In addition to evaluating the experience of pain itself, much of the diagnostic evaluation in the ED is centered on determining the etiology of the pain. For traumatic injuries, the emphasis is directed toward identifying injuries that benefit from treatment. There are relatively few data regarding the effect of analgesia on interpretation of these studies in traumatic injuries.
In an atraumatic context, it has been shown that pain control does not have a negative effect on the interpretation of diagnostic studies requiring elicitation of symptoms. Perhaps the most thoroughly studied is the sonographic Murphy sign during right upper quadrant sonography. It has been reproducibly demonstrated that analgesia does not negatively influence management, and, in some cases, increases diagnostic accuracy.63-65 Fortunately, few diagnostic tests that rely on subjective findings are relevant to traumatic injuries.