The Unconscious Patient

This is a hot case where the candidate is launched at a comatose patient, with the objective of discovering the cause of that unconsciousness. 

For the candidate, the key is to distinguish between the different flavours of coma. The chapter on the approach to the examination of an unconscious patient contains a long comprehensive list of differentials, and digresses extensively on the examination. For the time-poor candidate, the LITFL entry on this topic is much easier to use for revision.

An abbreviated version of that huge list of differentials would resemble the following:

Differential Diagnosis of Unconsciousness

With focal  signs






Without focal  signs


Metabolic problem: one of the many encephalopathies (see COATPEGS):

  • Carbon dioxide
  • Oxygen (hypoxia)
  • Ammonia
  • Temperature
  • pH (acidosis)
  • Electrolytes, eg. sodium
  • Glucose
  • Serum osmolality

Diffuse cerebral vascular issues

Brainstem problem (eg. stroke)




With meningism

Vascular causes:

  • Subarachnoid haemorrhage

Infectious causes:

  • Meningitis

One can get far using the LITFL TOMES/COATPEGS mnemonics. TOMES stands for "toxins, organ failure, metabolic, endocrine, seizures" and COATPEGS stands for "oxygen, carbon dioxide, ammonia, temperature, pH, electrolytes, glucose and serum osmolality".  Sure, some of the causes of non-focal unconsciousness are missing, but if you add them all, you end up with "COMATOSE GREAT APE"


  • Carbon dioxide
  • Oxygen (hypoxia)
  • Metabolism of drugs is slowed
  • Ammonia
  • Temperature
  • Ovedose on drugs
  • Seizures
  • Encephalitis (infection)
  • Glucose
  • Renal (uraemia)
  • Ethanol (Wernicke's)
  • Adrenal insufficiency
  • Thyroid
  • Autoimmune (eg.vasculitis)
  • pH (acidosis)
  • Electrolytes, eg. sodium

Pattern of examination

A suggestion made by an ex-examiner is as follows:

  • Start by asking whether there is a language barrier.
  • Observe the respiratory pattern.
  • Start with the GCS. In the completely unconscious patient, you should ask before inflicting pain.
  • Next check for neck stiffness. This is
  • Then, start with the cranial nerves.
    • CN II and III: pupillary reflex
    • CN V and VII: corneal reflex
    • CN III, IV, VI: note any gaze deviation
    • CN VII:  painful stimulus over the orbit
    • CN VII: oculocephalic or caloric reflex
    • CN IX and X: gag reflex, cough reflex
    • CN XII, tongue fasciculation
  • Then, go on to examining the rest of the neurological system:
    • Observe the exposed patient
    • Tone
    • Power (may have to inflict pain again)
    • Reflexes
    • Clonus

Number of previous hot cases in this topic: 16

2015, Paper 2

Unspecified hospital in Adelaide

73-year-old male day 1 ICU admitted following a MET call for decreased conscious state that required intubation. He had been admitted with shortness of breath, fever, headache and collapse and found to have meningococcal meningitis. Background included ischaemic heart disease on dual anti-platelet therapy and COPD. Findings on examination included ecchymoses, bronchial breathing left lung, right upgoing plantar and the absence of meningism.

Candidates were directed to determine the likely cause for the decrease in conscious state.

Discussion points included interpretation of the CSF results, management of meningitis and the role of steroids.

Unspecified hospital in Adelaide

54-year-old female, day 5 ICU, admitted with massive haematemesis from oesophageal varices on a background of Child’s B cirrhosis secondary to auto-immune hepatitis. Other co-morbidities included biventricular failure, atrial fibrillation, hypothyroid disease and polycythaemia. Findings on examination included generalised oedema, bilateral crackles on auscultation with decreased breath sounds at the bases, distended abdomen and neurological signs with brisk reflexes and ankle clonus.

Candidates were told that she had presented with upper GI bleeding that had been treated and were directed to examine her focussing on the neurological system and provide a differential diagnosis for her current clinical status.

Discussion points included interpretation of biochemistry, causes of encephalopathy and management of bleeding oesophageal varices.

2015, Paper 1

Unspecified hospital in Melbourne

24 - year - old male with a history of intravenous drug use and mitral valve endocarditis, which resulted in an embolic str oke. The patient subsequently had surgery for a mitral valve replacement from which he was recovering. Candidates were directed to perform a neurological examination and a relevant general examination.

Unspecified hospital in Melbourne

44 - year - old female with acute liver failure and hypox ia on a background of alcohol excess and heavy smoking. Transferred from a peripheral hospital and intubated on arrival for hypoxia and delirium . Candidates were directed to identify and discuss active issues and make a plan for the following week.

2014, paper 2

Unspecified hospital in Sydney

  • 60-year-old male, day 6 ICU admitted with GCS 3, query cause, and persisting coma and a background history of alcohol abuse. Clinical findings included GCS 5-7 off sedation, brain stem reflexes present (except oculo-vestibular), weak extension of upper limbs to pain, global hyporeflexia with up going plantar responses bilaterally, and presence of skin abrasions and sacral pressure sore.
  • Candidates were asked to examine him with a specific focus on his neurology with a view to establishing a differential diagnosis for his presentation and a management plan.

Unspecified hospital in Sydney

  • 17-year-old male, day 50 in the ICU. Initially admitted with a reduced level of consciousness secondary to a new onset of a seizure disorder. Current clinical findings include GCS 3, ongoing benzodiazepine infusion, BIS monitor in-situ, intermittent clinical and EEG seizures, bilateral leg swelling, gross global muscle wasting, and still requiring mechanical ventilation via a tracheostomy.
  • Candidates were asked to assess his current issues given his prolonged ICU stay.

Unspecified hospital in Sydney

  • 65-year-old man, Day 10 ICU. Post operative sterotactic biopsy lesion right temporal lobe. Subsequently slow neurological recovery. Clinical findings included a VP shunt, VI cranial nerve lesion on the right, monoparesis of the right arm, upward plantar on the right.
  • Candidates were informed the patient was slow to recover following a neurosurgical procedure. They were asked to assess his neurological state, provide a differential diagnosis, and outline a plan for his further management.
2014, Paper 1

Royal Brisbane and Women’s Hospital

  • 75-year-old female 5 days following right hemi-hepatectomy for a mass lesion that initially had an uneventful recovery but was readmitted for a decrease in conscious level. Clinical findings included jaundice, lower body swelling and encephalopathy with lateralising signs L>R. Candidates were directed to examine her and discuss the possible causes of her decreased conscious state.

Royal Brisbane and Women’s Hospital

  • 69-year-old female day 19 ICU post SAH secondary to left peri-callosal aneurysm treated with craniotomy, clipping and insertion of EVD and with slow neurological recovery and failed extubation for fluctuating conscious state and retained secretions. Clinical findings included drowsiness but able to obey commands and no focal neurological signs and high urine output. Candidates were directed to examine her and provide a differential diagnosis for her fluctuating neurological state.
2013, paper 2

Westmead Hospital

  • 39-year-old male, day 3 ICU, following presentation with uncontrolled hypertension and subsequent right parietal bleed, and pulmonary oedema (now resolved), on a background of obesity, type 2 diabetes and chronic renal failure. Clinical findings included altered conscious state with no localising signs, reduced breath sounds at both bases, elevated CVP, pericardial rub and a gallop rhythm, generalised anasarca and the presence of a right femoral venous vascath. Candidates were told that he had presented 3 days earlier with altered sensorium and shortness of breath on the background of diabetic nephropathy and were asked to examine him and to identify the reason for his presentation. Discussion points included interpretation of imaging and investigations, contributing factors for his presentation and reasons for the elevated CVP.
2013, Paper 1

Queen Elizabeth Hospital

  • 53-year-old man with liver failure admitted with increasing confusion. Candidates were asked to determine the cause of his altered state.
2011, Paper 2

Royal Prince Alfred Hospital

  • 30-year-old female, day 3 ICU with a diagnosis of TTP who presented with fever, headaches, vomiting for one day and decreased conscious state. Candidates were asked to examine the patient to determine the differential diagnosis.

Royal North Shore Hospital

  • 77-year-old male with meningitis and also head injury following fall, recent NSTEMI, pneumonia, liver lesions under investigation and chronic leukaemia.
2011, Paper 1

Westmead Hospital

  • 77-year-old female admitted to ICU from the ward with decreased level of consciousness and respiratory distress requiring intubation. In hospital for one month following fall at home and subsequent problems with swallowing, confusion and delirium. Uncertain underlying diagnosis.
2009, paper 1

Royal Brisbane Hospital

  • A 64 year old man was 7 days in ICU post AVM resection. , returned to OT 3/7 later for a craniotomy.
    Candidates were asked to assess general examination, neurological state and outline plan of management.
    Areas of weakness identified by examiners: Failure to comment on ICP monitor, CT scan (extensive pneumocephalus), tracheostomy, nosocomial pneumonia.
2008, Paper 2

Unspecified hospital

  • A 33 year old man with a history of schizophrenia was found unresponsive at home in a pool of vomit and faeces. He has been slow to wake up. Findings: A ventilated patient, low GCS, pressure areas, biochemical features of rhabdomyolysis and an old infarct on a CT scan.