Good Morning

10 June 2002

Perioperative Stroke Prevention

R2 林子富

Anaesthesia 1997;52:879-83

Incidence 0.02 to 0.7% In the postoperative period (the majority events)

The average time : 7 days after surgery

Anaesthesia 1997;52:879-83

Significance High mortality Assisted care for living Large impact and cost

Risk Factors

Perioperative period itself Type of surgery Coexisting conditions Cardiac disease Age Others

hypotension, dehydration, hypercoagulable state and emergency surgery

Anesthesiology 2000;92:425-32

Pathophysiology

Intraoperative hypotension Thrombotic or embolic events – more impo

rtant Hypercoagulable state after surgery Others

Extended bad rest Thrombogenic devices Dehydration

Stroke 1982;13:766-73

Prevention

Identifying patients at risk (ex. CVA)

Altering risk factors (ex. delay surgery for 4-6 wk)

Carotid endarterectomy for carotid stenosis? Consumption of aspirin? Control of hypertension Good anesthetic technique Effect of anesthetic agents on postoperative hyper

coagulability (ex. propofol)

Anaesth Intensive Care 2000;28:227-28

Cerebral Protection

Techniques To increase the supply of oxygen to the injur

ed tissue To reduce the metabolic demands To affect specific pathways in the ischemic c

ascade to reduce the production of unwanted metabolites

Cerebral Protection

I. Physiological BP maintained within 20% of normal range Maintain CPP greater than 70 mm Hg Hemodilution Maintain normocarbia Mild hypothermia Treat fever aggressively Avoid hyperglycemia

Cerebral Protection

II. Anesthetic Agents Barbiturates Isoflurane Propofol Lidocaine

Anesthesiology 1999;90:1446-53

Anesthesiology 2000;93:858-75

Cerebral Protection

III. Other Pharmacological Agents Calcium antagonist Magnesium• Other agents under investigation

• Prostanoids

• Free radical scavengers

• Lipid membrane peroxidation inhibitors

• NMDA receptor antagonists

Stroke 1992;23:3-8

Summary

Uncommon but devastatingKnowledge of important risk factorsMeasures to prevent ischemic cerebral even

tsCurrent and experimental pharmaceutical a

gents

Have A Nice Day