It's really tough when someone is a doctor, especially an ICU doctor in an underserved area. Because he may feel that he needs to work such long hours, not just to make money, but to save lives that perhaps would die if he didn't work so much.

The way OP describes the situation, it sounds like the husband loves his job and always prioritized it, but that this issue is being exacerbated by staffing problems at the hospital. This could mean there aren't enough doctors to go around, and so if he takes time off patients may die.

That would weigh heavily on him and would make him less likely to consider cutting back.

My dad is a doctor, he worked a lot of hospitals during residency although he now works as a GP (Australian word for Primary Care Provider) in nursing homes. Doctors usually have deep devotion towards their jobs because they're not just "jobs" they're vocations. Doctors have to study for over a decade, including years of residency that involve 100hr weeks. Most people who do that, do so because they consider it a vocation.

My mum was in a similar situation to OP when me and my brothers were young, but my dad actually took time off his residency and paused his studies for about a year to be a stay at home dad. However that had massive long lasting ramifications on his career, and that was without the "being in an underserved area" complexity...