CNN Exam- Vascular Access Exam Questions and Answers 100% Correct

CNN Exam- Vascular Access Exam Questions and Answers 100% Correct List when patients should be referred for evaluation when an access clot is suspected - Answer- - Any abnormal finding with measurement techniques such as U/S or MRA should NOT prompt immediate evaluation - It is better to obtain serial measurements and conduct a trend analysis (i.e if each measurement suggests less flow than suspect stenosis) - AV Grafts- - Flow rate of less than 600 ml/min = referral -Fistulas- - Flow rate should be 400-500 ml/min Other measurements- venous segment static pressure ration > 0.5 and arterial segment static pressure > 0.75 in grafts. - Access re circulation or inadequate dialysis (Kt/V or urea reduction ratio) should lead to evaluation ***ANY INDICATION OF LIMB ISCHEMIA AT THE ACCESS SITE REQUIRES EMERGENT EVALUATION BY THE VASCULAR SURGEON*** Describe how to properly prepare the skin prior to cannulation of the graft or fistula - Answer- - Skin should be palpated for the thrill of the graft or fistula (this is where the needle will be inserted) - Site is to be washed with CHG solution in combo with alcohol - If site gets contaminated must re-wash - Clean gloves must be worn by staff throughout the entire process. Must be changed if they become contaminated - After cannulation, new gloves must be worn between patients List the major disadvantages of tunneled cuffed catheters - Answer- - High rates of infection - High rates of thrombosis - Central venous stenosis - Cosmetically displeasing - Short shelf life - Lower blood flow rates which increases dialysis times Define monitoring, surveillance and diagnostic testing as they relate to vascular access as listed by the National Kidney Foundation - Answer- Monitoring refers to the examination and evaluation of the vascular access via physical examination to detect physical signs which suggest the presence of dysfunction - Surveillance is the periodic evaluation of the vascular access by using tests that me involve special instrumentation and for which an abnormal test result suggests the presence of dysfunction - Diagnostic testing refers to specialized testing and is prompted by some abnormality or other medical indication and that is undertaken to diagnose the cause the vascular access dysfunction Describe how an arteriovenous fistula is made - Answer- Fistula access are done by vascular surgeons. Small incisions are made in the forearm or elbow and an adjoining artery and vein is anastomosed. The increased blood flow from the artery into the vein causes venous dilation. The vein must be allowed to fully dilate and mature which is about a 6 month process. Fistula are the most preferred method for hemodialysis access because of their decreased infection and clotting rates. The procedure is usually done in an office setting and is relatively quick. Arm exercises are also prescribed to the patient to help facilitate fistula maturation. List the advantages of arterio-venous grafts - Answer- - Large vessel for easier access during dialysis - Shorter time to maturation for use (3-6 weeks) - Many insertion sites - Technically easier for surgeons - Easy to repair Describe the normal physical findings for both fistula and AV grafts - Answer- Fistula - Well developed venous outflow with no areas of aneurysms - Vessels partially collapse when the patient raises his/her arm above head - Low pitch diastolic and systolic murmur with auscultation - Thrill felt best at the arterial site but can be felt throughout the entire outflow vein AV grafts - No irregular areas or sites of aneurysms - Low pitch systolic and diastolic sounds - Thrill palpated best at the arterial anastomosis but also throughout the graft with easy compressibility Describe how infected dialysis catheters should be treated - Answer- - Suggested when the patient presents with fever, access site in duration or elevated white blood cell count -Initial step should be to draw 2 sets of blood cultures. The first set should come from the catheter itself and the second from a peripheral site. Empiric intravenous antibiotics are indicated to cover gram (+) organisms until culture and sensitivities return. - Most dialysis catheters are in the IJ or SC veins with their tips lying near the right atrium. That leaves the patient at risk for right sided endocarditis. Thus, echo cardiograms are indicated if a new regurgitant heart murmur is auscultated or if patient has persistently positive blood cultures. Describe the proper technique for cannulating a mature fistula or graft - Answer- - Skin should be properly cleaned with infection control techniques - A tourniquet must be applied proximal to fistula. This will decrease the venous return and help engorge the fistula for easier access - Pull skin in the opposite direction from the needle insertion - For arterial puncture, the needle can be either in the same direction OR opposite direction as blood flow