RESEARCH
IMMERSION PULMONARY EDEMA B Y
B R I A N
H A R P E R
PULMONARY EDEMA IS AN ABNORMAL LEAKAGE of fluid from the bloodstream into the alveoli, the microscopic air sacs in the lungs. It is most often the result of heart failure or other cardiac problems. Sometimes, however, pulmonary edema is observed in swimmers and divers when no underlying medical cause is apparent. This condition, immersion pulmonary edema (IPE), presents as a rapid onset of shortness of breath, cough and sometimes bloodtinged, frothy sputum. Because the fluid builds up in the air-containing spaces of the lungs and interrupts gas exchange, IPE resembles drowning. The important difference is that the obstructing fluid comes from within the body rather than from inhalation of surrounding water. DAN Medical Services receives a few calls each month in which divers report symptoms suggestive of IPE. Anyone who experiences sudden shortness of breath or persistent cough while diving should abort the dive in as safe a manner as possible and breathe 100 percent oxygen on the surface. Further diving should be postponed until a physician can be consulted. Although IPE often resolves quickly once a diver has exited the water, respiratory distress in the diving environment can be extremely dangerous. Why does IPE occur? Douglas Ebersole: IPE is an uncommon condition first reported in 1989. It was originally described in cold-water diving and called “cold-induced pulmonary edema,” but it has now been reported in warm-water diving as well. An absence of chest pain helps differentiate IPE from pulmonary decompression sickness (“chokes”). The exact mechanism is not known, but it is thought to be due to a combination of the increased hydrostatic pressure in the pulmonary 98 |
2021 SPECIAL EDITION
