Makindo Medical Notes

Related Subjects: |Assessing Chest Pain |Hypertension |Hypertension in Pregnancy |Malignant Hypertension |Preeclampsia, Eclampsia and HELLP |Acute Heart Failure |Chronic Heart Failure

In many cases, patients with malignant hypertension may be volume depleted due to pressure-induced natriuresis. As a result, they may require careful intravenous fluid replacement with normal saline in addition to appropriate antihypertensive therapy.

About

• Malignant Hypertension: A severe elevation in blood pressure accompanied by acute end-organ damage (e.g., retinal, renal, or neurological involvement).
• More commonly observed in middle-aged men, though overall incidence has declined thanks to improved hypertension screening and management.

Diagnosis

• Blood Pressure Thresholds: Systolic >220 mmHg and/or Diastolic ≥120 mmHg.
• End-Organ Damage: Examples include:
  • Severe hypertensive retinopathy (haemorrhages, exudates, papilloedema)
  • Acute kidney injury (AKI)
  • Acute coronary syndrome (ACS)

Clinical Features

• Headache, severe anxiety, distress
• Acute pulmonary oedema
• Microangiopathic haemolytic anaemia
• Renal impairment, retinal changes
• Neurological complications: Stroke (ischaemic or haemorrhagic), confusion, delirium

Hypertensive Retinopathy Scale

Investigations

• Laboratory Tests: FBC, U&E, LFTs, plus urinalysis to check for proteinuria or haematuria.
• ECG: For signs of left ventricular strain or ischaemia.
• Echocardiogram: To assess left ventricular hypertrophy (LVH) or systolic/diastolic dysfunction.
• Renal Imaging: Renal ultrasound or MRA for renal size, asymmetry, or renal artery stenosis.
• Secondary Hypertension Screening:
  • Cortisol levels for Cushing’s syndrome
  • Urinary catecholamines/metanephrines for pheochromocytoma
  • Toxicology screen if stimulant (e.g. cocaine) misuse is suspected

Red Flag Situations Requiring Urgent Treatment

• Aortic dissection
• Acute left ventricular failure and pulmonary oedema
• Acute or worsening renal failure
• Hypertensive encephalopathy
• Stroke (thrombotic or haemorrhagic)
• Hyperadrenergic states (e.g., pheochromocytoma, cocaine overdose)
• Unstable angina or myocardial infarction
• Eclampsia

In severe hypertension, the immediate goal is to reduce the mean arterial pressure (MAP) by no more than 20–25% within the first few hours. There is limited evidence to support exact targets, but aiming for a systolic BP <200 mmHg or <180/120 mmHg can be reasonable depending on clinical context. Expert consultation is advised.

Management Principles

• Gradual Reduction in Most Cases: In older patients with long-standing hypertension and no acute end-organ injury, blood pressure should be lowered slowly (over hours) to avoid cerebral hypoperfusion. A target of around 160–180 mmHg systolic initially may be appropriate.
• Identify and Address Contributing Factors: Treat pain, agitation, urinary retention, or alcohol withdrawal, as these may elevate blood pressure.
• Medications:
  • Initial oral agents in less urgent situations: Amlodipine 5 mg, a low-dose beta-blocker, or a small dose of an ACE inhibitor can be trialed.
  • Urgent Scenarios (e.g., aortic dissection, acute MI, pulmonary oedema, encephalopathy, eclampsia): Use IV medications and achieve more rapid control under close monitoring. IV labetalol, nitroprusside, or nitroglycerine may be required.
  • Volume overload: Consider IV loop diuretics (furosemide).
  • Chest pain: IV nitrates and beta-blockers (unless contraindicated) may help control blood pressure and reduce myocardial oxygen demand.
  • Aortic dissection: IV beta-blockade (labetalol) first to reduce aortic shear forces, followed by nitroprusside to reach a target BP ~120/80 mmHg.
• Rare True Malignant Hypertension: IV labetalol or nitroprusside may be used in a high-dependency unit. Invasive arterial BP monitoring and expert guidance are essential.
• Hypertension in Pregnancy (Preeclampsia/Eclampsia): Obtain obstetric input. Labetalol is commonly used and considered safe.
• Haemorrhagic Stroke: Carefully lower BP to around 140–150/90 mmHg, typically with IV labetalol, nicardipine, or esmolol. Monitor every 10–15 minutes to avoid excessive reductions.

Specific Clinical Scenarios