Care of the Haemodialysis Patient with Vascular Access

Vascular Access for Haemodialysis

The need for vascular access in chronic renal failure patients can be either temporary or permanent.

Haemodialysis is effected by the extracorporeal circulation of blood through an artificial kidney,

wherein the blood is separated from the dialysate by semipermeable membranes.

An effective vascular access should be able to ensure a blood flow rate of >200 ml/ min

during an effective haemodialysis treatment.

Temporary Access

Indications

Temporary access is used to treat patients with acute renal failure, patients in chronic renal

failure without available permanent access, peritoneal dialysis patients or transplant recipients

needing temporary haemodialysis, and patients requiring plasmapheresis or haemoperfusion.

Percutaneous Venous Cannula

Venous cannulas are available in both a single-lumen and a double-lumen design fig. 1.

Temporary access involves percutaneous insertion of a cannula into a large vein.

The common sites are:-

subclavian veins,

internal jugular veins , fig. 2

femoral veins, fig. 4 Femoral location is a good choice when the

need for haemodialysis is expected to be quite short, or for patients

with acute pulmonary odema.

Nursing Care of Patients with Central Vein Catheter

1.Prevention of infection

Catheter infection may be either local or systemic, or both.

Blood stream: Blood stream refers to the bacteremias present with fever, positive blood culture,

and a clean exit site. Treatment with systemic antibiotics for 14 days, and catheter should be

changed over guide wire after antibiotic treatment for 48 hours .

Exit site infections: Exit site infections are confirmed by exit site purulent exudate but without

signs of systemic infection. Site is cultured and vancomycin and tobramycin are administered

until culture sensitivities results are available. Appropriate antibiotic regimen are continued for

2 weeks. Catheter is changed over guide wire when exit site is pus-free and appears clean.

Nursing actions:-

Adhere to unit specific policies and procedures designed to prolong the functional life of

vascular access and minimize, reduce, or eliminate vascular access complications.

- proper hand washing techniques be performed starting with proper aseptic techniques when

handling CVC or catheter exit site.

- maintain catheter exit site clean and dry at all times. Application of povidine-iodine ointment

to exit site and occlusive local dressing with Tegaderm or Opsite is required fig. 3. Styles of

dressings used in central vein catheter vary among dialysis centres.

- observe for any signs and symptoms of local or systemic infections, early detection and

treatment can save the catheter. Commonly caused by Staphylococcus aureus or S. epidermidis.

- eliminate interdialytic infusion through catheter.

- avoid catheter use by non-nephrology staff.

- educate patient for proper care of catheter on discharge.

: observe for any itchiness, pain, tenderness and swelling around exit site.

: observe for any pyrexia, chills and vigors, or flu-like symptoms.

: observe for any pyrexia, chills and vigors, or flu-like symptoms.

: avoid any dragging or injury of the catheter.

: avoid wetting the catheter and its exit site.

- remind physician to change the catheter at certain intervals, around 6 - 8 weeks.

2.Prevention of injury, bleeding, air-embolism related to

dislodgement or damage of catheter

: ensure catheter is securely anchored.

: never use forceps to clamp the extension tubes, only use the clamps provided.

: use luer-lock blood lines or tape all connections to prevent accidental separation.

: keep catheter clamped at all times except during haemodialysis treatment.

: prevent dragging or pulling of the catheter.

: apply direct pressure to exit site for at least 10 mins when catheter is removed or during

accidental slipping out of catheter, in order to prevent haematoma formation.

: educate patients on knowledge regarding potential air emboli dangers. Patients must

know the appropriate interventions should air enter the body via the catheter. If air enters

the CVC, patients should:-

clamp the catheter;

immediately lie on the left side to trap air in the heart's right atrium;

position the head below the heart to prevent air travelling to the brain;

elevate feet to increase venous return to the heart and call the renal

3.Prevention of clotting of the catheter

centre for help.

: proper heparinisation post haemodialysis helps to reduce thrombus formation. Heparin diluted

with normal saline is the most common preparation used. The dilution is usually 5,000 units of

heparin per lumen volume.

: when infusing heparin, flush quickly to ensure heparin reaches the distal part of each lumen;

slow infusion may cause the heparin to exit the catheter at the proximal inlet holes leaving

the distal hole unprotected from thrombus formation.

: never forcibly flush an obstructed lumen of catheter. Aspirate with a syringe, if aspiration fails,

refer to nephrologist.

: adjust anticoagulation regimen based on clotting time results, patient's condition, patency

of extracorporeal circuit, and response to previous anticoagulation.

4.Prevention of over heparinsation

: prior to each dialysis treatment, aspirate the lumen to remove any soft clots or residual heparin.

: periodic checking of prothrombin time, partial thromboplastin time and adjust heparin

Accordingly.

: educate patients to self-monitor for any signs of prolonged haemostasis or bleeding e.g.

gum bleeding, and notify the dialysis staff immediately.

5.Observation for any subclavian vein thrombosis or stricture

: may be clinically silent.

: manifested with swelling of the involved arm or chest wall, report to nephrologist and treatment

by anticoagulation agent may be required. Oral anticoagulation using warfarin and aspirin, or

systemic thrombolytic therapy using urokinase may be used to dissolve the clots.

: or treatment by angioplasty or endovascular stent.

6. Intervention in poor blood flow

: lower patient's head to increase pressure in central vein.

: have patient cough while you aspirate catheter.

: change patient's position (try several).

: check for catheter kinks at exit site.

: rotate catheter shaft 180 degrees, in temporary catheter only. Do not remove sutures to do so.

: use fibrinolytic agents as prescribed.

: change catheter when necessary.

Nursing Care of Patients with Percutaneous

Cannulation via Femoral Vein

: infection and clotting are rare.

: the femoral cannula is best to be removed after 48-72 hours to prevent infection.

: firm pressure applied to puncture site when the catheter is removed to prevent groin

haematoma.

Nursing Care of Patients with Arteriovenous Shunt

Description

The external arteriovenous shunt, developed in 1960 by Quinton and Scribner, consists

of two silastic vessel tips.

One vessel tip is implanted into an extremity artery and the other into a nearby vein, they

are connected to a piece of silicone tubing. After implantation, the two silicone tubes are

connected with each other to establish the external shunt. fig 5. AV shunt can be used

immediately after placement and requires no venipuncture.

Continuous flow of blood through the shunt helps prevent clotting.

Sites

Mostly placed in forearm, connecting radial artery with the cephalic vein just proximal

to the wrist.

Other possible sites for A-V shunt creation are: upper arm, ankle shunt (between posterior

tibial artery and the long saphenous vein) , these sites have an advantage of sparing

the upper extremity vessels for subsequent permanent vascular access creation.

Post-operative Care of Patients with A-V Shunt

: the operated extremity is kept elevated for serveral days to reduce oedema.

: cover skin exit site with povidone-iodine ointment and clear dressing, and

changed regularly.

: apply dry dressing to the exit site after several days.

: no blood pressure taking and venipuncture on the operated arm.

: no circumferential tape around the extremity proximal to the shunt.

: check for patency every 12 hours (more frequent initially).

: feel for thrill and listen for a bruit.

Long Term Care

1.Prevention of injury and bleeding

: clear instruction to patient on proper care of A-V shunt during accidental disconnection

using A-V shunt clamps.

: always keep A-V shunt clamps with patient.

: tape shunt connection securely.

: apply firm pressure to wound site if shunt is accidentally slipped out.

2.Prevention of infection

: infection is a major complication, mostly caused by gram positive cocci. Usually begins as

local cellulitis at insertion site, increased risk of skin erosion and haemorrhage if insertion

site infection untreated. Septicaemia may occur if early signs and symptoms not observed

and treated medically.

: culture from skin exit or blood culture may be required.

: other nursing care similar to care of patient with central vein catheter.

3.Prevention of thrombosis

: thrombosis is the most common complication. Mostly caused by

: bending of the vessel wall.

: arterial narrowing close to the cannula tip.

: fibrosis at cannula tip.

: inadequate anticoagulation.

: extrinsic pressure by tight bandage, watch or garment.

: hypotension.

: bending of shunt connector.

: recent thrombi.

: clotting is more common in infected shunts and poor flow. Aspiration of clots may be attempted.

Nursing actions

: closely monitor and check for any signs and symptoms of clotting, manifested with

diminished venous pulsation, coolness or frank separation of blood and plasma.

: educate patient to observe and care for the A-V shunt on discharge, report immediately

if any complication occurs, shunt declotting should be performed as early as possible.

: instruct patients on self care of shunt at home and report for any abnormalities.

* assess patient frequently for signs and symptoms of depression and verbalization of

hopelessness to prevent any intentional disconnection of AV shunt.

Permanent Vascular Access

Arteriovenous fistula is the safest and longest lasting permanent vascular access. A well

developed A-V fistula has the potential to withstand repeated cannulations and last for

10 or 20 years. The reason for creating a permanent vascular access in patients with

ESRD is to facilitate repeated venipuncture to the circulation for long-term haemodialysis.

Native A-V fistula is the vascular surgical anastomosis of artery to vein for haemodialysis

access. It was first described by Brescia, Cimino, Appel, and Hurwich (1966).

The common site for A-V fistula is at the wrist, the radial artery is joined surgically to

the cephalic vein. When the radial artery is found to be sclerotic, a previous fistula at

the wrist has failed, or the cephalic vein in the forearm is defective, then a brachio-

cephalic fistula, or basilic vein is joined to brachial artery may be considered. The

nondominant arm is preferred for the first vascular access.

Sometimes, veins of the lower limbs can also be used: proximal fistula at the thigh,

using the long saphenous vein anastomed to the femoral artery. The legs are considered

less preferable because vascular access creation in these areas may cause ischaemia and

increased risk of infection.

Normally, it takes 6-8 weeks for a new fistula to get mature, the venous limb of the

fistula dilates and the vessel wall thickened, permitting repeated puncture of fistula

needles.

An uninterrupted maturation of fistula prior to use is associated with better long

term fistula survival.

Types of A-V fistula

side-artery to side-vein: may lead to venous hypertension of the hand. fig. 6

end-artery to end-vein fig.8

end-vein to side-artery fig. 7 : the technique used most often is end of a divided vein to an

opening in an artery, whereby the complication of excessive flow of blood distally into the

veins of the hand is avoided.

Post-operative Care of A-V fistula

Similar to care of A-V shunt.

Long term care of Patient with A-V fistula

1.Education of patient on self care of A-V fistula

: not to allow blood pressure taking and venipuncture on fistula arm.

: not to sleep on the fistula arm.

: avoid wearing tight-fitting clothing or watch over fistula arm.

: avoid excessive direct pressure on fistula arm during haemostasis.

: not to carry heavy items on that arm.

: not to allow the fistula arm to be injured.

: patients should know how to examine the fistula for proper functioning , signs of infection

and how to prevent thrombosis. The patients should be taught to check for the thrill daily

and notify the dialysis staff if it is absent. Patients are taught to observe for any signs of

redness, swelling, sorenes, pain or discharge from the vascular access; advise to keep the

arm clean and dry to prevent infection.

Prevention of an episode of hypotension and dehydration will prevent thrombosis of the

access. Patients at home should learn to self monitor their own blood pressure.

: patients with new fistula creation are taught to perform fistula exercise.

2. Prevention of infection

: infection is rare, usually caused by staphylococcus. If infection untreated, it may lead to

thrombosis, erosion of skin over infected area or septic emboli.

: observe for local signs of inflammation. Treatment with antibiotics is effective.

: proper disinfection of skin prior to puncture, never cannulate an inflammed area of fistula.

3. Observation for any oedema of hand

: mild oedema postoperatively can be relieved by elevating the affected arm for 2 days and

should resolve over 4 to 6 weeks.

: acute oedema occurs if there is a venous stenosis or occlusion in the veins proximal to the

creation of the access and will not be relieved by elevation of the affected limb. Further

surgery to ligate the vascular access may be required to remedy this condition.

: oedema may also be due to transmission of arterial pressure to the veins of the hand

through side of artery to side of vein anastomosis.This condition can be corrected by

converting anastomosis from side to end.

4. Observation of ischaemia of hand

: if, after the surgical creation of an AV fistula, there is significant diversion of the arterial flow

from the extremity to the new fistula, then arterial ischaemia of the distal part can develop.

This condition is called a `steal' phenomenon. In severe condition, gangrene may develop

in the affected digits, then, the access must be ligated and the arterial anastomotic site

reconstructed. Patients with severe peripheral vascular disease and diabetes are at risk

for this complication. This incidence can been reduced by use of end to side venous-

arterial ananstomosis.

: the nurse should examine the operated arm for adequate perfusion by observing for signs

of pallor, palpating for coolness, testing the nail beds for delayed capillary refill, and testing

the fingers for changes in sensation, especially numbness and pain.

5. Prevention of excessive bleeding

: patients at increased risk for haemorrhage are those with a hypocoagulopathy, e.g. S.L.E.

: maintain A.P.T.T. within therapeutic range.

: avoid excessive manipulation of fistula needle. Renal nurses should acquire good needling

technique. fig.11, 12. Avoid multiple venipuncture on the same site to prevent fibrosis

leading to partial obstruction of venous limb and aneurysmal dilatation.

: always rotate venipuncture sites.

6. Prevention of aneurysms

: usually caused by repeated cannulation of vessel at same site. Dilation of vessel wall is

predominant sign, bounding pulse and more sensitive to pain at area of dilation.

Nursing Actions

: rotate cannulation sites to prevent incidence.

: avoid cannulation of surface area of aneurysm.

: instruct patient to avoid trauma to aneurysm and report signs and symptoms of infection.

Long Term Care of Patients with AV Graft

Indication

When a native AV fistula cannot be created, or has failed, a graft can be used. It serves

as a conduit to conduct blood from an artery to the vein which allows needle puncturing

for dialysis or acts as a vein substitute. fig. 13.

Types of AV grafts

: autogenous graft using the long saphenous vein.

: bovine carotid graft

: synthetic material, e.g. gortex or ePTFE expanded polytetrafluoroethylene

: the configuration of the graft can be straight, curved, or looped.

At the wrist, a straight graft can be used between the radial artery and antecubital,

basilic, or upper arm cephalic vein. If the radial artery is inadequate, the a graft can

be looped into the forearm between the brachial artery at the elbow and the antecubital

, basilic, or upper arm cephalic vein. A loop graft can be placed in the inner thigh area,

joining the superficial femoral artery to the saphenous vein.

Post-operative Care

: similar to care of fistula

: can be used immediately with tight heparin, but ideally delay use for 2-3 weeks to allow

proper healing of the subcutaneous tunnel; the graft should be used only after oedema and

inflammation from surgical procedure have subsided.

: early use may lead extravasation of blood through the tunnel with subsequent haematoma

formation and graft compression.

Possible complications

1. Graft infection

: graft at groin site increases incidence of infection, mostly caused by staphylococcal species,

rarely caused by gram negative organisms such as Escherichia Coli.

: infected graft may lead to haemorrhage.

2. Stenosis and thrombosis

: poor flow in graft mainly due to stenosis at the anastomotic site, may be corrected by

balloon catheter declotting or thrombolytic therapy.

fig. 14

Nursing Care

: nursing care similar as care of fistula.

Care of Patients with Permanent Device

: indicated for patients when other forms of permanent access have failed e.g. patients with

diabetes or paediatric patients. It can be used immediately and eliminate venipuncture.

: it is the implantation of a central vein double lumen catheters that are subcutaneously

tunneled and have cuff to minimize bacterial movement along course of tunnel. The

common sites are internal jugular veins, subclavian vein is rarely used because of higher

incidence of large vein thrombosis and stenosis.

: ingrowth of connective tissure at the cuff greatly reduces the rate of infection.

Nursing Care of Permcath

: nursing care similar to care of central venous catheter.

References

Gillian Brunier. (1996). Care of the haemodialysis patient with a new permanent

vascular access: Review of assessment and teaching. ANNA Journal. Vol. 23, No. 6.

pp. 547-558.

Ouwendyk M. and Helferty, M. (1996). Central venous catheter management: How to

prevent complications. ANNA Journal Vol.23, No. 6. pp. 575-579.

Daugirdas, J.T. and Ing, T.S.(Eds.). (1994). Vascular access for haemodialysis. Handbook of

dialysis (second edition). pp. 53-77. Boston: Little, Brown and Company.

Deborab, J. Brouwer. (1995). Cannulation camp: Basic needle cannulation training for

dialysis staff. Dialysis and transplantation. Vol. 94, No. 11. pp. 606-612.

Burrows-Hudson, S. (Ed.). (1993). Modality specific standards of care: haemodialysis:

vascular access. Standards of clinical practice for nephrology nursing. ANNA. pp.59-135.

Hartigan, F. M. and Thomas-Hawkins, C. (1995). Circulatory access for haemodialysis.

Core curriculum for nephrology nursing. ANNA. pp. 259-280.

Speaker:

MOK Lai-chun Anna

Unit Manager,

Precious Blood Hospital, (Caritas).

Oct, 1999.