(Peri-Op & Anaesthesia) (Endocrine & Metabolic) (GP)

Overview

• Defined as a blood pressure persistently ≥140/90 mmHg + 24 hour blood pressure average reading (ABPM/HBPM) ≥135/85 mmHg
• Primary (Essential) Hypertension (90%) → hypertension with no identifiable cause
• Secondary Hypertension (10%) → hypertension caused by an identifiable underlying condition (eg. renal artery stenosis, primary hyperaldosteronism - conn syndrome, cushing syndrome, phaeochromacytoma, acromegaly)
  • Primary Hyperaldosteronism is most common cause of secondary hypertension
• Risk Factors → age >65 yrs, alcohol intake, lack of exercise, any FH of hypertension, obesity, DM, black ancestry, diet high in sodium
• Stages 1-3

Making Diagnosis

Clinical Features:

• Usually asymptomatic unless blood pressure is very high
• Nonspecific Symptoms → headache, blurred vission, dizziness
• Hypertensive Retinopathy
  • Grade 1 → arteriolar narrowing and tortuosity. Silver wiring.
  • Grade 2 → AV nipping
  • Grade 3 → flame haemorrhage and cotton wool exudates
  • Grade 4 → papilloedema (poorly defined margins of optic disc on fundoscopy)

Investigations:

• Ambulatory Blood Pressure Measurement (ABPM) → confirmation. Device measures BP at fixed intervals over 12-24 hours allowing average to be taken (use average value of 14 measurements - at least 2 measurements per hour during persons normal waking hours) .
  • If ABPM is declined → HBPM (Home Blood Pressure Monitoring), measured by individual at periodic intervals
• To assess for any end-organ damage → fundoscopy (retinopathy), urine dipstick (renal disease), ECG (LVH)
  • If new BP ≥180/120mmHg then first step is to investigate for end organ damage