A night at the hospital- is it circadian rhythm or process of care that increase cardiac arrests?

Have you seen the movie "A night at the museum" with Ben Stiller from 2006? Do you remember the single dad Larry applying for an easy nightshift job at the museum of natural history, how hard can it be to watch stuffed animal's night time? What was not included in the job description was the fact that that the animals became alive night-time. I just read an article by Mc Guigan et al.'s1 and got a dejavu from that movie. The article left me with two main questions; "What's going on at hospitals night-time?" and the naiver version of the same question "How hard can it be to predict and prevent in-hospital cardiac arrest (IHCA)?" Several studies have shown that more IHCA occur night-time than daytime and they have poorer survival,2–6 which has been speculated due to associations to circadian rhythm.