Awake, alert and alive: Is two hours enough sleep?

Awake, alert and alive: Is two hours enough sleep? - The sun's rays had not yet illuminating the sky at dawn on 10 August 2008, when two lives changed forever.

Lynn Baldwin new candy on the way home after being awake for much of the day and night. Bridge over the Chesapeake Bay, she fell asleep.

Here the car swerved over the median and hit a truck. He collapsed in the bay, killing its driver.Ms. Baldwin suffered non-fatal injuries, but will live with his guilt for the rest of his life. The pilot, John Short, became one of more than 6,000 people die each year due to drowsy driving.

He joins an unfortunate list that includes limousine driver comedian Tracy Morgan (hit by a truck whose driver had been without sleep for 24 hours) and Maggie McDonnell (killed in a head on collision with a truck driver who had been awake for 30 hours in a row).

The death of Ms. McDonnell has inspired as "Maggie's Law," which makes it illegal in New Jersey to drive knowing with problems of lack of sleep.

How can you (technically) go? 

Chances are that everyone drove a car drowsy at least once. But how much sleep do you really need before it is definitely dangerous to drive? Recently, the National Sleep Foundation, in consultation with experts in the field of sleep medicine and the transportation industry, to convene a panel to answer this question.

It is complex because there are several other factors that sleep duration to determine the level of sleepiness. For example, a large amount of "sleep debt" preexisting magnify the impact of acute sleep deprivation. In addition, the time of the day makes a difference.

At night, the natural body clock (circadian rhythm) is set to "sleep," and thus reduce the vigilance of acute sleep loss will be worse than during the day. This is why accidents occur drowsy driving especially at night. And, of course, the quality of your sleep is essential - which is why, for example, is not advisable to try to repay your sleep debt with a motel room beside the tracks!

After considering all these issues and available evidence, the Committee concluded that the driver is definitely compromised if he or she has had less than two hours of sleep in the previous 24 hours.

Put in perspective drowsy driving 

Does this mean that it is safe to drive if you sleep for only two hours mean? The answer to this question is a resounding no. Most people still affected by a lack of sleep even if they sleep for more than twice that amount.

As chairman of the committee, Dr. Charles Czeisler, chief of the division of sleep and circadian disorders Harvard-affiliated Brigham and Women's Hospital and professor Baldino of Sleep Medicine, Harvard Medical School, "the two-hour limit should be a warning red flag for individuals as a guide to those responsible for public policy. 

" In other words, in the development of future legal status as "Maggie's Law," should be the absolute lower limit used to define drowsy driving, similar to the way of driving under the influence is defined as a content alcohol blood of 0.08%.

Are there ways to reduce the impact of sleep deprivation on driving performance? Stimulants like caffeine can certainly reduce sleepiness during a short period of time, but not indefinitely. 

Other commonly used methods have been ineffective. For example, increasing the volume of the radio and opening the car window are both useless. 

Moreover, even if you do not feel sleep, it can still be affected because there is a weak correlation between sleepiness and performance. Only sleep can reverse the impact of sleep deprivation! 

Drowsy driving is a danger to public health in the United States. According to an estimate from the Institute of Medicine, up to 20% of all car accidents, they are related to drowsy driving. This means that drowsy driving causes more than 1 million accidents per year. And the actual number could be much higher due to drowsy driving is often under-reported.

The only remedy is for people who do not drive without enough sleep. Two hours can be the lower limit, but should not be fooled into thinking that it is safe, even if you have slept longer. The end result: "Private-Sleep not drive." 
By: Stuart Quan, MD.