Drips for the Neurosurgeon

Anti-Hypertensives

Nicardipine (Cardene)

• Primary Effects: Smooth arterial vasodilation / rapid, precise BP lowering

• Typical Starting Dose: 2.5–5 mg/hr

• Reasonable Range: 2.5–15 mg/hr (Most neuro ICUs run 5–10 mg/hr)

• Pros: Very titratable with rapid onset/offset, ninimal ICP disturbance, safe for tight BP targets (SAH, ICH), Less HR impact than other vasodilators

• Cons: reflex tachycardia, may require higher doses in chronic hypertension, needs frequent titration early on

• Red Flag: Over-titration can rapidly drop MAP → ↓ CPP, Monitor closely in TBI/SAH where CPP is critical

Clevidipine (Cleviprex)

• Excellent for tight, minute-to-minute BP control

• Primary Effects: ultra-rapid arterial vasodilation, very fast onset/offset (seconds)

• Typical Starting Dose: 1–2 mg/hr

• Reasonable Range: 1–32 mg/hr

• Pros: fastest titratable antihypertensive available, ideal for fluctuations or labile BP (SAH, ICH, neuro-OR), causes less reflex tachycardia than nicardipine at equivalent doses, smooth, predictable BP lowering

• Cons: expensive, requires dedicated line (lipid emulsion), triglycerides can rise with prolonged high-dose use

• Red Flag: void in severe egg or soy allergy, use caution in pancreatitis or severe hypertriglyceridemia

Pressors

Norepinephrine (Levophed)

• Primary Effects: ↑ MAP, supports CPP, minimal HR change

• Typical Starting Dose: 0.02–0.05 µg/kg/min

• Reasonable Range: 0.02–1.0 µg/kg/min

• Pros: Predictable, titratable, best for maintaining CPP, minimal ICP effect

• Cons: Mild tachycardia, peripheral vasoconstriction

• Red Flag: High doses → digital ischemia / mottling

• Use: First-line for TBI, ICH, SAH, SCI MAP goals, sepsis with neuro injury

Phenylephrine (Neo-Synephrine)

• Primary Effects: Pure α1 → vasoconstriction, ↑ MAP, may cause reflex bradycardia

• Typical Starting Dose: 0.3–0.5 µg/kg/min (or 20–40 µg/min)

• Reasonable Range: 0.2–2 µg/kg/min (or 20–200 µg/min)

• Pros: Good for SAH MAP goals, tachycardic patients, clean α1 pressor

• Cons: May ↓ cardiac output; risk of bradycardia

• Red Flag: Avoid in poor EF or cardiogenic shock

• Use: SAH vasospasm MAP augmentation, hypotension with tachycardia, neuro OR cases

Vasopressin

• Primary Effects: V1 vasoconstriction, ↑ SVR, minimal effect on HR

• Typical Starting Dose: 0.01–0.03 units/min

• Reasonable Range: 0.01–0.04 units/min

• Pros: Catecholamine-sparing, helpful in septic shock; also treats DI

• Cons: Vasoconstriction can reduce peripheral perfusion

• Red Flag: High doses → limb ischemia, hyponatremia

• Use: Add-on in septic shock, treatment of DI after pituitary surgery

Epinephrine

• Primary Effects: β1/β2 → α1 at higher doses; ↑ HR, ↑ MAP, ↑ CO

• Typical Starting Dose: 0.01–0.05 µg/kg/min

• Reasonable Range: 0.01–1 µg/kg/min

• Pros: Potent inotrope + pressor; useful in refractory shock

• Cons: Tachycardia, arrhythmias, ↑ lactate, can ↑ ICP

• Red Flag: Tachyarrhythmias or active ischemia

• Use: Anaphylaxis, peri-arrest states, refractory shock (not routine for CPP goals)

Dopamine (low relevance, but must know why to avoid)

• Primary Effects: Dose-dependent dopaminergic → β → α activity

• Typical Starting Dose: 5 µg/kg/min

• Reasonable Range: 5–20 µg/kg/min

• Pros: Historically used for bradycardia or low CO

• Cons: Tachyarrhythmias, ↑ ICP risk, unpredictable hemodynamics

• Red Flag: Avoid in TBI/ICH — worsens outcomes

• Use: Generally avoid in modern neurocritical care unless no other agents available

Dobutamine (inotrope important in SAH vasospasm)

• Primary Effects: β1 > β2 → ↑ contractility, ↑ CO, mild ↓ SVR

• Typical Starting Dose: 2.5–5 µg/kg/min

• Reasonable Range: 2.5–20 µg/kg/min

• Pros: Improves cardiac output for CPP; useful when EF is low

• Cons: Can ↓ MAP → often needs simultaneous NE

• Red Flag: Tachyarrhythmias; myocardial ischemia

• Use: SAH vasospasm with low cardiac output, cardiogenic shock limiting CPP

Intra-arterial Vasodilators

IA Nicardipine

• Primary Effects: Potent cerebral arterial vasodilation (Ca-channel blocker)

• Typical Starting Dose: 0.5–1 mg per vessel

• Reasonable Range: 1–5 mg per vessel, repeatable

• Pros:
• Very effective, predictable vasodilation
• Minimal systemic hypotension
• Longer duration than verapamil

• Cons:
• Can cause transient ICP rise during infusion

• Red Flag:
• Excessive dosing → prolonged hypotension, reflex tachycardia

• Use:
• First-line IA treatment for moderate–severe vasospasm in SAH

IA Verapamil

• Primary Effects: Cerebral vasodilation (non-DHP Ca-channel blocker)

• Typical Starting Dose: 5–10 mg per vessel

• Reasonable Range: 5–20 mg per vessel, titratable

• Pros:
• Very commonly used
• Good vessel penetration
• Helpful for refractory MCA/ACA vasospasm

• Cons:
• More systemic hypotension than nicardipine

• Red Flag:
• Hypotension → ↓ CPP → may need concurrent NE

• Use:
• Widespread first-line IA therapy; great when multiple territories involved

IA Milrinone

• Primary Effects: PDE-3 inhibition → vasodilation + ↑ contractility

• Typical Starting Dose: 0.25–0.5 mg bolus

• Reasonable Range: 0.25–1 mg per vessel

• Pros:
• Excellent for refractory vasospasm
• Less systemic hypotension than IV administration

• Cons:
• Still can drop MAP → pressor often required

• Red Flag:
• Avoid in severe cardiomyopathy without inotrope support

• Use:
• Refractory vasospasm, especially after nicardipine/verapamil

Sedatives

🟩 Propofol — ICP Control Workhorse

• Mechanism: GABA-A agonist

• Primary Effects: ↓ ICP, ↓ CMRO₂, ↓ CBF

• Typical Starting Dose: 5–20 µg/kg/min

• Reasonable Range: 20–80 µg/kg/min

• Pros: Best ICP control, rapid on/off, ideal for TBI/ICH/post-crani

• Cons : Hypotension → ↓ CPP

• Red Flag: PRIS risk when > 80 µg/kg/min or prolonged use

• Use: ICP control, deep sedation, status epilepticus

🟥 Fentanyl — First line sedative

• Primary Effects: Potent analgesia, minimal hemodynamic change, prevents pain-triggered ICP spikes

• Typical Starting Dose: 25–50 µg/hr (drip)

• Reasonable Range: 25–200+ µg/hr

• Pros:
• Very stable for MAP/CPP
• No histamine release → avoids vasodilation
• Excellent for ventilator synchrony & CO₂ management
• Rapid onset, easy to titrate
• Safe in renal dysfunction

• Cons:
• Accumulates with prolonged high doses
• Respiratory depression (intubated patients only)
• Ileus risk

• Red Flag:
• Rapid large boluses can cause chest wall rigidity (rare with drips)

• Use:
• First-line analgesia in TBI, ICH, SDH, SAH, post-crani
• Preventing ICP spikes during stimulation (turning, suctioning, EVD pulls)
• Pairing with propofol/dexmedetomidine/ketamine
• Procedural analgesia (EVD, bolt, dressing changes)

🟦 Dexmedetomidine (Precedex) — Cooperative Sedation

• Mechanism: α2 agonist

• Primary Effects: Sedation without respiratory depression

• Typical Starting Dose: 0.2–0.3 µg/kg/hr

• Reasonable Range: 0.2–1.5 µg/kg/hr

• Pros : Preserves neuro exam; minimal ICP effect

• Cons : Bradycardia, hypotension

• Use: Post-op crani, need frequent neuro exams, agitation without intubation

🟧 Ketamine — Hemodynamically Friendly

• Mechanism: NMDA antagonist

• Primary Effects: ↑ MAP (supports CPP), ICP-neutral or ↓ when ventilated

• Typical Starting Dose: 0.5 mg/kg/hr

• Reasonable Range: 0.5–4 mg/kg/hr

• Pros : Supports CPP; useful in hypotensive neuro trauma; analgesic

• Cons : Tachycardia, hypertension, secretions

• Use: Hypotensive TBI, analgesia + sedation, refractory seizures, bronchospasm

🟨 Midazolam Drip (Versed) — Seizure-Focused Sedation

• Mechanism: GABA-A agonist

• Primary Effects: Sedation + anticonvulsant

• Typical Starting Dose: 0.02–0.05 mg/kg/hr

• Reasonable Range: 0.02–0.2 mg/kg/hr

• Pros: Helpful in status epilepticus

• Cons: Accumulates, long wake-up, hypotension, tachyphylaxis

• Use: Status epilepticus, when propofol contraindicated

🟥 Pentobarbital — Refractory ICP “Nuclear Option”

• Mechanism: Potent GABA-A potentiation + ↓ CMRO₂

• Primary Effects: Profound ↓ ICP, burst suppression on EEG

• Loading Dose:
• 10 mg/kg over 30 minutes
• then 5 mg/kg/hr × 3 hours

• Maintenance Dose:
• 1–3 mg/kg/hr (titrated to EEG burst suppression)

• Pros: Best rescue for malignant ICP

• Cons: Severe hypotension, immunosuppression, ileus, long recovery

• Use: Refractory ICP after tier-1 & tier-2 failure

🟫 Etomidate — Neuro-Stable Induction (Not a true drip)

• Mechanism: GABA-A agonist

• Primary Effects: ↓ ICP, stable MAP during RSI

• Typical Dose (RSI): 0.3 mg/kg IV push

• Continuous Infusion: Not recommended (adrenal suppression)

• Pros : Best for intubating TBI/ICH with shock

• Cons: Suppresses cortisol synthesis

• Use: Airway control in neuro patients

Misc

Glucagon

• can be used for hypotension 2/2 beta-blockers

• Dosing: 2-3 IV bolus + 5mg gtt over 1 hr