One of the first things you learn in driver education class is that a vehicle will cover a distance of 88 ft in a single second while traveling at 100 km/h. That’s just a bit longer than your typical Super B-train. A lot can happen in one second at highway speed, and if your eyes are closed because you’re experiencing a fatigue-induced micro-sleep, you won’t be in a position to respond.

Humans respond to acute fatigue by, well, sleeping. Lapsing into sleep is an automatic response triggered by a physiological need, the same way you’ll pull your finger back if you touch something hot. Remaining awake while your brain is trying to sleep requires considerable conscious effort and sometimes despite our best efforts, the onset of sleep can occur at the most inopportune moments -- like while seated at the dinner table with your in-laws, or driving along a highway.

The most common cause of such fatigue is chronic short sleep, where you just don’t get enough rest to meet your body’s needs. Whether you choose to remain awake for more time than is good for you, or some external factor prevents you from resting properly matters not. The point is, if you’re not getting adequate rest, you’re going to be dangerously tired sooner or later. Obstructive sleep apnea (OSA)  is one of those external factors.

OSA is essentially a cessation of breathing during sleep, caused by an obstruction -- in this case, it’s often the soft tissues at the back of the throat relaxing during sleep and easing downward, closing off the airway. This condition is said to be very common among males with a collar size of 17 in. or larger.

Dr. Allan Pack, MD, PhD, director of the sleep center at the University of Pennsylvania, says the inability to draw a breath is what wakes you up.

When the airway closes, the oxygen level in the blood declines. The brain senses this and wakes you to a lighter stage of sleep. As you wake, the brain sends a signal to these muscles to open up so you can breathe,″ says Pack. ″When you go back to a deep sleep, the whole thing repeats. An OSL sufferer will have multiple episodes where breathing actually stops or markedly declines during sleep.″

And the sleeper is often not aware this is occurring. The classic response when sleep researchers ask subjects if they wake up during the night is to say they wake to go to the bathroom. Sometimes they will wake up snoring or gasping for air, but usually they just wake to a lighter stage of sleep where they’re not aware of waking. The result, Pack says, is non-consolidated, very fragmented sleep.

″We can test for this in the lab by disturbing a person’s sleep throughout the night. You can make that perfectly normal person excessively sleepy during the day. And because of the fragmented nature of this kind of sleep, you don’t get into the deeper stages of sleep that we believe are the most restorative, ″ he notes. ″Patients with severe sleep apnea are very, very sleepy people. They will fall asleep in all sorts of circumstances: talking to people, even eating, and of course while driving.″

That’s why the U.S. Federal Motor Carrier Safety Administration (FMCSA) is now very interested in OSA.

One of the consequences of excessive sleepiness is a higher propensity of falling asleep while driving. No studies have been done with commercial drivers who suffer from sleep apnea at this point, Pack says, but multiple studies done on passenger car drivers show motorists with significant sleep apnea have roughly twice the normal risk of a crash.

The second reason to be concerned is that the commercial driver population has shown a high degree of prevalence of this disorder. The commercial driver community is believed to have a higher percentage of sleep apnea sufferers than the general population because as a group they tend to be more obese than normal -- particularly at a young age.

THE CARROT OR THE STICK

Results from a Fatigue Management Program study at a January 2008 Transportation Research Board meeting showed very positive rates of therapy compliance with drivers taking part in the study. As a result, FMCSA is expected to issue a proposed rule that would mandate sleep apnea screening for drivers fitting the profile of a sleep apnea sufferer as part of the required DOT medical exam.

″We expect, on the DOT physical, that all drivers who display OSA symptoms would be required to have an in-home or in-lab sleep study done,″ says Dr. Kirsty Kerin, director of strategic development for Sleep Health Centers in Brighton, Mass. ″If drivers test positive, they would be steered toward CPAP therapy.″

Dr. Pack, who was a member of the expert panel reporting to FMCSA on the OSA issue, says the panel recommended to the agency a three-part process to screen, treat, and verify compliance.

(To hear the complete Obstructive Sleep Apnea interview with Dr. Allan Pack, check out Truck Talk by clicking here). 

″We understand drivers may see this as a threat, but the goal here is not to have this sword of Damacles hanging over anyone’s head. Our plan is to keep [drivers] driving for one month following the screening in order to get diagnosed. If they are shown to have obstructive sleep apnea, they would have three more months to get effectively treated and onto a therapy program. They’d also need to show that they are using the therapy,″ Pack explains

″The goal is not to drive people off the road and to lose their jobs, the goal is to give them time to get diagnosed and begin a treatment program and to document the efficacy of the treatment.″

Dr. Kerin understands that drivers would be very nervous about this, but stresses that they really should prepare for this eventuality.

″If I was a driver at this point, and I really did expect these regulations to be coming in, I’d rather deal with the regulation now; get compliant on treatment, prove my compliance so that the regulation would not be an issue,″ she says.

There’s a Canadian component to this as well. While the NPRM has not even been written yet, it’s expected that these new medical requirements would apply to Canadian drivers in much the same way current drug and alcohol testing rules do. We may even have a similar medical standard of our own on the books before too long.

The Fatigue Management Plan study that looked at sleep apnea among truck drivers has been underway for several years now. It was sponsored by several U.S. and Canadian government agencies, including Alberta Transportation, Alberta Workers’ Compensation Board (WCB), Commission de la sante el de la securite du travail du Quebec (CSST), Societe de I’assurance automobile du Quebec (SAAQ), and Transport Canada.

Canadian researchers on the project included doctors Diane Boivin of Alpha Logik in Montreal, John Remmes of SagaTech Electronics in Calgary, and Alison Smiley, of Toronto-based Human Factors North who will be presenting findings of this research at the upcoming meeting of CCMTA’s Standing Committee on Compliance & Regulatory Affairs in Regina in May.

Three fleets participated in the study: U.S.-based JB Hunt Transport, Transport Robert  of Boucherville, Que., and Alberta-based ECL Group.

″The fleets that I have been talking to are treating this as a wellness campaign, not a targeting exercise to instill fear in the drivers,″ stresses Kerin. ″I think that speaks volumes to the management of those companies.″

Still, there is fear among some drivers that OSA screening could cost them their jobs, and they have expressed concern about the confidentiality of medical records being shared across so many government agencies and with various carriers.

Next time out, we’ll tell you about an OSL screening program that Schneider National Carriers voluntarily implemented several years ago. It has since reduced the frequency of preventable crashes experienced by drivers under treatment by 30 percent, and they saw a 48-percent reduction in the median cost of crashes within the group. Schneider also saved $534 per driver per year in health care costs.

We’ll also have more on the Canadian side of this story. Stay Tuned.