PVD reduced Flashcards
What is PVD
- Compromised blood flow to the extremities
- Ankle-brachial index of less than 0.9
- Ratio of SBP in ankle vs SBP in brachial artery
What causes PVD
- Atherosclerosis- most common cause
- goes hand in hand with CAD
- Arterial embolism- acute cause
- Vasculitis - inflam of vasculature
Is someone has PVD, it can be assumed that they likely have ___
Over what age can it be assumed that someone has PVD
CAD
Over 75 y.o. (exceeds 70%)
Atherosclerosis risk factors
- DM
- Obesity/Inactivity
- Advanced age
- Male gender
- Family Hx of early atherosclerosis
- HTN
- HLD
- Smoking
- Hyper-homo-cystein-emia
Atherosclerosis s/s
-
Intermittent claudication → most common symptom
- pain that starts with walking/exercise and <strong>stops with rest</strong>
-
cool/cold feet or leg pain while lying flat
- relieved by sitting
- sign of advanced disease
- loss of pulses in feet/legs
-
pale color in legs when raised
- <strong>dependent</strong> <strong>rubor</strong> - redness in dependent position
- shiny skin
- loss of hair on feet
- thinckened toenails→may have fungal infection
-
critical limb ischemia
- Most severe symptom
- “rest pain”
- lack of O2 to the limb at rest
- associated with non-healing ulcers & gangrene
Diagnostic tests for atherosclerosis
-
Duplex and Doppler Ultrasonography
- measures lamilar flow it is either red = towards probe, blue = away
-
Ankle/Brachial Index
- Normal index is 0.95 at rest
- < 0.9 = claudication
- < 0.4 = pain with resting
- < 0.25 = ischemic ulceration or impending gangrene
-
Transcutaneous oximetry
- 60 mm/Hg = Normal
- < 40 mmHg in patients with limb ischemia
- MRI
- Contrast angiography - locates blocked area
atherosclerosis treatment
-
LIfestyle modification
- exercise, weight loss, smoking cessation
-
Lipid-lowering medications
- statin drugs
- Vitamin C, E, folate
- Antiplatelet therapy
-
Revascularization
- PTA w/stent, Bypass, Intra-arterial thrombolytic therapy, balloon embolectomy, endarterectomy
- Amputation :-(
Surgical approach to Peripheral Revascularization
- Donor and Recipient arteries are exposed and a tunnel is created for a bipass graft
- Graft either Saphenous vein or prosthesis
- Heparin given IV
- must note the time (3-5 min onset)
- Still able to use regional anesthesia (dose 3000-5000)
- Anastamosis is made
- Arteriogram to confirm flow
- Heparin is usually NOT reversed
Giving what drug during revascularization will likely get you sent home for the day
Phenylephrine
Don’t get sent home for the day.
PVD
Anesthetitc risks and considerations
-
Principal risk - athlerrosclerosis and ischemic heart disease (manage like they have CAD)
- AVOID hypo/hypertension
- AVOID tachycardia
- Patients with PVD have 3-5x greater risk of stroke, MI and death
- To reduce risks of revascularization suregery:
- Patents who experience angina and claudication will get a CABG prior to revascularization surgery
Risks with revascularization
- Pulmonary embolism (watch ETCO2)
- MI
- Low CO→ischemia
- Hemorrhage
- Infection
- Pulmonary edema
- Risks associated with the lithotomy position -
- nerve palsy, limb ischemia
peripheral revascularization
Pre-op meds and Monitoring
- Preop → make sure pt takes beta-blockers and/or other chronic medication
-
Intra-op monitoring→ Consider co-morbidities (<strong>CAD</strong>, <strong>diabetes</strong>, <strong>HTN)</strong>
-
Fluid and volume status
- A-line + CVP or foley to monitor fluid volume status/end organ profusion
- Estimate blood loss and 3rd space fluid loss
- Pulse ox oxygenation
- Follow Blood Gasses + coags + electrolytes
- Note Cross-clamp time (limb ischemia time)
- Note when heparin is given(peaks in <strong>3-5</strong>min)
-
Fluid and volume status
peripheral revascularization
Anesthetic management
Regional is preferred (spinal > epidural = less hematoma risk)
- Increased graft blood flow (grafts do better)
- spinal is preferred - less hematoma risk
- Less increase in SVR with cross-clamping (sympatectomy)
- Better Postop pain relief (less SNS outflow and less vasoconstriction)
-
Less activation of the coagulation system
- less risk of grafts clotting and having to return to the OR
- decreased SNS outflow = less inflammation
- Make sure to check INR and platelets prior to regional
- There is NO difference if CV complications with regional vs GA
- BUT there is a SIGNIFICANT difference in complication rate of GRAFT OCCLUSIONS
- General hage an increased risk of occlusions!!!
In revascularization which is prefered, spinal or epidural?
Spinal
higher risk of hematoma with epidural
What advantage has been shown with regional vs general in revascularization
Regional has improved outcomes for graft occlusion, and post op pain management
…but shows no benefit in terms of cardiopulmonary complications