RE:

SEARCH

Fit enough to save lives?

chool of Nursing and Department of Kinesiology researchers are examining the amount of energy the body needs to perform cardiopulmonary resuscitation.

Carolyn Cason, nursing associate dean for research, says American Heart Association guidelines on delivering effective CPR don’t consider all facets of human capabilities.

“No one has actually looked at what it takes for an average person to deliver CPR,” said Dr. Cason, who also directs UT Arlington’s Center for Nursing Research. “We know that effective CPR requires that chest compressions be delivered to a certain point on the chest, that they be delivered to a certain depth (usually 1.5-2 inches) and that the recommended rate is 100 beats per minute.”

Bouncing up and down on someone’s chest is strenuous. The researchers are measuring how long individuals can perform CPR before they get tired and the compressions no longer deliver oxygenated blood to the brain. The participants receive feedback about the rate and depth of their compressions.

Co-investigators are kinesiology Associate Professor Mark Ricard and Assistant Professor Cynthia Trowbridge. The project director is kinesiology graduate student Adrienne Bullins.

The study targets two groups of women, ages 45-60 and 22-35.

“If you were to look at our typical graduating class, you would see that the women are petite,” said Cason, the project’s principal investigator. “But most of the training initiatives have targeted middle-aged men. Yet it is this very group who are likely to have a sudden collapse associated with a heart problem. Those left standing to help are usually the wives and daughters of these men, or the typical hospital health care provider, such as a nurse.”

The study uses electromyography to gauge onset of fatigue. Sensors at critical muscle bundles in the arms, back, abdomen and upper legs determine what effect compressions have on the body’s electrical muscle activity.

“We know that when the primary muscle being used in a given activity starts to fatigue, it will recruit other muscle groups to help out,” Cason said. “So we’re not only identifying the primary muscles being used, but we’re also looking at what point other muscles are recruited.”

In their first study, the researchers found that joint action was important to delivering sufficient force to depress the chest. All participating women reported pain in the wrists at the end of CPR. The pain may result in an unconscious shift of the hips during chest compressions.

The researchers are also monitoring CPR performance, noting that even with rapid EMT response, the average time required to perform effective CPR is eight minutes. Conversely, hospital CPR resuscitation guidelines suggest changing out every two minutes.

Even the mannequin being used for the chest compressions has a recording system that measures whether the compressions are being delivered at the right rate, depth and hand position on the chest.

— Susan M. Slupecki