9/16/2020 - Awake Craniotomy, The True Art of Anesthesia

Christopher W. Fjotland, MD

Transcript

1. Rutgers, The State University of New Jersey Awake Craniotomy, The True Art of Anesthesia Case Conference, Rutgers Robert Wood Johnson University Hospital Department of Anesthesiology September 16, 2020 Christopher W. Fjotland, MD Assistant Professor & Chief Division of Neuroanesthesiology & Division of Head and Neck Anesthesia & Advanced Airway Management Co-director of Medical Education Department of Anesthesiology & Perioperative Medicine Rutgers Robert Wood Johnson University Hospital Communications Board Member, Director of Content & Assistant Editor Society for Neuroscience in Anesthesiology and Critical Care
2. Robert Wood Johnson Medical Group Financial Disclosures • None
3. Robert Wood Johnson Medical Group 10% Myth • “We only use 10% of our brain.”
4. Robert Wood Johnson Medical Group Contents • Introduction • Indications • Benefits • Eloquent cortex & Contemporary Psycholinguistic Theory • Anesthetic management • Patient selection • Positioning • Scalp block • Anesthetic options • Brain mapping & cognitive testing • Adverse events & management • Airway obstruction, hypercabia & hypoxemia • Nausea, vomiting & aspiration • Brain swelling • Anxiety, disinhibition & patient movement • Seizure • Deep brain stimulator placement
5. Robert Wood Johnson Medical Group INTRODUCTION
6. Robert Wood Johnson Medical Group INTRODUCTION to Awake Craniotomy • What is an awake craniotomy? • Surgery that is performed on the brain while the patient is in a state of awareness • Cooperation with functional testing of the cortex • Indications • Eloquent cortex preservation (tumor or ictal foci resection) • Epilepsy surgery • Deep brain stimulator placement • Minimally invasive surgery • Benefits (Reduce) • Size of resection • Surgical time • Post-operative neurological deficits • Early post-operative nausea and vomiting • Hospital stay • Post-operative opioids
7. Robert Wood Johnson Medical Group ELOQUENT CORTEXT
8. Robert Wood Johnson Medical Group Eloquent Cortex Motor Language Vision Sensory Primary motor Secondary Motor Accessory motor Broca’s Wernicke’s Auditory Secondary auditory Secondary visual Primary visual
9. Robert Wood Johnson Medical Group Eloquent Cortex - Contemporary Psycholinguistic Theory • Semantic-to-lexical mapping • Identify appropriate lexical unit (word, part of a word, phrase) • ❌ Nonsensical speech, omission • Phonological encoding • Lexical unit’s sound form, retrieved from long-term memory • ❌ Phonological errors (spont. speech, picture naming, repetition) • Articulatory-motor planning • Full motor plan, multiple lexical units, phrase context/physical constraints • ❌ Slowed, distorted-sounding speech, articulatory simplifications • Goal-driven language selection • “Control” process, supervise lexical unit selection • ❌ Difficulty when several lexical units are competing (verb generation, abnormal “Stroop effect” <RED>)
10. Robert Wood Johnson Medical Group Eloquent Cortex Continued
11. Robert Wood Johnson Medical Group Mapping eloquent cortex: A voxel-based lesion-symptom mapping study of core speech production capacities in brain tumour patients Josh W. Faulkner, Carolyn E. Wilshire⁎ Eloquent Cortex Continued
12. Robert Wood Johnson Medical Group ANESTHETIC MANAGEMENT
13. Robert Wood Johnson Medical Group Patient Selection • Age & maturity • Anxiety, claustrophobia, other psychological d/o • Airway, H/o OSA • H/o GERD or N/V • Relative contraindications • Children <14 y/o • Potential difficult airway/OSA • Poorly controlled hypertension • Alcohol abuse • Lack of maturity
14. Robert Wood Johnson Medical Group Anesthetic Management • Strong patient rapport • Very clearly/honestly describe the perioperative process • Set realistic expectations • YOU are their advocate • Make it clear that they have options intra-operatively • Goals: • Best possible resection • Patient comfortable • Patient safety
15. Robert Wood Johnson Medical Group Scalp Block
16. Robert Wood Johnson Medical Group Anesthetic Management Continued • Monitored Anesthesia Care • Propofol, Dexmedetomidine, opioid infusions • Asleep-awake-asleep • ETT vs. LMA • Emerging in pins!! • Pre-extubation direct visualization topicalization • Laryngospasm Load Maintenance Propofol 0.5 mg/kg 75-250 mcg/kg/ min Dexmedetomidine 1 mcg/kg over 10 min 0.1-0.6 mcg/kg/h (0.3 mcg/kg/h) Remifentanyl None 0.01-0.1 mcg/kh/ min (0.08 mcg/kg/min)
17. Robert Wood Johnson Medical Group My Anesthetic Plan & Clinical Pearls • MAC: Varying levels of sedation (very deep until dura is open) • Airway: O2 4L/min via salter nasal cannula • **Appropriate size nasal trumpets w/ lido jelly for lubrication, appropriate size oral airway, appropriate size LMA & video laryngoscope/ETT all readily available** • Access: 2 PIV Monitors: Standard ASA + A-line + Foley • *1 PIV - TIVA* *1 PIV - bolus line* • **TIVA line carrier on a pump set at a constant rate and must be clearly marked with all stop-cocks taped closed to prevent accidental bolus** • Sedation: TIVA: Dexmedetomidine: Load 1mcg/kg over 10 minutes, Maintenance 0.3 mcg/kg/h; Remifentanil: 0.08 mcg/kg/min. Carrier (NS): 200 cc/h. Bolus: Propofol 0.1 mg/kg *titrated very slowly as can work synergistically with Dex/Remi cause obstruction/apnea with low doses* • Scalp Block: 0.25% Bupivacaine (~80cc total *under toxic dose) • Anti-epileptic: Levetiracetam 500-1000mg, Special: +/- Mannitol 0.5-1g/kg, +/- Furosemide, +/- Dexamethasone • **The brain will be “tight” (secondary to hypoventilation) and so a pre-op discussion with the surgeon should occur as far as how to handle that** (positioning - reverse trendelenburg, minimize head turn will help) • Antibiotic: Cefazolin 2g (3g >120kg) • Ice cold saline irrigation on the field & additional irrigation on ice • Continue TIVA sedation until dural opening, then turn off all drips including carrier. Patient expected to emerge over 7-8 minutes. • **Important to have a propofol syringe on the bolus line ready for administration, if needed**
18. Robert Wood Johnson Medical Group Cortical Mapping & Cognitive Testing • Preoperative preparation! • Anesthesiologist’s role: Re-orient, calming, guiding (+patient safety) • Highest risk of seizure • Motor • Sensory • Cognitive • Speech • Cortical evoked potentials - sensory (SSEPs) & motor (MEPs) • Electrocorticography (ECoG) - intracranial electroencephalograp hy (iEEG)
19. Robert Wood Johnson Medical Group 6 10
20. Robert Wood Johnson Medical Group
21. Robert Wood Johnson Medical Group ADVERSE EVENTS & MANAGEMENT
22. Robert Wood Johnson Medical Group Adverse Events & Management • Airway obstruction, hypercarbia & hypoxemia • Prevention: sedation should be slowly titrated and weaned appropriately *Avoid boluses through TIVA line* *if bolusing propofol to help deepen sedation - start small, slow titration* • Treatment: Wean sedation/turn off sedation, nasal trumpet(s), oral airway, facemask positive pressure ventilation vs CPAP, LMA, video laryngoscopy w/ endotracheal intubation
23. Robert Wood Johnson Medical Group Adverse Events & Management Continued • Nausea, Vomiting & Aspiration • Propofol > mixed agent sedation • Prevention: prophylactic antiemetic • Treatment: (RAPID) Metoclopramide, ondansetron. Additional local anesthetic to dura. • If aspiration does occur these patients should be intubated with the use of video laryngoscopy and thoroughly suctioned
24. Robert Wood Johnson Medical Group Adverse Events & Management Continued • Brain swelling • Prevention: Optimize positioning (head up, less head turn), early mannitol 0.5-1 g/kg +/- furosemide • Treatment: Wean sedation to respiratory rate of 8-12 BPM, controlled hypotension, steepen reverse trendelenburg or back-up, consider re-dose mannitol or add furosemide, discuss possible CSF drainage from the surgical field, consider waking the patient up to increase RR
25. Robert Wood Johnson Medical Group Adverse Events & Management Continued • Anxiety, disinhibition & patient movement • Prevention: Patient selection & preoperative counseling! Careful/ patient specific anesthetic selection. • Treatment: reorienting the patient on emergence, reassuring, PROPOFOL —> deepen sedation and re-attempt emergence, consider continuing Dexmedetomidine drip during “awake” portion, consider converting to general anesthesia vs continuing deep sedation
26. Robert Wood Johnson Medical Group Adverse Events & Management Continued • Seizure • Most common during cortical mapping • Vigilance is critical! - communication with neuromonitoring technologist and surgeon • Prevention: prophylactic antiepileptic, early recognition of aura or seizure-like activity (patient or iEEG), use of ice cold irrigation between cortical stimulation, breaks between cortical stimulation (30 seconds-1 minute) • Treatment: Ice cold irrigation on the brain immediately followed by propofol (0.75-1.25 mg/kg), assess EEG for resolution, attempt re-emergence, repeat with increased dose of propofol if persists, consider re-dose antiepileptic, benzodiazepine, consider converting to GA
27. Robert Wood Johnson Medical Group DEEP BRAIN STIMULATOR PLACEMENT
28. Robert Wood Johnson Medical Group Deep Brain Stimulator Placement • Indications: • Neurological d/o causing an alteration in function but not accompanied by gross structural or anatomical changes • Movement d/o (Parkinson’s, dystonia, essential tremor, Tourette’s) • Psychiatric d/o (depression, OCD, anorexia) • Other (chronic pain, epilepsy, Alzheimer’s, dementia) • Improve quality of life
29. Robert Wood Johnson Medical Group Deep Brain Stimulator Placement Continued • Placement of electrode for microelectrode placement • Stimulator placement for macrostimulation & clinical testing (Instant resolution of symptoms!! & determining therapeutic window) • Targets: • STN - Parkinson’s • GPi - Dystonia • Vim nuclei - Ess. Tremor • AIC/NAcc - Depression & OCD
30. Robert Wood Johnson Medical Group Deep Brain Stimulator Placement Continued • Microelectrode recordings (MER) • Anesthetic effect is variable MER/STN (Neuronal firing) MER/GPi (Neuronal firing) Inhalational Substantially decreased Substantially decreased Propofol Decreased Substantially decreased Propofol & Remifentanyl Minor decrease Substantially decreased Propofol & Dexmedotomi dine Minor decrease Substantially decrease Dexmedetomid ine Minimal/ Potentially enhanced Minimal/ Potentially enhanced
31. Robert Wood Johnson Medical Group THANK YOU.