Murtagh – DDx of Fatigue

The Murtagh diagnostic model consists of 5 questions

  1. What are the probability diagnoses?
  2. What are the serious disorders not to be missed? (Red Flags)
  3. What are the pitfalls? (Commonly missed)
  4. Does the patient have one of the classic masquarades?
  5. Is the patient trying to tell me something else?

This is also called the PROMPT model 

  • P – Probability (What are the most likely and common diagnoses?)
  • R – Red flag conditions (What serious disorders are not to be missed?)
  • O – Often missed (conditions often missed (pitfalls) eg pregnancy, drugs, allergies, constipation, menopause)
  • M – Masquerades (ie other diagnoses that can be missed, eg depression, drugs, diabetes, anaemia, thyroid, UTI, spinal)
  • PT – Is this Patient trying to Tell me something?

Using the presenting complaint of fatigue as the example?

  1. What are probability diagnoses?
    • Stress and anxiety
    • Depression
    • Viral/postviral infection, eg. EBV
    • Sleep related disorders, eg. sleep apnoea
  2. What are serious disorders not to be missed?
    • Malignant disease
    • Cardiac arrhythmia, eg. sick sinus syndrome
    • Cardiomyopathy
    • Valvular disease
    • Anaemia
    • Hypothyroidism
    • HIV infection
    • Hepatitis especially, hepatitis C
    • Haemochromatosis
    • B12 deficiency
  3. What are the pitfalls?
    • ‘Masked’ depression
    • Coeliac disease
    • Food intolerance
    • Chronic infection, eg. tuberculosis
    • Incipient CCF
    • Fibromyalgia
    • Lack of fitness
    • Drugs: alcohol, prescribed, withdrawal
    • Menopause syndrome
    • Pregnancy
    • Neurological disorders, i.e. cerebral ischaemia
    • Renal failure
    • Metabolic, eg. hypokalaemia, hypomagnesaemia
    • Chemical exposure, i.e. occupational
    • Endocrine
      • Hyperparathyroidism
      • Addison disease
      • Cushing disease
      • Adrenal insufficiency
      • Low testosterone
    • Narcolepsy
    • Multiple sclerosis
    • Myasthenia gravis
    • Connective tissue disorders, i.e. rheumatoid arthritis, systemic lupus erythematosus
  4. Seven masquerades checklist
    1. Primary
      1. Depression
      2. Diabetes
      3. Drugs
      4. Anaemia
      5. Thyroid disease
      6. Spinal dysfunction
      7. Urinary tract infection (UTI)
    2. Secondary
      1. Chronic renal failure
      2. Malignant disease
      3. HIV/AIDS
      4. Baffling bacterial infections
      5. Baffling viral and other infections
      6. Neurological dilemmas
      7. Connective tissue disorders and vasculitides
  5. Is the patient trying to tell me something else?
    • Highly likely.
    • Psychogenic and lifestyle disorders are very common in this presentation in general practice

The PDF below discusses the diagnosis of fatigue using the Murtagh Model in detail.

View Fullscreen