Determining if a syringe is damaged requires a comprehensive assessment through visual inspection, functional testing, and user feedback to ensure its safety and accuracy.
Visual Inspection
Syringe: Check for cracks, deformation, blurred graduations, or residual stains. Structural damage to plastic or glass materials can easily lead to leakage or inaccurate dosage.
Pump: Check the rubber piston for aging, cracks, looseness, or sticking. A compromised seal may cause rebound or leakage during injection.
Needle: Confirm that it is free of bending, burrs, barbs, and corrosion. Even minor damage can increase the risk of tissue trauma and infection.
Functional Testing
Smoothness of Sliding: Push the piston in and repeatedly pull it back and forth. There should be no jamming or excessive looseness. Abnormal resistance indicates internal wear or contamination.
Sealing Test: Seal the needle tip, push the piston, and release it. Under normal circumstances, the piston should remain in its position without rebounding. If the liquid rebounds rapidly, it indicates a poor seal.
Dosage Accuracy Verification: Draw a fixed volume of liquid (e.g., 1 mL) and observe whether the graduations are consistent, paying particular attention to accuracy deviations in the small dose range.
Abnormal Signals During Use
Sudden changes in resistance (sudden increase or decrease) during injection
Leakage, dripping, or uneven spraying of medication
Patient feedback: Increased pain, local redness, swelling, or induration
Abnormal sounds from the device (e.g., alarms from infusion pumps)
Damage Manifestations for Special Types of Equipment
Micro-infusion pumps: False alarms such as "medication running low," inaccurate propulsion speed, or motor malfunction may indicate a faulty propulsion device, a damaged positioning optocoupler, or incomplete syringe calibration.
Injector systems (e.g., insulin pumps): Poor atomization, dripping, or complete lack of spraying may indicate a blocked valve orifice, a stuck needle valve, or abnormal electrical connections.
