- stimulates alpha adrenergic receptors resulting in
- decreased heart rate
- increased peripheral resistance
- used to increase blood pressure
- Bolus dose:
- hypotension or shock: 0.1-0.5mg as slow IV direct injection q10-15min (or 1-10mg IM/SC q1-2hours)
- PSVT: 0.5-1mg as rapid direct IV injection q60-90 seconds
- IV infusion:
- 0.04-0.18mg/min (40-180 mcg/min), titrated to effect
100 mg/250ml D5W or NS
- hypovolemia, hypoxemia and acidosis should be corrected concurrently with initiation of therapy
- should be weaned off
- increased myocardial oxygen consumption; avoid in patients with left ventricular dysfunction
- peripheral or mesenteric ischemia
- renal failure
- restlessness or excitability
- extravasation of drug will cause tissue necrosis and ulceration (treat with 5-15mg phentolamine in NS - see phentolamine monograph)
- phenylephrine + atropine = increased BP and tachycardia
- phenylephrine + halogenated anaesthetics = increased cardiac irritability
- phenylephrine + alpha blocking agents = blockade of vasopressor effect
- phenylphrine + other sympathomimetics = increased risk of toxicity
- HR, ECG
- urine output, BUN, creatinine
- cardiac index
- arterial lactate
- changes in skin colour or tempurature
- chest pain
- May be administered by IV infusion by an approved nurse in CCTC.
- May be administered IV direct by an approved nurse in CCTC.
- May be titrated by an approved nurse in CCTC.
- Must be administered via a central line.
- Continuous infusion must be administered via an infusion pump.
- Should not be infused via the proximal injectate port (blue) of the Swan Ganz catheter.
- Patient requires placement of an arterial line to monitor BP.