Blood Drawing Technique:
Horses with an IV Catheter
The technician or doctor in charge of a case will have written instructions in the horses chart for the required blood samples and the time samples are to be collected and analyzed.
Horses on fluids will have an IV catheter in place.¬† The catheter may also have an IV extension set and a Win-set in place.¬† The blood samples will be drawn through the catheter/or tubing sets.¬† IV tubing has ‚Äúports‚Äù for sampling or adding medications to the IV line.¬† Note: you will not be asked to obtain a blood sample from a patient without an IV catheter because multiple needle sticks increase the likelihood of the vein being lost permanently to thrombosis.
If the horse is not on IV fluids but has an IV catheter and IV extension in place, the sample will be drawn through the male adapter plug after you have swabbed the site with alcohol.
If the horse is on fluids, a Win-set will be in use.¬† To obtain a blood sample, slide the white slide clamp over the Win-set tubing to shut off the flow.¬† Swab the injections port on the Win-set with an alcohol swab.¬† Crimp the tubing above the Y-injection site/port with your fingers.¬† Using a 12 cc syringe with an attached 20G 1¬Ωinch needle (yellow package), draw 10-12 ccs of blood to clear the line of fluids.¬† This provides whole blood that is not diluted with the fluids for testing. After this step, using a vacutainer needle and sleeve, collect blood in a purple top tube, (for PCV/TPs & CBCs), and gently invert the sample.¬† Inject the blood/fluid solution previously drawn out while clearing the lines back into the line.¬† Flush the IV extension with 5-8 cc of heparinzed saline or enough to clear the line of blood.¬† Note: do this quickly before blood can clot in the line.
If a glucose or lactate test is also required at this time, use a 10cc to draw the sample instead of a vacutainer needle.¬† Collect 6ccs of blood and inject only 5 ccs into a purple top tube gently rocking as you inject.¬† The remaining blood can be used for the glucose or lactate testing.¬† Note: do this quickly before the blood clots.
You may be asked to take additional samples for the technician to test at a later time.¬† Do not take extra blood unless specifically asked to do so.¬† Purple top tube samples must be inverted gently at the time of sampling and then placed on the rotator in the lab if they are being saved for a CBC at a later time.¬† If the technician requests a sample to be drawn for a profile: The sample is drawn with a syringe/needle and injected into a green top tube.