The Expert: Dr. Stefanos Kales, a professor of occupational and environmental medicine at Harvard University, testifies for the plaintiff and outlines the factors he believes contributed to the trucker’s collision with the disabled car. Those factors included fatigue aggravated by a sleep disorder.
Dr. Stefanos Kales, a Harvard professor of Occupational and Environmental medicine, testifies in a 2017 Florida wrongful death trial over a late-night crash that killed a mother and son. The plaintiff claimed a sleep-deprived trucker was responsible for the deaths, because he struck the car after it had been disabled in a wreck with a third vehicle.
Testifying in clear, authoritative tones, the doctor uses a chart to help lay out his criteria for determining the factors that contributed to the defendant’s negligence. The list contains a plus sign when the factor is present, a minus sign when it is absent, and a question mark when he cannot be sure.
The presence of a sleep disorder is number one with a plus. The driver had a history of sleep apnea. His other conditions associated with fatigue, according to the expert, included Class-2 obesity, diabetes mellitus, and the truck driver’s individual vulnerability related to the sleep apnea. The driver had not been consuming alcohol or any drugs which would cause drowsiness— leading to a minus sign in that category. Although there is not an objective way to determine how much sleep the driver had, there was a 10-hour window of opportunity for him to have slept before his shift—leading to a question mark in that field.
Most adults need 7-8 hours of sleep in a 24-hour period in order to function at an optimal level. Acute sleep deficit is a term referring to an impairment of the quantity or quality of sleep within the previous 24 hours. The driver here had the opportunity to get an optimal amount of sleep in hours, but due to his sleep apnea, this could not have been quality slumber. It was known that he woke up frequently, and slept during the day, in opposition to the normal circadian rhythm. Such sleep can be frequently interrupted by the daytime activities of those around him. The expert concludes that whatever sleep the driver got prior to his work shift could not have been “fully restorative.”
Chronic sleep deficit refers to the poor quality of sleep for the week or 72 hours prior to an incident. Examination of the defendant’s cell phone records indicated that he could not have slept more than 6 hours on 3 of the 5 nights before the crash. Short sleep is considered less than 6 hours. In a chronically sleep deprived person, even one night of adequate sleep is not fully restorative.
Changing shifts or travelling across time zones can affect the normal circadian rhythm. In this case, the driver was irregularly changing shifts according to his logs, and this would merit a plus sign on the expert’s chart. The time of day affects the risk of a highway accident, as well. The best times for being on the highway would be from 8-10 in the morning when people tend to be most alert, and again between 6-8 at night, when there is another surge in energy. After 8 PM or between 1 and 4 PM, when there is a post lunch dip in energy, things become more dangerous. The early morning hours, around the time this accident occurred, present the absolute highest risk for a highway accident.
This time has a 6 fold increase in accidents over the best time of day because people are not as alert.
When this particular accident was examined, it was noted that, despite the lights of the stopped vehicles being visible from over 3570 feet away, the truck driver made no attempt to brake or take evasive maneuvers until the truck was 10 seconds beyond the point of impact. This is called “failure to respond to the hazard.” The professor states that this is either because the driver was not sufficiently alert or intentionally failed to avoid the collision, giving the jury a stark choice.
Kales concludes that the driver was severely impaired by his medical conditions, the schedule that he had been keeping, and the lack of proper sleep that he had been getting. He was either asleep or so drowsy and impaired at the time of the collision that he failed to respond appropriately. Indeed, there was no evidence of a response until 10 seconds after the collision had occurred.
This testimony was essential as the jury awarded $3.9 million and found the truck driver to be 22% responsible for the crash.
Gary Gansar, MD, is residency-trained in general surgery. He served as Chief of Surgery and Staff at Elmwood Medical Center and on the Medical Executive Committee at Touro Infirmary and Mercy Hospital in New Orleans, LA. Dr. Gansar was Board Certified in general surgery while in active practice. He joined AMFS in 2015 as a Physician Medical Director.
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