From Kim Kinney, IU Health in Indianapolis: We offer mixing studies all shifts, 24/7. If not ordered STAT, we call the floor and ask if it can be set up the next day. Do other institutions run mixes 24/7 regardless of status or just STAT’s? Our PM and night folks are short-handed and have a large workload! Kim, to encourage responses, I’ve arranged to post this as my next Quick Question. Check back by Thursday, the new question should appear. Meanwhile, I invite comments below.
By the way, are your mixing studies ordered from the unit or do you reflex? Geo.
We have been doing automated mixing studies for years; easy
We have been doing automated mixing studies for years; easy to set up on an automated analyser. We typically reserve these tests for non-hospitalised patients unless otherwise specifically requested, since most of the test prolongations for in-patients are anticoagulant based. We also don’t perform automated mixing tests when PT/INR only requested (assuming the patient is on warfarin unless otherwise advised).
In our lab mixing studies are rarely requested
In our lab mixing studies are rarely requested by the doctor but we do perform a handful each day. We follow a flow chart, some of which is automated using rules but the part that requires mixing is decided by the scientist and follows along the lines of an abnormal PT or APTT, provided the patient is not/appears not to be on any anticoagulant, has not previously had a normal PT or APTT on current admission, is not postoperative or post plasma phoresis, etc. This way we may perform a few unnecessary mixing studies but don’t miss any that would be clinically helpful.
The other considerations are how you set your analyser to do the mixing (i.e. normal plasma as diluent or another reagent) and of course the source of the normal plasma.
We only do mixing studies on the dayshift in the special coa
We only do mixing studies on the dayshift in the special coagulation lab. If a physician needs one done after hours we have someone on call that is called in after approval by a staff hematologist.
George, our mixing studies begin as a PT/PTT/TCT. Depending
George, our mixing studies begin as a PT/PTT/TCT. Depending on what is prolonged and to what extent, we may then add on the incubated 2 hour mix. If just the PT is prolonged, only an immediate mix is performed. If the PTT is prolonged, mix and incubation. we then reflex testing based on if results correct or not.