Anesthetic Management for Neurosurgical Procedures

General Principles

The American Society of Anesthesiologists recommends maintaining euvolemia, normotension, isotonicity, normoglycemia, and mild hypocapnia to ensure optimal cerebral physiology during intracranial procedures 1
Avoiding profound hypocapnia unless specifically indicated for control of brain swelling is recommended by the American College of Surgeons 1
Direct arterial pressure monitoring is essential, particularly when manipulating systemic pressure with vasoactive agents, as stated by the American Heart Association 1

High-dose fentanyl (3-5 μg/kg), alfentanil (10-20 μg/kg), or remifentanil TCI (target-controlled infusion) with Cpt ≥ 3 ng/ml is recommended for induction by the European Society of Anaesthesiology 2
Neuromuscular blockade with rocuronium (1 mg/kg) or suxamethonium (1.5 mg/kg) is suggested by the American Society of Anesthesiologists 2
Having vasoconstrictors (ephedrine or metaraminol) available to treat immediate hypotension is advised by the European Society of Anaesthesiology 2

Avoiding nitrous oxide due to its potential to increase cerebral blood flow and intracranial pressure is recommended by the World Health Organization 3

Standard monitoring includes ECG, SpO2, NIBP, and capnography, which should be checked before induction and continued throughout anesthesia, as stated by the American Society of Anesthesiologists 4 and the European Society of Anaesthesiology 5
Processed electroencephalogram (pEEG) monitoring is essential when TIVA is administered with neuromuscular blocking drugs, according to the American Clinical Neurophysiology Society 4 and the American Society of Anesthesiologists 6
Quantitative neuromuscular monitoring should be used whenever neuromuscular blocking drugs are administered, as recommended by the American Society of Anesthesiologists 4 and the European Society of Anaesthesiology 5
Direct arterial blood pressure monitoring with the transducer placed at the level of the tragus is suggested by the European Society of Anaesthesiology 2

Maintaining blood pressure targets specific to the neurosurgical condition (e.g., lower targets for aneurysm surgery, higher for traumatic brain injury) is recommended by the European Society of Anaesthesiology 2
Induced hypotension may be useful during certain phases of surgery but should be used cautiously in patients with impaired cerebral autoregulation, as stated by the American Heart Association 1

For elderly patients (>60 years), targeting a lighter level of anesthesia with a BIS of approximately 50 to reduce postoperative delirium is recommended by the American Geriatrics Society 6
For transfer of brain-injured patients, maintaining PaCO2 at 4.5-5.0 kPa and PaO2 ≥ 13 kPa is suggested by the European Society of Anaesthesiology 2

Direct arterial blood pressure monitoring with transducer at the level of the tragus is recommended to accurately reflect cerebral perfusion pressure, as suggested by the American Heart Association 7
Processed EEG monitoring (BIS) is mandatory when using TIVA with neuromuscular blockade to prevent awareness and guide anesthetic depth 7
The American Stroke Association recommends frequent intraoperative BP monitoring and tight control in patients with unsecured aneurysms to prevent both ischemia and rerupture 8 9

Mannitol or hypertonic saline are effective for reducing ICP and cerebral edema intraoperatively, according to the American Stroke Association 8 9 10
The American Stroke Association suggests that hyperventilation and hypocarbia should accompany propofol administration when increased ICP is suspected 8 9

Prevention of both hyperglycemia and hypoglycemia during surgery is reasonable to improve outcomes, as recommended by the American Stroke Association 8 9
The American Stroke Association recommends titrating anesthetic depth to facilitate rapid neurological examination immediately post-procedure 8 9

Intraoperative neuromonitoring may be reasonable to guide anesthetic and operative management in patients with aneurysmal subarachnoid hemorrhage, according to the American Stroke Association 8 9
Adenosine may be considered for uncontrolled intraoperative aneurysmal rupture to induce temporary cardiac standstill and facilitate clip placement, as suggested by the American Stroke Association 8 9