Return to Scenario ListShow Learning Points most relevant to Phase 1:


Clinical Discipline(s)/Organ System(s)
Clinical Biochemistry, Clinical Pharmacology, Geriatric Medicine, Infectious Diseases
Progress Test Topic(s)
An 83 year old Chinese woman is brought to the Emergency Department by her son. She developed a productive cough in the last week but has become increasingly confused over the last two days. She lives alone and is fully independent. Her past history consists of hypertension for which she is treated with bendrofluazide and mild depression treated with fluoxetine. On examination she has a fever and crackles at the left lung base. Her serum sodium is found to be 121 mmol/L. Previous blood tests in recent months have been normal.
Progress Test-Type Questions:   Question 1 | Question 2
Applied Science for Medicine 
   - Physiology of water and sodium homeostasis
   - Physiology of factors that may lead to syndrome of inappropriate antidiuretic hormone secretion (SIADH)
   - Role of adrenal hormones and thyroid function and how derangement in these systems can affect water and sodium homeostasis
   - Pharmacology of medications that commonly cause hyponatraemia and have an awareness of their effect on sodium and water homeostasis
Clinical and Communication Skills 
   - History from a confused patient, being aware of the benefits and limitations of a collateral history
   - Perform multisystem examination on the confused patient. Accurately examine the signs of fluid status
   - Differential diagnosis of hyponatraemia
   - Request appropriate investigations guided by the differential diagnosis
   - Interpret plasma and urinary sodium and osmolality
   - Consider sampling and laboratory errors when interpreting results
   - Management of hyponatraemia
   - Consequences of aggressive sodium correction
   - Non-pharmacological elements to treatment and prevention of delirium
Personal and Professional Skills 
   - Assess competency
   - Involve family in discussions of prognosis and management with patients consent
   - Access additional information from a variety of resources if needed to help solve clinical problems
Hauora Māori 
   - Be aware of barriers to early treatment, that result in exposure to greater harm from complications of the illness, risks of invasive investigations and prolonged treatment
   - Communicate effectively with patient and family/whānau
Population Health 
   - Epidemiology of hyponatraemia and which populations are most at risk
Conditions to be considered relating to this scenario
SIADH (pneumonia, other infection, drugs particularly carbamazepine and selective serotonin reuptake inhibitors (SSRIs), postoperative), diuretic toxicity, extra-renal salt loss, hypothyroidism, hyperglycaemia, pseudohyponatraemia, oedematous states (cirrhosis, heart failure, nephrotic syndrome)
Less common but 'important not to miss'
SIADH in head injury including stroke and intracranial haemorrhage, adrenal insufficiency
rare causes of SIADH including ADH-secreting tumours and chemotherapy agents, atrial natiuretic peptide-secreting tumours, primary polydipsia
Related Scenarios
[Delirium / dementia]