What are the key considerations for nursing care when administering phenylephrine (vasopressor) to patients?

Nursing Care Considerations for Phenylephrine Administration

When administering phenylephrine as a vasopressor, nurses must carefully monitor blood pressure and heart rate throughout administration, as this is the most critical aspect of phenylephrine nursing care. 1

Preparation and Administration

• Phenylephrine must be diluted before administration as either bolus intravenous infusion or continuous intravenous infusion 2
• For bolus administration: Dilute 10 mg (1 mL of 10 mg/mL) with 99 mL of 5% Dextrose or 0.9% Sodium Chloride to yield 100 mcg/mL 2
• For continuous infusion: Add 10 mg (1 mL of 10 mg/mL) to 500 mL of 5% Dextrose or 0.9% Sodium Chloride to yield 20 mcg/mL 2
• Inspect solution for particulate matter and discoloration prior to administration 2
• Diluted solution should not be held for more than 4 hours at room temperature or more than 24 hours under refrigerated conditions 2

Dosing Considerations

• For perioperative setting: 50-250 mcg IV bolus (most common initial doses are 50 or 100 mcg) or 0.5-1.4 mcg/kg/min continuous infusion 2
• For septic or vasodilatory shock: No bolus; start at 0.5 mcg/kg/min up to 6 mcg/kg/min continuous infusion 2
• Doses above 6 mcg/kg/min do not show significant incremental increase in blood pressure 2

Vital Monitoring Requirements

• Continuous blood pressure and heart rate monitoring is essential during phenylephrine administration 1
• Establish baseline vital signs before administration 1
• Monitor for hypertensive response, which can occur rapidly after administration 1
• For topical phenylephrine (e.g., in surgical settings), be aware that significant systemic absorption can occur, requiring the same vigilant monitoring 1

Patient Risk Assessment

• Identify patients at higher risk for adverse effects, including those with: 1
  • History of cardiovascular disease
  • Hypertension
  • Prior stroke
  • Patients using monoamine oxidase inhibitors (MAOIs)
  • Long-standing insulin-dependent diabetes
  • Advanced arteriosclerosis
• Use caution in patients with cocaine use history, as severe hypertension and pulmonary edema have been reported 1

Managing Complications

• Recognize signs of excessive vasoconstriction: marked hypertension, reflex bradycardia, decreased peripheral perfusion 1
• Be prepared to treat hypertensive crisis if it occurs, but avoid beta-blockers as first-line treatment 1
• If severe hypertension develops, consider increasing anesthetic depth rather than administering beta-blockers, as beta-blockade can precipitate pulmonary edema when combined with alpha-agonists 1
• For extravasation: Phentolamine injected intradermally at the extravasation site may help counteract dermal vasoconstriction 1

Special Considerations

• Correct intravascular volume depletion before or during administration 2
• Correct acidosis, as it may reduce phenylephrine effectiveness 2
• When used for septic shock, phenylephrine should be considered when norepinephrine is associated with serious arrhythmias, cardiac output is known to be high with persistent low blood pressure, or as salvage therapy 1
• For intracavernosal administration (priapism treatment), use gradual dose escalation in patients on MAOIs 1

Documentation Requirements

• Document baseline vital signs and ongoing monitoring results 1
• Record dose, route, time of administration, and patient response 1
• Document any adverse effects and interventions performed 1
• Track fluid balance, as phenylephrine is often used alongside fluid resuscitation 1

Nursing Evaluation of Response

• Assess for target mean arterial pressure achievement (typically 65 mmHg or as prescribed) 1
• Monitor for signs of improved tissue perfusion: improved urine output, decreased lactate levels, improved mental status 3, 4
• Assess for signs of excessive vasoconstriction: decreased peripheral perfusion, cool extremities 3