Do Medical Assistants Draw Blood? Phlebotomy & Venipuncture Explained

Medical assisting is a dynamic career with plenty of opportunities to specialize. From tackling administrative responsibilities to working in a lab, a medical assistant can do it all, or they can choose to focus on a single area of interest. Phlebotomy is one such specialty that may appeal to students with an aptitude for science and a love of hands-on patient care.

What is Phlebotomy?

Phlebotomy, also called venipuncture, is the art of drawing blood from veins using a needle and special collection vials. Samples help diagnose, monitor and treat disease, and they have significant clinical importance. So-called arterial sticks, or blood draws from deep arteries, are performed only by doctors, nurses or specially trained respiratory specialists and are not within a medical assistant’s scope of practice.

The Medical Assistant’s Role

Depending on the practice, phlebotomy may be a medical assistant’s sole occupation, or it may be only one part of their job. Regardless of how it fits in, the duties and the venipuncture process remain the same.

Review the Venipuncture Order

What goes on inside a patient’s body is often reflected by changes in the blood. As part of an examination, doctors may choose to investigate specific symptoms by ordering blood tests. In most cases, routine tests require only venipuncture. So, a medical assistant with phlebotomy training is the perfect person to take samples in an office setting.

When receiving an order, the medical assistant should review it for completeness and verify that the tests ordered match the diagnoses codes. A perceptive medical assistant can catch mistakes. It’s also critical to check test parameters before drawing blood. Some require a period of fasting or other criteria before venipuncture can be done.

Educate the Patient

Before performing venipuncture, medical assistants should first and foremost educate patients on the purpose of testing and how tests are performed. A phlebotomist in a hospital can’t always answer a patient’s questions about why a test was ordered. But the medical assistant who takes care of the patient’s other needs may have more insight. When it comes to venipuncture, a medical assistant is truly a doctor’s partner.

Obtain Consent

Like all medical treatments, venipuncture is performed only with the patient’s consent. Once the order has been reviewed, and the patient understands the purpose of the testing, the medical assistant is responsible for obtaining a signed consent for treatment. If the patient is a minor, consent is obtained from the parent or guardian. This is also the ideal time to clarify to whom the results may be released. Anxious patients will also want to know when and how they will receive results.

Performing the Venipuncture

There are strict rules to follow when taking blood samples. A standardized process improves quality control and ensures that blood is correctly drawn the first time, every time. Samples mishandled through a faulty technique may not be usable because the equipment that processes blood is carefully calibrated. Samples that don’t meet stringent criteria may be rejected, delaying treatment, and the patient may have to endure a second draw.

What Kind of Equipment Does a Medical Assistant Use for Venipuncture?

Tools of the trade include:

Gloves – universal precautions require considering most body fluids, including blood, as potentially contaminated. Anyone performing venipuncture must protect themselves with gloves.

Alcohol Pads– used to cleanse the area where the needle will be inserted. Whenever the outer layer of the skin is punctured, there’s potential for infection. Alcohol doesn’t sterilize skin, but it does help disinfect it when combined with a vigorous scrubbing motion.

Needles – come in all shapes and sizes to accommodate different veins. Their diameter is measured by gauge from 14 to 27. The larger the gauge, the smaller the needle is. Why so many choices? Because a medical assistant may need to draw to blood from patients of all ages. A 25 G needle, for example, is recommended for children. Most adults require a 20 or 22 G.

Needles are also measured by length. In an office setting, blood is most often drawn from the medial cubital vein at the bend of the elbow. But in some patients, the vein runs deeper than usual, and it can be difficult to reach with a standard one-inch needle. Phlebotomists choose the most appropriate needle length based on the size of the patient, the location of the vein and the angle of approach.

Vacuum Tubes – blood draws were once done with the same type of syringes used to give injections. Today, they’re done with specialized vacuum tubes. The phlebotomist screws the covered needle into a plastic needle holder. Once the needle is inserted into the patient’s vein, the vacuum tube is pressed onto the back of the rubber-coated needle. The strength of the vacuum alone pulls the blood out of the vein.

Tubes are color-coded because they contain different additives required for specific tests. Tube colors vary by brand, and how they’re used by different laboratories is consistent, but not standardized.

Tourniquets – the purpose of using a tourniquet for venipuncture is to confine blood to the extremity from which it will be drawn. It helps keep the vein full, making it easier to locate and giving it a firmer texture though which to insert the needle.

Gauze and Bandages – when the draw is complete, the site is compressed with gauze to stop any bleeding. A quick bandage is recommended to catch any remaining drops and to keep it off the patient’s clothing.

Expediting Results

Fast and accurate test results depend in large part on the medical assistant’s efficiency after the blood draw. Some physician’s offices may perform select blood tests, but most are processed and sent to outside labs via courier.

Tubes must be clearly and accurately labeled per the laboratory’s instructions, and samples must always be processed and stored as directed by the test catalog. Some need to be separated via centrifuge, while others must be kept refrigerated or shipped on ice. Even a small error can be cause for rejection.

Doctors do order blood tests for routine monitoring, but in many instances, the patient is unwell and waiting anxiously for results. Following procedures by the book is the fastest way to expedite results. If practice management software doesn’t keep track of result due dates, the medical assistant should keep a calendar and plan to follow-up with the lab as needed.

When results return, medical assistants are never responsible for their interpretation, but the doctor may ask them to call the patient to explain results and schedule follow-up care.

Common Blood Tests

Simple blood tests can diagnose a host of medical conditions including:

  • Anemia
  • Cancer
  • Diabetes
  • Autoimmune disorders
  • High Cholesterol
  • Hypothyroidism
  • Nutritional deficiencies
  • Heart, liver and kidney diseases
  • Infections

Blood samples are also used to establish a patient’s blood type so they can donate their own blood before surgery. And they’re also useful for monitoring medications that have specific therapeutic thresholds such as some blood thinners, anticonvulsants and antibiotics.

Skills for Venipuncture

A medical assistant performing venipuncture needs many of the same qualities that an administrative assistant does, but these skills are among the most helpful. These skills include empathy, critical thinking, manual dexterity, and attention to detail.


Venipuncture isn’t major surgery, but for the patient afraid of needles, it feels like it is. An empathetic medical assistant understands that and takes the time to make the client as comfortable as possible during the procedure. Patients who have a history of fainting when blood is drawn should be carefully positioned for safety.

Critical Thinking

Venipuncture is a dynamic procedure that requires clinical judgment on the part of a medical assistant. From questioning an order that isn’t clear to troubleshooting how to best obtain a sample from a frail elderly patient with small, sunken veins, the process is never identical twice. Medical assistants should feel confident assessing patients for phlebotomy needs. And they should be equally comfortable asking for help or acknowledging if a draw is too difficult for their level of expertise.

Manual Dexterity

Using vacuum tubes to draw blood is mostly advantageous, but there are also challenges. Doctors often order more than one test at a time. So, to avoid having to puncture a vein several times, phlebotomists fill multiple tubes of different colors to match each test. This is made possible by the unique design of the tube and needle holder. But it does require a bit of manual dexterity to hold them firmly in place with one hand while removing and replacing tubes.

A slight change in position could withdraw the needle from the vein or force the point thorough it, stopping the flow of blood. At several points in the venipuncture process, the medical assistant will have each hand doing a different task.

Attention to Detail

Mistakes in medicine are not only costly, but they can also adversely impact a patient’s health. A simple error in labeling the date or time on some draws, for example, affect how the test is interpreted. Names that don’t match between the tube label and the test requisition are cause for immediate rejection. No medical assistant wants to ask a patient to come back for another blood draw because of an error, so attention to detail is a must.

Final Thoughts

As physicians seek to offer more in-house services for their patients’ convenience, medical assistants with venipuncture skills are in high demand. Training programs teach the basics, but with experience, medical assistants can pursue certifications that only add to their credentials and resume. For medical assisting students interested in working a lab, there’s no more exciting specialty than phlebotomy. It’s both an art and a science.

Did learning about a medical assistant’s role in venipuncture and phlebotomy interest you? Ready to become a medical assistant? Gwinnett Colleges & Institute offers medical assisting courses to gain essential skills and training. The core curriculum focuses on the medical assisting skills and training you will need to seek entry-level employment in physicians’ offices, clinics, hospitals, and other medical settings needing the services of associates trained in both front and back office medical assisting skills. These medical assisting courses will be the first step in starting a rewarding career.