Fundamentals of Testing Infusion Pumps Pflegewiki-User Würfel (2007), Infusion Pump [photograph]. Retrieved from

Hazards and Safety Mechanisms Over Infusion Causes: –Device Malfunction –Free Flow occurs –User Error: Incorrect flow rate or volume programmed into device

Hazards and Safety Mechanisms Occlusion Detection Hazard: Failure to detect Occlusion Causes: –Occlusion threshold set too high –Device Malfunction –Occlusion is not sufficient pressure to trigger alarm Safety Mechanism A pressure sensor is designed into an infusion pump for continuous monitoring of the IV line back/downstream pressure. Occlusion alarm threshold can be configured on most IV pumps.

Hazards and Safety Mechanisms Occlusion Detection Safety Considerations Occlusion alarms on infusion pumps are not designed to detect or prevent infiltration or extravasation Be sure clinicians are aware that you cannot rely on the IV pump to detect a potential infiltration / extravasation. Ensure after servicing IV pump to set occlusion limits back to clinical defaults. An occlusion limit for an adult is much higher than limit set for a pediatric patient. Smithpie (2007), Infusion Pump [photograph]. Retrieved from

Hazards and Safety Mechanism Alarm Response Time Hazard Once an occlusion occurs, the elapsed time before the alarm sounds can be critical. Flow rate also affects alarm response time. Higher flow rates result in more rapid alarm response than lower flow rates. Safety Mechanism Infusion pump manufacturers have Time to Alarm specifications based on occlusion pressure settings. AAMI Standard ANSI/AAMI ID26:2004

Hazards and Safety Mechanisms Air-in-line Detection Hazard Air embolisms can cause death if the bubble becomes lodged in the heart, stopping blood from flowing from the right ventricle to the lungs. Safety Mechanism The ANSI/AAMI ID26:2004 standard requires pump designs to protect patients from 1 ml of air within 15 minutes. Manufacturers are required to describe the sensitivity of the air detection circuitry in the instructions for use.

Different IV Pump Mechanisms Linear Peristaltic Piston/Diaphragm (Cassette) Lead Screw

Linear Peristaltic (IV Pump) Richard Schneider (2005) Linear peristaltic pump [diagram]. Retrieved from

Piston/diaphragm Pumps IV Fluid Patient Virginia Reid 92-15), Piston/diaphgram pumps.

Lead Screw/Syringe Syringe Plunger Gearbox Motor Carriage Guide Syringe Nut Lead Screw Virginia Reid (2015) Lead screw [drawing]

Optimizing Testing Accuracy

Testing Recommendations General Inspection and Testing For PCA pumps, inspection and testing of patient cabling to ensure no intermittent connection can create an unintended infusion Inspect units for physical damage, particularly where the IV set/syringe is placed onto pump. Test keypads for key bouncing issues

Preventive Maintenance Replace IV tubing, cassette, and/or syringe Clean machine and chassis from any enteral solution residue Examine plug and line cord Examine internal cables and connectors Examine controls and switches for proper function. Verify batteries, chargers and indicators are working Confirm lights, indicators, and displays are working. Verify flow stops when device is turned off Calibrate machine as necessary Check for unusual noise or vibration. lubricate as required by syringe pump manufacturer

Common Failures No power Battery not holding charge No display Bad keypads Broken handles Flash memory errors Plunger sensor errors (syringe) Close door errors (Large Volume)

Troubleshooting DHT Lab, Infusion Pump Repair and Troubleshooting [flowchart]. Retrieved from

Burets & Graduated Cylinders Improved accuracy can be achieved by: –Use Class A glassware for highest tolerance (Class A burette: 0.06 cm3 tolerance vs. Class B burette: tolerance of 0.1 cm3) –Always identify volume delivered at eye level with the top of the liquid while measuring the bottom of the meniscus. –Keep inside of glassware clean. –Avoid running subsequent tests with residual fluid remaining on inside of glass from previous test. Correct measurement of volume PRHaney (2008), Meniscus [photograph]. Retrieved from

PCA vs IV PCA pumps are tested at much lower volumes than IV pumps, usually 1-2 ml/hr PCA pumps have comprehensive lockouts and safety features and a patient controlled feature; patients are allowed to request an extra volume of pain reliever up to a max/hr. PCA maximum volumes are typically 60ml or less PCA's are only used in the largest hospitals Typically IV pumps run at ml/hr. Most commonly approximately ml/hr. IV pumps can inject up to 1.5litres before the bag is changed IV pumps are used in larger hospitals in developing nations. IVs typically use piston and peristaltic mechanisms

Testing Recommendations: Digital Scales Digital scales for laboratory use are not rated in terms of accuracy as we might expect. Rated in: Capacity Readability Repeatability/Precision Linearity Resolution: Per ANSI/AAMI ID standard: a balance (Digital Scale) accurate to five decimal places is required for pumps with low minimum rates (below 1ml/hr) – for PCAs ONLY Stan Zurek (2006), Electronic weighing scale [photograph]. Retrieved from czna.jpg

Testing Recommendations: Digital Scales Vibrations: Ideally the table being used for a scale has rubber feet to isolate vibrations in the floor/room. Air Currents- drafts, extreme air currents (air conditioning vents) can cause unstable readings. Document environmental/temp of fluid during test Calibration requirements: Government regulation requires periodic inspections by licensed technicians using weights whose calibration is traceable to an approved laboratory. (NIST Handbook 44) Stan Zurek (2006), Electronic weighing scale [photograph]. Retrieved from czna.jpg

Testing Recommendations: Digital Scales continued Manage the test set up to avoid drips/drops that don’t make it into the receptacle. Use 18 gauge needle per AAMI standards, ensuring it has a rigid connection above the receptacle and edge of the needle is submerged in the fluid within receptacle before starting test. Virginia Reid (2015), Testing Recommendations [diagram},

Testing Recommendations: Automated Testers Research Product Requirements Select a test system that meets your needs for accuracy, flow rates and volumes that you require. Some products claim 1% accuracy, but can require a minimum of 20ml of volume to be delivered during a test to reach that accuracy. This could mean it would take 20 hours if you are testing at 1ml/hr. Research if automated tester has “Blind Spot” or Dead Zones, and what impact they have on the accuracy of the results. Research carefully before purchasing a tester on what is required to ensure accuracy of the measurements Determine if tester must be started/stopped simultaneously with IV pump under test.

Testing Recommendations: Automated Testers Manage the KVO setting on the IV pump KVO (Keep Vein Open) features on infusion devices should be considered when testing volume or flow rate. Typically configured at 5ml/hour, this feature will have a dramatic impact on the accuracy of volume and flow rate if the tester is not “stopped” before the KVO feature begins. Be aware of the height of the output bottle Some manufacturers have specific requirements for height relative to the tester itself. Not following requirements could affect accuracy.

Testing Recommendations: Automated Testers - Continued Be aware of the delivery tube compliance Some testers create a momentary “blockage” or occlusion to the fluid flow from the IV pump when the measurement transducer is emptied, can cause some of the flow to be forced back toward the IV pump, and can have an effect on accuracy of the measurement. Only use manufacturer’s recommended testing fluids

What Volumes/Flow Rates should be tested? Test at manufacturer recommended rates and volumes only? Test at rates and volumes most typically used by the clinical users of the IV pumps being tested? Both? What actual flow rates are being used by clinical departments?