[Medical errors]

Untoward effects can result from the various procedures involved in patients care. Because of its risks and consequences it is very important to determine the causal factors of these events to improve the procedures at stake and be sure to obtain from them the results to be expected. Several recent and somehow disturbing reports about the magnitude and type of these said medical errors, have raised interest to review the subject and phase this problem under the scope of a quality control system, as to prevent its occurrence or mitigate its effects when there is no chance to avoid them properly.