Essential Critical Care Medications Every ICU Nurse Should Know

Essential Critical Care Medications Every ICU Nurse Should Know

Critical care nursing requires a deep understanding of the medications used to manage life-threatening conditions. From stabilizing hemodynamics to managing pain and sedation levels, the medications you administer in the ICU can significantly impact patient outcomes. As a nurse who has worked in Cardiac, Trauma and Neuro ICUs, I know how challenging it can be to keep track of all the critical medications, especially as a new graduate! This quick guide will cover some of the most commonly used ICU drugs, breaking down their mechanisms of action, dosing considerations, and key side effects. Whether you're just starting out in critical care or looking to refresh your knowledge, these are the medications every ICU nurse should have in their toolbox.

 

Want a physical copy of this resource? Check out our best-selling guide, New to ICU 2.0: A Visual Guide to Critical Care Nursing!

 

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1. Vasopressors: Norepinephrine (Levophed)

  • Mechanism of Action:  
    • Norepinephrine (Levophed) is a potent vasopressor that primarily acts on alpha-1 adrenergic receptors, causing vasoconstriction and increasing blood pressure. It also has some beta-1 effects, which can increase heart rate and cardiac output.
  • Uses: 
    • Management of septic shock
    • Cardiogenic shock
    • Hypotension unresponsive to fluid resuscitation
  • Dosing:
    • Initial dose: 0.01-0.03 mcg/kg/min, titrate as needed for MAP/SBP order parameters
    • Typical range: 0.02-0.3 mcg/kg/min (depending on your unit protocol)
  • Side Effects:
    • Hypertension
    • Bradycardia (due to baroreceptor reflex)
    • Peripheral ischemia (monitor for IV patency!)
  • Nursing Considerations:
    • Monitor blood pressure frequently (e.g. continuous blood pressure monitoring from arterial lines)
    • Ensure adequate volume resuscitation before administration to avoid severe vasoconstriction (ex: having continuous SVV monitoring is helpful, too!)
    • Administer through a central line when possible to avoid extravasation.

 

2. Sedatives: Propofol (Diprivan)

  • Mechanism of Action:
    • Propofol is a sedative-hypnotic agent that works by enhancing the effect of the inhibitory neurotransmitter GABA, leading to sedation and a decrease in anxiety and agitation.
  • Uses:
    • Sedation for mechanically ventilated patients
    • Procedural sedation
  • Dosing:
    • Initial dose: 5-10 mcg/kg/min, titrate to desired sedation level (e.g. RASS -2 to 0)
    • Typical range: 5-50 mcg/kg/min (e.g. MAX dose 80mcg/kg/min in TBI patients)
  • Side Effects:
    • Hypotension
    • Bradycardia
    • Respiratory depression
  • Nursing Considerations:
    • Monitor for hypotension and adjust dosage accordingly
    • Propofol is lipid-based, so monitor triglyceride levels during prolonged infusions, as well as signs and symptoms of Propofol Infusion Syndrome.
    • Change tubing every 12 hours to prevent infection due to its high lipid content.

 

3. Paralytics: Vecuronium

  • Mechanism of Action:
    • Vecuronium is a non-depolarizing neuromuscular blocker that competes with acetylcholine at nicotinic receptors, preventing muscle contraction.
  • Uses:
    • Facilitating endotracheal intubation
    • Maintaining muscle paralysis in mechanically ventilated patients
  • Dosing: 
    • Bolus: 0.08-0.1 mg/kg IV
    • Maintenance infusion: 0.8-1.7 mcg/kg/min (TIP: obtain baseline Train of Four (TOF) score before initiating paralytic medication!)
  • Side Effects:
    • Prolonged paralysis
    • Hypotension (rare)
  • Nursing Considerations:
    • Ensure adequate sedation and analgesia before administering paralytics.
    • Monitor train-of-four (TOF) to assess the depth of paralysis.
    • Be aware of the potential for prolonged paralysis in patients with renal or hepatic impairment.

 

4. Antiarrhythmics: Amiodarone

  • Mechanism of Action:
    • Amiodarone is a class III antiarrhythmic that prolongs the action potential and refractory period by blocking potassium channels. It also has sodium and calcium channel-blocking effects, contributing to its antiarrhythmic properties.
  • Uses:
    • Ventricular fibrillation (VF)
    • Ventricular tachycardia (VT)
    • Atrial fibrillation (AF) with rapid ventricular response
  • Dosing:
    • For VT/VF: 300 mg IV push, followed by 150 mg if needed.
    • Maintenance infusion: 1 mg/min for 6 hours, then 0.5 mg/min for 18 hours.
  • Side Effects:
    • Hypotension (especially with rapid administration)
    • Bradycardia
    • Pulmonary toxicity (with long-term use)
  • Nursing Considerations: 
    • Monitor ECG for QT prolongation and bradycardia.
    • Watch for hypotension during the loading dose.
    • Avoid in patients with iodine allergy due to its iodine content.

 

5. Pain Management: Fentanyl

  • Mechanism of Action:
    • Fentanyl is a synthetic opioid analgesic that binds to mu-opioid receptors, blocking the transmission of pain signals to the brain.
  • Uses:
    • Pain control in mechanically ventilated patients
    • Postoperative pain management
  • Dosing:
    • Bolus: 25-100 mcg IV push
    • Continuous infusion: 0.7-10 mcg/kg/hr
  • Side Effects:
    • Respiratory depression
    • Bradycardia
    • Hypotension
  • Nursing Considerations:
    • Monitor for respiratory depression, especially when combined with sedatives.
    • Ensure frequent pain assessments, as fentanyl has a short duration of action and may require frequent titration.

 

6. Anticoagulants: Heparin

  • Mechanism of Action:
    • Heparin enhances the activity of antithrombin III, inhibiting thrombin and preventing the conversion of fibrinogen to fibrin, thus reducing clot formation.
  • Uses:  
    • Deep vein thrombosis (DVT) prophylaxis and treatment
    • Pulmonary embolism (PE)
    • Acute coronary syndrome (ACS)
  • Dosing:
    • DVT/PE treatment: 80 units/kg bolus, followed by 18 units/kg/hr infusion (dose varies by protocol).
    • Adjust dose based on aPTT or anti-Xa levels (often collected every 6-8 hours!)
  • Side Effects:
    • Bleeding
    • Heparin-induced thrombocytopenia (HIT)
  • Nursing Considerations: 
    • Monitor aPTT or anti-Xa levels regularly (follow your hospital protocol)
    • Watch for signs of bleeding (e.g., hematuria, melena, low hemoglobin).
    • Be vigilant for signs of HIT, such as a sudden drop in platelet count.

 

7. Antibiotics: Vancomycin

  • Mechanism of Action:
    • Vancomycin is a glycopeptide antibiotic that inhibits bacterial cell wall synthesis, making it effective against Gram-positive bacteria, including MRSA.
  • Uses:
    • Methicillin-resistant Staphylococcus aureus (MRSA) infections
    • Severe skin infections, endocarditis, and osteomyelitis
  • Dosing: 
    • Based on renal function and weight.
    • Typical dosing: 15-20 mg/kg IV every 8-12 hours.
  • Side Effects:
    • Nephrotoxicity
    • Red man syndrome (rapid infusion)
    • Ototoxicity
  • Nursing Considerations:
    • Infuse over 60-90 minutes to avoid Red Man Syndrome.
    • Monitor trough levels to ensure therapeutic dosing (10-20 mcg/mL).
    • Adjust dosing based on renal function.

 

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These essential medications are just a glimpse of what you’ll encounter in the ICU, but having a solid understanding of them will make you a more confident and effective critical care nurse. As you progress in your career, you'll continually learn about new drugs and updates in ICU pharmacology. Remember, medication management is one of the most crucial aspects of patient care in the ICU, so always stay informed, ask questions, and consult your colleagues or pharmacy team when in doubt!

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