Chest sonography detects lung water accumulation in healthy elite apnea divers

[fpernett]

This is the citation: Chest sonography detects lung water accumulation in healthy elite apnea divers. Frassi F - J Am Soc Echocardiogr - 01-OCT-2008; 21(10): 1150-5

Abstract: BACKGROUND: Ultrasound lung comets (ULCs) detected by chest sonography are a simple, noninvasive, semiquantitative sign of increased extravascular lung water. Pulmonary edema may occur in elite apnea divers, possibly triggered by centralization of blood flow from the periphery to pulmonary vessels. We assessed the prevalence of ULCs in top-level breath-hold divers after immersion. METHODS: We evaluated 31 consecutive healthy, top-level, breath-hold divers (10 female, 21 male; age 31 +/- 5 years) participating in a yearly international apnea diving contest in Sharm-el-Sheik, Egypt, November 1 to 3, 2007. We performed chest and cardiac sonography with a transthoracic probe (2.5-3.5 MHz, Esaote Mylab) in all divers, both on the day before and 10 +/- 9 minutes after immersion. In a subset of 4 divers, chest scan was also repeated at 24 hours after immersion. ULCs were evaluated on the anterior and posterior chest at 61 predefined scanning sites. An independent sonographer, blind to both patient identity and status (pre- or post-diving), scored ULCs. RESULTS: Diving depth ranged from 31 to 112 m. Duration of immersion ranged from 120 to 225 seconds. The ULC score was 0.5 +/- 1.5 at baseline and 13 +/- 21 after diving (P = .012). At individual patient analysis, ULCs appeared in 14 athletes (45%) after diving. Of these 14 athletes, 4 were asymptomatic, 6 showed aspecific symptoms with transient loss of motor control ("Samba"), 2 had palpitations with frequent premature ventricular contractions, and 2 had persistent cough with hemoptysis and pulmonary crackles. In a subset of 4 athletes with post-diving ULCs in whom late follow-up study also was available, chest sonography findings fully normalized at 24 hours of follow-up. CONCLUSION: In top-level breath-hold divers, chest sonography frequently reveals an increased number of ULCs after immersion, indicating a relatively high prevalence of (often subclinical) reversible extravascular lung water accumulation.

I'm reading the full article, to write down conclusions

 

[Mullins]

Diving depth ranged from 31 to 112 m. Duration of immersion ranged from 120 to 225 seconds.

The diver who went to 31m took at least 2 minutes??

 

[bubbleless]

Hi Frank

I'd be interested to hear your conclusions from the full article

Cheers
Joy

 

[fpernett]

The diver who went to 31m took at least 2 minutes??

No, it's just the statistical analysis it means that the depth range from 31 to 112 m, and dive times range from 120 - 225 secs, counting all dives

 

[Mullins]

No, it's just the statistical analysis it means that the depth range from 31 to 112 m, and dive times range from 120 - 225 secs, counting all dives

Yes, which means the 31m diver must have taken at least 120 seconds... equalising problems perhaps?

Anyway, I'm also interested to hear about the rest of the conclusions; I was one of the 2 divers who had heart palpitations post-dive (they are actually quite common for me).

 

[fpernett]

You're right Dave- They don't specify the reason. As you say the 31m diver, at least did 120 sec, could be more, anyway.

I didn't know about the technique of ULC's but after reviewing some articles it seems to be valid to quantify liquid or fibrosis in lung interstitium. So, the method can be accurate. They didn't find any relation between the number of ULC´s (water in the lungs) and the depth, so as many of us know, is not a problem of only depth. It will be interesting to do this test, after many days of deep diving, take into account the equalizing method, analyze early vs late contractions. They didn't mention the use of medications as aspirin. There was also an slight increase on pulmonary pressure after diving (but this is not completely reliable).
A big limitation of the study is the number of subjects (and dives), and that water in the interstitial tissue is not the same as pulmonary edema. In fact only 14%, of the ULC's positive group had overt clinical pulmonary edema.
But it's a good start