1. Choice of Anaesthesia for Patient with Cardiac Disease: General versus Regional? K. Lebedinski St. Petersburg

2. «…Epidural anesthesia and analgesia exerted a significant beneficial effect on operative outcome in a group of high risk surgical patients: Totally 53 high risk patients,Totally 53 high risk patients, Randomized between GA (25) and EAA (28) groupsRandomized between GA (25) and EAA (28) groups EAA group had a reduction in:EAA group had a reduction in: overall postoperative complication rate (P = 0.002),overall postoperative complication rate (P = 0.002), incidence of cardiovascular failure (P = 0.007),incidence of cardiovascular failure (P = 0.007), major infectious complications (P = 0.007),major infectious complications (P = 0.007), 24-h urinary cortisol excretion (P = 0.025),24-h urinary cortisol excretion (P = 0.025), hospital costs (P = 0.02)…»hospital costs (P = 0.02)…» Yeager MP, Glass DD, Neff RK, Brink-Johnsen T. Epidural Anesthesia and Analgesia in High Risk Surgical Patients. Anesthesiology 1987; 66: 729-36

3. A retrospective cohort study of 9425 consecutive hip fracture patients, aged  60 yr, who underwent surgical repair at 20 US hospitals (1983-1993), divided between GA (6206) and RA (3219) groups: “The authors were unable to demonstrate that RA was associated with better outcome than was GA… These results suggest that the type of anesthesia used should depend on factors other than any associated risks of mortality or morbidity.” O’Hara DA, Duff A, Berlin JA, et al. The effect of anesthetic technique on postoperative outcomes in hip fracture repair. Anesthesiology 2000; 92: 947-57

4. “…Although clinical perceptions and theoretic considerations suggest regional anesthesia should be safer than general anesthesia in elderly patients, current studies indicate no difference in outcomes. Regional anesthesia may still prove superior to general anesthesia if the right patient population or right endpoints are identified for comparison.” Roy RC Choosing general versus regional anesthesia for the elderly. Anesthesiology Clinics of North America 2000; 18: 91-104

5. Epidural bupivacaine added to GA, despite of mild hypotension, led to severe reduction in blood flow distal to the experimental coronary stenosis in swine. Mergner GW, Stolte AL, Frame WB, Lim HJ. Combined epidural analgesia and general anesthesia induce ischemia distal to a severe coronary artery stenosis in swine. Anesth Analg 1994; 78: 37-45 In 47 healthy parturients, underwent Cesarean section under spinal anesthesia, 30% demonstrated ST depression due to hyperkinetic contractile state. Roy L, Ramanathan S. ST-segment depression and myocardial contractility during cesarean section under spinal anesthesia. Can J Anaesth 1999; 46: 52-5 !

6. So, where is Truth?...

7. The primary event: vasodilation, dose- and level- dependentThe primary event: vasodilation, dose- and level- dependent Compensatory response: cardiac output rise, sometimes reaching >50% from baselineCompensatory response: cardiac output rise, sometimes reaching >50% from baseline Possible limiting factors:Possible limiting factors: Hypovolemia Hypovolemia High (>Th5) central block level High (>Th5) central block level “Fixed” cardiac output (e.g., aortic stenosis) “Fixed” cardiac output (e.g., aortic stenosis) Neuraxial Block !

8. The Equilibrium of Central Neuraxial Block Compensation: Afterload decline  LVESV decreases Afterload decline  LVESV decreases Baroreflex  HR rise Baroreflex  HR rise Decompensation: Preload decline  LVEDV decreases Preload decline  LVEDV decreases Block above Th5  cardiac depression Block above Th5  cardiac depression

9. The primary event: cardiac output decline, reaching 25% of baselineThe primary event: cardiac output decline, reaching 25% of baseline Compensatory response: vascular tone riseCompensatory response: vascular tone rise Possible limiting factors:Possible limiting factors: Low initial cardiac output Low initial cardiac output Use of vasodilators Use of vasodilators Low central sympathetic outflow - inability to vasoconstriction Low central sympathetic outflow - inability to vasoconstriction General Anaesthesia !

10. The Equilibrium of General Anaesthesia Compensation: Vascular tone rise Vascular tone rise Baroreflex  HR rise Baroreflex  HR rise Decompensation: Contractility falls  VESV increases Contractility falls  VESV increases Central sympathetic outflow restricts  Vascular tone depression Central sympathetic outflow restricts  Vascular tone depression

11. Pre-operative Functional Tests Vladimir A. Schtange (1913): Vladimir A. Schtange (1913): Inspiratory hold-up test (Schtange test) Physical exercise tests (treadmill, veloergometer, etc.) Physical exercise tests (treadmill, veloergometer, etc.) Pharmacological stress-tests Pharmacological stress-tests Pre-op dipyridamol-thallium scintigraphy (Mangano et al.) – ?... Pre-op dipyridamol-thallium scintigraphy (Mangano et al.) – ?...

12. Challenges (e.g., physical exercise) are different from those at the OR!Challenges (e.g., physical exercise) are different from those at the OR! General conditions are different,General conditions are different, Responses are also different,Responses are also different, Criteria are based on another endpoints…Criteria are based on another endpoints… So, at least the challenges must be the same! Why pre-op functional tests are unable to predict complications?

13. Modeling Almost a universal tool, when the risk is high and possible losses are unacceptable: Shipbuilding, Shipbuilding, Aviation, Aviation, Nuclear power, Nuclear power, Defense, etc… Defense, etc… And what about anaesthesiology?...

14. Our aim was to elaborate clinical prognostic models to substantiate the individual choice of anaesthesia based on specific patients’ response to physiological challenges, similar to those of the anaesthesia The first step was … Systemic Vasodilation with p.o. Nitroglycerin as a Prognostic Test for Hypotension after Spinal Block

15. to investigate the possibility of individual prognosis based on the analogy between local (spinal block) and systemic (nitroglycerin p.o.) vasodilation Aim of the study: Problem: severe hypotension under spinal block

16. 58 ASA I-III patients aged 22—89 Monitoring: ECG, SpO 2, NIBP Impedance cardiography: CI, SVRI LV Power Index (W  m -2 ) = 0.0022  CI  mean BP Nitroglycerin test: 500 mkg p.o. Nitroglycerin test: 500 mkg p.o. Crystalloid fluid loading 6.2  3.8 ml  kg –1 Spinal anesthesia: L3-L4, isobaric bupivacaine 0.2  0.05 mg  kg –1 Spinal anesthesia: L3-L4, isobaric bupivacaine 0.2  0.05 mg  kg –1 Mean sensory block level: T8 Mean sensory block level: T8 Hypotension: mean BP <75% of base level, requiring ephedrine Hypotension: mean BP <75% of base level, requiring ephedrine Materials and methods:

17. Normotensive (N) group: 44 patients Hypotensive (H) group: 14 patients No difference between N and H: age, gender, body weight and length, nitroglycerin and bupivacaine doses, time interval between test and puncture, sensory block level Similar response to test and SA Test CI rise (P=5.5  10 -5 ): N-group 42.9% H-group 22.2% Test LVPI changes (P=10 -6 ): N-group +29.7% H-group –0.77% Results:

18. Hemodynamic Response To Nitroglycerin Test

19. Preoperative systemic vasodilation test with p.o. nitroglycerin may be used as simple, fast, safe and relevant prognostic test for severe hypotension after spinal block Conclusion: Lebedinski K, Shevkulenko D Eur J Anaesth 2006; 23, Suppl. 37: A408

20. Our next steps… Esmolol i.v. bolus as a Prognostic Test for Hemodynamic Response to General Anaesthesia Postural Tests as a Prognostic Tool for Hemodynamic Responses during Surgery and Anaesthesia From á priori choice of anaesthesia – to modeling-based choice!

21. The Choice of Anaesthesia for Patient with Cardiac Disease: Brief Summary Peripheral neuraxial block – if sufficient regarding surgery – the superior choice anyway! If there are no direct contraindications to central neuraxial block – choice between RA and GA based on prognostic modeling tests

22. Our specialty develops more and more methods of anaesthesia – ingenious, elegant and effective. But we should always remember, that the aim of our patient is to survive surgery, but not to confirm any paradigm – even those reported just now!…

23. Thank you for the attention!