Wanawimol Saengchote M.D.Department of Anesthesiology,

Ramathibodi Hospital, Mahidol U

SAFETY SAFETY

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

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.

DO2 = CO x 10 x CaO2

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

Preoperative Intraoperative & 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 I Class II Class III Class IVPulse rate <100/min >100/min >120/min >140/min

BP normal normal dropped dropped

Pulse pr. normal decreased decreased decreased

RR 14-20/min 20-30/min >30/min >35/min

Urine >30ml/hr 20-30ml/hr 5-15ml/hr minimal

Capill.refil normal delayed delayed delayed

Mental st. Sl.anxious anxious confused lethargic

Bl.loss(ml.,%) <750

<15%

750-1,500

15-30%

1,500-2,000

30-40%

>2,000

>40%

Fluid crystalloid +colloid +colloid,bl. +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 shockValvular 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 < 0.1 ng/L, cTnI < 2.0 ng/L, CK-MB 0-25 u/L ( > 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 surgery5. Supine hypotensive syndrome

1. drug interactions : concurrent drug use + anesthetic effectACEI, 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 HTN1.Response to laryngoscopy and intubation2.Light anesthesia 3.Hypercarbia4.Hypoxemia5.Drug effect6.Hypervolemia7.Specific surgical procedure

Causes of HTN postop and at emergence1. Stimuli from endotracheal & extubation2. Pain3. Hypoventilation, airway obstruction4. Hypothermia,shivering5. Acidosis6. Full bladder7. Antihypertensive withdrawal

Risk Factors1.Hypertension2.Diabetes mellitus3.Underlying heart disease : CAD, VHD4.Liver disease, renal disease5.Head injury6.Sepsis7.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 SPO2 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 disturbancesCAD : heart block, PVC,Thyrotoxicosis, MH, pheochromocytoma3. Pharmacological causes :ketamine, NMB4. 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