A small sample of saliva could help determine if a surgeon is too exhausted to perform a complicated procedure or a fighter pilot is too fatigued to get in the cockpit for a mission.
Dr. David Giovannucci and his research associate, Muncharie Brooke Saepoo, loaded saliva samples into an automated liquid handler for biomarker analysis.
“There is no ‘gold standard’ used to measure fatigue, but there are many individuals, such as health-care providers, pilots and truck drivers, who perform tasks for long periods of time and need to be able to make critical decisions without fatigue impacting performance,” Giovannucci said. “Currently people self-report and, as you might imagine, that is inaccurate. Someone may say they are doing fine and actually feel that way, but in reality they shouldn’t be performing.”
There are chemical signatures in body fluid that change in response to stress and fatigue. Saliva is a useful biofluid because it reflects what is in your blood, but is easy and noninvasive to collect, Giovannucci said. The salivary glands are under the same neural control as the adrenal gland and can therefore be used to assess sympathetic neural activity, he explained.
Giovannucci’s research involves periodically collecting saliva from study participants, primarily medical residents at UT Medical Center, and administering psychological tests to correlate chemical markers of fatigue with performance ability.
The saliva samples will be studied using an immunoassay technique for proteins, peptides, steroid hormones and other common markers of stress and fatigue, such as cortisol and salivary amylase. The team, which includes research technician Muncharie Brooke Saepoo, also will look for other markers that were not predicted. This will be achieved using a technique called liquid chromatography-mass spectrometry that can identify hundreds of proteins in saliva.
At the same time the saliva is collected during their shifts, the volunteers will participate in psychological tests to measure attention and executive decision-making skills. The brain teaser tests will be performed on a computer or tablet and include scenarios such as focusing on the screen to see if a colored ball appears to measure attention, or examining a group of arrows to find the one pointed in a different direction to study executive decision-making.
“The combination of fatigue biomarkers and decision-making tests will give an indication of the person’s ability to perform under varied energy levels,” Giovannucci said. “Our prediction is that there is not one thing that changes due to stress and fatigue, but rather a panel of changes that would indicate a decreased ability to perform.”
The end goal is to be able to create a sensor that would be able to measure those indicators for a quick and easy way to test performance ability — something similar to a Breathalyzer test to measure alcohol levels, but used with saliva to test fatigue. Dr. Brent Cameron, UT professor of bioengineering, is working with Giovannucci to explore creating the device.
“Medical professionals often work long hours directly with patients and mistakes can be made, so this could help minimize some medical errors,” Giovannucci said. “The military invests heavily in training and equipment, and their personnel performance is an important area for them. From an economic standpoint, there are billions of dollars lost each year to fatigue in both the public and private sectors.”
Giovannucci’s research is funded with a $600,000, three-year grant from the Air Force Office of Scientific Research with matching funds from the UT College of Medicine and Life Sciences, and is enrolling interested residents into the study.
In addition to Cameron, the cross-disciplinary work also involves co-investigators Dr. Dragan Isailovic, UT assistant professor of chemistry and biochemistry, and Dr. Kenneth Hensley, UT associate professor of pathology.
