• A victim of an automobile accident was lying in pain by the side of the road with a thoracic wound which was making a strange sucking noise with each labored inhalation. A passing off-duty paramedic applied a moist plastic sheet to the wound and the sound stopped. Why was the patient in pain? What would eventually have happened to the lung on the injured side if no care had been administered? Why was it important that the plastic sheet be moist?