1. Anaesthesia for intracranial SOL, including vascular surgeries
Dr. Megha Aggarwal
University College of Medical Sciences & GTB Hospital, Delhi

2. Outline Introduction to SOL Neuroanaesthetic goals
Classification
Presentation
Management strategies
Neuroanaesthetic goals
Hemodynamic concerns
Conduct of anaesthesia
Pre anaesthetic assessment
Monitoring
Induction, maintenance and emergence
Post-operative concerns

3. Classification of SOL CONGENITAL Dermoid, epidermoid, teratoma.
TRAUMATIC
Subdural & extradural haematoma
INFLAMMATORY
Abscess, tuberculoma, syphilitic gumma,fungal granulomas.
PARASITIC
Cysticercosis, hydratid cyst, amebic abscess, Schistosoma
NEOPLASMS 
Meningionas, gliomas, choroid pappilomas , metastasis
VASCULAR
Aneurysms, A-V malformations

4. Neoplasms

5. Common SOLs
1. Meningioma- 90% supratentorial 5-6th decade benign Highly vascular with large feeding vessels 2. Gliomas - most common 1⁰ intracranial tumors slow growing astrocytomas to malignant glioblastomas seizures, focal deficits, ↑ ICP as per tumour type

6. Common SOLs (cont …) 3. Tumors of ventricular system
Choroid plexus papillomas, ependymomas,
Obstructive hydrocephalus, midbrain compression
4. Metastatic
Most common intracranial tumors
Multiple
5. Intracerebral abscess
Frontal sinus, middle ear, blood born, foreign body
Meningitis , ↑ ICP

7. How do they present ? ANATOMICAL REGION CLINICAL SIGNS
Supratentorial (forebrain)
Seizures
Headache
Motor/ sensory deficits
Infratentorial (brainstem)
(RAS, CN, Cardiac & resp centres)
- CN deficit (3-12)- ocular palsy, dysphagia, laryngeal dysfunction (chronic aspiration).
- Arrhythmias/ respiratory irregularities
Sleep abnormality
Infratentorial (cerebellum)
Ataxia
Tremors
Vestibular signs
Hydrocephalus
Infratentorial (vestibular system)
Head tilt
Postural deficit
Nystagmus

8. Herniation / midline shift
HTN ,
Tachy/ brady arrythmias,
3 & 6th CN palsy (I/L pupil dilation + no light reflex),
C/L hemiplegia/ paresis,
Coma ,
Resp arrest

9. Treatment
Chemotherapy
Surgical resection
Radiotherapy

10. Goals of anaesthesia
Preserve both injured & uninjured cerebral territories by global maintenance of cerebral homeostasis.
Maintain normocarbia, normotension, normoxia, euthermia, euglycemia.
Avoid secondary brain insults
Optimizing operative conditions to facilitate resection

11. Anaesthetic implications
Depending on type (vascularity) and location (supra/ infratentorial) of tumor
Supratentorial
ICP management
Monitoring brain function
Massive intraoperative hemorrhage
Seizures
Air embolism (if venous sinuses traversed)
Infratentorial
Air embolism
Care during vital structure handling
Positioning
Higher mortality

12. Secondary insults INTRACRANIAL SYSTEMIC
Increased intracranial pressure
Hypercapnia/hypoxemia
Epilepsy
Hypo-/hypertension
Vasospasm
Hypo-/hyperglycemia
Herniation: falx, tentorium, foramen magnum, craniotomy
Low cardiac output
Midline shift: tearing of cerebral vessels
Hypo-osmolality
Shivering/pyrexia

13. WHY CONTROL BP ? AVM/ aneurysm/ head injuries/ tumors
Disruption of cerebral autoregulation
BP fluctuation poorly tolerated
↑BP – Vasogenic edema, ↑ tumor / aneurysm size, aneurysmal rupture
↓ BP – Ischemia/ infarction

14. Stimuli for BP fluctuation Preventive measures
Laryngoscopy
Intubation
Positioning
Suction
Skeletal fixation of head
Preventive measures
Deep plane of anesthesia
Additional dose of iv anesthetic agent
Adequate muscle relaxation
Lignocaine (1.5 mg/kg)
Esmolol (0.5 – 1 mg/kg)

15. Preoperative assessment
INVESTIGATIONS
EXAMINATION
HISTORY
Assessment & documentation

16. Preoperative assessment
HISTORY
Level of consciousness
Seizures - ↑ CMRO2 , ↑ ICP
↑ ICP – headache, vomiting, without nausea, blurred vision, ocular palsy (CN 6)
Hydration – fluid intake, NPO status, diuretics, SIADH
Medications – steroids, antiepileptic drugs, aspirin/ clopidogrel, diuretics, mannitol
CN palsies- dysphagia, laryngeal dysfunction
Associate systemic illness-
Cardiac – HTN (hypotensive anaesthesia)
Respiratory
Renal – intraoperative mannitol and diuretics, SIADH, DI

17. Preoperative assessment
EXAMINATION
Mental status, level of consciousness (GCS)
Hydration status
Systemic examination
a) CNS
↑ICP – papilloedema, cushing response (↑BP, ↓HR), sutural diastasis, bulging fontanels.
Focal signs (CN palsies) - Dysphagia, strabismus, focal seizures, speech deficit, motor & sensory examination.
Midline shift - I/L Pupillary dilatation and absent light reflex (3rd CN)

18. Preoperative assessment
EXAMINATION
b) Respiratory- effect of positioning, resp. pattern, neurogenic pulm. edema
c) CVS – Cushing reflex, HTN (resets limits of cerebral autoregulation), BP (cerebral perfusion)
d) GI -↑ Aspiration (steroids, ↑ ICP , low GCS, emergency)
e) Renal - ↓fluid intake, diuretics, mannitol, SIADH, DI
f) Paraneoplastic syndromes

19. Preoperative assessment
INVESTIGATION
Complete blood count – Hb, TLC, Platelet count
RBS – hyperglycemia – cerebral edema , ↑ischemic brain injury
KFT – urea, Na, K
Coagulation profile
ECG – ischemic changes, arrhythmias
CXR

20. Preoperative assessment
INVESTIGATION
7. CT/ MRI – tumor assessment
Location – silent/ eloquent area
Size – degree of compromise of intracranial dynamics including auto regulation.
Ventricular distortion / CSF obstruction
Midline shift
Perilesional edema - makes tumor functionally bigger
Contrast enhancement - degree of BBB disruption
Proximity to venous sinuses - blood loss

21. ASA physical status ???? Nature of surgery
High incidence of systemic involvement – CN palsies, motor/ sensory involvement
Higher comorbidities
Poor surgical outcome

22. Premedication
1. Sedation -Risk assessment, individualised - often avoided 2. Others - Continue anticonvulsants, antihypertensives, steroids till morning of surgery - mannitol, furosemide
Sedation - hypoventilation (hypercapnia, hypoxia, airway obst )
Sedation - ↓stress→↓ICP→↓ vasogenic edema

23. Vascular access
1. Intravascular a) 2 large bore i.v cannulas b) CVP -VAE (diagnostic + therapeutic ) - vasoactive drugs 2. Arterial canulation a) NIBP (anticipated blood loss) b) ABG c) Hypotensive anaesthesia

24. Monitoring ECG, HR – myocardial ischemia, arrhythmias SpO2 ETCO2
NIBP/ IBP – at level of operative field
NMT – on non hemiplegic limb
Temperature
CVP
Urine output
Precordial doppler, TEE, ETN2
ICP – currently rarely used, except in neurotraumatology
UMN lesion
↑ Ach receptor density
Resistance to NDMR

25. GOALS – Normotension, Normocarbia, Normoxia
Induction
GOALS – Normotension, Normocarbia, Normoxia
Preoxygenation
P/M – opioid (fentanyl 1-2 μg/kg , morphine 0.1 mg/kg)
Lignocaine , Esmolol, 2nd dose of i.v induction agent sec earlier
I/W – Thiopentone (3-5 mg/kg)
Propofol (1.5 – 2.5 mg/kg)
Myorelaxation – Sch (transient ↑ ICP)
Use intermediate acting relaxants
Atracurium – histamine release ( cerebral vasodilatation)
Vecuronium, Rocuronium – commonly used
Only after adequate muscle relaxation achieved, perform quick + gentle laryngoscopy
Intubation – armoured ETT
Tape on opposite side of surgery
Bandaging may ↓cerebral venous return
Controlled ventilation

26. Positioning
GOAL- Slow and gentle positioning with ⁰ head up tilt to aid cerebral venous drainage
Verify cautiously – 1. All potential pressure points padded
2. Eyes protected & padded
3. Peripheral pulses palpable
4. Nerve compression absent
5. Ventilation adequate ( PEEP, ETT position)
ETT – Kinking in post. Oropharynx
Advancement / extubation
Neck – Extreme rotation / flexion may cause ↑ ICP,
quadriparesis, tongue swelling
Head pins – Adequate plane of anaesthesia
Local infiltration / bolus opioid (fentanyl)

27. Optimization of ICP Dural opening in presence of high ICP –
- sudden decompression & transcalvarial herniation
- herniated tissue cannot be interposed back
- permanent neural damage
ICP to be brought within normal limits before opening the dura.
Methods – head elevation, mannitol, furosemide, CSF drainage

28. Optimize ICP (cont…) Mannitol (20%) Hyperosmolar agent
Dose : 0.5 – 2 mg/kg i.v. (0.5-1 mg/kg over 15 min just before opening dura)
Action reaches peak at min.
Advantages : Draws water from brain (↓ brain bulk)
↓ Hct (↑CBF , O2 delivery)
Disadvantages: 1.If given fast, it transiently ↑ blood vol. & may cause CHF , pulmonary edema
2. Hypokalemia
3. Worsen C. edema if BBB disrupted

29. Optimize ICP (cont…) Furosemide
Loop diuretic (Na K 2Cl channel blocker)
Dose : 0.5 – 1 mg/kg i.v.
use : sole agent to ↓ ICP
adjunct to mannitol
Mannitol draws fluid out of brain & lasix discards it through kidneys

30. Optimize ICP (cont…) CSF drainage Lumbar subarachnoid drainage system
Ventriculostomy drain (EVD)
(connected by tubing to a CSF collection device which can be elevated or lowered)
CSF drainage (↑ICP, aneurysm / ENT surgeries)
ICP measurement
CSF drainage
Slow
bolus ≤ ml
Complications
hematoma formation
infection
if abrupt ↓ICP – aneurysmal rupture

31. Maintenance ANAESTHETIC AGENT VOLATILE ANAESTHETIC I.V. ANAESTHETIC
GOAL- Maintain cerebral homeostasis + Aid “slack” brain.
TARGET – Anaesthetic agent , Fluid therapy, Neuroprotection strategies.
ANAESTHETIC AGENT
VOLATILE ANAESTHETIC
I.V. ANAESTHETIC
PROS
Easy,
Extensively available
Intact CBF – CMRO2 coupling
↓brain bulk
Propofol blunts N2O cerebrostimulation
CONS
CBF – CMRO2 uncoupling
↑ICP
1. Short acting
RECOMMENDATION
Use in short, uncomplicated surgeries
At < 1.5 MAC
Avoid combination with N2O
1. Use in cases with high risk of ↑ICP/ brain bulk

32. Maintenance (cont…) FLUID THERAPY
Principle – BBB is selectively permeable
Water crosses freely, most ions (Na+) don't.
If BBB disrupted (ischemia, head injury, tumors) – hyperosmolar agents may ↑brain water instead of drawing water out.

33. Maintenance (cont…) RECOMMENDATIONS (FLUID RESTRICTION)
FLUID LOSS – Do not replace fasting / III space losses
BLOOD LOSS – Assessment difficult (drapes + continuous irrigation)
SERUM OSMOLARITY –
Maintain at mosm/L
Give NS (309 mosm/L)
Avoid RL (272 mosm/L)
Use them alternately
Avoid glucose containing solutions (5%D , DNS)
Mannitol (0.5 – 2 mg/kg)
Furosemide ( mg/kg)

34. Maintenance (cont…) NEUROPROTECTION OTHERS PaO2
PaCO2
BP (sympatholysis, antihypertensives)
Glucose ( <170 mg/dL )
Temperature ( controlled hypothermia 32-34⁰C)
Analgesia
Adequate depth of anaesthesia
OTHERS
Seizure prophylaxis/ control
Steroids
Nimodipine (SAH)
Barbiturates
Magnesium (experimental)

35. Maintenance (cont…) The chemical brain retractor concept
Mild hyperosmolality
Adequate head-up positioning
Lumbar cerebrospinal fluid drainage
Intravenous anesthetic agent (propofol)
Avoidance of brain retractors
Venous drainage: jugular veins free

36. Emergence Due to pain and shivering, associated with
Most important but often neglected
“ A well planned procedure is often rewarded by a fully awake patient who is appropriately responding to verbal commands and neurological examination.”
Due to pain and shivering, associated with
↑ catecholamine release
↑ O2 Consumption ( X 5 times)
AIMS
To maintain intra + extracranial homeostasis
(MAP- CPP- CBF- ICP- CMRO2 - PaO2 - PaCO2- temp)
Avoid intracranial bleed ( coughing, ventilator fight)

37. Emergence (cont…) EARLY AWAKENING LATE AWAKENING
Early neurological examination & reintervention
Less ↑BP/ catecholamine burst
↓ cost of postop care
Less risk of ↓O2,↑CO2 associated with anaesthesia hangover
Better respiratory & hemodynamic control
RECOMMENDATION – Early awakening is recommended unless contraindicated.

38. Emergence (cont…) Checklist for early extubation
Good preop GCS (>8)
CVS stability + normothermia + normoxia
Limited brain surgery, no major brain laceration
No extensive post fossa manipulation ( CN 9 – 12)
No major AVM removal

39. Emergence (cont…) Indication of late extubation Low GCS
Inadequate airway control
Intraop catastrophe
Brain edema/ deranged cerebral homeostasis
(long duration/ extensive/ repeat surgery)
5. Surgery around vital areas

40. Immediate postoperative concerns
Failure to awaken
Nonanaesthetic causes – seizures, cerebral edema, intracranial hematoma, pneumocephalus, vsl occlusion, metabolic/ electrolyte disturbance, herniation.
Anaesthesia hangover – opioid, volatile anaesthetic, muscle relaxant.

41. Immediate postoperative concerns (cont….)
2. Post operative care
a) Head end elevation (15-30⁰)
b) Adequate ventilation & oxygenation
c) Monitoring of neurological function
d) Check for serum electrolytes and osmolarity (mannitol, frusemide to continue)
e) Seizure prophylaxis (phenytoin / fosphenytoin)
f) Seizure treatment (thiopentone mg, midazolam 2-4 mg , lorazepam 2 mg)

42. Immediate postoperative concerns (cont….)
g) SIADH
Hyponatremia, S. hyposmolarity, high U. osmolarity
T/T restrict free water intake
h) DI
After pituitary surgery
Hyponatremia, S. hyposmolarity, low U. osmolarity
T/T ↑ water intake, vasopressin , desmopressin
i) Tension pneumocephalus
Skull X ray / CT
T/T opening the dura

43. Concerns for posterior fossa surgery
Presentation
Cranial nerve palsies (IX, X) may impair gag reflex- aspiration
Hydrocephalus
Cerebellar dysfunction
Edema in floor of fourth ventricle- damage to resp. centers
2. Cardiovascular instability
Bradycardia and hypertension – due to V nerve stimulation (resolve with cessation of stimulus)
Bradycardia, asystole/ hypotension- due to IX/X nerve stimulation

44. Concerns for posterior fossa surgery
3. Sitting position
Advantages
Better surgical exposure
Improved venous/CSF drainage
Low bleeding
Improved access to airway, chest
Disadvantages
VAE
CVS instability

45. Concerns for pituitary surgery
Trans-sphenoidal resection through nasal/ labial incision
Endocrine manifestations- normo/hypo/ hyperpituitarism
ICP is not a concern due to small size of tumor
Uncontrolled bleeding is rare
Throat pack to prevent blood from accumulating in stomach / aspiration
Nasal breathing obscured by postoperative nasal packs.

46. References Miller’s anaesthesia.Ronald D Miller. 7th ed.
Stoelting's Anesthesia and Co-Existing Disease, 5th ed.
Handbook of neuroanaesthesia. James E Cottrell. 4th ed.
Clinical anaesthesia procedures of massachusettes general hospital. 7th ed.
Morgan’s clinical anaesthesiology.4th ed.

47. THANK YOU