Transcript Perioperative Stroke in Noncardiac, Nonneurosurgical Surgery Ng

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 0.25%
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 ratecontroling 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