Peripheral Vascular Disease (General)
- Results in compromised blood flow to the extremities. Ankle-Brachial index of less than 0.90.
- Higher risk of cardiovascular ischemic events
- Chronic: atherosclerosis
- Acute: arterial embolism
Peripheral Vascular Disease (Risk Factors)
- Similar to those causing ischemic heart disease: Diabetes mellitus, HTN, tobacco use, dyslipidemia, hyperhomocysteinemia, and a family Hx
- Prognosis with PAD is related to increased risk of CV ischemic events and cerebrovascular disease
Peripheral Vascular Disease (Signs/Symptoms)
- Intermittent claudication (requirements of exercise exceeds oxygen delivery) and rest pain
- Decreased or absent arterial pulses (most reliable)
- Normal transcutaneous oxygen tension is 60 mm Hg in the foot and may be less than 40mm Hg w/ skin ischemia
Peripheral Vascular Disease (Treatment)
- Smoking cessation
- Lipid-lowering therapy
- Anti-HTN (except B-blockers)
- Ravascularization (rapid and completeness)
- Operative risk related to the presence of atherosclerotic vascular disease (ischemic heart disease and cerebrovascular disease)
Peripheral Vascular Disease (Anesthesia)
- Principal risk if ischemic heart disease
- Beta-blockers indicated for surgery
- Heparin is common before vascular cross-clamp to reduce the risk of thromboembolic complication
Peripheral Vascular Disease (Postoperative)
Dexmedetomidine can attenuate the increase in HR and catecholamine release during emergence from anesthesia (produces analgesia and sedation w/o cardiac/respiratory depression)
Subclavian Steal Syndrome
- Occlusion of subclavian artery proximal to the vertebral artery reverses blood flow from the brain to supply the arm
- Symptoms of CNS ischemia
Acute Arterial Occlusion
- S/S: limb ischemia (pain, paresthesia, motor weakness)
- Tx: heparin and thrombolysis
- Anesthesia: similar to Peripheral Vascular Disease
Coronary Artery Disease
- Cerebrovascular accident (stroke): sudden neurologic deficits due to ischemic, hemorrhagic, or thrombotic events.
- Brain receives 20% of CO via internal carotid and vertebral arteries to form major intracranial vessels and circle of willis.
- Acute ischemic stroke: Small vessel occlusion due to DM or systemic HTN, HTN is the most significant risk factor for acute ischemic stroke.
- Preop: Examine for CV and renal disease. Ischemic hear disease is a major cause of morbidity and mortality. Check the effect of a change in head position on cerebral function.
- GA Anesthetic: BP lability may be large but decrease in CMRO2 may provide protection.
- Monitoring: Intraarterial catheter, cerebral function
- Postop: Hypertension and hypotension (cerebral edema and ischemia) should be avoided. NTG for HTN + hydrazine or labetolol.
Peripheral Venous Disease
Deep vein thrombosis and subsequent pulmonary embolism are leading cause of posts morbidity and mortality. Tx with anticoagulation to an INR of 2-3