Wanawimol Saengchote M.D. Department of Anesthesiology, Ramathibodi Hospital, Mahidol U

SAFETY

 Anesthesia Incident Monitoring Study  January to June  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

 Arrhythmia 25%  Desaturation 24%  Death within 24 hrs. 20%  Cardiac arrest 14%

 inexperience,  lack of vigilance,  inadequate preanesthetic evaluation,  inappropriate decision,  emergency condition,  haste,  inadequate supervision,  ineffective communication.

 DO 2 = CO x 10 x CaO 2 Tissue O2 delivery = cardiac output x arterial O2 content  CO = SV x HR  SV ∞ preload, contractility, afterload  CO = EF x LVEDV x SVR x HR

 Patient’s comorbid : controllability?  Anesthetic management : drugs, techniques, process, anesthesia personnel  Surgical procedure

PreoperativeIntraoperative & PO. Hypovolemia  Preop NPO  Trauma-fractures  Peritonitis  N/v, diarrhea  Bowel prep  Diuretics  Blood loss  Major fluid shift  Tissue edema  Effusion  Diuresis  (concealed blood loss)

 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

Class IClass IIClass IIIClass IV Pulse rate<100/min>100/min>120/min>140/min BP normal dropped Pulse pr.normaldecreased RR 14-20/min20-30/min>30/min>35/min Urine>30ml/hr20-30ml/hr5-15ml/hrminimal Capill.refilnormaldelayed Mental st.Sl.anxiousanxiousconfusedlethargic Bl.loss(ml.,%)<750 <15% 750-1, % 1,500-2, % >2,000 >40% Fluidcrystalloid+colloid+colloid,bl.

 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

 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)

Coronary artery disease  Myocardial ischemia / infarct  Cardiogenic shock Valvular heart disease  Congestive heart failure most common rheumatic heart disease : mitral, aortic, tricuspid valve

 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 2 x normal)

 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

 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% of population with hypertensive diseases  Causes of intraoperative HTN 1. Response to laryngoscopy and intubation 2. Light anesthesia 3. Hypercarbia 4. Hypoxemia 5. Drug effect 6. Hypervolemia 7. Specific surgical procedure

 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

 Risk Factors 1. Hypertension 2. Diabetes mellitus 3. Underlying heart disease : CAD, VHD 4. Liver disease, renal disease 5. Head injury 6. Sepsis 7. Carbon monoxide poisoning (elderly, malnutrition, hypoalbuminemia)

 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 S P O 2 drop  IV fluid 800 mL, minimal blood loss  Diuretic given, PACU > 2 hrs.  At ward SBP drop, intubate –ventilate,on dopa

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

 Serious cardiac ♥arrhythmia :  6H, 5T  Hypovolemia,  hypoxemia,  acidosis, K- Ca hypothermia, PE, ♥ tamponade  tension pneumothorax

Know how, Know why, Care why