MRCP Part 1 Clinical Sciences 2

Question 1

A patient on warfarin has an INR of 8.5 with no active bleeding. According to NICE guidelines, what is the most appropriate management?

Accepted Answer

Stop warfarin and give oral vitamin K 1-5 mg

Answer

For an INR >8.0 without major bleeding, NICE recommends stopping warfarin and administering 1-5 mg of oral vitamin K. FFP or IV vitamin K at high doses is reserved for major bleeding. The INR should be rechecked within 24 hours.

Question 2

Which acid-base disturbance is most commonly seen in pyloric stenosis?

Accepted Answer

Hypochloraemic hypokalaemic metabolic alkalosis

Answer

Pyloric stenosis causes persistent vomiting of gastric acid (HCl), leading to loss of hydrogen and chloride ions. The kidneys compensate by retaining hydrogen ions and excreting potassium, resulting in hypochloraemic hypokalaemic metabolic alkalosis.

Question 3

In autosomal dominant polycystic kidney disease (ADPKD), which gene mutation accounts for approximately 85% of cases?

Accepted Answer

PKD1 on chromosome 16

Answer

PKD1 mutations on chromosome 16 account for approximately 85% of ADPKD cases and are associated with more severe disease and earlier onset of end-stage renal failure compared to PKD2 mutations on chromosome 4.

Question 4

Which cytokine is most important in the pathogenesis of septic shock?

Accepted Answer

Tumour necrosis factor alpha (TNF-alpha)

Answer

TNF-alpha is the key pro-inflammatory cytokine released by macrophages in response to bacterial lipopolysaccharide. It triggers the inflammatory cascade leading to vasodilation, increased vascular permeability, myocardial depression, and multi-organ failure in septic shock.

Question 5

A 55-year-old man has a plasma osmolality of 295 mOsm/kg but his urine remains maximally dilute at 80 mOsm/kg despite water deprivation. After desmopressin administration, urine osmolality rises to 600 mOsm/kg. What is the diagnosis?

Accepted Answer

Cranial diabetes insipidus

Answer

The failure to concentrate urine despite water deprivation (raised plasma osmolality) indicates diabetes insipidus. The response to desmopressin (synthetic ADH) confirms the kidneys can respond, meaning the problem is insufficient ADH production — cranial diabetes insipidus.

MRCP Part 1 Practice Test

MRCP Part 1 Practice Test

MRCP Part 1 Clinical Sciences 2