 Most patients present to emergency departments with low-acuity conditions (such as minor injuries or exacerbations of chronic disease), but a small proportion will be critically ill or injured.Therefore, the emergency physician requires a broad field of knowledge and procedural skills often including surgical procedures, trauma resuscitation, advanced cardiac life support and advanced airway management.They must have some of the core skills from many medical specialities—the ability to resuscitate a patient (intensive care medicine), manage a difficult airway (anesthesiology), suture a complex laceration (plastic surgery), set a fractured bone or dislocated joint (orthopedic surgery), treat a heart attack (cardiology), manage strokes (neurology), work-up a pregnant patient with vaginal bleeding (obstetrics and gynecology), control a patient with mania (psychiatry), stop a severe nosebleed (otolaryngology), place a chest tube (cardiothoracic surgery), and conduct and interpret x-rays and ultrasounds (radiology).