Hypertension

Systemic hypertension after open heart surgery can be caused by:

• Pain, anxiety

• Vasoconstriction from hypothermia

• Reflex vasoconstriction associated with a low cardiac output state

 
Hypertension may contribute to:

• Increased risk of mediastinal bleeding

• Vascular graft suture line disruption

• Myocardial ischaemia

Approach to Hypertension in the cardiothoracic patient.

Consider circumstances of hypertension and all potential contributing factors.

Decide goals for SBP and/or MAP on return from theatre.
SBP         90 -120
MAP         60-90

It may be due to vasoconstriction associated with a low cardiac output.  Withdrawal of inotropes may lead to rapid deterioration in cardiac output.  If a PA catheter or PICCO and the patient is unstable haemodynamically, consider putting one in.

Volume to increase preload will often be needed as vasodilators are introduced.  Vasodilation will also occur as patients re-warm.

Treatment

1. Sedation and analgesia – morphine/midazolam

2. If hypothermic, active re-warming with Blair hugger

3. Control shivering – rocuronium

4. Check cardiac output.  If < 2.2 1/min/m2 maintain or increase inotropes as vasodilators are given

5. Vasodilator:  Nitro-glycerine is the first line agent.  Often ineffective at low dose, so rapidly increase to 10-20 mls/hr.

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