Quality control lockout function on Medtronic ACT Plus coagulation timer system can be bypassed for same-patient...

If Medtronic's ACT Plus automated coagulation timer system (an activated clotting time analyzer) is used on a single patient, its quality control (QC) lockout function may not activate--that is, the device may not lock the user out from performing sample analysis when QC has not been performed within the required time frame. The unit will indicate that QC is due by beeping three times and providing an onscreen message, but it will still analyze the sample and provide the user with results. These results may be inaccurate, and if they are used to make anticoagulation therapy decisions, they may lead to incorrect and potentially dangerous heparin therapy. Users should be made aware of this behavior (which is not described in the device's user manual) and should be instructed to verify that required QC checks have been performed before analyzing each sample.