Are Early Morning Laboratory Studies Really Necessary in Hospitalized Patients?

Whenever we get sick with an infection, a very important component of our treatment and recovery plan is sufficient sleep. It allows the body to rest and focus its energy on fighting the infection. Sleep deprivation, in fact, can be quite deadly.

In the classic rat sleep deprivation trials, total sleep deprivation ended up killing the rats in 11-32 days. When the researchers deprived the rats of REM sleep, or commonly known as “dreaming sleep,” the rats also died, although they did survive for a longer time period, 16-54 days. Nevertheless, sleep deprivation is very detrimental, and when I was training as a sleep specialist, I learned about myriad health problems when people become sleep deprived.

So, when patients are admitted to the hospital, why do we wake them up in the early morning to draw blood tests? Yale University researchers studied this, and they found that nearly 40% of laboratory studies occurred between 4:00 AM and 6:59 AM:

The traditional thinking behind this is that, by the time the physicians and APPs come in to see their patients in the morning, usually at 7:00 AM, the blood tests are ready for them, and they can act on the findings of those blood tests to help care for the patients.

Yet, this begs the question: do we really need to get blood tests that early in the morning? Would care suffer significantly if those blood tests were drawn at, say, 8:00 AM? There should be enough time to act on any abnormal test results in the morning and before morning rounds. At my hospital, we round at 10:00 AM, and so if blood tests were drawn at 8:00 AM, they should be back by the time I round with the rest of the team.

As far as I can remember – and into today – “AM Labs” are usually drawn at 4:00 or 5:00 AM by default or even tradition. Unless the patient is comatose in the ICU, getting a blood test at 4:00 or 5:00 AM can disrupt the sleep of our patients, which can be very detrimental and can hinder their recovery from illness.

It can also precipitate delirium in our patients due to the sleep deprivation, the effects of which can also be very detrimental to the recovery of our patients. Moreover, it can also disrupt the sleep of the clinicians caring for those patients at night, who have to be awakened also at 4:30 or 5:00 AM to receive notification of critical results and act on them. This sleep disruption can also affect clinician well-being and burnout.

Good sleep is often the elusive treasure of a hospital stay. Many clinicians chuckle when they hear this, but it really is no laughing matter. It may be time to rethink the necessity of getting blood tests so early in the morning, so that our patients can actually get a good night’s sleep and be well on their way to a good recovery from illness.