a brief history of venous blood draws
by Neoteryx, on Feb 2, 2017 7:05:00 AM
The use of blood analysis to understand the causes of illnesses and symptoms has not always been a routine part of medical practice. Phlebotomy has its roots in a much more ancient art: bloodletting.
Blood in the Ancient World
Bloodletting, the practice of withdrawing blood from a patient to cure or prevent disease or illness, was once common practice across much of the world and has been documented as far back as ancient Egypt around 1000 BCE. Physicians and philosophers in Ancient Greece and the Roman Empire both extolled the virtues of the practice as it purged the body of bad humors. In this system of medicine, the key to good health was seen as the ability to keep the humors in balance. Removing blood or other bodily fluids that contained the humors could restore this balance when illness occurred.
18th and 19th Century Medicine
Nearly 2000 years later and the practice of bloodletting was still commonplace, being routinely practiced by surgeons and physicians, even though the theory of humors had fallen into disrepute. It wasn’t until the end of the 18th century that the practice began to be called into question with the rise of evidence-based medicine and a better understanding of how the body worked. However, it was not a quick transition, and cases of bloodletting were still documented as providing effective treatments for certain illnesses and conditions well into the 20th century.
Modern Medicine’s Understanding of Blood
While the ancients and early doctors got the treatment very wrong, they had the right idea about the blood holding the answers to patient’s illnesses. Modern medicine employs bloodletting in a very different way: to find the cause of the illness, rather than as a form of treatment. However, it should be noted that there rare cases when blood is removed as part of treatment, such as with hemochromatosis.
In medicine, venipuncture is the process of procuring intravenous access to the veins for blood sampling. In healthcare, this technique is achieved by medical laboratory scientists and medical practitioners. Venous blood draws are taken to allow blood analysis to take place. The blood is most frequently attained from the superficial veins of the arm where the vein is close to the surface of the skin and not surrounded by many large nerves.
While venepuncture remains common, it is routinely joined and sometimes replaced by fingerstick sampling. One of the many benefits of this approach is that it does not require a medical practitioner to take the sample. Fingerstick collection can be done quickly, hygienically, with little pain or discomfort by the patient, and in their own home. The ability to store these much smaller samples of blood as dried blood spots reduces the risk of cross-contamination and damage through improper storage, meaning even less discomfort for the patient.