What is the protocol for managing acute hypertension with a Cardene (nicardipine) drip?

Protocol for Managing Acute Hypertension with Nicardipine (Cardene) Drip

Nicardipine is a first-line intravenous antihypertensive agent for managing acute hypertension, with initial dosing of 5 mg/hr and titration by 2.5 mg/hr every 5-15 minutes to a maximum of 15 mg/hr to achieve target blood pressure. 1

Preparation and Administration

Preparation

• Single dose vials (25 mg) must be diluted with 240 mL of compatible IV fluid to create 250 mL of solution at 0.1 mg/mL concentration 1
• Compatible IV fluids include:
  • Dextrose (5%) Injection
  • Dextrose (5%) and Sodium Chloride (0.45% or 0.9%) Injection
  • Sodium Chloride (0.45% or 0.9%) Injection 1
• Not compatible with Sodium Bicarbonate (5%) or Lactated Ringer's Injection 1

Administration

• Administer via slow continuous infusion through a central line or large peripheral vein 1
• Change infusion site every 12 hours if administered via peripheral vein to minimize risk of venous irritation 1

Dosing Protocol

Initial Dosing

• Start at 5 mg/hr for gradual blood pressure reduction 1
• For more rapid titration in hypertensive emergencies:
  • Initial dose: 5 mg/hr
  • Titrate up by 2.5 mg/hr every 5-15 minutes
  • Maximum dose: 15 mg/hr 2, 1

Monitoring

• Monitor blood pressure and heart rate continuously during infusion and after discontinuation 1
• Blood pressure begins to fall within minutes of starting infusion
• Reaches approximately 50% of ultimate decrease in about 45 minutes 1
• After discontinuation, 50% offset of action occurs in approximately 30 minutes 1

Target Blood Pressure Goals

Hypertensive Emergency (with target organ damage)

• Reduce SBP by no more than 25% within the first hour 2
• Then, if stable, reduce to 160/100 mmHg within the next 2-6 hours
• Cautiously reduce to normal over the following 24-48 hours 2

Specific Clinical Scenarios

1. Aortic Dissection:

   • Reduce SBP to <120 mmHg within 20 minutes
   • Beta-blockade should precede nicardipine administration 2

2. Acute Renal Failure:

   • Nicardipine is a preferred agent 2

3. Eclampsia/Preeclampsia:

   • Nicardipine is appropriate; ACE inhibitors and nitroprusside are contraindicated 2

4. Acute Coronary Syndromes:

   • Nicardipine is one of the preferred agents 2

5. Acute Ischemic Stroke:

   • For patients eligible for thrombolytic therapy with BP >185/110 mmHg:
     • Nicardipine 5 mg/hr IV, titrate up by 2.5 mg/hr every 5-15 minutes to maximum 15 mg/hr 2
   • During/after thrombolytic therapy:
     • Maintain BP ≤180/105 mmHg
     • For systolic BP 180-230 mmHg or diastolic BP 105-120 mmHg: Nicardipine 5 mg/hr IV, titrate up to desired effect 2

6. Intracerebral Hemorrhage:

   • Nicardipine has shown safety and efficacy with low rates of hematoma expansion (3.4%) and neurological deterioration (2.2%) 3

Special Considerations

Impaired Renal Function

• Nicardipine has been shown to be more efficacious than labetalol for acute BP control in patients with renal dysfunction 4
• Use with caution and monitor closely in patients with more than mild renal impairment 1

Impaired Hepatic Function

• Consider lower dosages and monitor response closely
• Use caution in patients with portal hypertension 1

Congestive Heart Failure

• Monitor vital signs carefully, particularly when combined with beta-blockers
• Nicardipine reduces afterload without significantly impairing myocardial contractility 1

Common Pitfalls and Precautions

1. Avoid too rapid decrease in blood pressure:

   • Rapid decreases can lead to organ hypoperfusion
   • Particularly important in patients with acute cerebral infarction or hemorrhage 1

2. Peripheral vein irritation:

   • Change infusion site every 12 hours
   • Use large peripheral veins or central lines rather than small peripheral veins 1

3. Reflex tachycardia:

   • Monitor heart rate closely
   • May increase by approximately 10 beats/minute 5

4. Drug interactions:

   • Use caution when combining with beta-blockers in patients with CHF 1
   • Do not abruptly withdraw beta-blockers during nicardipine therapy 1

Nicardipine's rapid onset, predictable dose-response relationship, and ease of titration make it an excellent choice for managing acute hypertension in various clinical scenarios.