Reference Guide
Critical Medications
Vasopressors, inotropes, sedation, anticoagulation, and antiarrhythmics
Vasopressor Reference
| Agent | Mechanism | Typical Dose | Key Considerations |
|---|---|---|---|
| Norepinephrine | α₁ >> β₁ | 0.02–1 mcg/kg/min | First-line for septic, mixed, post-cardiotomy vasoplegia |
| Epinephrine | α₁, β₁, β₂ | 0.01–0.5 mcg/kg/min | Inotrope + vasopressor; ↑ lactate; cardiac arrest 1 mg IV q3–5 min |
| Vasopressin | V1 receptor | 0.01–0.04 U/min (fixed) | Adjunct in septic/vasoplegic shock; useful in RV failure (no ↑ PVR) |
| Phenylephrine | Pure α₁ | 0.2–5 mcg/kg/min | Reflex bradycardia; useful in HOCM/AS; ↑ afterload |
| Dopamine | Dose-dependent | 2–20 mcg/kg/min | Tachyarrhythmias; rarely first-line |
| Methylene Blue | NO synthase inhibition | 1–2 mg/kg bolus | Refractory post-CPB vasoplegia |
| Angiotensin II | AT1 receptor | 20–80 ng/kg/min | Catecholamine-resistant vasodilatory shock |
Inotrope Reference
| Agent | Mechanism | Typical Dose | Notes |
|---|---|---|---|
| Dobutamine | β₁ >> β₂ | 2.5–20 mcg/kg/min | ↑ CO, ↓ SVR; tachyarrhythmia; tachyphylaxis |
| Milrinone | PDE-3 inhibitor | 0.125–0.75 mcg/kg/min | Inodilator; pulmonary vasodilator (RV failure); renally cleared; hypotension |
| Epinephrine (low dose) | β₁, β₂, α₁ | 0.01–0.1 mcg/kg/min | ↑ lactate, hyperglycemia |
| Levosimendan | Ca²⁺ sensitizer | 0.05–0.2 mcg/kg/min × 24h | Where available; long-acting metabolite |
| Digoxin | Na/K-ATPase inhibition | 0.125–0.25 mg/day | Modest inotropy; rate control in AF |
Agents
- Inhaled Nitric Oxide: 10–40 ppm; selective pulmonary vasodilator; monitor methemoglobin
- Inhaled Epoprostenol: 50 ng/kg/min nebulized; less expensive alternative
- Milrinone: Systemic + pulmonary vasodilator
- Sildenafil: 20 mg PO/NG TID for chronic PH or wean from iNO
Sedation Agents
| Agent | Dose | Notes |
|---|---|---|
| Propofol | 5–80 mcg/kg/min | Rapid on/off; hypotension, hypertriglyceridemia, PRIS at high/prolonged doses |
| Dexmedetomidine | 0.2–1.5 mcg/kg/hr (avoid bolus) | Light sedation; analgesic-sparing; bradycardia, hypotension; preferred for extubation |
| Midazolam | 1–10 mg/hr | Avoid prolonged use (delirium, accumulation) |
| Fentanyl | 25–200 mcg/hr | Hemodynamically neutral; chest wall rigidity with rapid bolus |
| Morphine | 2–5 mg IV PRN | Histamine release → hypotension |
| Hydromorphone | 0.2–1 mg IV PRN | Useful in renal dysfunction |
| Ketamine | 0.1–0.5 mg/kg/hr | Analgesic-sparing; ↑ HR/BP; useful in shock |
Assessment Tools
Use validated tools: RASS (target −2 to 0), CPOT/BPS for pain assessment, and daily awakening trials when feasible.
Anticoagulant Reference
| Agent | Dose | Monitoring |
|---|---|---|
| UFH (therapeutic) | Bolus 60–80 U/kg, infusion 12–18 U/kg/hr | aPTT 1.5–2.5× control or anti-Xa 0.3–0.7 |
| Heparin (DVT prophylaxis) | 5000 U SC q8–12h | — |
| Enoxaparin | 1 mg/kg SC q12h (tx) or 30–40 mg daily (ppx) | Anti-Xa if renal impairment |
| Bivalirudin | 0.15–0.2 mg/kg/hr (HIT) | aPTT or dilute thrombin time |
| Argatroban | 0.5–2 mcg/kg/min (HIT) | aPTT 1.5–3× control; hepatic dose adjustment |
| Warfarin | 2.5–5 mg PO daily | INR 2.0–3.0 (most); 2.5–3.5 mech mitral |
| Heparin for CPB | 300–400 U/kg | ACT >480 s |
| Protamine Reversal | 1 mg per 100 U heparin | Risk: hypotension, pulmonary HTN, anaphylaxis |
HIT (Heparin-Induced Thrombocytopenia)
Suspect with platelet drop >50% from baseline 5–10 days after heparin exposure (or earlier with prior exposure). Calculate 4Ts score. Stop ALL heparin (including flushes, line locks, IABP/ECMO circuits). Start non-heparin anticoagulant (argatroban or bivalirudin).
Antiarrhythmic Reference
| Agent | Indication | Typical Dose | Notes |
|---|---|---|---|
| Amiodarone | AF, VT, VF | 150 mg IV over 10 min, then 1 mg/min × 6h, then 0.5 mg/min × 18h | Hypotension with rapid bolus; thyroid/pulmonary/hepatic toxicity |
| Lidocaine | VT/VF | 1–1.5 mg/kg bolus, 1–4 mg/min infusion | CNS toxicity; reduce in hepatic failure |
| Procainamide | VT, AF with WPW | 20–50 mg/min (max 17 mg/kg); then 1–4 mg/min | Watch QRS widening, hypotension |
| Esmolol | Rate control | 500 mcg/kg load, 50–300 mcg/kg/min | Short half-life (~9 min) |
| Metoprolol | Post-op AF | 2.5–5 mg IV; 12.5–100 mg PO BID | Avoid in decompensated HF |
| Diltiazem | AF rate control | 0.25 mg/kg bolus, 5–15 mg/hr | Avoid in low EF/HF |
| Adenosine | SVT | 6 mg rapid IV, then 12 mg | Transient asystole; lower dose in transplant |
| Magnesium | Torsades, AF ppx | 1–2 g IV over 5–60 min | Keep Mg²⁺ >2 mg/dL |
Post-Operative AF
Occurs in 20–40% of cardiac surgery patients, peaks POD 2–3. Beta-blockers first-line for prevention and rate control. Amiodarone for rhythm control. Maintain K⁺ >4 mEq/L and Mg²⁺ >2 mg/dL.
S.K.
The World-Class Cardiac Intensivist
This content is for educational reference only. Always follow institutional protocols and exercise clinical judgment.