As a current resident, I feel obligated to point out that there have actually been some real improvements in the past 10 years on resident work hours. The most important ones being:
* No more than 80 hours worked in a week (Many surgery residencies previously averaged up to 100.)
* No more than 30 hours in a row (Previously 36 was the standard; 48 was not unheard of.)
* 4 days completely off out of every 4 weeks.
There are some loopholes (e.g. you can stretch the 80 hours to 88 if the time is categorized creatively) and abuses (some programs encourage their residents to under-report time), but I think it's generally a big step in the right direction for patient safety and resident quality of life.
Something to think about: These rules only apply to residents, who are always supervised to at least some extent. They don't apply to attendings (fully boarded doctors). So you won't be treated by a resident who hasn't slept in 72 hours, but if you're in a non-teaching hospital it's still possible that the non-resident doctor treating you there hasn't slept in 72 hours.