What are the most commonly used medications in neurosurgery practice?

Most Commonly Used Medications in Neurosurgery Practice

The most commonly used medications in neurosurgery practice include opioids (particularly fentanyl and morphine), local anesthetics, neuromuscular blockers, sedatives, and anticonvulsants, which are essential for perioperative pain management, anesthesia induction, and seizure prevention in neurosurgical patients. 1

Intraoperative Medications

Anesthesia Induction and Maintenance

1. Opioid Analgesics

   • Fentanyl: 1-2 μg/kg (standard dose); 3-5 μg/kg (high dose for neurosurgery) 1
   • Alfentanil: 10-20 μg/kg 1
   • Remifentanil: 0.05-0.3 μg/kg/min (continuous infusion) 1
   • Sufentanil: 0.5-1 μg/kg bolus, with optional continuous infusion of 0.5-1 μg/kg/h 1

2. Induction Agents

   • Propofol: Standard for induction due to rapid onset/recovery and reduced PONV 1
   • Ketamine: 1-2 mg/kg (particularly useful in hemodynamically unstable patients) 1
   • S-Ketamine: 0.25-0.5 mg/kg (lower dose than regular ketamine) 1

3. Neuromuscular Blockers

   • Rocuronium: 1 mg/kg 1
   • Suxamethonium: 1.5 mg/kg 1

Hemodynamic Management

1. Vasopressors/Vasoconstrictors

   • Ephedrine: For immediate hypotension management 1
   • Metaraminol: Both bolus and infusion for blood pressure control 1

2. Alpha-2 Agonists

   • Dexmedetomidine: IV bolus 0.5-1 μg/kg, continuous infusion 0.2-0.7 μg/kg/h 1
   • Clonidine: IV bolus 1-3 μg/kg 1

Perioperative Pain Management

Systemic Analgesics

1. NSAIDs

   • Ketorolac: 0.5-1 mg/kg (max 30 mg) single intraoperative dose; 0.15-0.2 mg/kg (max 10 mg) every 6 hours postoperatively 1
   • Ibuprofen: 10 mg/kg IV every 8 hours 1

2. Non-Opioid Analgesics

   • Paracetamol (Acetaminophen): IV loading dose 15-20 mg/kg, then 10-15 mg/kg every 6-8 hours 1
   • Lidocaine: IV bolus 1.5 mg/kg, continuous infusion 1.5 mg/kg/h 1

3. Corticosteroids

   • Dexamethasone: 0.15-0.25 mg/kg (max 0.5 mg/kg) - reduces swelling and has antiemetic properties 1
   • Methylprednisolone: 1 mg/kg - reduces postoperative swelling 1

Postoperative Medications

Breakthrough Pain Management

1. Opioids for PACU

   • Morphine: 25-100 μg/kg depending on age, titrated to effect 1, 2
   • Fentanyl: 0.5-1.0 μg/kg, titrated to effect 1
   • Tramadol: 1-1.5 mg/kg, titrated to effect 1

2. Patient-Controlled Analgesia (PCA)

   • Morphine PCA: According to institutional protocols 1
   • Fentanyl PCA: According to institutional protocols 1

Seizure Management

1. Anticonvulsants
   • Levetiracetam: Loading dose of 1g (or 20 mg/kg) before transfer if seizure has occurred 1, 3
   • Phenytoin: 20 mg/kg (max 2g) as loading dose 1

Regional Anesthesia in Neurosurgery

Local Anesthetics

1. Long-acting Local Anesthetics
   • Bupivacaine 0.25%: Maximum dose 1 ml/kg (2.5 mg/kg) 1
   • Ropivacaine 0.2%: Maximum dose 1.5 ml/kg (3 mg/kg) 1
   • Levo-bupivacaine 0.25%: Maximum dose 1 ml/kg (2.5 mg/kg) 1

Important Considerations and Pitfalls

Medication Safety

• Opioid-related respiratory depression: Monitor closely, especially with high-dose opioids or when combined with other CNS depressants 2
• Adrenal insufficiency: Can occur with prolonged opioid use; presents with non-specific symptoms including nausea, fatigue, weakness, and hypotension 2
• Drug interactions: Avoid combining opioids with benzodiazepines when possible; if necessary, use reduced doses of both medications 2

Special Considerations for Neurosurgical Patients

• Blood pressure management: Maintain appropriate MAP targets to prevent secondary brain injury 1
• Intracranial pressure concerns: Avoid medications that increase ICP
• Neurological assessment: Consider using shorter-acting agents when frequent neurological assessments are needed

Emerging Trends

• Opioid-sparing techniques: Multimodal analgesia approaches are increasingly used to reduce opioid requirements 1, 4
• Intrathecal opioids: Provide effective postoperative analgesia with lower systemic effects 5
• Non-opioid analgesics: Dexmedetomidine shows comparable efficacy to fentanyl in controlling surgical stress response during craniotomy 4

By understanding these medication classes and their appropriate use, neurosurgical teams can optimize perioperative care, minimize complications, and improve patient outcomes.