#6 | FREEDIVING SCIENCE | LUNG ULTRASOUND STUDY IN FREEDIVERS | ANDY CHI 齊英仁
The FREEDIVING SCIENCE series explores freediving science in depth.
IN THIS EPISODE:
In March 2022 the 2nd Taiwanese Cup freediving depth competition was held off Xiao Liuqiu Island in Taiwan. During the pre-comp a group of researchers led by Andy Chi 齊英仁 studied many of the athletes using various methods including lung ultrasounds before and after their dives.
Donny was also participating in the study and in the competition. In this episode we discuss the interesting prelimenary findings which delivers much food for thought for the world’s freediving community.
There is much yet to be researched and discussed on this subject but let’s add comments between Andy Chi (Doctor of Emergency Medicine at Kaohsiung Chang Gung Memorial Hospital), who I interviewed in this episode, and Bizo Silva (Emergency Medicine physician) .
Andy: I agree with that the result of lung ultrasound should be interpreted in caution. B line is a sign of pulmonary edema but not directly referred to it. By excluding other causes could be a method to get closer to the truth. As Bizo mentioned, atelectasis might be another possible cause, but we just don’t know the prevalence for diver’s lung failing to re-expand upon surfacing. A CT scan right after surfacing may help, but very difficult to operate. As for the “blood shift”, I don’t think it creates B line easily even still presented on surface, because the shifted blood will mostly be in the pulmonary vessels situated in the central part of lung (especially veins with better compliance), that is too deep for ultrasound to reach theoretically. Alveolar flooding with serum sounds very alike to the fact with pulmonary edema, and I feel it impossible to distinguish between them in any method. Serum in alveolar also disturbs gas exchange and causes breathing problem, maybe we don’t have to separate if from pulmonary edema?
Donny’s Lung Ultrasound Images (pre-dive on left, post-dive on right), can you spot the 3 B lines on the middle right image?
Other athletes ultrasound images: