Dialysis is a life-sustaining treatment for individuals experiencing kidney failure, removing waste products and excess fluid from the blood. A frequent concern is blood clot formation, which can disrupt treatment and compromise vascular access. Preventing clotting is crucial for safe and effective dialysis.
Understanding Clotting in Dialysis
Blood clotting during dialysis occurs when blood thickens and forms blockages within the dialysis access or the extracorporeal circuit (the tubing and artificial kidney). It occurs due to several factors, including the blood’s contact with artificial surfaces of the dialysis machine and tubing, which can activate the coagulation cascade. Changes in blood flow, such as reduced or turbulent flow, also contribute to clot formation. Underlying patient conditions, like inflammation or a predisposition to clotting, can further increase this risk.
Preventive Measures During Treatment
During a dialysis session, measures prevent blood clotting. Anticoagulation medications, most commonly unfractionated heparin, are administered to reduce the blood’s ability to clot. Heparin works by preventing the coagulation cascade from activating within the dialysis circuit. Alternatives like low molecular weight heparin or regional citrate anticoagulation may be used for patients who cannot receive standard heparin.
Dialysis machines monitor blood flow and detect clotting issues. They continuously monitor pressures within the blood tubing and the dialyzer; changes can trigger alarms to alert staff to potential problems. Maintaining an optimal blood flow rate through the circuit is also important, as slow flow can promote clot formation. The dialysis team manages machine settings and observes the patient to minimize clotting risk.
Maintaining Your Vascular Access
Patients are responsible for maintaining vascular access health outside of dialysis sessions. Daily hygiene, including washing the access site with antibacterial soap before dialysis, is important. Protecting the access from injury is also important; patients should avoid activities that could cause cuts or bumps.
Regularly checking the access for proper function helps identify issues early. For fistulas and grafts, patients should feel for a “thrill” (a buzzing sensation) and listen for a “bruit” (a whooshing sound), both indicating good blood flow. The absence or change in these sensations can signal a potential problem. Avoiding pressure or constriction on the access limb is also important. This includes:
- Not wearing tight clothing or jewelry.
- Not sleeping on the access arm.
- Ensuring blood pressure cuffs are performed on the opposite arm.
- Ensuring blood draws are performed on the opposite arm.
Maintaining good hydration and nutrition supports overall vascular health and adequate blood flow.
Recognizing Potential Clotting Issues
Recognizing signs of a clotting issue in the vascular access is important for timely intervention. A significant indicator for fistulas and grafts is the loss or weakening of the “thrill” or “bruit,” suggesting reduced blood flow. Other signs include swelling, pain, redness, or warmth around the access site, which could indicate a clot or infection.
Patients might also experience difficulty with blood flow during dialysis, such as slower treatment times or machine alarms. Prolonged bleeding from the needle sites after dialysis can also signal a problem. If any of these signs are observed, patients should contact their dialysis center or healthcare provider immediately to prevent further complications.