Anticoagulation in Hemodialysis Flashcards

A patient's prescribed heparin dose is 2,000 units bolus followed by 1,000 units/hour. The session runs 4 hours. What is the total heparin administered (assuming the infusion stops 30 minutes before the end)?

Answer: 5,500 units

Bolus: 2,000 units. Infusion runs 3.5 hours (stopped 30 min early): 1,000 × 3.5 = 3,500 units. Total = 2,000 + 3,500 = 5,500 units.

Which patient condition is a contraindication to standard heparin anticoagulation during hemodialysis?

Answer: Active intracranial hemorrhage or recent neurosurgery

Active intracranial bleeding is an absolute contraindication to heparin use. Anticoagulation would expand the hemorrhage. In such cases, heparin-free dialysis or regional citrate anticoagulation (for CRRT) must be used.

What is 'tight heparin' dosing in hemodialysis?

Answer: A protocol using the minimum effective heparin dose, with lower bolus and infusion rates than standard, used for patients at moderate bleeding risk

Tight heparin (also called minimal heparinization) uses reduced bolus and infusion rates to achieve ACT of 140–170 seconds rather than the standard 150–200 seconds. It is used for patients with moderate bleeding risk to balance clotting prevention and hemorrhage risk.

Why must the hemodialysis machine alarm be checked if blood appears in the dialysate effluent?

Answer: It indicates a blood leak through the dialyzer membrane, which can expose the patient to dialysate contaminants and cause blood loss

Blood in the dialysate indicates a ruptured dialyzer membrane (blood leak). This is a serious emergency: blood is lost into the drain, the patient is exposed to dialysate, and treatment must be stopped immediately. The machine's blood leak detector alarm should have activated.

The heparin lock solution placed in catheter lumens between dialysis sessions serves what purpose?

Answer: To prevent clot formation within the catheter lumen during the interdialytic period

Heparin lock (typically 1,000–5,000 units/mL, volume-matched to the catheter lumen) fills and seals the catheter between sessions, preventing intraluminal thrombosis. It must be aspirated and discarded before treatment to avoid bolusing systemic heparin.

Heparin resistance in a dialysis patient is most commonly associated with:

Answer: Antithrombin III (AT-III) deficiency, since heparin requires AT-III to exert its anticoagulant effect

Heparin binds and activates antithrombin III, which then inhibits thrombin and Factor Xa. AT-III deficiency (from nephrotic syndrome, liver disease, or hereditary causes) renders heparin ineffective. Treatment includes AT-III supplementation or alternative anticoagulants.