seminar of 27/08/2012

1. Moderator: Residents:
Dr Preethy Dr Shakthivel
Dr Indranil
Dr Ashwini

2. SURGERY: Open vs Laparoscopic
 Open lateral retroperitoneal approach- Traditional.
 Transabdominal approach necessary in a few patients.
 Laparoscopic transperitoneal excision feasible now-a-days.
 Open surgery- Quicker, shorter duration of tumour handling, longer
duration of postoperative stay.
 Laparoscopic surgery- Persistent and sustained tumour handling for longer
duration, may be very difficult, shorter postoperative stay.

3. PRE ANESTHETIC ASSESSMENT
 Verification of history
 Severity of hypertension
 Adequacy of α blockade
 End organ damage
 Cardiology evaluation-
 ECG
 CXR
 Echocardiography
 Renal function-
 Urea
 Creatinine
 Electrolytes
 Serial hematocrit
 Blood sugar, Calcium

4. Intraoperative Principles
 Administer an anxiolytic
 Place an intra-arterial catheter before induction
 Place an intravenous catheter for antihypertensive administration
 Place a central venous catheter for intravascular volume monitoring
 Treat hemodynamic fluctuations with antihypertensives and
adrenergic antagonists
 Monitor for hypotension and hypoglycemia after tumor isolation

5.  Premedication:
 Sedation, anxiolysis, assurance prevent marked hemodynamic
changes intraoperatively.
 Benzodiazepine preferred
 Opioids can provoke CCA release
 Buprenorphine- potent analgesic with anxiolytic & sedative
properties, cardiovascularly more stable
 Phenoxybenzamine should be withdrawn 48 hours prior to surgery
 Last dose of α adrenergic blocker to be given at night prior to surgery.

6. INTRAOPERATIVE MANAGEMENT
 Teamwork between surgeon, anesthesiologist, physician and
endocrinologist.
 First successful operation by Roux in 1926.
 Various techniques tried till date.
 Rational technique-
 Combined regional and general anesthesia
 Selective adrenergic antagonists to control hemodynamic surges.

7.  Patient to be shifted cautiously
 ECG, pulse oximetry, NIBP
 Two large bore intravenous catheters
 Arterial catheter & central venous catheter put under LA
 PA catheter mostly not needed
 May be useful in patients with preoperative cardiovascular
compromise or severe LV dysfunction
 Epidural catheter before/after GA at mid (T9-10) or low(T12-L1)
thoracic level

8. Induction
 Should be smooth
 CCA surge during induction, hypotension due to volume contraction
unlikely in an adequately prepared patient
 Preoxygenation
 Opioids-
 Morphine/Pethidine: Histamine release
 Fentanyl: Most commonly used (2-5 µg/kg)
 Alfentanil/Sufentanil/Remifentanil
 Induction agents-
 Thiopentone : Can cause histamine release
 Etomidate: Cardiovascularly stable, but, pain on injection
 Propofol: Logical choice
 Midazolam: Useful for co-induction

9.  Muscle relaxants-
 Succinylcholine: Sympathetic stimulation, muscle fasciculation
 Atracurium, Mivacurium: Histamine release
 Pancuronium: Indirect Sympathomimetic action
 Vecuronium, Rocuronium, Cisatracurium: Suitable agents

10. Positioning
 Must be done carefully
 Transabdominal approach-
 Supine, one or both arms tucked alongside body, flank elevated 30 degrees,
table flexed to open up space between costal margin and ASIS
 Posterior approach-
 Not recommended, prone, table flexed at waist
 Thoracoabdominal approach-
 Side to be operated elevated 45 degree, arm slinged above head
 Laparoscopic approach-
 Full lateral, operative side uppermost, operative side hyperextended till
flank musculature slightly taut

11. Monitoring
 ECG
 Pulse oximetry
 Invasive BP
 CVP
 Urine output
 Temperature
 Inspired oxygen conc.
 EtCO2
 EtAA
 PA catheter (+/-)
 Blood sugar

12. Maintenance
 Anesthetic depth more important than agent
 Halothane/Enflurane- Arrhythmogenic
 Isoflurane- Commonly used
 Sevoflurane- Preferred due to rapid titrability of anesthetic depth,
hemodynamics
 Desflurane- Causes significant sympathetic stimulation
 N2O- Not contraindicated
 Air/Oxygen mixture, FiO2 0.5, TV 7-10ml/kg, EtCO2 35-38mm Hg
 Epidural continuous infusion/repeated boluses with bupivacaine
with/without fentanyl
 Further IV opioids usually not needed

13. Control of Perioperative CCA Release
 CCA release during tumour handling inevitable despite adequate preoperative
control
 Noxious stimuli- Hypertension: Deepening anesthesia
 Tumour handling- ↑SVR, PCWP; ↓CO: Careful handling, vasodilators
 Direct vasodilators-
 Sodium Nitroprusside: Potent arterio-venodilator, rapid onset, brief action,
cyanide toxicity uncommon with small quantity used (Initial 0.5 to
1.5µg/kg/min, mean 3 to 5 µg/kg/min)
 Nitroglycerine: Mainly affects capacitance vessels, rapid acting, large doses
may be needed
 α adrenergic antagonists-
 Phentolamine: Competitive α1 & weak α2 receptor antagonist, as infusion or 1-
2 mg boluses, causes tachycardia.

14.  β adrenergic antagonists- Help control tachycardia/tachyarrhythmias
 Esmolol: Ultrashort acting β1 antagonist. Rapid titrability. Uniquely
suitable.
 Bolus 500µg/kg, infusion 50-200µg/kg/min
 Metoprolol 1-2 mg boluses
 Labetalol ( 0.25 mg/kg, upto 20 mg over a period of 10 min)
 Atenolol (2.5 to 10 mg), propranolol (1 to 10 mg) also used

15.  Calcium channel blockers- little reduction in preload, less potential for
overshoot hypotension, no rebound hypertension, less increase in heart rate,
absence of cyanide toxicity
 Nicardipine: Inhibits CCA release from adrenal medullary cells in vitro,
Intra-operative 2.5-7.5µg/kg/min, onset 1 to 5 min, duration 3-6 hours
 Dopa-1 receptor agonist-
 Fenoldopam: Peripheral vasodilation, ↑Renal blood flow. Undesirable
diuresis

16.  Magnesium sulphate-
 Pioneered by James et al in 1960
 Inhibits CCA release from adrenal medulla, alters adrenergic receptor
response
 Loading dose 40-60mg/kg followed by 1-2g/hr continuous infusion
 Target blood level 2-4 mmol/L
 Additional doses necessary during tumour handling
 Has been used in pregnant patients, patients with CAD
 Other drugs reported-
 Diltiazem, Prostaglandin E1, Midazolam/Sufentanil infusion,
Midazolam/Fentanyl infusion, Propofol/Fentanyl infusion, MgSO4/GTN
infusion, Desflurane, Sevoflurane with adenosine triphophate, Esmolol
infusion

17. Post Resection Hypotension
 After adrenal vein ligation and removal of tumour
 Reasons-
 Suppression of contralateral adrenal gland
 Downregulation of adrenergic receptors
 Effect of preoperative adrenoceptor antagonists
 Sudden increase in venous capacitance
 Mostly amenable to modest fluid load and discontinuation of vasodilators
 Blood replacement according to losses
 Vasopressor if hypotension unresponsive to fluid
 Noradrenaline
 Phenylephrine
 Dopamine
 Angiotensin II agonist

18. POST OPERATIVE MANAGEMENT
 Reversal depends upon preoperative state and intraoperative course
 Neostigmine and Glycopyrrolate
 Shift to ICU/HDU
 Most important post-operative complications-
 Hypertension: Approx. 50% patients
Recovery from anesthesia
Pain- Opioids, epidural analgesia, clonidine
Persistence of high plasma CCA level- restart antihypertensives
Residual tumour- further evaluation and work up
 Hypotension:
 Supression of contralateral adrenal
 Downregulation of adrenoceptors
 Persistent effect of preoperative adrenergic blockade
 Intra-abdominal bleed- high index of suspicion

19.  Hypoglycemia
 Disappearence of pancreatic β cell suppression
 Lipolysis, glycogenolysis no longer present
 Slow emergence, lethargy
 β-blockers impair recovery, mask symptoms
 Encephalopathy may occur
 Frequent monitoring of blood glucose needed
 Glucose containing IV fluids started after tumour removal

20. Perioperative steroid replacement in bilateral
adrenalectomy

21. SPECIAL CONSIDERATIONS
 Pheochromocytoma patient for non-pheo surgery-
 Elective surgery to be postponed and elective resection of
pheochromocytoma planned
 Patients for emergency surgery should be tried to be optimised as far as
possible before surgery
 Pheochromocytoma in pregnancy-
 Misreading of warning symptoms common
 Maternal mortality 2 to 4% if diagnosed antenatally, 14 to 25% if
diagnosed intrapartum or postnatally
 Early pregnancy: Medical optimisation for 1to 2 weeks f/b resection
before 24th week
 Late pregnancy: Medical optimisation till fetus mature, f/b elective
caesarean and resection at same sitting
 Vaginal delivery preferrably avoided

22.  Cardiac pheochromocytoma-
 Significant morbidity, mortality
 Thoracolaparotomy, CPB with cardioplegia
 Exsanguination, myocardial infarction
 Orthotopic Cardiac Transplantation can be considered
 Carotid Body Tumour and Paraganglionoma excision-
 Major hemorrhage
 Need for carotid cross clamping, grafting
 Postoperative complications: Airway compromise, disturbed
baroreceptor function, cerebral ischemia

23. THANK YOU