Document Detail


Ultrasound lung "comets" increase after breath-hold diving.
MedLine Citation:
PMID:  20972574     Owner:  NLM     Status:  In-Data-Review    
Abstract/OtherAbstract:
The purpose of the study was to analyze the ultrasound lung comets (ULCs) variation, which are a sign of extra-vascular lung water. Forty-two healthy individuals performed breath-hold diving in different conditions: dynamic surface apnea; deep variable-weight apnea and shallow, face immersed without effort (static maximal and non-maximal). The number of ULCs was evaluated by means of an ultrasound scan of the chest, before and after breath-hold diving sessions. The ULC score increased significantly from baseline after dynamic surface apnea (p = 0.0068), after deep breath-hold sessions (p = 0.0018), and after static maximal apnea (p = 0.031). There was no statistically significant difference between the average increase of ULC scores after dynamic surface apnea and deep breath-hold diving. We, therefore, postulate that extravascular lung water accumulation may be due to other factors than (deep) immersion alone, because it occurs during dynamic surface apnea as well. Three mechanisms may be responsible for this. First, the immersion-induced hydrostatic pressure gradient applied on the body causes a shift of peripheral venous blood towards the thorax. Second, the blood pooling effect found during the diving response Redistributes blood to the pulmonary vascular bed. Third, it is possible that the intense involuntary diaphragmatic contractions occurring during the "struggle phase" of the breath-hold can also produce a blood shift from the pulmonary capillaries to the pulmonary alveoli. A combination of these factors may explain the observed increase in ULC scores in deep, shallow maximal and shallow dynamic apneas, whereas shallow non-maximal apneas seem to be not "ULC provoking".
Authors:
Kate Lambrechts; Peter Germonpré; Brian Charbel; Danilo Cialoni; Patrick Musimu; Nicola Sponsiello; Alessandro Marroni; Frédéric Pastouret; Costantino Balestra
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Publication Detail:
Type:  Journal Article     Date:  2010-10-23
Journal Detail:
Title:  European journal of applied physiology     Volume:  111     ISSN:  1439-6327     ISO Abbreviation:  Eur. J. Appl. Physiol.     Publication Date:  2011 Apr 
Date Detail:
Created Date:  2011-03-14     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100954790     Medline TA:  Eur J Appl Physiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  707-13     Citation Subset:  IM    
Affiliation:
Environmental & Occupational Physiology Laboratory, Haute Ecole Paul-Henri Spaak, 91, Avenue Charles Schaller, 1160 Auderghem, Brussels, Belgium.
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