Information Processing and Mental Models: World Views

Abstract

At 10:35 in the morning, two ambulances are sent to the site of a rural two-car traffic accident. The first unit that arrives at the scene confirms that two cars are involved and three people have been injured. According to eyewitnesses, the driver of one of the cars lost control of his vehicle, and the two cars had a head-on collision. The two occupants of the second vehicle have only minor injuries, but the driver who caused the accident is comatose. After assessment and triage, the second EMS team focuses on the two mildly injured occupants, one of whom is complaining of paresthesia, likely secondary to a whiplash injury. The unconscious victim is rescued from his vehicle and transferred to the ambulance by the first team. He receives oxygen via face mask and two large-bore intravenous lines are inserted. A normal blood sugar finger stick rules out hypoglycemia as a cause for the unconsciousness. Volume resuscitation is started and the patient is intubated. As the victim shows no external injuries, the working diagnosis at this point includes deceleration injury with severe internal bleeding, injuries to major intra-abdominal organs, and severe head injury. After 2,000 ml of crystalloid solution is infused without any effect on the arterial blood pressure, an epinephrine drip is started. The jugular veins are noted as markedly distended which suggests the possibility of a pneumothorax. However, chest auscultation reveals bilateral breath sounds, and chest palpation shows no rib fractures or subcutaneous emphysema. Thus, the diagnosis of pneumothorax is ruled out. On arrival at the emergency department, the patient continues to be hemodynamically unstable. An ultrasound scan shows no intra-abdominal organ injuries or free intraperitoneal fluid. The chest X-ray reveals adequately ventilated lungs, marked perihilar congestion, normal aortic arch, and significantly enlarged cardiac silhouette. Up to this point, 3,500 ml of crystalloid solution has been infused, and the rate of the epinephrine drip has reached 5 mg per hour. A transesophageal echocardiography is performed revealing a dilated left ventricle with severe inferior and apical akinesia. The patient dies shortly after admission to the ICU as a result of severe cardiogenic shock.