Handbook of Neurosurgery 7th Edition PDF
For issues related to intracranial pressure (ICP), cerebral perfusion pressure (CPP), intracranial constituents, etc., see page 867. For cerebral blood flow (CBF) and cerebral metabolic rate of oxygen consumption (CMR02), see page 1010. Parameters of primary relevance to neurological surgery that can be modulated by the anesthesiologist:
1. blood pressure: one of the factors that determines CPP. May need to be manipulated (e.g. reduced when working on an aneurysm, or increased to enhance collateral circulation during cross clamping). Measurement by arterial line is most accurate and depending on the patient’s presentation and the planned procedure, often should be placed prior to induction of anesthesia.
For intracranial procedures, the arterial line should be calibrated at the external auditory meatus to most closely reflect intracranial blood pressure
2. jugular venous pressure: one of the factors that influences ICP
3. arterial C02 tension (PaC02): C02 is the most potent cerebral vasodilator. Hyperventilation reduces PaC02 (hypocapnea) which decreases CBV but also CBF. Goal is generally end tidal C02 (ETC02) of 25-30 mm Hg with a correlating PaC02 of 30-35. Use with care for stereotactic procedures to minimize shift of intracranial contents when using this method to control ICP