Delirium is a common problem in the ICU. The reason is usually multi-modal, but sleep deprivation and alterations in the sleep-wake cycle are often a big part of it. so, if we ensure that patients get good sleep, that should prevent delirium, or at least SOME cases, right? to that end, we often will start patients who we deem at-risk for ICU delirium on melatonin in order to help them sleep and thereby prevent delirium. But does it actually work?
Pharmacy Joe looks at a recent study examining the efficacy of melatonin as a preventative strategy for ICU delirium and the results were not what I was hoping to see. The study was a multi-center RCT of around 800 patients in ICUs across Australia. Patients in the study group were all given 4mg of melatonin every night during their ICU stay. All patients were assessed twice daily using the CAM-ICU for delirium. There was no significant differences between the study group and the control group in terms of delirium.
One thing that isn’t clear is if 4mg might not be enough. Although I typically start with 3mg, I will often escalate it to 6mg pretty quickly if 3mg doesn’t seem to effective. I also typically don’t start melatonin until either the patient or the nurse complains of poor sleep. Further study is needed to determine if melatonin plays any role in delirium prevention.
For right now, it seems that the best strategy to prevent delirium (and we know that prevention is superior to treatment) is to focus on the nonpharmacological interventions. Maintaining a normal sleep-wake cycle is key. I encourage lights on during the day and having the TV on if there are no visitors to converse with the patient. It’s ok for patients to nap, but they shouldn’t be sleeping all day. If able, ambulation in the hallway or at least being up to the chair are beneficial as well.
Likewise, minimizing disturbances at night are important. Often patients are very ill and staff need to be in and out of the room frequently, but if possible, minimize these disturbances. Lights should be left off or low as much as possible. Don’t leave the TV on all night in the room. And, remember that sedation does not = sleep. I was a night shift ICU nurse for 10 years and often saw that the same care not to disturb day/night cycle was not observed in patients who were sedated.
The biggest pharmacological therapy you can do for prevention is to avoid the use of drugs known to cause or exacerbate delirium. The big offenders here are benzodiazepines. Benzo drips should almost never be used except in the case of status epilepticus. They were also found to be helpful in some cases of COVID back in 2020-2021 when nothing else would keep patients sedated, but they should be avoided in most cases.
The Critical Illness, Brain Dysfunction, and Survivorship (SIBS) Center has some great resources on delirium prevention and treatment.
critical care notes 