Cardiovascular Complications related to Anesthesia

1. Cardiovascular Complications related to Anesthesia Wanawimol Saengchote M.D. Department of Anesthesiology, Ramathibodi Hospital, Mahidol U

2. Anesthetic Goals SAFETY

3. THAI AIMS J Med Assoc Thai 2008; 91 (7): 1011-9 • Anesthesia Incident Monitoring Study • January to June 2007. • 200,000 cases, 2537 incidents • A standardized incident report form was developed in order to fill in what, where, when, how, and why it happened

4. Common CVS Complications • Arrhythmia 25% • Desaturation 24% • Death within 24 hrs. 20% • Cardiac arrest 14%

5. Important Factors related to Incidents • inexperience, • lack of vigilance, • inadequate preanesthetic evaluation, • inappropriate decision, • emergency condition, • haste, • inadequate supervision, • ineffective communication.

6. Basic CVS physiology • DO2 = CO x 10 x CaO2 Tissue O2 delivery = cardiac output x arterial O2content • CO = SV x HR • SV ∞ preload, contractility, afterload • CO = EF x LVEDV x SVR x HR

7. Factors contributing to CVS complications • Patient’s comorbid : controllability? • Anesthetic management : drugs, techniques, process, anesthesia personnel • Surgical procedure

8. A. HYPOTENSION Hypovolemia • Preop NPO • Trauma-fractures • Peritonitis • N/v, diarrhea • Bowel prep • Diuretics • Blood loss • Major fluid shift • Tissue edema • Effusion • Diuresis • (concealed blood loss) Preoperative Intraoperative & PO.

9. Symptoms & Signs of Hypovolemia • Tachycardia • Peripheral vasoconstriction • Low systolic blood pressure • Narrow pulse pressure • Cold ,clammy skin and extremities • Low urine output • (anemia not apparent in acute loss without adequate volume replacement) • With beta blocker effect, no tachycardia detected

10. Clinical Classes of Severity of Hypovolemic Shock

11. Intraoperative management • Alert to environment, notice surgeon’s (and team) expression • Good communication • Adequate volume loading is all the time necessary (crystalloid – colloid) • Blood and blood component as required • Critical perfusion pressure should be maintained (MAP > 65 mmHg) • Concern about distribution of regional blood flow

12. Accessory for fast IV infusion

13. Colloids availability

14. B.Impaired myocardial contractility • 1. Drug effect : nearly all anesthetic agents depress myocardial contractility • Potent inhalation agents • Nitrous oxide in compromised heart • Intravenous : thiopental , propofol, ketamine • Opioid : pethidine ( arrhythmogenic effect to be discussed later)

15. B. IMC : Pumping failure Coronary artery disease • Myocardial ischemia / infarct • Cardiogenic shock Valvular heart disease • Congestive heart failure most common rheumatic heart disease : mitral, aortic , tricuspid valve

16. Ischemic heart disease • Acute ischemic episode  large or significant myocardial loss ⇨ serious ventricular arrhythmia, pulmonary congestion , hypotension ..... Hemodynamic support : inotropes , antiarrhythmic , mechanical device • Cardiac markers : troponin I, AST, LDH, CK-MB • cTnT < 0.1 ng/L, cTnI < 2.0 ng/L, CK-MB 0-25 u/L ( > 2 x normal)

17. B. Obstructive lesions • Obstruction to heart, cardiac chambers or great vessels  reduced stroke volume Causes : 1.Cardiac tamponade from injury, post cardiac surgery, cardiac catheterization * 2.Tension pneumothorax * 3. Pulmonary embolism * 4. Surgical manipulation in chest, esophageal, cardiac surgery 5. Supine hypotensive syndrome

18. Acute onset of pulmonary embolism

19. C.Decreasedafterload • 1. drug interactions : concurrent drug use + anesthetic effect ACEI, CCB, opioids, IV anesthetic, inhalation agent • 2. regional anesthesia : spinal, epidural an. with sympathetic blockade effect • 3. various drug effect : antibiotics, protamine, • 4. bone cement • 5. sepsis, adrenal insufficiency, blood transfusion

20. D.HYPERTENSION • 20% of population with hypertensive diseases • Causes of intraoperative HTN • Response to laryngoscopy and intubation • Light anesthesia • Hypercarbia • Hypoxemia • Drug effect • Hypervolemia • Specific surgical procedure

21. HYPERTENSION • Causes of HTN postop and at emergence 1. Stimuli from endotracheal & extubation 2. Pain 3. Hypoventilation, airway obstruction 4. Hypothermia,shivering 5. Acidosis 6. Full bladder 7. Antihypertensive withdrawal

22. HYPERVOLEMIA, pulmonary edema • Risk Factors • Hypertension • Diabetes mellitus • Underlying heart disease : CAD, VHD • Liver disease, renal disease • Head injury • Sepsis • Carbon monoxide poisoning (elderly, malnutrition, hypoalbuminemia)

23. Interesting Case • A 62 yr-old female suspected CBD stone, scheduled for ERCP , plan for post procedural admission. • Anesthetic time 1 hr 15 mins. ,uneventful an. and surgical procedure • After extubation, ? Abn. breathing pattern, occ. fine crepitations BLL. Later SPO2 drop • IV fluid 800 mL, minimal blood loss • Diuretic given, PACU > 2 hrs. • At ward SBP drop, intubate –ventilate,on dopa

24. F.CARDIAC ARRHYTHMIA 1. Physiological disturbances during anesthesia Anesthetics modify body mechanism + vagal dominant, acidosis, hypoxia/ hypercarbia, electrolyte disorder, hypovolemia 2. Pathological disturbances CAD : heart block, PVC, Thyrotoxicosis, MH, pheochromocytoma 3. Pharmacological causes :ketamine, NMB 4. Anesthesia procedures : IT, CVP, SA

25. Serious cardiac ♥arrhythmia : 6H, 5T Hypovolemia, hypoxemia, acidosis, K- Ca hypothermia, PE, ♥ tamponade tension pneumothorax Considerations in Arrhythmia Rx

26. Q & A

27. Thank you for your attention Know how, Know why, Care why