Science Scene: Why seeing blood can be draining

Eva Frederick

Aside from the patient’s well-being, UT pre-med students have a lot on their minds when in the operating room — heavy course loads, MCAT preparation and coping with the sight of blood.

The effect of some medical training on students’ bodies is often overlooked. Physical reactions such as fainting at the sight of blood are fairly common and can have a discouraging effect on the student.

These reactions are more prevalent than many people realize. Around 12 percent of medical students have either fainted or come close to fainting while in the operating theater, according to a 2009 study by researchers at the University of Nottingham.

The condition of passing out in response to an external stimulus is called syncope and is caused by a sudden drop in heart rate and blood pressure as a reaction to certain triggers, such as the sight of blood. The reaction leads to insufficient blood flow to the brain and results in a brief loss of consciousness.

An inherent evolutionary protection mechanism causes syncope — basically, the body recognizes the sight of blood and takes precautions as though the blood were its own. To prevent further blood loss, a person’s blood pressure will fall. Syncope can occur when the blood pressure drops too low, depriving the brain of oxygen.

The Nottingham study survyed 630 medical students. Of the 12 percent who said they experienced syncope while in the operating room, more than half intended to become surgeons — like the saying goes, “the most squeamish person in the class is the one who ends up becoming a surgeon.”

Squeamishness, which refers to feelings of disgust, repulsion or physical discomfort, is brought on by some external stimulus. Effects of squeamishness range from the typical feeling of crawling skin, to feeling physically sick. Syncope could be described as an extreme example of squeamishness.

While the health care industry is not a place for feeling sick or fainting at the sight of blood, the problem of syncope is usually overcome during medical training through a variety of psychological tools.

One method is exposure therapy, which is based on the idea that repeated exposure to the stimulus in a safe environment will eventually condition the subject to stop having adverse reactions. This treatment is often used in a clinical setting to treat phobias such as exposing arachnophobic patients to spiders.

By seeing blood in safe situations during medical school, students’ bodies are conditioned to stop this unnecessary reaction. In the same 2009 study, 10 percent of affected students cited increased attendance in the operating theater as a preventative measure to help cure their syncope.

Another method to prevent fainting is less mental and more physical. Students can clench their hands to raise blood pressure, preventing the drop that leads to passing out. Some students in the study reported that sitting down, a position that increases blood pressure, helped prevent passing out.

Passing out in the operating theater and feeling sick or squeamish at the sight of blood are inconvenient and can be embarrassing, but they can be overcome through these methods and others. Although the most squeamish person in the class may or may not become a surgeon, psychological techniques make it possible for students to overcome syncope and go on to have successful medical careers.