Malignant Hypertension

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Definition

-  Severe HTN + papilloedema

 

Features

-  Medical Emergency

-  1% pts w essential HTN

-  Avg Age 40yrs

-  Men > women

-  Mortality from CCF, stroke or ARF

-  Survival rate 90% at 1yr, 80% at 5yrs

-  End organ damage

-  Fibrinoid necrosis or small arteries & arterioles

 

Causes

-  Eclampsia

-  Essential HTN

-  2o HTN

-  Meds: cocaine, MAOIs, OCP

-  Withdrawal from BB, Alpha stimulants, EtOH

 

Associated S/S

-  Most common presentation

-  Chest pain 27%

-  Dyspnoea 22%

-  Neuroligical defecit 21%

-  Nausea, vomiting

-  Cardio

-  LVH, S4, dilated cardiomyopathy

-  Angina, AMI, CCF w APO

-  Neuro

-  Occipital headaches

-  Stroke

-  PRES (Post. Reversible Encephalopathy Syndrome)

-  Hypertensive encephalopathy

-   HTN, headache, vomiting, visual changes, mental state changes, seizures & retinopathy w papilloedema

-  Renal

-  Hypokalaemia

-  Hypovolaemia

-  ARF

-  Microangiopathic haemolytic anaemia

 

Ix

-  Fundoscopy

-  Flame shaped haemorrhages

-  Soft exudates

-  Papilloedema

-  FBE: haemolytic anaemia

-  U&E

-  Hypokalaemia

-  Urea, Cr: ARF

-  Urinalysis

-  Proteinuria

-  Microscopic haematuria

-  RBC or hyaline casts

-  CXR: cardiomegaly, APO

-  ECG: ischaemia, AMI

-  Ix for 2o causes of HTN

 

 

Mx

-  Rapid decrease in BP may cause organ hypoperfusion

-  Reduce MAP by 25% over 24-48hrs

-  Best Mx w monitored bed ie: CCU w arterial line for continuous BP monitoring

-  IV Fluids: hypovolaemia

-  IV Meds

-  Nitroprusside

-   0.25-10 mcg/kg/min via IV infusion pump

-   Used w arterial line for continous BP monitoring

-  Hydralazine

-   Only during pregnancy (eclampsia)

-   Increases ICP (IICP)

-   10-40mg IV every 15-30min OR

-   Infusion at 1.5-5 mcg/kg/min

-  Verapamil (CCB)

-   5-10mg IV infusion over 2min

-   Repeat 15-30min later if poor initial response

-   Infusion 0.005-0.375 mg/kg/min

-  Labetalol (BB)

-   20mg IV infusion over 2min

-   Followed by 40-80mg every 10min OR

-   Continuous IV infusion at 2mg/min