3.1. A 35-year-old female with no known previous medical history presents to the emergency department with a decreased conscious level.
- a) Give one diagnosis which will explain the clinical and laboratory findings. (10% marks)
- b) List six possible aetiologies. (20% marks)
3.2. The following data were obtained from a patient who had been observed overnight in the Emergency Department with minor fractures. The patient is otherwise well and currently asymptomatic.
- Give the most likely cause for the above biochemical abnormalities? Justify your answer. (40% marks)
3.3. You are asked to review a 44-year-old male known epileptic following a prolonged generalised tonic-clonic convulsion. He is intubated and ventilated. The arterial blood gas analysis is below.
- List the abnormalities on the blood gas and give the most likely cause of each abnormality. (30% marks)
Answer and interpretation
3.1a. Give one diagnosis which will explain the clinical and laboratory findings. (10% marks)
- Acute liver failure
3.1b. List six possible aetiologies. (20% marks)
- Toxins – paracetamol, alcohol, mushrooms.
- Viral hepatitis – Hep A,B,C,D,E, EBV,CMV
- Idiosyncratic drug reaction
- Ischaemic hepatitis due to shock – cardiogenic, septic
- Acute fatty liver of pregnancy
- Congenital/genetic – Wilson’s disease
- Hyperthermia – Heat stroke
- Autoimmune hepatitis
- Budd-Chiari syndrome
- Malignant hepatic infiltrations – breast cancer, lung cancer, melanoma, lymphoma, myeloma
3.2 Give the most likely cause for the above biochemical abnormalities? Justify your answer. (40% marks)
Artefact; – This blood sample was left longer than 6 hours before it was processed for above investigations. (Note to examiners – This is not just a haemolysed sample – haemolysis alone does not cause hypoglycaemia and lactic acidosis, though it will cause other abnormalities).
- Potassium, phosphate and LD enter the serum from red cell due to haemolysis and Na/K pump dysfunction
- Low Na – shift into red cell in exchange for potassium
- RBCs consume glucose and generate lactate
3.3 List the abnormalities on the blood gas and give the most likely cause of each abnormality. (30% marks)
- Metabolic acidosis – lactic acidosis secondary to prolonged seizures
- Respiratory acidosis (or inadequate compensation) – central hypoventilation or Inadequate mechanical ventilation
- Increased A-a gradient – aspiration pneumonia
- Pass rate: 61%
- Highest mark: 9.5
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.