How to manage a blocked catheter?

From the Guidelines

To manage a blocked catheter, the most effective approach is to use recombinant tissue plasminogen activator (tPA) or urokinase to unblock the catheter, as recommended by the most recent and highest quality study 1.

Management of Blocked Catheter

The following steps can be taken to manage a blocked catheter:

• First, attempt to flush the catheter gently with 30-50 ml of sterile normal saline using a 50 ml syringe.
• If this fails, try instilling a solution of 5,000-10,000 units of heparin in 3-5 ml of saline and leave it in place for 30-60 minutes before attempting to aspirate the blockage.
• For more stubborn blockages, particularly those caused by mineral deposits, instill 30 ml of a citric acid solution (like Renacidin) and clamp for 30 minutes.
• If blood clots are suspected, tPA at 1-2 mg in 2 ml of saline may be effective when left in place for 30-60 minutes, as supported by the evidence 1.

Prevention of Catheter Blockage

Prevention is key to reducing the risk of catheter blockage. The following measures can be taken:

• Regular flushing with saline after each use
• Maintaining adequate hydration
• Following proper care protocols
• Using catheters made from less thrombogenic materials
• Placing the catheter tip in the caudal SVC
• Using a catheter with the least number of lumens required

Important Considerations

• Never use excessive force when attempting to clear a catheter as this can damage the catheter or surrounding tissues.
• If these measures fail, the catheter may need replacement.
• Catheter blockages typically occur due to blood clots, medication precipitates, or mineral deposits, with the management approach varying based on the suspected cause of obstruction, as noted in the studies 1.

From the FDA Drug Label

Catheter dysfunction may be caused by a variety of conditions other than thrombus formation, such as catheter malposition, mechanical failure, constriction by a suture, and lipid deposits or drug precipitates within the catheter lumen. If catheter function is not restored at 120 minutes after 1 dose of Cathflo Activase, a second dose may be instilled

To manage a blocked catheter, consider the following steps:

• Check for conditions other than thrombus formation that may be causing the catheter dysfunction, such as malposition or mechanical failure.
• Instill Cathflo Activase into the occluded catheter at a concentration of 1 mg/mL.
• For patients weighing ≥30 kg, use 2 mg in 2 mL, and for patients weighing <30 kg, use 110% of the internal lumen volume of the catheter, not to exceed 2 mg in 2 mL.
• Allow the solution to dwell in the catheter for 30 minutes to 120 minutes before assessing catheter function.
• If catheter function is not restored after one dose, a second dose of equal amount may be instilled 2, 2.

From the Research

Managing a Blocked Catheter

To manage a blocked catheter, several methods can be employed:

• Thrombolytic therapy: This involves using medications to dissolve blood clots that may be blocking the catheter. According to 3, alteplase can clear 52% of obstructed catheters within 30 minutes, with an overall clearance rate of 86% after two doses.
• Use of tissue plasminogen activator (t-PA): t-PA has been shown to be effective in clearing occluded central venous catheters, with a success rate of 80% in one study 4.
• Vibration: A novel device that uses vibration to clear blockages within biomedical catheters has been developed, with vibration in the 50-60 Hz range able to maintain patency in catheters or clear blockages when the catheter is completely occluded 5.

Thrombolytic Agents

Various thrombolytic agents can be used to clear blocked catheters, including:

• Alteplase: Clears 52% of obstructed catheters within 30 minutes, with an overall clearance rate of 86% after two doses 3.
• Reteplase: Clears 67-74% of obstructed catheters within 30-40 minutes, with an overall clearance rate of 95% 3.
• Tenecteplase: Resolves occlusions in 70% and 83% of patients with one and two doses, respectively 3.
• Urokinase: Clears 60% of obstructed catheters at 30 minutes, with an overall clearance rate of 73% 3.
• Alfimeprase: Demonstrates rapid catheter clearance, with resolution in 40% of subjects within 5 minutes, 60% within 30 minutes, and 80% within 2 hours 3.

Prevention of Catheter Occlusions

To prevent catheter occlusions, urokinase prophylaxis can be used, which has been shown to decrease the incidence of catheter occlusions from 16-68% in the control group to 4-23% in the treatment group 3. Additionally, vibration can be used to maintain patency in catheters, with vibration in the 50-60 Hz range able to maintain patency in catheters or clear blockages when the catheter is completely occluded 5.