Edward Fohrman shares his lecture slides on anesthesia for pituitary surgery. Edward founded Fohrman Anesthesia Services & Consulting in 2010. Read more at EdwardFohrman.com.

1. ANESTHESIA
FOR
PITUITARY SURGERY
Edward B. Fohrman, MD
Neuroanesthesiology
Northwestern University
Feinberg School of Medicine

2. Introduction
Pituitary tumors comprise approximately 10% of
intracranial neoplasms and 20% of all intracranial
operations for 1˚ Brain Tumors
Peak incidence: Age 40-60
Unique considerations related to Endocrine disease

3. Classification
Size:
■ Macroadenomas > 1 cm
■ Microadenomas < 1 cm
Function:
■ Functioning: single, predominant hormone
■ Non-functioning: presents later & larger (macroadenomas)

4. DDX Suprasellar Masses “SATCHMOE”
Sellar lesion, sarcoid
Aneurysm, arachnoid cyst
Teratoid lesion (Epidermoid/Dermoid, germ cell tumor)
Craniopharyngioma
Hypothalamic glioma
Metastases, meningioma
Optic nerve glioma
Eosinophilic granuloma

5. Pituitary Anatomy

8. Preoperative Concerns
Local mass effect
! Headache (#1)
! Visual field defect
■ (Bitemporal Homonymous Hemianopsia)
! Pituitary compression/dysfunction
! ↑ ICP
■ Direct mass effect
■ Compression 3rd ventricle
■ Nausea/vomiting
■ Papilledema
Visual Field
Deficit?

9. Functioning Adenomas:
Clinical Dz and Medical Therapy

10. Neurohypophysis-Posterior Pituitary:
Functional Adenomas

12. Pre-Op Labs
! CBC
■ Anemia (rare, but seen in Men with low testosterone)
■ Baseline Hgb (EBL potential intraop)
! Chem Panel
■ Hyponatremia
■ Hypercalcemia
■ Hyperglycemia
! Thyroid panel (TSH, free T4)
! Cortisol level
! ACTH, Insulin-like Growth factor-1, testosterone, LH, FSH,
Prolactin
■ Women with secondary amenorrhea – hCG (r/o preggers!)

13. Endocrine Disease
Pre-op Hypopituitarism:
! Panhypopituitarism?
! Hormone replacement (thyroxine / hydrocortisone)
! Stress dose steroids
Null Cell (Non-functioning adenomas): 2nd most common pituitary
tumor (20-25%)
Pre-op Secreting Tumor
! Prolactinoma (PRL)
! Acromegaly (GH)
! Cushing’s Disease (ACTH)
! Thyrotropic Adenoma (TSH)

14. Prolactinoma
Most common functional adenoma
! 20-30% of all Pituitary adenomas
Symptoms of Prolactinomas
■ ♀ Amenorrhea, galactorrhea, infertility, ↓libido,
■ ♂ Nonspecific: ↓libido, impotence/ED, premature ejac,
oligospermia
Microadenomas 20:1 female predominance
Macroadenomas similar incidence for ♂ ♀
90% respond medically do not need surgery :
! bromocriptine (dopamine agonist)

15. The 8th Wonder of the WORLD?

16. Robert Pershing Wadlow, 8’ 11” Zhao Liang 8” 1” 27yrs old

17. Acromegaly (Growth Hormone) “Gigantism”

18. Acromegaly (cont’)
Airway considerations in Acromegaly:
! Difficult anatomy:Soft tissue/tongue enlargement
■ Often not predicted by Malampatti classification
! ETT SIZE? small glottic opening/calcinosis of the larynx
! Difficulty placing LMA and FOI techniques
! OSA (25% of females and 70% of males)
Cardiac Dz (50% die before 50 if untreated)
! HTN (40%)
! LVH (independent of systemic hypertension)
! Diastolic Dysfct. (even w/o LVH)
■ Interstitial myocardial fibrosis
! CAD – small vessel
! Dysrhythmias – stress and exertion (>50%)

19. Cushing’s Disease
Kronenberg: Williams Textbook of Endocrinology,
11th ed.
A. Identical Twins
(s/p Bilat. Adrenalectomy)
B. Ptosis
C.Meiosis
D.Invasion of Cavernous Sinus
E.Nelson’s Syndrome

20. Cushing’s Disease/Syndrome (Cortisol)
Fat Redistribution
! Striae, Buffalo Hump, Moon
Facies
HTN (80%)
! DBP>100 in 50%
LVH: systolic & diastolic dysfct.
Airway Mgmt.
! May be difficult in those
patients with OSA (30%)
! Diabetics (60%) with GERD
Exophthalmos (30%)
Prox. Muscle myopathy
! sensitivity to muscle relaxants?

21. Cushing’s Etiology
Pituitary Adenomas
Exogenous Steroids
! Prednisone –RA, SLE, Asthma, Transplant Pts.
Ectopic ACTH Syndrome
! Paraneoplastic CA syndromes (Lung CA)
Adrenal Tumors
Familial Cushing’s
! MEN-1 (Pituitary, Pancreas, Parathyroid tumors) adrenal
tumors, exogenous ACTH

22. Thyrotropic Adenomas
Hyperthyroidism
! Palpitations – dilated cardiomyopathy
! Tremor
! Weight loss
! Goiter
Tumors tend to be larger (why?)
■ 60% are locally invasive at the time of surgery
Antithyroid medications
! PTU (reduce thyroid hormone production)
! Octreotide (suppresses TSH production)

23. Corticosteroid Administration
Historically: “Stress Doses”
■ Hydrocortisone 50-100mg iv q 6-8 hrs
Often NOT necessary
■ rarely required beyond 24 hours postoperatively
Cushing’s Disease
■ Dexamethasone (No interference w/ cortisol assays)
Current Practice:
■ Avoid perioperative corticosteroids and follow cortisol levels
and symptomatology postoperatively
■ Only tx if sx of adrenal insuff. Serum cortisol < 2 ucg/dL

24. Intraoperative Considerations
Transnasal/transphenoidal
Translabial for peds or larger tumors
Fluroscopy
CT-guided frameless stereotaxy
Endonasal approach with endoscopy (less DI)
Lumbar Drain
! Tumor visualization
■ adding or removing fluid
■ Contraindicated in cases of elevated ICP…
■ Frequently placed to aid in CSF leak prevention post-op

25. Surgical Considerations
Head-up positioning
■ 10% VAE risk in semi-seated position, but no reports of
clinically significant VAE with associated M&M
Local infiltration of nasal mucosa with lido/epi
! HTN/tachycardia
! Rx with Antihtn meds…choices?
Topical vasoconstrictor?

26. Intraoperative Management
Monitors:
! Arterial catheter
! Central venous catheter (usually NOT needed)
! Lack of evidence for visual evoked potentials (VEP)
Anesthetic choice:
! Comorbidities
! Rapid emergence
! Hemodynamic stability
! Muscle relaxation
! Minimal blood loss (ICA / Cavernous sinus)
! Valsalva maneuver: test for CSF leak
! Gastric suctioning / Antiemetics

27. Postoperative Considerations
Inherent complications of TNTS/Resection
! Visual loss
! CSF leak
! Meningitis
! Cranial nerve dysfunction (II – VI)
■ Post-op CT/MRI/re-exploration
Nausea and Vomiting (40%)
! Routine prophylaxis advocated
Pain
! Headache – use narcs cautiously with OSA pts.

28. Disorders of Water Balance
Abnormalities in ADH Secretion
! DI (Diabetes Insipidus)
■ 2-3 ml/kg/hr x > 2 hrs. should raise suspicion for DI
■ Relatively common (30% transient/6% chronic)
■ Usually seen btwn first 24 to 48 hours
■ Abrupt polyuria (dilute and voluminous)
■ Hypernatremia with volume contraction
■ Desmopressin (DDAVP) Synthetic analog of ADH

29. Postoperative Concerns:
Disorders of Water Balance
! SIADH:
■ Free water intake exceeds free water excretion
■ Concentrated urine with euvolemia or slight hypervolemia
■ Fluid restriction (CAUTION!)
■ Hypertonic saline (3% NaCl) esp. if serum Na<120
■ Beware CPM
■ Demeclocycline
! CSWS (Cerebral Salt Wasting Syndrome)
■ Main distinguishing features:
■ HYPOVOLEMIA and DILUTE URINE Na and Osm

30. Hypopituitarism
25-30% of preop panhypopit pts. will recover normal pituitary
function post-op!
Majority that are normal preoperatively will remain normal
postoperatively
Rapidly wean corticosteroid supplementation and check cortisol
assay daily
Most patients do NOT require additional supplementation

31. Transphenoidal Surgery M&M
Mortality (< 0.5%)
Major Complications (1.5%)
! CSF leak, meningitis, ischemic CVA, vascular injury, ICH,
CN palsy, visual loss
Minor Complications (6.5%)
! Sinus disease, septal perforation, epistaxis, wound
infection and hematoma
Nemergut et al. Anes. Analgesia 2005