Sleep Deficit: The Performance Killer

Abstract & Commentary

By John Shufeldt, MD, JD, MBA, FACEP, Chief Executive Officer, NextCare, Inc.; Attending Physician/Vice Chair, Department of Emergency Medicine, St. Joseph's Hospital and Medical Center, Mesa, AZ, is Editor for Urgent Care Alert.

Chief Executive Officer, NextCare, Inc. Attending Physician/Vice Chair Department of Emergency Medicine, St. Joseph's Hospital and Medical Center

Dr. Shufeldt reports no financial relationship to this field of study.

Synopsis: A discussion about the dangers of sleep deprivation.

Source: Czeisler CA. Sleep deficit: The performance killer. Harv Bus Rev. 2006;84:53-59.

More than 1.35 million auto accidents in the last 5 years have been caused by driver fatigue. The effect of sleep deprivation on cognitive performance has been well documented; when an individual has been awake for more than 18 hours, reaction speed, short-term and long-term memory, ability to focus, decision making ability, math processing, and spatial orientation all suffer. Sleep deprivation has even been linked to high blood pressure and obesity.

Encouraging a culture of sleeplessness is downright dangerous and antithetical to intelligent management. Most corporations have policies about drugs, drinking, and sexual harassment; however, they often push employees to the brink of self-destruction by encouraging a level of sleep deprivation, with a resultant impairment every bit as risky as intoxication. Therefore, managers, owners, and clinicians have a societal responsibility to take sleep deprivation seriously.

Four major sleep-related factors affect cognitive performance. The first major factor is the body's homeostatic drive for sleep at night. Throughout the day, humans build up a stronger and stronger drive for sleep until at some point the sleep switch ignites. Once that happens, a person only has a few seconds before they are asleep. So, if they are driving, flying, or with a patient, they just have a few seconds to respond to the brain's automatic shut-off.

The second major factor has to do with the total amount of sleep you get over several days. If you get at least 8 hours of sleep, your level of alertness should remain stable throughout the day; however, if you have a sleep disorder, or get less than 8 hours for several days in row, the sleep deficit you start to build up will make it more and more difficult for the brain to function. Individuals who average 4-5 hours of sleep for several nights in a row have the same level of cognitive impairment as those who have been awake for 24 hours in a row, which is also the same level as an individual who is legally intoxicated.

The third factor has to do with the circadian pacemaker, which is the body's neurological timing device for sleep. Oddly enough, for reasons that are still not understood, it works in opposition to homeostatic drive. The pacemaker sends out its strongest signal for sleep just before we wake up and its strongest drive for wakefulness about 2-3 hours before the homeostatic drive for sleep peaks. These 2 competing factors work in harmony to give us a restful night of sleep and a level of alertness throughout the day.

The fourth and final factor is what is called sleep inertia. The brain is like a car engine that needs time to warm up before running at peak efficiency. Typically, this warm-up takes between 5 and 20 minutes. You do not want to make important decisions before your brain has the time to warm up. Remember when the nurse woke you up on-call during residency? Do you really think they listened to the answer you gave them? Thank God they didn't listen to me when they woke me up at 3am!

Sleep also becomes more difficult over the age of 40. Indeed, the risk of sleep disorders increases over the age of 40. Many people gain weight as they age, which may precipitate sleep apnea (the cessation of breathing during sleep). Sleep deprivation also reduces an individual's ability to metabolize glucose and increases the production of the hormone ghrelin, which makes people crave carbohydrates that can cause weight gain and may increases the risk of sleep apnea. Some researchers postulate that the epidemic of obesity in America may be related to chronic sleep deprivation.

In one study on interns, those that had been awake for 24 hours or more had a 61% increase in risk of stabbing themselves with a needle or scalpel and a 168% increase in risk of being involved in a car accident. Today, some states include sleep deprivation of more than 24 hours in their definition of recklessness.

Companies should focus on educating their workforce on sleep and the problems associated with sleep deprivation. Policies should also limit the number of hours worked in a day and the total number of hours worked in a week. More sleep equates to better performance, a healthier lifestyle, and a safer and more productive workforce.

Commentary

You may wonder why I included a Harvard Business Review article in Urgent Care Alert. For those of us who have lived through the years of sleep deprivation associated with medical residency and shift work, the reasons for including this topic are self-evident. Sleep deprivation is a major contributing factor in medical error. As physicians and managers, we should work to improve the sleep patterns of our colleagues and employees, if for no other reason than to protect our patients.

Gone are the days of "I suffered through it during my training, so you must do it during years." As health care professionals, we must treat ourselves and our colleagues with the same level of diligence and intelligence we reserve for our patients.