How to Pass the FRACP Written Examination. Jonathan Gleadle

      Lee P, Dixon J. Bariatric–metabolic surgery: A guide for the primary care physician. Austral Family Physician. 2017;46(7):465–471.

       https://www.racgp.org.au/download/Documents/AFP/2017/July/AFP-Focus-Bariatric-metabolic-surgery-2017.pdf

       35. Answer: F

       36. Answer: H

      Hypothyroidism is one of the most common endocrine disturbances alongside diabetes. It may present in the elderly with very non‐specific symptoms and signs. It should be considered in the differential diagnosis of anyone presenting with confusion (so‐called part of the ‘dementia’ screen) and general deterioration with no readily identifiable cause. It should not be missed as a cause of a range of symptoms from neurological signs, typically bradykinesia, reduced deep tendon reflexes, and paraesthesias from nerve entrapment (especially carpal tunnel syndrome) to abdominal pain from chronic constipation to mental disturbance manifest as confusion and apparent memory impairment. Other subtle signs of hypothyroidism include loss of the outer one‐third of the eyebrows with male‐pattern frontal balding, hypothermia, bradycardia, non‐pitting oedema (myxoedema), and dry, coarse skin.

      TFTs are usually diagnostic and demonstrate a low free thyroxine (T4) with a high TSH in primary hypothyroidism. Very occasionally a low TSH and a low free T4 may be seen in the context of panhypopituitarism and assay of levels of sex hormones, ACTH, and other pituitary hormones will confirm the diagnosis.

      Lithium is used in the treatment of bipolar disorder. It can cause major disturbance in water balance, manifest by polyuria and secondary polydipsia. This is because of decreasing urinary concentrating ability resulting from impaired responsiveness of the distal nephron to anti‐diuretic hormone (ADH) which is known as nephrogenic diabetes insipidus. In most cases there is a correlation between impaired urinary concentrating ability and duration of lithium therapy or total lithium dose.

      Nephrogenic diabetes insipidus in adults is usually partial with mild symptoms. Usually the serum sodium is normal or mildly elevated, the plasma osmolality is within normal range, the urine osmolality is low (<300 mOsmol/kg) and the urine volume is between 2.5 and 6 L/day. However when patients are fluid depleted, there is a marked rise in serum sodium, a rise in plasma osmolality urine osmolality that may exceed that of plasma. The water deprivation test is useful in diagnosis: the urine osmolality is usually <300 mOsmol/kg after dehydration with no further or a minimal (<95) rise after desmopressin. In partial nephrogenic diabetes insipidus, the urine osmolality is between 300 and 750 mOsmol/kg after dehydration and is <750 mOsmol/kg after desmopressin. Lithium‐induced nephrogenic diabetes insipidus is usually reversible on stopping therapy but a few patients remain symptomatic long after the lithium has been discontinued. If the urine volume exceeds 4 L/day, treatment with thiazides and amiloride has been advocated. Preventive measures include education of patients and their carers about maintaining adequate hydration. The serum lithium level should be kept between 0.5 and 0.8 mmol/L. Annual measurement of 24‐hour urine volume is a simple and effective screening test.