When the IV fluid refuses to flow, several factors might be responsible. Understanding the cause is essential for effective troubleshooting. Below are the common causes with their respective solution. Troubleshoot this situation in this order. 

• A kinked catheter (common): Inspect the catheter to rule out a kink. Try to unkink the catheter, remembering that this often requires catheter replacement.
• Clotted catheter (common): Use a small syringe filled with saline to “flush” the catheter and re-establish the flow. Using a small syringe allows for generating higher injection pressure needed for catheter flushing (e.g., 3 mL) when the catheter is obstructed. When successful, a small, fresh thrombus dissolves in the bloodstream or is caught in the lung circulation without consequences. 
• Kinked or twisted IV tubing: Straighten the IV tubing and verify it is free from obstructions or bends.
• Catheter position: Alter the position of the patient’s limb or adjust their overall position. Even minor repositioning can help re-establish the flow.
• Catheter against the vein wall: Gently aspirate and flush with saline to reposition the catheter tip. If unsuccessful, consider insertion at a new site.

Examples of common causes of the absence of IV flow. A) The catheter is positioned against the vein wall. B) The IV fluid refuses to flow. C) Pull back the catheter gently to adjust its position. D) The IV fluid will flow again.

• Infiltration (fluid in surrounding tissue): Stop the infusion and remove the IV catheter. Choose a new cannulation site and reinsert. Elevate the affected limb and apply a cold or warm compress, depending on the type of infiltrated fluid. 
• Blocked filter or valve: Check all parts of the IV system, including any filters or valves, and replace them if needed.
• IV bag position: Hang the IV bag above the insertion site to promote flow aided by gravity.
• Empty IV bag: Replace the IV bag.
• Air in IV line: Remove air from the tubing by priming the line.