Craniotomy for Excision of Meningioma

General: Patients may be symptomatic or asymptomatic. Symptoms may be due to location of tumor or increased ICP. You should know the size and location of the tumor, any preop deficits and if the patient is at risk for increased ICP. Many meningiomas are highly vascular and may be embolized preoperatively.
Preop: Premedicate with up to 2 mg of midazolam depending on patient’s mental status. None if altered mental status (prevent further increase in ICP).
Monitors: Routine monitors. Arterial and Foley catheters inserted after induction of anesthesia. Sufficient IV access to handle significant blood loss.
Anesthesia: Goals are to decrease ICP (if high), to provide brain relaxation for good surgical exposure and to prevent cerebral ischemia from brain retraction, used when the meningioma is not easily accessible. Patients typically receive 1-2 g of Cefazolin, 10 mg of decadron and 1 g/kg of mannitol on skin incision (verify all with surgeon). Induction with propofol. In case of increased ICP, have patient hyperventilate during preoxygenation and continue hyperventilation with mask as soon as possible after induction of anesthesia. Fentanyl 5 μg /kg in divided doses throughout induction, but prior to intubation. Verify adequate neuromuscular blockade prior to intubation to avoid coughing/straining. Tape eyes, insert esophageal temperature probe, and at least one additional large bore IV. Meningiomas are vascular tumors (bleeding). Fortunately, most are embolized before the operation to reduce bleeding. Patient position will depend on location of tumor. Maintain anesthesia with propofol infusion, low dose inhalation agent (less than 0.5 MAC), and a fentanyl infusion 2 μg /kg/hr. Use mild hyperventilation (PaCO2 30-35 mmHg). Maintain euvolemia (Lactated Ringer’s) and neuromuscular relaxation (vecuronium or rocuronium). Once the bone flap is removed, have the surgeon assess the tightness of the dura. Decrease ICP further if necessary (pCO2, mannitol, propofol, head up etc.). Fentanyl infusion is usually stopped at the beginning of dural closure/patch. Normalize pCO2 to facilitate spontaneous breathing at the end of the operation. Use of inhalation agents and propofol is usually stopped about 10-15 min before the end of surgery. Reverse residual neuromuscular blockade once the Mayfield pins have been removed.
Potential complications: Intraoperative bleeding. Delayed awakening from anesthetics and/or intracranial pathology. Cerebral ischemia from brain retraction.
Recovery: Wake patient up, and extubate if possible, immediately after the operation to allow neurologic examination. Consider prophylactic use of labetalol to attenuate emergence hypertension which can cause intracranial bleeding. Do not allow persistent coughing or bucking on the endotracheal tube. Use a hemodynamic monitor and supplemental oxygen during patient transport to ICU.