perioperative stroke in noncardiac, nonneurosurgical surgery
DESCRIPTION
Perioperative Stroke in Noncardiac, Nonneurosurgical Surgery. Ng et al, Anesthesiology 2011; 115:879-90 Presented by Paul Larsen. Stroke Definitions. Stroke - Focal or global neurologic deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours - PowerPoint PPT PresentationTRANSCRIPT
Perioperative Stroke in Noncardiac, Nonneurosurgical
Surgery Ng et al, Anesthesiology 2011; 115:879-90
Presented by Paul Larsen
Stroke Definitions
Stroke - Focal or global neurologic deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours
TIA - <24 hours
Covert Stroke - Asymptomatic ischemic event detected with imaging
Stroke Incidence
In cardiac, neurologic, and carotid surgery, the incidence is 2.2-5.2%
Other procedures have a range of 0.05-4.4%
Differences in patient population, changing clinical practice over 40 year study design, diagnostic tests, and duration of follow up may account for the large variance in reported stroke rates
Outcomes
12.6% mortality rate in non-surgical strokes
Perioperative stroke mortality ranges from 26% in general surgery to 87% in patients with a previous stroke
Pathophys
Pathophys
The majority of perioperative strokes occur after the second postoperative day
Only 5.8% of strokes are thought to have occured during surgery
Cardiothoracic surgery related strokes are 60% embolic
Other surgeries have a 68% thrombotic etiology of the stroke
Why Thrombosis?
Post-op endothelial dysfunction?
General anesthetics impair endothelial function
Withholding antiplatelet/anticoagulant agents may aggrevate surgically induced hypercoaguability
Who is at risk?
Comorbidities:
Age, history of stroke, atrial fibrillation are among the most important risk factors
Others include COPD, PVD, DM
Who is at risk?
Type of Surgery
Hip arthoplasty, peripheral vascular surgery have a higher incidence of stroke than knee arthroplasty or general surgery
Head and neck surgery increases risk by 0.2-5%
Who is at risk?
B-blockers - increase in non-fatal stroke, hypotension, and bradycardia in patients undergoing noncardiac surgery
It is unclear if there is causation, and no temporal relationship between the stroke and hypotension has been defined.
Risk modification
Timing elective surgery after a recent stroke
Acute stroke impairs cerebral autoregulation so blood flow becomes passively dependent on perfusion pressure
Occurs within 8 hours of a stroke, can last 2-6 months
Recommend delaying nonurgent surgery for at least 1-3 months
Risk modification
A fib:
If pre-existing, continue antiarrhythmic or rate-controling agent perioperatively
Correct post-op electrolyte imbalances and fluid volume
Risk modification
Anticoagulants:
Perioperative stroke management
ID at risk patients and make an early diagnosis
Non-contrast CT within 25 minutes, consider thrombolysis, correct hypotension, fever
ASA is the only oral antiplatelet agent found to be beneficial