Lung Ultrasound Detects Extravascular Fluid After Competitive Breath-Hold Dives and Tracks Their Natural Resolution within 1 Hour
Monday, April 8, 2024
12:14pm – 12:21pm
Location: 412
Authors: Elaine Yu, UC San Diego Fernando Silva, Kaiser Permanente Northern California Anna Lussier, UCSD School of Medicine Peter Lindholm, UCSD
Objectives: To investigate whether B-lines on pulmonary ultrasound can diagnose immersion pulmonary edema (IPE) in competitive breath-hold divers and whether B-lines correlate with respiratory symptoms and/or hypoxemia.
Methods: We performed ultrasound on breath-hold divers before and immediately after surfacing from a competition dive, and then again within 1 hour before they left the competition area (follow-up). B-lines were counted in the anterior, lateral, and posterior lung fields. B-lines were counted for each intercostal space, and the space with the highest number of B-lines was recorded for each lung region. Each diver’s oxygen saturation (SpO2), and symptoms were recorded. Statistical analysis included odds ratios and linear regression.
Results : Dives ranged 40-133m. B-lines were 5.8 times more likely post-dive than pre-dive (95%CI[2.29,14.99], p<0.001) and 2.7 times more likely post-dive than at follow-up (95%CI[1.38,5.43], p=0.006). Oxygen saturation decreased by 0.63% for every additional B-line (p < 0.001). B-lines were found to be 36.4% sensitive and 28.3% specific for symptoms at follow-up.
Conclusions: B-lines are a common phenomenon in competitive breath-hold divers upon surfacing from a deep dive, even in the absence of symptoms. B-lines are negatively correlated with oxygen saturation, thereby indicating that extravascular fluid impairs gas exchange in the lung. B-lines decreased within 1 hour of surfacing without treatment, suggesting a natural homeostatic fluid shift once on the surface.