Imagine if you went to sleep at your normal bedtime, but 5 minutes later, the lights went on. You hear multiple peoples’ conversations right next to your bed. The TV turns on and stays on. A car alarm goes off just opposite your window, and a siren-screeching ambulance drives by your house every few minutes.
This may sound a bit far fetched, but this is essentially what most patients who are in the intensive care unit (ICU) experience. It’s not just at night, but 24/7.
This is what I saw during my recent time spent in a COVID-19 ICU. Fluorescent lights are on constantly. Doctors, nurses, technicians, and various other staff members are repeatedly going in and out of the room. You’re being poked for blood samples on a regular basis. Invasive and noninvasive procedures are performed on a regular basis. You may even have to be on a ventilator with a tube in your windpipe.
This experience brought back memories of articles I read many years ago on the consequences of sleep deprivation in the ICU. In particular, there are many papers on delirium during or after time spent in the ICU. A good overview of this subject can be found in this review article in 2014. It’s highly technical in nature, but you can get an idea of the basic concepts just by looking at the figures and tables.
In general, sleep studies on patients in the ICU generally have much higher durations of light sleep and arousals, and much lower time spent in deep and REM sleep.
What all these review articles show is that you’re not really getting any quality or good quality of sleep in the ICU. Here are 6 main areas of concern:
This is the most obvious factor that prevents good sleep quality. The World Health Organization (WHO) recommends average background noise in hospitals not be higher than 30 decibels, with nighttime peaks not higher than 40 decibels. As you can see from this paper, average noise levels range from 55 to 70 decibels and can peak as high as 120 decibels. (A chainsaw or motorcycle reaches 100 decibels.) These levels stay the same at night as well as during the daytime. Staff conversations can reach 85 decibels and were found to be the most disruptive for ICU patients. Sleep studies in ICU patients have found that about 11% of all brain wave arousals and 17% of all awakenings are due to noise.
Most ICU rooms are separated and closed off with a door, but with glass doors and walls. Even if the lights are off inside the room, hallway lights are still on, and various lights from electronic devices next to the patient can light up the room. Circadian rhythms are severely disrupted as a result. Studies from China and Jordan found that using eye masks and earplugs improved perceived sleep quality.
Patient Care Activities
Patient care activities are unavoidable in the ICU. Studies have estimated around 50 direct patient care contact points within a 24 hour period. These activities include dressing changes, medications, and baths. These disruptions are thought to be responsible for about 10% of arousals and awakenings.
Various medications given in the ICU can disrupt sleep. Although you may think that sedatives such as valium or narcotics such as morphine may help with sleep, it’s not always the case. For example, medications in the benzodiazepine classification such as valium as well as narcotics are known to lower slow-wave (deep sleep) and REM sleep (dreams).
Any degree of sleep deprivation (including via medications) will lead to what’s called REM rebound, where you see much higher levels of REM sleep. But during stage REM is when muscles are most relaxed, and hospital patients are kept on their backs. This can lead to more obstructed breathing episodes. Note that patients are protected from obstructed breathing if they are intubated (on a ventilator with a breathing tube).
Being on a ventilator is not a normal experience. There are a number of settings that control your respiratory rate, pressure, volume, and how it responds to your breathing efforts. Oftentimes, sedatives are given if a patient is uncomfortable with ventilation. Undoubtedly, having a tube in your throat and adjusting to the machine’s artificial breathing patterns can be uncomfortable.
Sleep and Your Immune System
It’s also commonly acknowledged that chronic sleep deprivation can lower your body’s ability to fight infections. Take a look at tip #1 on my blog post on 5 Ways to Combat Coronavirus. It’s not surprising that rats that were sleep deprived were susceptible to much higher rates of bacterial infections.
5 Ways to Improve Sleep in the ICU
Because there are so many factors in an ICU that can disrupt sleep, it’s hard to pinpoint one or even a handful of things to address. It’s safe to say the sleep quality is not a high priority for doctors in the ICU, for many legitimate reasons. However, there are a number of steps that can be taken to lessen the degree of sleep disturbances in the ICU:
- Do an inventory of all sources of noise and try to minimize levels. Keep conversations to a minimum and lower voice levels. Lower machine alert sound levels. Consider earplugs or headphones to lower sound exposure.
- Minimize patient-related activities or disruptions. Order blood tests or take vitals more often during the daytime.
- Turn off all lights at night. Consider using an eye mask.
- Minimize medications that can lower sleep quality.
- Optimize ventilator settings for patient comfort.
Hopefully, you or your loved ones won’t ever have to spend time as a patient in the ICU. But if you do, talk to your ICU team to make them aware of your concerns about this important issue.