How should a nurse administer a 20 mg intravenous push of labetalol, including patient verification, monitoring, and repeat dosing?

Administration of 20 mg IV Labetalol

Administer 20 mg labetalol as a slow intravenous push over 2 minutes with the patient in a supine position, measure blood pressure at baseline, 5 minutes, and 10 minutes post-injection, and keep the patient supine until their ability to tolerate an upright position is established. 1

Pre-Administration Requirements

Patient Verification and Contraindication Screening

• Verify patient identity using two identifiers before drug administration 1
• Screen for absolute contraindications including second- or third-degree heart block, bradycardia, decompensated heart failure, reactive airway disease (asthma), COPD, and hypotension (systolic BP <100 mmHg) 2, 3
• Confirm the patient is hospitalized, as IV labetalol is intended only for inpatient use 1

Patient Positioning

• Place patient in supine position before administration and maintain this position throughout the treatment period 1
• Do not permit ambulation (including using toilet facilities) until the patient's ability to tolerate an upright position has been established, as substantial orthostatic hypotension should be expected 1

Administration Technique

Injection Protocol

• Administer 20 mg labetalol IV push over 2 minutes as the initial dose 4, 2, 1
• This 20 mg dose corresponds to approximately 0.25 mg/kg for an 80 kg patient 1
• Use slow injection technique to minimize adverse effects and allow for controlled blood pressure reduction 1

Monitoring Requirements

Blood Pressure Monitoring Schedule

• Measure supine blood pressure immediately before injection to establish baseline 1
• Measure blood pressure at 5 minutes post-injection to evaluate initial response 1
• Measure blood pressure at 10 minutes post-injection to assess peak effect, which typically occurs within 5 minutes of injection 1
• Continue monitoring every 15 minutes until blood pressure stabilizes 3

Monitoring for Adverse Effects

• Watch for excessive or rapid falls in either systolic or diastolic blood pressure, which should be avoided 1
• Monitor for bradycardia, hypotension, nausea, scalp tingling, and burning sensations as common adverse effects 2
• Assess for orthostatic symptoms before allowing any position changes 1

Repeat Dosing Protocol

Escalation Strategy

• If blood pressure remains elevated at 10 minutes, additional doses of 40 mg or 80 mg may be given at 10-minute intervals 4, 1
• The maximum cumulative dose is 300 mg in a single treatment episode 4, 2, 1
• Each subsequent dose should be doubled (20 mg → 40 mg → 80 mg) until desired blood pressure is achieved 1

Clinical Context-Specific Targets

• For acute ischemic stroke (thrombolytic-eligible): Maintain BP <185/110 mmHg; may repeat 20 mg dose once if needed 4, 3
• For acute ischemic stroke (non-thrombolytic): Aim for 10-15% reduction in blood pressure when systolic >220 mmHg or diastolic 121-140 mmHg 4, 3
• For severe preeclampsia/eclampsia: Target systolic <160 mmHg and diastolic <105 mmHg 2, 3
• For general hypertensive emergency: Reduce mean arterial pressure by 20-25% over several hours, avoiding reductions >50% 2, 3

Critical Safety Considerations

Positioning Precautions

• Keep patient supine for the entire treatment period to prevent severe orthostatic hypotension 1
• Test orthostatic tolerance carefully before allowing any ambulation by having the patient sit at the bedside first, then stand with assistance 1

Drug Interactions

• Do not administer sublingual nifedipine concurrently with labetalol due to risk of precipitous blood pressure decline 2

Special Populations

• In pregnancy, labetalol is considered safe and effective with minimal teratogenicity risk, but avoid in patients with reactive airway disease 3
• In neurosurgical patients, doses exceeding 300 mg per 24 hours have been used safely when clinically necessary, though this exceeds standard FDA recommendations 5

Transition to Oral Therapy

• Begin oral labetalol when supine diastolic blood pressure begins to rise after IV treatment 1
• Typical oral maintenance dose is 200-400 mg twice daily, with a maximum of 2400 mg daily if needed 2, 6