmol/kg/d

Other additives Zinc, copper, iron, chromium, manganese, selenium,

molybdenum. May also need to supplement vitamins A, B, C, D, E

and K, folate and niacin, etc.

After 13 days in critical care, you manage to correct Belle's electrolyte

imbalances and establish her on enteral feed. She has remained stable from

a cardiac point of view and is now safe to be discharged to a medical ward.

https://t.me/medicina_free

The Young Patient Who Collapses

237

What are the possible outcomes for Belle now?

Mortality risk in anorexia is approximately 6%. With appropriate treatment and

follow-

up, Belle could be part of the 50% who make a full recovery. Approxi-

mately 20% will suer relapses in their lifetime. Belle is likely to require long-

term follow- up with psychiatric and nutritional support.