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OverviewAetiologyPathophysiologyClinical features and red flagsInvestigationsDifferential diagnosisManagementComplicationsMonitoring and follow-upSpecial situationsCommon pitfallsQuestionsSources
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Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.

Medical instability and emergency admission criteria

Psychiatry · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

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One unstable domain can demand urgent care

An awake heart rate below 40 beats/minute, recurrent syncope with marked postural change, severe dehydration, hypothermia, major ECG or electrolyte abnormality, hypoglycaemia, acute food or fluid refusal, organ dysfunction or serious suicide risk can indicate impending risk to life.

Action: Use ABCDE, bedside glucose, full observations and immediate senior medical or paediatric review; obtain ECG and urgent laboratory tests and contact the specialist eating-disorder team. Admit for medical stabilisation and monitored refeeding when these cannot be delivered safely elsewhere, selecting ward, HDU or specialist setting by the active risks rather than BMI alone.

Overview

Apply the all-age MEED framework to identify impending risk to life, choose an appropriate admission setting, and avoid false reassurance from weight, appearance or isolated normal tests.

Eating-disorder emergencies are often missed because the person is walking, conversing or not visibly underweight. Starvation can blunt ordinary inflammatory and cardiovascular responses, while purging can cause abrupt biochemical danger at any weight. The MEED framework therefore examines multiple domains: trajectory and age-adjusted weight, cardiovascular observations, hydration, temperature, muscle function, ECG, biochemical and haematological findings, intake and behaviours, engagement, exercise, purging, self-harm and support. No single domain safely describes the whole risk.

MEED uses green, amber and red to signal low, alert and high impending risk to life. It states that one or more red ratings or two or more amber ratings should probably be considered high risk, but also warns that a red item in one domain is not necessarily equivalent to another. Use the framework to structure senior clinical judgement, not to automate admission or discharge. Repeat measures when technique, anxiety, recent activity, water loading or concealed behaviour could distort them.

Practice

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PsychiatryOriginal SBA

Admission beyond BMI

An adult with BMI 16 has lost more than 1 kg weekly for two weeks, has recurrent syncope and an awake heart rate of 38. Which decision is safest?

Choose one answer, then submit
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Sources and review status3 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • RCPsych CR233 Medical Emergencies in Eating DisordersUpdated December 2025; risk framework, admission and transfer guidance.
  • NICE NG69 eating disorders recommendationsEmergency care and inpatient or day-patient decisions.
  • NICE QS175 eating disorders quality standardTimely assessment and coordinated age-appropriate treatment.

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateComplete draftClinical stateAwaiting reviewJurisdictionUnited Kingdom
Several red examples are memorable because they require action: awake heart rate below 40 beats/minute; adult BMI below 13 or under-18 median BMI below 70%; severe dehydration; marked hypothermia; serious ECG abnormality; potassium below 2.5 mmol/L; glucose below 3 mmol/L; falling phosphate; and life-threatening medical illness. Adult postural red risk is a combined pattern of standing systolic pressure below 90 mmHg with recurrent syncope and a systolic drop over 20 mmHg or pulse rise over 30 beats/minute. Paediatric centiles and the MEED age-specific pulse change must be used for younger patients.

Admission is a treatment decision, not a reward or punishment. NICE advises medical inpatient or day-patient care when severe compromise needs stabilisation and refeeding that cannot be delivered safely as an outpatient, and rejects an absolute BMI admission threshold. An acute medical or paediatric ward is appropriate for unstable electrolytes, hypoglycaemia, organ failure, severe dehydration or need for high-dependency support. A specialist eating-disorder bed may be suitable when it can provide the necessary medical monitoring and has robust transfer arrangements.

Safe care is shared care. A written plan specifies nutrition, thiamine, fluids, electrolyte replacement, ECG or cardiac monitoring, blood frequency, activity, observation of meals and compensatory behaviours, capacity or mental-health legislation, and thresholds for ICU or specialist transfer. If a specialist bed is unavailable, the acute ward remains responsible for physical treatment with regular eating-disorder input. Discharge requires stable physiology, a feasible intake and monitoring plan, identified result ownership and rapid follow-up; a single improved pulse is insufficient.

Key points

  • MEED is an all-age traffic-light aid, not a score that replaces judgement; one red or two amber ratings should probably be treated as high risk and prompts review of the detailed management table.
  • High-risk weight ranges include adult BMI below 13 and under-18 median BMI below 70%, but NICE explicitly says not to use an absolute BMI or weight threshold alone to decide admission.
  • A recent loss of at least 1 kg/week for 2 consecutive weeks in an undernourished person is red in MEED, and rapid loss at any weight can be dangerous.
  • Assess pulse, lying and standing blood pressure, temperature, hydration, muscle function, ECG, glucose, sodium, potassium, bicarbonate, renal function, phosphate, magnesium, calcium, liver tests and blood count according to acuity.
  • Children need age- and sex-adjusted observations and growth measures; adult cut-offs must not be copied directly into paediatric decisions.
  • Medical admission is for active physical stabilisation and initiation of safe refeeding; specialist eating-disorder units require the capability to manage the identified medical risks or rapid transfer arrangements.
  • Psychiatric danger, treatment resistance and carer capacity belong in the same formulation as physiology, but a mental-health assessment must not delay emergency medical care.
  • Every transfer needs named medical, psychiatric, dietetic and nursing responsibilities, a feeding and monitoring plan, and escalation instructions that travel with the patient.

Aetiology

01

Energy deficit

Severe restriction, malabsorption or excessive activity reduces substrate and circulating volume, progressively impairing cardiovascular and organ function.

02

Purging losses

Vomiting, laxatives, diuretics and treatment manipulation can abruptly disturb electrolytes, acid-base balance, glucose and renal perfusion at any weight.

03

Care-system mismatch

Risk rises when medical and psychiatric teams split responsibility, monitoring capability is inadequate or transfers interrupt nutrition and replacement.

Pathophysiology

  1. 1
    Cardiac adaptation

    Low energy and reduced cardiac mass produce bradycardia and low output; hypovolaemia, electrolytes and drugs can convert adaptation into instability.

  2. 2
    Impaired stress response

    Starvation can blunt fever and tachycardia, so an inappropriately normal pulse or temperature may conceal infection or physiological stress.

  3. 3
    Organ substrate failure

    Hypoglycaemia, dehydration and micronutrient depletion impair brain, liver, renal and muscle function, sometimes before dramatic examination findings appear.

  4. 4
    Refeeding shift

    Renewed carbohydrate drives insulin-mediated intracellular electrolyte uptake and sodium retention, creating a second high-risk phase during necessary nutrition.

Clinical features and red flags

Trajectory risk

Speed and method of loss can destabilise circulation and electrolytes before a low BMI is reached, particularly with fasting, purging or exercise.

Cardiovascular red pattern

Extreme bradycardia, syncope with marked postural change, arrhythmia or prolonged QTc can precede sudden deterioration and requires urgent senior assessment.

Metabolic emergency

Hypoglycaemia, severe potassium depletion, falling phosphate, sodium disturbance and organ dysfunction demand acute treatment while nutrition is planned.

Functional collapse

Inability to sit up or rise from a squat, confusion, oliguria and inability to complete basic activity reveal compromise beyond appearance.

Behavioural escalation

Acute refusal, multiple daily purging, uncontrolled movement, water loading or physical struggle over nutrition can make an otherwise feasible plan unsafe.

Red flags requiring action

  • MEED classifies an awake heart rate below 40 beats/minute as red; tachycardia or an inappropriately normal pulse in severe undernutrition can also signal hypovolaemia or infection.
  • For adults, standing systolic pressure below 90 mmHg with recurrent syncope and a systolic fall over 20 mmHg or heart-rate rise over 30 beats/minute is a red pattern, not a single-number rule.
  • Tympanic temperature below 35.5°C, severe dehydration, inability to sit up or rise from a squat, prolonged QTc or another significant ECG abnormality requires urgent escalation.

Investigations

  1. 01
    Full MEED domain assessmentFirst step
    Why
    Integrate medical history, trajectory, examination, behaviour, psychiatric risk and support.
    Interpretation and limitations
    One red or two amber ratings usually justify high concern, but location and intervention follow the specific abnormality and clinical judgement.
  2. 02
    Standardised postural observations
    Why
    Detect low circulating volume and autonomic compromise using reproducible technique.
    Interpretation and limitations
    Interpret standing pressure and pulse change with syncope, age and baseline; repeated or symptomatic abnormalities carry more weight than an isolated reading.
  3. 03
    ECG and cardiac assessment
    Why
    Identify bradycardia, arrhythmia, conduction change and prolonged QTc.
    Interpretation and limitations
    Review electrolytes and QT-active medication simultaneously; significant ECG abnormality, symptoms or heart rate below 40 warrants monitored senior management.
  4. 04
    Urgent biochemical panel
    Why
    Detect glucose, electrolyte, renal, hepatic and refeeding hazards.
    Interpretation and limitations
    Very low potassium or glucose and falling phosphate are red; correction route and care setting depend on severity, symptoms, renal function and ECG.
  5. 05
    Paediatric growth and centiles

Differential diagnosis

01

Sepsis

Occult infection may cause deterioration without robust fever or leucocytosis and must be actively considered in a malnourished patient.

02

Endocrine or metabolic disease

Adrenal, thyroid, diabetic and inborn metabolic disorders can produce weight, glucose or electrolyte abnormalities requiring disease-specific treatment.

03

Cardiac disease

Conduction disease, myocarditis and congenital rhythm syndromes may coexist; not every bradycardia or prolonged QTc is caused solely by starvation.

04

Substance or medication effect

Stimulants, alcohol, diuretics, laxatives, QT-active drugs and overdose can alter observations and determine immediate emergency management.

Management

01Front doorStabilise before debating destinationFirst stepAn eating-disorder patient presents with collapse, acute refusal, abnormal observations or concerning behaviour.+
  1. 1Perform ABCDE, glucose, ECG and urgent blood sampling while treating immediately reversible threats.
  2. 2Call senior medical or paediatric staff and specialist eating-disorder or liaison psychiatry colleagues without making either review conditional on the other.
  3. 3EscalationUse the active MEED domains to select acute ward, monitored bed, HDU or specialist unit and document escalation thresholds.
02Age-specific riskChoose the correct referenceA child, adolescent or older teenager has weight loss or abnormal cardiovascular observations.+
  1. 1Plot growth and calculate percentage median BMI using age-adjusted data through age 18.
  2. 2

Complications

01

Sudden cardiac death

Extreme bradycardia, arrhythmia, electrolyte depletion and QT-active medication can interact unpredictably, particularly during purging or refeeding.

02

Neurological injury

Hypoglycaemia, sodium disturbance, thiamine deficiency and circulatory failure can cause confusion, seizure, coma and lasting harm.

03

Renal and hepatic failure

Dehydration, rhabdomyolysis, hypoperfusion and severe malnutrition can impair kidney and liver function and alter replacement safety.

04

Iatrogenic deterioration

Excess fluid, delayed feeding, inadequate monitoring or an unsafe transfer can worsen oedema, heart failure, undernutrition and refeeding complications.

Monitoring and follow-up

  • Repeat observations and glucose at a frequency matched to instability, using consistent posture, rest and measurement conditions and recording symptoms.
  • Trend potassium, phosphate, magnesium, sodium, renal and liver function through stabilisation and refeeding; assign each result to a named clinician.
  • Review ECG or continuous monitoring indications after electrolyte correction, medication change or new syncope, chest pain or palpitations.
  • Document actual intake, fluid balance, purging, exercise, water loading and ability to follow the care plan rather than relying on stated intentions alone.
  • Reassess self-harm, suicide, capacity, distress and carer or ward capability at every transition because these determine whether a theoretically safe plan is deliverable.

Special situations

A normal pulse may be abnormal

Tachycardia or a pulse that is unexpectedly normal in profound malnutrition can signal infection, hypovolaemia or another physiological stress.

Red is not an algorithm

Traffic-light colour communicates urgency within a domain; it does not prescribe one identical bed or intervention for every red finding.

Median BMI is paediatric

MEED recommends percentage median BMI up to age 18, while simultaneously considering growth history, puberty and the limitations of reference data.

Capability determines location

A specialist unit is safe only if it can deliver the monitoring and acute response required by the patient's current physiology.

Transfer creates risk

Omitted nutrition, delayed bloods and unclear legal authority commonly arise at interfaces, so the handover itself is a clinical intervention.

Common pitfalls

  1. 01

    Using BMI as the sole admission criterion despite NICE's explicit instruction not to do so.

  2. 02

    Copying adult pulse or blood-pressure thresholds into an under-18 assessment.

  3. 03

    Calling one normal electrolyte panel reassuring during ongoing purging or early refeeding.

  4. 04

    Waiting for psychiatry before treating hypoglycaemia, dehydration or arrhythmia.

  5. 05

    Sending an unstable patient to a unit that cannot provide the required medical monitoring.

  6. 06

    Discharging after short-lived observation improvement without a named nutrition and results plan.

  • Potassium below 2.5 mmol/L, glucose below 3 mmol/L, falling phosphate, symptomatic or marked hyponatraemia, or evidence of organ failure is a medical emergency regardless of diagnosis or weight.
  • Rapid loss at any starting weight, acute intake below roughly 500 kcal/day for at least 2 days, multiple daily purging, uncontrolled exercise or serious self-harm can markedly raise overall risk.
    • Why
    Assess under-18 weight, height, puberty and observations against age-adjusted references.
    Interpretation and limitations
    Use percentage median BMI to age 18 and appropriate blood-pressure centiles; adult thresholds can materially misclassify paediatric risk.
    Use paediatric blood-pressure centiles and MEED's age-specific postural pulse criteria rather than importing adult values.
  • 3Include growth failure, pubertal delay, family capacity and rate of loss when agreeing admission intensity with paediatrics and the eating-disorder service.
    • 03Transfer and dischargeMake shared care explicitThe patient moves between acute medical, specialist eating-disorder, day or community care.+
    1. 1Send the latest observations, ECG, laboratory trends, intake, refeeding stage, replacement and behavioural risks with the handover.
    2. 2Name who prescribes nutrition, checks results, provides meal support, assesses capacity and responds to refusal or deterioration.
    3. 3Confirm physiological stability, feasible follow-up and emergency return criteria before transfer or discharge; do not rely on weight alone.