Download Accelerated – malignant Hypertension

ACCELERATED – MALIGNANT HYPERTENSION
Hla Chaw and Jeff Ball
A systemic disease characterised by an extreme elevation of blood pressure
(mean arterial BP greater than 120 mmHg, persistent diastolic blood pressure
exceeding 130 mmHg) associated with acute microvascular damage (bilateral
retinal haemorrhage, exudates or papilloedema). This demands emergency
treatment and close follow-up care.
BACKGROUND
Incidence - less than 1% of primary hypertension.
Incidence increases with age.
RISK FACTORS
Male, black race, smoking, oral contraceptive use, low socio-economic status.
PRESENTATION
Headache, visual loss, neurological deficit, seizures, confusion, coma.
Nausea, vomiting.
Sudden and marked elevation in blood pressure, diastolic > 130 mmHg.
Congestive heart failure.
Renal failure.
DIFFERENTIAL DIAGNOSIS
Acute left ventricular failure.
Uraemia from any cause.
Cerebrovascular accident.
Subarachnoid haemorrhage.
Brain tumour.
Head injury.
Epilepsy (postictal).
Collagen diseases.
Encephalitis
Overdose and withdrawal from narcotics, amphetamines, etc.
Hypercalcaemia
Acute anxiety with hyperventilation syndrome.
INITIAL ASSESSMENT
PHYSICAL EXAMINATION
Cardiovascular system examination:
- Heart rate, BP, cardiomegaly, heart sounds.
- Features of heart failure: JVP, pedal oedema, bibasal crackles.
Fundoscopy: Haemorrhage, exudate, and papilloedema..
Neurological system examination – Focal neurological deficit.
INITIAL INVESTIGATION
Urinalysis – Protein, Blood.
ECG - LVH, ischaemic changes.
CXR - Cardiomegaly, acute pulmonary oedema.
U&E - Renal Impairment.
FBC – Anaemia.
Clotting Screen – DIC.
TREATMENT
- Lower the diastolic BP to 100 -110mmHg over the first 24 hours.
- IV Frusemide 40 -80 mg if there is evidence of acute pulmonary oedema
or encephalopathy (refer to management of acute pulmonary oedema).
- If no feature of acute pulmonary oedema, IV Labetalol, 20-80mg (bolus)
followed by an infusion, 20-200mg / min (increasing every 15 minutes).
- Nitroprusside (0.25-10 micro gram/kg/min IV infusion) or Hydralazine
(5-10 mg IV over 20 min) in LVF.
- GTN infusion (1-10 mg/hr) in LVF or Angina.
- Switch to oral medications as BP control improves (refer to BHS guidelines
for 'High BP 2004').
MONITORING
BP, respiratory rate, oxygen saturation, fundus, neurological signs.
Catheterise the bladder, intake-output chart.
U&E, FBC, ECG.
FURTHER/SPECIALIST MANAGEMENT
Admit to medical HDU/ITU.
Arterial line, Central venous line.
Renal team consultation in ARF (refer to management of acute renal failure).