ABG collection Part 2
Preparation for my study begins at 7am, for the subject usually arrives at 8:30/9pm and lots of stuff needs to be done.
For blood collection we need to heparinize the syringes to prevent clotting in the samples. A little bit about heparin: Anticoagulants – How It Works
Anticoagulants are complex organic or synthetic compounds, often carbohydrates, that help prevent the clotting or coagulation of blood
. The most widely used of these is heparin, which blocks the formation of thromboplastin, an important clotting factor in the blood. Most anticoagulants are used for treating existing thromboses (clots that form in blood vessels) to prevent further clotting. Oral
anticoagulants, such as warfarin and dicumarol, are effective treatments for venous thromboembolisms (a blockage in a vein
caused by a clot), but heparin is usually prescribed for treating the more dangerous arterial thrombosis
In this case, this heparin was derived from porcine intestinal mucosa, and we plan to give little to none of it to our subject, again just for sample quality purposes.
The back room, dubbed the post-doc room, has been partially converted to become a psuedo-clean room. This is where the sterile prep will happen, where the arterial lines will be inserted and eventually removed. Prior to the study we had the floors stripped and cleaned, and after every study I wipe down ALL surfaces with antiseptic (Lysol)
Everything all setup… except for our subject, who forgot their shoes at home…
I should say from here on out there will be less pictures, as more pressing matters were at hand. Any pictures with the subject included will be blurred to protect their confidentiality.
The blue luer-lock 3-way stopcocks were assembled on the 3ml syringes, and then heparin was flushed in and out of each, making sure no air-bubbles remained in the syringe. Why might bubbles be a problem?
Well, since our primary measures involve arterial pressures of O2 and CO2, introduction of an atmospheric air bubble would increase PaO2 and decrease PaCO2, since PatmO2 ~ 150 torr, and Patm CO2 is nearly 0.
In the next post I will talk about Arterial-Alveolar Oxygen Difference, how and why it increases with exercise, and how we measured the above using these blood samples.
Til’ next time!