Continuity mistake: Most of the time, whenever House puts down his Nintendo DS, the angle at which it is bending changes. For example, in one shot, it is not bent at all and in the next it is almost closed.
Deliberate mistake: When a patient who is given CPR is seen in the shot, the person giving the CPR does so with bent arms (the correct way to do it is with straight arms). This is deliberate, as straight-arm CPR puts in an amount of strength that frequently breaks ribs. Many films do CPR with bent arms rather than straight to avoid harming the actor.
Factual error: There are several episodes where doctors continue to defibrillate a patient even after s/he flatlines. A flatline (asystole, where there is no electrical activity in the heart) cannot be corrected by defibrillation, which stops a heart that's in an abnormal rhythm and gives it a chance to start in a normal one (the heart has already stopped when there is a flatline).
Factual error: In an episode with a severely overweight patient who is thought to have diabetes, it is discovered he instead has Chagas disease. Cameron then informs the patient that he acquired this illness from his food when, in fact, Chagas disease is a protozoan that is spread through the bite of the triatomine bug.
Suggested correction: While the main vector for the infection is through the triatomine bug, Trypanosoma cruzi (the parasitic organism that causes the disease) can be transmitted through food, and thus Chagas was caused by the food the patient ate. It should also be noted that Trypanosoma cruzi is not transmitted by the bite of the triatomine bug, but rather through its feces, and it's only spreads once the feces enters the blood stream (which it can do through a bite site or scratching an open wound).
Factual error: Every time there is a patient given a non-rebreather O2 mask, the bag is uninflated. The correct way of administering O2 through a NRB is to inflate the bag first, which would be the reservoir for the O2; a common mistake in many Hollywood medical shows.