Anaesthesia for renal transplant

1. Anaesthesia for renal transplant Dr Kajal Jain Dr Deepak Saini Dr Seelora Sahu Dr Seema www.anaesthesia.co.inanaesthesia.co.in@gmail.com

2. Cadaveric donors

3. Organs recovered from heart beating, brain-dead donors are the mainstays of transplant • Need to recognize the concept of brain death

4. History of brain death • Diagnosing brain death • Confirmatory lab studies • Physiology of brain death • Anaesthetic management • Procurement

5. Brain death • Total irreversible cessation of brain functions • Central Nervous System and the Brain Stem

6. History • 1902 – Cushing reported cessation of cerebral circulation • 1959 – Mollaret and Goulon described cessation of brain functions – coma dépassé • 1968 – criteria for brain death by Harvard medical School • 1970 – Mohandas and Chou emphasized importance of loss of brain stem functions in brain death • 1995 – American Academy of Neurology – Criteria for brain death

7. Diagnosis of brain death • Performed in three steps • Establishing the cause of disease • Excluding certain potentially reversible syndromes that may produce signs similar to brain death • Demonstrating signs of brain death: coma, brain stem areflexia, apnea

8. Confirmatory tests • Two examinations separated by 6 hours • Two or three physicians who are independent of the transplant team • At least one of the physicians is required to be a specialist in • Neurology • Neurosurgery • Anaesthesia

9. Diagnostic criteria for clinical diagnosis of brain death A. Prerequisites. Brain death in the absence of clinical brain function when the proximate cause is known and demonstrably irreversible. • Clinical or neurological evidence of an acute CNS catastrophe compatible with clinical diagnosis of brain death • Exclusion of complicating medical conditions that may confound clinical assessment • No drug intoxication or poisoning • Core temperature > 32°C (90°F)

10. ….contd B. The three cardinal findings in brain death are – • Coma • Absence of brainstem reflexes • Apnea Coma or unresponsiveness – No cerebral motor responses to pain in all extremities (nail bed pressure and supraorbital pressure)

11. ….contd Absence of brainstem reflexes • Pupils • No response to bright light • Size: midposition (4mm) to dilated (9mm) • Ocular movements • No oculocephalic reflex • No deviation of eyes to irrigation of each ear with 50 ml cold saline • Facial sensation and facial motor response • No corneal reflex • No jaw reflex • No grimacing to deep pressure • Pharyngeal and tracheal reflexes • No gag reflex • No cough reflex

12. ….contd Apnea testing performed as follows • Prerequisites • Core temperature > 36.5 C or 97 F • SBP > 90 mm Hg • Euvolemia • Normal PaCO2: > 40 mm Hg • Normal PaO2: > 200 mm Hg • Connect pulseoxymetry,disconnect ventilator • Deliver 100% O2, 6 L/min, into the trachea • Respiratory movements • Measure arterial PaO2, PaCO2, pH after 8 min. reconnect ventilator

13. Confirmatory lab studies • Electroencephalographic recording • Evoked responses • Measurement of blood flow • Angiography • Contrast angiography • Radio nucleotide angiography • CT • MRI • Transcranial doppler sonography • Positron emission tomography

14. Physiology of brain death Neurophysiology • Brain edema • Progressive herniation of brain stem structures • Associated haemodynamic changes • Medullary ischemia – loss of vagal activity – unopposed sympathetic activity • Autonomic storm: peaks within 5 to 15 min of brain death

15. ….contd Respiration • No spontaneous respiration even with high PaCO2 levels • No congh on stimulation of carina • Respiratory centre in medulla oblongata • Deminished oxygenation • Pulmonary edema • Diabetes insipidus

16. ….contd Cardiovascular functions • Unopposed sympathetic activity • Massive outpouring of catecholamines to preserve cerebral perfusion • Autonomic storm • Tachycardia, sever hypertensin and 2-3 times increase in cardiac output • Dysrhythmia, myocardial ischemia, severe peripheral vesoconstriction

17. ….contd • Circulatory collapse • Automaticity of vasomotor and cardioaccelerating neurons in spinal cord – return of haemodynamics to normal • Autonomic spinal cord reflexes

18. ….contd Temperature • Loss of neural connection between temperature regulating centre and peripheral body tissues • Deminished metabolism • No vasoconstriction • Poikilothermia • No fever

19. ….contd Endocrine functions • Hypothalamus and anterior pituitary functions preserved for some time • Diabetes insipidus • Hyperglycemia • Insulin resistance • Excess administration • Thyroid insufficiency • Other hormones also sunormal

20. ….contd • Immune system • Increased levels of cytokines • Immune dysfunction

21. Anaesthetic management Criteria • Potential cadaveric donors • Previously healthy or relatively healthy people • No extracaranial malignancy • No untreatable infection

22. ….contd Preoperative management • Cardiovascular • Adequate volume replacement • Ionotropic agents • Vasopressin or catecholamines • Invasive monitoring – arterial line, cvc line, PAC monitoring • Maintain CVP 10-12 mm Hg • Maintain PCWP < 12 mm Hg

23. …contd • Ventillation • Optimising lung expansion • Vt 8-12 mL/kg • PEEP 5 cm H2O • Saturation > 90 % • FiO2 < 40 % • Endocrine replacement therapy • Prevent hypothermia

24. …contd Intraoperative management • Perioperative haemodynamic stabilization is important to prevent donor organ damage or loss • Guidelines • SBP > 100 mm Hg (mean 70 to 110 mm Hg) • Po2 > 100 mm Hg • Urine output > 100 mL/hr (1 to 1.5 mL/kg/hr) • Haemoglobin concentration > 100g/L • CVP between 5 and 10 mm Hg • FiO2 < 40 %

25. …contd Monitoring • Standard monitors: ECG, pulseoxymetry, NIBP • Urine output • Invasive measurements: IBP, CVC, PAC • Temperature

26. ….contd • Hypotension • IV Fluid – crystalloids, colloids or blood • Ionotrope – dopamine, others. • Heparin (20,000 or 30,000 IU) • Cold protection • Muscle relaxant – NDMR

27. …contd • Bradycardia – direct-acting chronotrope (isoproterenol) • volatile anaesthetic and narcotics • No analgesia • Spinal reflexes – β-blockade, peripheral vasodilation, ganglionic blockade

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