anesthesia for lower limb revascularization
TRANSCRIPT
Anaesthesia for lower limb
revascularizationPresented by:- Dr. Gopan. G
Date :- 27/04/ 2015
Introduction
Lower extremity arterial insufficiency, or
Peripheral artery disease (PAD) is a type of organic
PVD.
PVD manifests as insufficient tissue perfusion.
Peripheral vascular disease (PVD) is a marker for
severe multi-system atherosclerosis.
Classification
Acute - < 14 days ischemia
Acute on chronic – worsening of symptoms
& signs < 14 days
Chronic – ischemia stable for > 14 days.
Causes
Atherosclerosis.
Embolism, Thromboangiitis obliterans (Buerger
disease), Immune arteritis, Radiation arteritis,
Giant cell arteritis, Adventitial cystic disease,
Fibromuscular dysplasia, and Homocysteinemia.
Sites
Femoral artery
Popliteal artery
Any of the infrapopliteal arteries
Superficial femoral artery is the most common site
Acute limb ischemia
Pulselessness, pain, pallor, paresthesia, and
paralysis (the five Ps).
Embolism and thrombosis.
Trauma, iatrogenic (vascular interventions),
dissection of an arterial aneurysm.
Management
Immediate anticoagulation
Coexisting medical conditions - stabilized
Immediate surgical revascularization
Arteriography
Intra-arterial thrombolysis
Lower extremity bypass surgery
Implications for the anesthesiologist
Regional anesthesia is not an option.
Morbidity and mortality rates high.
Rapid sequence induction.
Severe reperfusion injuries.
Chronic arterial occlusion
Most patients are asymptomatic.
Mild intermittent claudication.
Severe disabling intermittent claudication or rest pain
Critical limb ischemia (CLI) is defined as chronic
ischemic rest pain, ulcers or gangrene attributable to
objectively proven arterial occlusive disease.
Ankle-brachial index (ABI)
Clinical standard
Ankle systolic pressure/ brachial systolic
pressure.
Normal value is between 1.0 and 1.1
Value < 0.9 indicates arterial disease.
Claudication 0.3 to 0.9.
Disabling claudication or rest pain < 0.5.
Gangrenous extremities < 0.2.
Treatment strategies Life style modification.
Cholesterol lowering therapy
Antiplatelet therapy
Optimum diabetic control
Blood pressure control <140/80 mm Hg
Non-surgical interventions.
Surgical revascularization- endarterectomy,
bypass grafting and amputation
Preoperative assessment
Cardiovascular symptoms.
Co-morbid conditions.
Functional capacity, assessed in terms of metabolic
equivalents (METs).
Full blood count, urea, electrolytes and glucose.
ECG and chest x-ray
Arterial blood gases and pulmonary function tests.
ACC/AHA clinical predictors of preoperative risk
MajorUnstable coronary syndromes (unstable angina/MI within 30 days)Decompensated congestive cardiac failureSignificant arrhythmiasSevere valvular disease
IntermediateMild angina pectorisPrevious MI ( >30 days earlier)Compensated or previous congestive cardiac failureDiabetes mellitusRenal insufficiency
MinorAdvanced age ( >70 yr)Abnormal ECGNon-sinus rhythmHistory of strokeUncontrolled systemic hypertension
ACC/AHA guidelines
Patients unable to meet a 4 MET and those with
intermediate clinical risk factors exercise stress
testing, dobutamine stress echocardiography (DSE), or
myocardial perfusion scanning.
Patients with acute or poorly controlled heart failure
Echo.
If Echo reveals MI coronary angiography and
revascularization.
ACC/AHA guidelines Coronary revascularization within the last 5 yrs and
have no cardiac symptoms further testing is not
necessary.
Symptoms have returned or revascularization was over
5 yrs ago coronary evaluation is recommended.
Peripheral vascular surgery should be delayed for at
least 4–6 weeks after balloon angioplasty, coronary
stenting or bypass surgery.
Preoperative management
Insulin therapy
Antihypertensive medication
Beta-blockers
a2-agonists
Statin therapy
Perioperative management
Ensure haemodynamic stability
Normothermia
Optimal perioperative hydration
Postoperative pain control
Peri-operative concerns
Tachycardia with hypertension or hypotension.
Hypothermia
Hypovolaemia
NTG infusion
Monitoring
Standard monitoring
Invasive arterial monitoring
Urinary catheterization
Central venous catheterization
Transoesophageal echocardiography
Pulmonary artery catheter
Anaesthetic techniques
Local anaesthesia with sedation
Regional anaesthesia
General anaesthesia (with or without regional
analgesic techniques)
REGIONAL Vs GENERAL ANESTHESIA
Choose the anesthetic and analgesic techniques
that are most familiar.
Optimization of perioperative care, rather than
anesthetic or analgesic selection, is the important
factor in improving outcome.
Anticoagulant and antiplatelet therapy often
precludes the use of spinal or epidural techniques.
REGIONAL Vs GENERAL ANESTHESIA
Use of regional techniques during intraoperative
systemic heparinization does not appear to
represent a significant risk.
Continuous catheter techniques preferable.
GA is preferred in patients who are unable to lie
still during lengthy surgery because of arthritis
or cardiorespiratory disease.
Peripheral nerve blocks
Sciatic, femoral, popliteal, and ankle.
Continuous catheter techniques can be used
Caution - when the neural structures are
deep or located in close proximity to vascular
structures
Theoretical advantages of RA
Attenuation of the stress response.
Improved postoperative respiratory function.
Improved graft flow and viability.
Attenuates the postoperative hypercoagulable
state.
Postoperative management
Epidural infusion
Patient-controlled analgesia
Normothermia
Oxygen supplementation is given for at least 24 h
Serial ECGs
Summary
PVS are associated with a high risk of cardiac
morbidity and mortality.
Preoperative cardiac risk assessment is
important and risk-reducing measures should be
started.
Quality of anaesthetic practice rather than
specific technique per se is important.
THANK YOU……