Awake craniotomy in a depressed and agitated patient.

Depressed patients with brain tumors are often not referred to awake craniotomy because of concern of uncooperation which may increase the risk of perioperative complications. This report describes an interesting case of awake craniotomy for frontal lobe glioma in a 41-year-old woman undergoing language and motor mapping intraoperatively. As she was fearful and apprehensive and was on antidepressant therapy to control depression, the author adopted general anesthesia with laryngeal mask airway during initial stage of skull pinning and craniotomy procedures. Then, the patient reverted to awake state to continue the intended neurosurgical procedure. The patient tolerated the situation satisfactorily and was cooperative till the finish, without any event.

INTRODUCTION

Intraoperative mapping of targeted areas of brain resection is an integral part of modern neurosurgery. Intraoperative stimulation of near speech and motor regions may prevent unnecessary nervous tissue damage, while using neuronavigation and intraoperative magnetic resonance imaging (iMRI), allowing maximum resection of the tumor. This procedure requires an awake, cooperative patient to assess motor and verbal responses. Sometimes the patient may not cooperate during this procedure due to psychological profile or extreme fear from the notion of being awake during initial surgical intervention while the skull is fixed and then opened. This report describes the author's experience with awake craniotomy in a middle-aged woman having anxiety and treated for depression, using initial sleep and maintaining the airway by laryngeal mask airway (LMA) and then awake technique before Testing eloquent cortex and to the end of surgery the end of the surgery.

CASE REPORT

A 42-year-old female (weight: 59 kg; height: 168 cm) presented to the Neuroscience Department at King Fahad Medical City (KFMC), with a complaint of progressively increasing headaches of 18 months duration. She was placed on anticonvulsant therapy with valproic. Clinical history revealed reports of depression since a long time, related to overwhelming psycho-social problems at home. Clinical examinations were unremarkable. Awake craniotomy was planned including intraoperative mapping for language and motor function. In the BrainSuite® Lab, intravenous line was started and sedation was given using both midazolam 1–2 mg i.v. and fentanyl 25–50 μg i.v. Standard anesthetic monitoring was initiated Electrocardiogram (ECG), non-invasive blood pressure monitoring (NIBP) and pulse oximetry). A right radial arterial line was inserted, under local anesthesia, for continuous blood pressure measurement and serial blood gases monitoring.

A nasal cannula was placed in position. Scalp block was established using 80 ml of 0.125% bupivacaine and 5 μg/ml of adrenaline, by the surgeon. The patient was positioned in supine position and her head was rotated to the left side. A four-pin frame failed to fix after many trials due to the patient being irritable. We gave 20–30 mg propofol bolus with 25–50 μg fentanyl and still the patient was uncooperative during the pins application. Anesthesia was induced with propofol 2 mg/kg and fentanyl 50 μg i.v. LMA size 3 was inserted easily and after demonstration of proper deep anesthesia. Airway and spontaneous breathing was maintained using 4 l/minute of 50% O2 in air. Anesthesia was maintained with combined continuous infusions of propofol 1% 20–30 ml/hour and fentanyl 25 μg/hour. The patient was then brought to the BrainSuite Lab for preoperative MRI and neuronavigation. MRI-compatible monitoring was included, i.e., ECG, Invasive blood pressure measurement (IBP), capnography, temperature and pulse oximetry.

The patient's urinary bladder was catheterized and mannitol 0.5 mg/kg was given in addition to Dexamethazone 8 mg i.v.

Surgery was started, and after the dura was opened, propofol and fentanyl were gradually decreased and later stopped. The patient became awake smoothly. LMA was removed without complications. Oxygenation was maintained with a nasal cannula. The patient became completely awake, was able to talk within 10 minutes following the removal of LMA. The surgery was commenced again while the patient was fully awake, with proper intraoperative motor and language assessments. The course of the surgery went uneventful. Hemodynamic variables were thoroughly stable. There was no desaturation or airway obstruction. Another MRI study was done while the patient was completely awake. After surgery, the patient was transferred to SICU in a good clinical condition.

DISCUSSION

BrainSuite Lab is newly established at KFMC [Figures 1–3]. Two years have passed and various difficult neurosurgical surgery operations have been performed here with great success. Awake craniotomy was done to benefit from iMRI and navigation facilities.[1]

Figure 1

BrainSuite settings: Surgeon looking at mural screens showing integrated iMRI with microscopic operating field screen

Figure 3

Intact corticospinal tracts in the motor area on the right side as well as preserved motor function on the right area. The activated motor area appeared to be away from the tumor by 3.4-4 cm

MRI vault: The patient is draped and protected with a head coil before the iMRI session

Awake craniotomy for seizure foci resection is currently popular since a complete resection of these foci can be achieved without increasing neurological deficit.[2-4] This requires “asleep, awake, asleep” anesthesia technique to be used on an awake, comfortable patient who cooperates with intraoperative testing.

Drugs are used to manage this state. They are seected according to their short half-lives and ease of titration. Using such drugs concurrently can cause powerful respiratory depression. We selected The anesthesia regimen in accordance with successful reports from the literature.[24] Neuroanesthesia team should be vigilant of events like hypoventilation, apnea, and chest wall rigidity. Several options are available for airway management during awake craniotomy including endotracheal intubation, LMA, nasal airway, and non intubation technique preserving natural airway.

Adverse events during awake craniotomy can include nausea, intraoperative anxiety, seizures, and brain engorgement.[4] Nausea and/or vomiting may result in significant morbidity. We chose to reduce this risk by administering ranitidine, ondansetron, metoclopramide, dexamethasone, and glycopyrrolate.

Appropriate patient selection is critical to success. This case was not an ideal patient for the technique but detailed preoperative explanation of the anesthesia plan was important for operators to go ahead. Despite uncontrollable anxiety and the concurrent state of depression, we expected that uncooperation could still occur. Our efforts focused on reassuring the patient, and use of sedo-analgesic drugs of sedo-analgesics regimen, and we explained to the patient that general anesthesia is possible for a short period and there would be no pain when she would wake up for testing. Intraoperative urgent intubation is technically difficult and slow to secure. The anesthesiologist was expecting intraoperative seizers. Although it did not happen in this case, the plan for its control should be swiftly taken, i.e., surgeon's application of ice water irrigation and discontinuation of stimulation, administration of anticonvulsants intravenously and if respiratory instability occurs, intubation and controlled ventilation.

In conclusion, a careful approach in handling a psychological patient may help the patient tolerate the current analgesia and anesthesia techniques during awake craniotomy. This case may open the field to operate on group of patients thought to be uncooperative for awake craniotomy and to manage them with success, rather keeping awake craniotomy for fully co-operative patient. Anesthesiologist should be malleable in his plan to the immediate needs of his patient.