AV fistula Examination

there are several purposes of examining patients with AV fistula.

• assessing function of present AV fistula.
• the diameter and flow of fistula
• where is the fistula? 
• radiocephallic
• brachiocephallic
• transposed cephallic 
• presence of other vascular access (which suggests previous AV fistula failure)
• central venous access
• peritoneal access
• graft
• looking for possible complications of AV fistula
• infective / inflammatory changes 
• aneurysm
• hematoma
• thrombosis
• central vein stenosis
• ischemia / steal syndrome
• outflow stenosis of fistula
• assessing adequacy of dialysis and renal failure
• uremia
• peripheral edema
• anemia of renal failure
• assessing complication of dialysis itself
• common non-serious side effects
• headache
• itching
• muscle cramps
• cerebral oedema secondary to osmotic change (disequilibrium syndrome) \
• hypertension
• hyperkalemia 

inspection

inspection may involve the hands, arms (with the fistula), head, chest and abdomen with main focus on the fistula itself.

• hands
• check for signs of ischemia or steal syndrome distal to AV fistula
• temperature
• pulse volume 
• capillary refill
• pitting edema
• head
• check for anemia in conjuctiva (ESRD patients commonly have anemia due to Erythropoietin deficiency)
• chest and proximal to AV fistula
• difference in size of upper limb between left and right (central stenosis)
• look for a scar for central vein catheterisation (subclavian site)
• abdomen 
• look or scars of peritoneal dialysis
• scars of nephrectomy
• legs
• pitting edema (fluid retention)

inspection of the fistula

• assess the location of the fistula
• radiocephallic
• brachiocephallic
• transposed cephallic 
• look for evidences of failed / old AV fistulas distally
• look for complications seen on the fistula
• infection / inflammation 
• redness
• swelling
• aneurism
• hematoma / bruising

palpation

• lightly palpate over the fistula for;
• increased temperature 
• tenderness 
• thrills (this is normal)
• pulsation (this is not normal - suggesting outflow obstruction)
• arm-elevation test for outflow stenosis
• elevate the arm with the AV fistula - the fistula should flatten if there is no outflow obstruction.
• sign is positive when AV fistula stays bulging
• more signs suggesting outflow obstruction;
• prolonged bleed after dialysis
• loud systolic murmur (discussed later)
• augmentation test to test for inflow stenosis
• occlude the outflow by pressing onto the proximal arm along the vascular pathway
• the thrills should become a strong pulsation- if not, there may be inflow obstruction
• the extent at which there is a pulsation - whether there is strong or weak pulse, may be an indication of inflow patency

auscultation

• on the fistula AND along the vascular pathway up till the chest
• there should be a systolic murmur (low-rumbling) throughout
• a harsh, high-pitched sound may suggest a stenosis somewhere along the vascular pathway.

Also check.... 

• check the condition of overall vascular health - so one may see the lower limb for signs of Periphiral vascular disease to assess if more proximal AV fistula is worth placing, if the current one isn't doing well.
• abdomen for evidences of previous / current CAPD - Continuous ambulatory peritoneal dialysis. Patient may have tried it, and then changed to AV fistula. 
• The most common cause of sudden death in patients with ESRD is hyperkalemia, which is often encountered in patients after missed dialysis or dietary cause. Check the pulse rhythm - just in case! do ECG if you can afford the time.