Evaluating the patient with loss of consciousness

Patients who have had an episode of altered awareness and are subsequently brought to the hospital for evaluation are common[9] amounting to more than 6% of all emergency room (ER) admissions. One of the key elements in properly evaluating these patients is to perform a good history. The history can come from a number of different sources including the patient, family, and/or others present at the time of the event. In each case, the information provided may be biased by the preconceptions of the person providing the history. Thus, it is critical to understand which aspects of the history are most important and most reliable in distinguishing between the possible diagnoses. For example, it is not uncommon for an observer to state that a patient was unconscious if he/she did not respond to voice. Only further questioning about other characteristics of the patient at that time such as loss of tone or abnormal movements may help sort out the actual events.