What doctors are usually available to see patients in er at night?

ER, hospitalists: Emergency medicine doctors work in the ed 24/7. If a patient needs to be admitted, then the next doctor who should see is a hospitalist or surgeon (if strictly a surgical problem).

Generalists: Most er's are staffed by emergency room specialist with a broad training in acute medical and surgical problems. The ones at night are more often newly trained (new hires get the worst schedules) and the odd one who likes to work at night. You can expect appropriate, focused care with good back up in any community hospital er.

Depends: Totally depends on what kind of hospital you go to. Academic teaching medical centers are going to have senior & fellow Emergency Medicine residents & ER attendings 24/7. If you go to a Level I trauma center, you are going to have the best of the best. Since Emergency Medicine became a boardable specialty in the 1970s, ERs are rarely staffed by general practitioners, family docs, or internists.