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Awake craniotomy requires a carefully tailored anesthetic strategy that balances patient comfort with the need for accurate neurological assessment. Techniques such as monitored anesthesia care and the sleep–awake–sleep approach enable spontaneous ventilation and allow intraoperative cortical mapping while minimizing risks associated with deep sedation or general anesthesia. The anesthetic plan must ensure smooth transitions between sedation and wakefulness, optimize pain control, and avoid interference with electrocorticography. Effective management demands meticulous airway planning, titration of sedatives and analgesics, and close communication among the neurosurgical and anesthesia teams to preserve neurological function while maximizing tumor resection and patient safety. By participating in this activity, clinicians comprehensively understand anesthetic principles, techniques, and perioperative considerations for awake craniotomy. They enhance their ability to select appropriate candidates, design individualized anesthetic plans, and manage the unique challenges of airway control, sedation, and patient cooperation. The activity strengthens interprofessional communication and team coordination skills, improves patient outcomes, minimizes complications, and ensures the safe and effective integration of awake craniotomy techniques into neurosurgical practice. Objectives: Identify early indicators of airway obstruction, hypoventilation, or excessive sedation requiring prompt intervention. Assess patient suitability and preoperative factors to optimize safety and cooperation during awake craniotomy. Apply appropriate anesthesia and sedation strategies, including scalp blocks and monitored anesthesia care, for indicated awake craniotomy procedures to ensure patient comfort and effective intraoperative mapping. Coordinate interprofessional team interventions to minimize perioperative complications and improve patient outcomes. Access free multiple choice questions on this topic.

Awake craniotomy is a specialized neurosurgical procedure in which the patient is deliberately kept awake during the entire operation or specific portions. The technique does not require the patient to remain fully conscious throughout the surgery; instead, sedation or anesthesia is usually administered during the more painful or surgically stimulating phases, such as application of Mayfield pins, skin incision, craniotomy (bone flap removal), and dural opening. Because brain tissue lacks pain receptors, patients can be fully awake during cortical mapping and lesion resection, crucial stages for preserving neurological function. During these phases, the patient can perform speech or motor tasks in response to intraoperative commands, while the head remains immobilized in a fixed position. Patients are typically maintained under minimal to moderate sedation for the remainder of the surgery.[1] Awake craniotomy was first performed by Sir Victor Horsley in 1886 to localize the epileptic focus with cortical electrical stimulation.[2] Now, awake craniotomy is most commonly used to map and resect the tumor in vitally important brain areas like the motor and language cortex, where imaging is not sufficiently sensitive.[3] The primary goal is maximal tumor removal while preserving functional brain tissue. During cortical mapping, the awake patient provides real-time feedback when functional areas are stimulated, enabling the surgeon to avoid resecting critical regions. The mapping process involves direct electrical stimulation of the cortex while the patient remains awake and performs relevant tasks, thereby identifying cortical areas where stimulation disrupts the function being tested.[4] With the integration of intraoperative neurophysiologic monitoring and cortical mapping, modern awake craniotomy has become the gold standard for tumors near eloquent areas, offering greater tumor resection, fewer postoperative neurological deficits, and improved survival compared with craniotomy under general anesthesia.[5]

Awake craniotomy was first performed by Sir Victor Horsley in 1886 to localize the epileptic focus with cortical electrical stimulation.[2] Now, awake craniotomy is most commonly used to map and resect the tumor in vitally important brain areas like the motor and language cortex, where imaging is not sufficiently sensitive.[3] The primary goal is maximal tumor removal while preserving functional brain tissue. During cortical mapping, the awake patient provides real-time feedback when functional areas are stimulated, enabling the surgeon to avoid resecting critical regions. The mapping process involves direct electrical stimulation of the cortex while the patient remains awake and performs relevant tasks, thereby identifying cortical areas where stimulation disrupts the function being tested.[4] With the integration of intraoperative neurophysiologic monitoring and cortical mapping, modern awake craniotomy has become the gold standard for tumors near eloquent areas, offering greater tumor resection, fewer postoperative neurological deficits, and improved survival compared with craniotomy under general anesthesia.[5] Beyond tumor surgery, awake craniotomy plays a significant role in the management of refractory epilepsy. Intraoperative mapping is essential for identifying seizure foci that often lie adjacent to eloquent areas. Performing the procedure with the patient awake minimizes the suppressive effects of anesthetic agents on cortical recordings.[6] Similarly, language and motor mapping have been successfully employed during resection of vascular lesions, such as arteriovenous malformations, located in functionally critical brain regions. Thus, awake craniotomy has become an invaluable neurosurgical technique, offering both therapeutic efficacy and functional preservation.[7]

Challenges and complications during the awake phase include: Seizures The incidence of seizures during awake craniotomy ranges from 2% to 22%.[24][25][30][31] Seizures most commonly occur during cortical or subcortical stimulation for brain mapping. They are often focal, brief, and self-limiting, though generalized seizures can also occur. Risk factors include a history of preoperative seizures, younger age, and tumor location, particularly in the frontal lobe or near the motor cortex. Higher stimulation intensity and frequency may further increase the risk.[25][30] Intraoperative seizures are associated with transient motor deterioration and longer hospital stays.[31] First-line management involves irrigation of the cortex with ice-cold sterile saline, repeated as needed. If seizures persist, intravenous propofol (10–50 mg) or midazolam (1–2 mg) can be administered. Most seizures resolve without lasting consequences, though rare cases may result in apnea or cardiac arrest.[24][30] Hypertension Hypertension is a commonly encountered intraoperative complication, reported in 27% of patients, while hypotension occurs in about 10%.[32][33] This issue is often secondary to pain, agitation, or anxiety, with higher intraoperative anxiety observed in female patients and in those younger than 60.[34] Other causes, such as hypoxia or hypercapnia, should be evaluated and addressed. Temporizing management may include administration of intravenous labetalol or esmolol. Nausea and vomiting Nausea occurs in approximately 4% of patients undergoing awake craniotomy and is usually related to opioids, anxiety, or surgical stimulation. Management options include ondansetron, dexamethasone, or propofol.[33] Respiratory complications Airway obstruction is a major concern during awake craniotomy, often resulting from excessive sedation and leading to hypoxia or hypercarbia.[24][32] Management begins with rapid assessment and immediate intervention, including alerting the surgical team, stopping sedative infusions, and providing mask ventilation with 100% oxygen using a jaw thrust and, if needed, oral or nasopharyngeal airways. Assisted ventilation or airway devices such as an LMA, video laryngoscope, or ETT should be readily available. LMA placement can be challenging due to patient positioning, and intubation may require assistance.

Airway obstruction is a major concern during awake craniotomy, often resulting from excessive sedation and leading to hypoxia or hypercarbia.[24][32] Management begins with rapid assessment and immediate intervention, including alerting the surgical team, stopping sedative infusions, and providing mask ventilation with 100% oxygen using a jaw thrust and, if needed, oral or nasopharyngeal airways. Assisted ventilation or airway devices such as an LMA, video laryngoscope, or ETT should be readily available. LMA placement can be challenging due to patient positioning, and intubation may require assistance. If apnea or chest rigidity occurs due to remifentanil, stopping the infusion and attempting mask ventilation is recommended; low-dose succinylcholine (0.5 mg/kg) may be used if necessary.[24] Air embolism Venous air embolism (VAE) can occur in 20% to 40% of craniotomies performed in the sitting position and may lead to intraoperative respiratory distress. Transesophageal echocardiography (TEE) is the most sensitive method for detecting air embolism, capable of identifying as little as 0.02 mL/kg of air; however, it is an invasive procedure. Precordial Doppler is the most commonly used noninvasive monitoring tool for VAE detection.[32] Neurological deficits Neurological deficits are among the most commonly reported complications of awake craniotomy, including hemiplegia, paresis, dysphasia or aphasia, cranial nerve dysfunction, hemianopia, and memory impairment. Most deficits are transient and improve with follow-up or supportive management, although a minority may persist as long-term impairments.[35] Hyponatremia Hyponatremia is the most frequent electrolyte imbalance in neurosurgical individuals, most commonly caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH).[36] Other causes, such as acute adrenocorticotropic hormone deficiency or cerebral salt wasting syndrome (CSWS), should also be considered. SIADH leads to water retention and dilutional hyponatremia in euvolemic individuals, whereas CSWS causes excessive natriuresis and relative hypovolemia. Perioperative factors—including rapid mannitol infusion, medications such as carbamazepine, thiazides, or desmopressin, and preexisting electrolyte disturbances—can contribute to hyponatremia.[36][37]

Hyponatremia is the most frequent electrolyte imbalance in neurosurgical individuals, most commonly caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH).[36] Other causes, such as acute adrenocorticotropic hormone deficiency or cerebral salt wasting syndrome (CSWS), should also be considered. SIADH leads to water retention and dilutional hyponatremia in euvolemic individuals, whereas CSWS causes excessive natriuresis and relative hypovolemia. Perioperative factors—including rapid mannitol infusion, medications such as carbamazepine, thiazides, or desmopressin, and preexisting electrolyte disturbances—can contribute to hyponatremia.[36][37] Hyponatremia may increase intracranial pressure, delay awakening, and cause neurological deterioration, ranging from mild attentional or gait disturbances to severe disorientation, seizures, or coma. Careful monitoring of plasma sodium and timely correction, often with intravenous hypertonic saline instead of mannitol, is essential to minimize neurological complications and maintain patient safety during awake craniotomy.[36][37] Bradycardia Although scalp nerve blocks are generally safe, they may occasionally cause significant hemodynamic disturbances. Sudden bradycardia and hypotension can occur, most often due to the trigeminal cardiac reflex triggered by stimulation of trigeminal nerve branches. Opioid use may increase susceptibility, emphasizing the importance of slow incremental infiltration and vigilant monitoring during awake craniotomy.[38] Failed awake craniotomy Awake craniotomy is considered a failure if conversion to general anesthesia is required or if adequate mapping or monitoring cannot be achieved. The failure rate is approximately 2% (range, 0%–6%) and can be minimized by selecting patients appropriately.[39] Causes of failure include intraoperative complications such as generalized seizures necessitating conversion to general anesthesia.[32] Postoperative Care

Awake craniotomy is considered a failure if conversion to general anesthesia is required or if adequate mapping or monitoring cannot be achieved. The failure rate is approximately 2% (range, 0%–6%) and can be minimized by selecting patients appropriately.[39] Causes of failure include intraoperative complications such as generalized seizures necessitating conversion to general anesthesia.[32] Postoperative Care After awake craniotomy, patients are typically transferred to a high-dependency or neurointensive care unit for overnight observation. Pain is managed using multimodal analgesia, including regional techniques (scalp block or local infiltration), acetaminophen, and small doses of intravenous opioids, sometimes administered via patient-controlled analgesia. Compared to craniotomy under general anesthesia, awake craniotomy is associated with lower postoperative analgesic requirements and a reduced incidence of nausea and vomiting. Hospital stays are generally shorter, averaging 3 to 4 days, compared to 9 days for craniotomy under general anesthesia, with some patients eligible for same-day discharge. Early postoperative visits allow anesthesia providers to assess patient experiences and short-term outcomes more effectively.[24]

Effective anesthesia management for awake craniotomy requires coordinated interprofessional collaboration to optimize patient-centered care, safety, and surgical outcomes. The anesthesiologist leads sedation, analgesia, and airway management, assisted by nurses and anesthesia technologists who ensure patient comfort, safe positioning, and continuous monitoring of vital signs throughout transitions in sedation. Neurosurgeons focus on the safe resection of tumors or lesions and functional mapping, while neurophysiologists provide intraoperative monitoring to guide the preservation of cortical and subcortical function. Preoperative planning, including patient counseling and selection, aligns team strategies, reduces patient anxiety, and prepares the team for anticipated challenges. Clear, continuous communication during the procedure ensures rapid response to seizures, hemodynamic changes, or airway compromise. By integrating specialized skills—such as airway management, sedation titration, neurocognitive assessment, and hemodynamic monitoring—while respecting patient autonomy, the interprofessional team minimizes complications, preserves neurological function, and improves procedural outcomes. Flattening traditional hierarchies and fostering shared responsibility empowers all team members, enhances patient cooperation, and strengthens collaborative decision-making across preoperative, intraoperative, and postoperative phases.

Successful awake craniotomy relies on coordinated interprofessional teamwork. Preoperative planning between the anesthesiologist and surgical team ensures that patient-specific considerations, required equipment, and optimal positioning are addressed before entering the operating room. Collaboration with operating room nurses, technicians, and other allied health professionals is essential to anticipate procedural needs and ensure patient safety. Clear, continuous communication among anesthesiologists, nurse anesthetists, surgeons, nurses, and technicians minimizes intraoperative complications, supports a smooth workflow, and contributes to optimal surgical outcomes.