Congestive heart failure can cause fluid buildup in the lungs, leading to one of the most dire respiratory emergencies: severe pulmonary edema.

Because the heart has been weakened by disease, blood does not flow through the lungs with normal force. As a result, something as common as eating too much salt can cause plasma to seep into the tiny sacs of the lungs where air is exchanged. Patients feel as if they are suffocating as fluid from their blood fills their lungs.

For more than 30 years, paramedics have been saving the lives of these patients by inserting, through the vocal cords, a breathing tube about the width of a small garden hose . Then , air is pushed into the lungs with an inflatable bag. The process is called intubating. Yet, the aggressive treatment is very uncomfortable for those on the receiving end. Also, it carries the risk of dangerous infection. So a device more commonly found in the hospital is making its way into ambulances, the nation over.

The breathing device is known as CPAP -continuous positive airway pressure. The football-size device with long plastic tubing and a plastic mask is being used now by emergency crews in seven other big cities, including Miami and Boston. Another 16, including Atlanta and Philadelphia, plan to put the device in ambulances soon. This is according to this month's Journal of Emergency Medical Services (JEMS).