Vascular access complications during dialysis - II Dr.

Hemodialysis vascular access The number of patients with end-stage renal disease (ESRD) are increasing The creation and maintenance of functioning vascular access, along with the associated complications, constitute the most common cause of morbidity, hospitalization, and cost in patients with ESRD

Vascular Access via Percutaneous Catheters useful method of gaining immediate access to the circulation. associated with higher risks. the use-life of this type of access is shorter than that of AVFs. Noncuffed catheters Short term: <3 weeks

Vascular Access via Percutaneous Catheters: cuffed catheters Patients who will require long-term access should have a tunneled catheter placed. allow so-called no-needle dialysis with high flow rates eliminate the problem of vascular steal placed in a subcutaneous tunnel under fluoroscopic guidance

Vascular Access via Percutaneous Catheters: cuffed catheters The Dacron cuff allows tissue ingrowth that helps reduce the risk of infection when compared with noncuffed catheters.

Hemodialysis access: Complications Complications can be divided into those that occur secondary to catheter placement and those that occur later The early complications of subclavian or internal jugular placement include pneumothorax, arterial injury, thoracic duct injury, air embolus, inability to pass the catheter, bleeding, nerve injury, and great vessel injury

Hemodialysis access: Complications (contd) A chest radiograph must be taken after catheter placement to rule out pneumothorax and injury to the great vessels and to check for position of the catheter The incidence of pneumothorax is 1% to 4%,the incidence of injury to the great vessels is less than 1% Thrombotic complications occur in 4% to 10% of patients

Hemodialysis access: Complications Infection may occur soon after placement (3 to 5 days) or late in the life of the catheter and may be at the exit site or the cause of catheter-related sepsis Rate of infection between 0.5 and 3.9 episodes per 1000 catheter-days Catheter thrombosis increases the incidence of catheter sepsis

Catheter complications The causes of haemodialysis catheter dysfunction are related to the Duration of implantation and Use Immediate/early dysfunction usually results from Mechanical problems, such as Malpositioning of the catheter tip (sucking the wall of the vein), kinking of the catheter or Strictures caused by ligatures or aponevrosis Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Late dysfunction (> 2 weeks) is more often caused by Thrombotic problems: Partial or total obstructive thrombosis of the catheter lumen, Thrombosis or stenosis of the cannulated vein, External fibrin sheath formation on the catheter distal end or Internal coating of the catheter (endoluminal fibrin sleeve) Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Endoluminal catheter thrombosis is the most common thrombotic complication Revealed by intermittent or permanent catheter dysfunction Such catheters may be re-opened by mechanical methods (brush) or chemical methods (fibrinolytic) External thrombosis, caused by a fibrin sheath covering the tip of the catheter, Requires either fibrinolysis, catheter stripping through a percutaneous femoral route, or removal and replacement Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Thrombosis of the cannulated vein is a severe complication and a Potential source of pulmonary embolism The incidence may vary from 20 to 70% depending on the site and diagnostic modality used Thrombosis of the right atrium is the most serious and potentially lethal complication Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Symptoms of thrombosis Rare and often deceptive, marked by a catheter dysfunction, by the onset of ipsilateral limb oedema or by unexplained fever Several factors contribute to the thrombogenicity, including The catheter itself (material and composition of the catheter, softness, aspect and surface treatment), the mode of insertion, the site of insertion (diameter, local haemodynamics), the duration of cannulation, the coagulation and inflammatory state of the patient (hyperfibrinaemia, inflammatory syndrome, hyperthrombocytaemia, previous venous thrombosis) and contamination of the catheter Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Infections represent a major threat for haemodialysis catheters in the ICU Nontunnelled polyurethane catheters, used for short-term therapy, entail a risk of bacteraemia estimated at 8.5 episodes per 100 patient-months compared to five episodes per 100 patients-months for cuffed tunnelled catheters The incidence of bacteraemia varies greatly according to units and clinical practices, being higher in teaching hospitals Non-tunnelled internal jugular access bears a higher risk of infection, particularly in patients with a tracheotomy Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Early infection may be related to problems associated with catheter placement or to skin and catheter track infection Placement of a percutaneous catheter disrupts the continuous protective layer of the skin The skin acts as a bacterial reservoir and contributes to the subcutaneous penetration of germs along the catheter pathway, explaining the need to disinfect the skin carefully prior to any catheter insertion, in order to prevent the onset of cutaneous lesions, and to ensure particular care in patients with catheters Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Late infections are most often associated with endoluminal catheter contamination It must be alleviated through suitable nursing care and handling Two types of infection are observed: Local infection (skin exit, tunnel infection) and Systemic infection (bacteraemia, septicaemia, infected thrombosis) Skin exit and bacteraemia are the most frequent forms of infection that may be treated with local and systemic antibiotic therapy while keeping the catheter in situ Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Catheter track infection (tunnellitis), septicaemia, fungaemia and infected venous thrombosis are the most severe form of infections requiring both catheter withdrawal and systemic antibiotic therapy Endoluminal contamination from hubs may form a microbial biofilm. In this case, bacteria entering the lumen adhere to the catheter surface, grow, produce glycocalyx (slime) and become resistant to antibiotics Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Occasionally, bacteria may be released from this biofilm (e.g. higher stress conditions due to the blood pump speed), being the source of bacteraemia and fever episodes In the event of an unexplained septic condition, it is advisable to consider the catheter as a source of infection Several authors have proposed catheter replacement over a guidewire through the same subcutaneous track This microbiologically unsafe approach appears undesirable Another approach is to change the catheter systematically every 3–4 days and insert it in a different venous site Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) In any case it is essential to culture the withdrawn catheter The insertion of soft tunnellized catheters (with or without anchoring system) for long-term use appears more suitable to prevent catheter hazards Strict aseptic rules (gloves, mask, drapes, antiseptic) should be followed at all times and particularly at the time of line connection to prevent contamination of catheter hubs Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications (contd) Stenosis of the host vein is a common long-term risk of catheters It is more common with semirigid catheters than with soft catheters and more frequently observed with the subclavian route than with the jugular one This troublesome complication may compromise the future creation of arteriovenous fistula in ESRD patients Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Catheter complications In conclusion, catheter-related complications may be significantly reduced by improving the quality of catheter care and implementing a continuous quality improvement programme with the nursing staff Best Practice & Research Clinical Anaesthesiology 2004;18:159-74

Vascular Access via Arteriovenous Fistulas The ideal vascular access permits a flow rate that is adequate for the dialysis prescription (³ 300 ml/min), can be used for extended periods, and has a low complication rate. The native AVF remains the gold standard

Arteriovenous fistulas The standard by which all other fistulas are measured, is the Brescia-Cimino fistula. (2 year patency: 55% to 89%) radial branch-cephalic direct access (snuffbox fistula), autogenous ulnar-cephalic forearm transposition, autogenous brachial-cephalic upper arm direct access (antecubital vein to the brachial artery), autogenous brachial-basilic upper arm transposition (basilic vein transposition). These options should be exhausted before nonautogenous material is used for dialysis access.

Noninvasive Criteria for Selection of Upper-Extremity Arteries and Veins for Dialysis Access Procedures Venous examination    Venous luminal diameter ³ 2.5 mm for autogenous AVFs, ³ 4.0 mm for       bridge AV grafts    Absence of segmental stenoses or occluded segments    Continuity with the deep venous system in the upper arm    Absence of ipsilateral central vein stenosis or occlusion Arterial examination    Arterial luminal diameter ³ 2.0 mm    Absence of pressure differential ³ 20 mm Hg between arms    Patent palmar arch

radiocephalic fistula (anatomic snuff-box) radiocephalic fistula (Brescia-Cimino)

Vascular access via AVFs: brachiocephalic fistula brachiobasilic fistula

Arteriovenous fistulas: Complications Failure to mature Stenosis at the proximal venous limb (48%). Thrombosis (9%) Aneurysms (7%) Heart failure The arterial steal syndrome and its ensuing ischemia occur in about 1.6%: pain, weakness, paresthesia, muscle atrophy, and, if left untreated, gangrene Venous hypertension distal to the fistula : distal tissue swelling, hyperpigmentation, skin induration, and eventual skin ulceration.

Complications of mature AVFs Venous thrombosis Due to needle trauma or prolonged compression after dialysis-needle withdrawal Venous aneurysm Can ease cannulation, and Surgical correction is only considered in the case of threatened rupture, when thrombus impairs blood flow or makes the needle insertion difficult J Vasc Nurs 2010;28:78-83

Complications of mature AVFs (contd) Edema due to central venous obstruction of the limb will require angioplasty or stenting of a lesion to relieve symptoms When distal hand ischemia is present due to the fistula robbing blood flow from the hand, the radial artery is ligated just distal to the fistula to relieve ischemic symptoms The access remains preserved for the hemodialysis treatments J Vasc Nurs 2010;28:78-83

Complications of mature AVFs (contd) Early thrombosis, or failure of the vein to dilate and mature, will require surgical revision of the primary fistula Late complications of low-flow, higher venous pressures, and increase in the dialysis recirculation time can indicate a failing access Late complications of the deteriorating AVF require prompt attention and patient should not delay seeking medical care J Vasc Nurs 2010;28:78-83

Complications of mature AVFs Imaging of the vessels can greatly assist to pinpoint the specific problem area of a failing access Surgical revision, endarterectomy or angioplasty can correct a fistula beforetotal occlusion occurs Attempts to salvage a failing AVF are preferable over placement of a new access in a fresh site A limited number of sites are available for access placement and serious complications may render a site unusable forever J Vasc Nurs 2010;28:78-83

Prosthetic Grafts for vascular access Upper arm grafts have a high flow rate and a low incidence of thrombosis. higher incidence of ischemia in the hand higher rate of stenosis, sec to endothelial hyperplasia.

Complications of prosthetic grafts Prosthetic grafts have complications similar to fistula, such as loss of patency due to poor blood flow, infection or vascular disease, and pseudoaneurysm due to repeated cannulation in the same area A decrease in blood pressure can reduce flow through the graft, causing clot formation and vein collapse Infection in other parts of the patient’s body can result in infection and damage to the prosthetic graft and at the operative site J Vasc Nurs 2010;28:78-83

Complications of prosthetic grafts (contd) The AV grafts are more prone to frequent stenosis and thrombosis, requiring surgical intervention and thus are more costly and labor intensive than a native AVF Patients with an AVF have fewer complications and less frequent hospitalizations and incur lower costs in comparison with patients with prosthetic grafts or catheters for hemodialysis J Vasc Nurs 2010;28:78-83

Options for treating steal DRIL procedure distal revascularization-interval ligation excision of a portion of the vein plication w/ mattress or continuous sutures crossed PTFE band interposition of a 4 mm PTFE

Treatment of venous access complications. Venous angioplasty Graft thrombolysis

Contraindications to Thrombolytic Therapy Absolute     Recent major bleeding   Recent stroke   Recent major surgery or trauma   Irreversible ischemia of end organ   Intracranial pathology   Recent ophthalmologic procedure Relative    History of gastrointestinal bleeding or active peptic ulcer disease   Underlying coagulation abnormalities   Uncontrolled hypertension   Pregnancy   Hemorrhagic retinopathy

Hemodialysis access Quality of life and overall outcome could be improved significantly for hemodialysis patients if two primary goals were achieved: Increased placement of native AVFs: a minimum of 50% of new dialysis patients should have primary AVFs. Detection of dysfunctional access before thrombosis of the access route occurs. National Kidney Foundation Dialysis Outcome and Quality Initiative (NKF-DOQI)

Conclusions Vascular access is associated with complications like stenosis, thrombosis, infections etc Early detection is required for better management of such complications

Conclusions Various interventions like surgical/pharmacological are available for the management of such complications Proper care is beneficial in prevention of such complications and thereby reducing morbidity and cost

VASCULAR ACCESS IS THE PATIENTS LIFE LINE , PLEASE LOOK AFTER IT. Many Thanks