Feasibility of intercostal blood flow measurement by echo‐Doppler technique in healthy subjects

• Published in: Clinical Physiology and Functional Imaging Vol. 37; no. 3; pp. 282 - 287
• Main Authors: Bisschop, Claire, Montaudon, Michel, Glénet, Stéphane, Guénard, Hervé
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.05.2017; Wiley-Blackwell
• Subjects: Adult; Airway Resistance; arterial blood flow; Arterial Pressure; Arteries - diagnostic imaging; Blood Flow Velocity; Electromyography; Feasibility Studies; Female; Healthy Volunteers; Heart Rate; Humanities and Social Sciences; Humans; intercostal muscle; Intercostal Muscles - blood supply; loaded breathing; Male; Middle Aged; Predictive Value of Tests; Regional Blood Flow; Reproducibility of Results; Respiratory Mechanics; Ultrasonography, Doppler; loaded breathing; intercostal muscle; humans; electromyography; arterial blood flow; arterial blood flow
• DOI: 10.1111/cpf.12298
• ISSN: 1475-0961; 1475-097X

Summary Intercostal artery blood flow supplies the external and internal intercostal muscles, which are inspiratory and expiratory muscles. Intercostal blood flow measured by the echo‐Doppler (ED) technique has not previously been reported in humans. This study describes the feasibility of this measurement during free and loaded breathing in healthy subjects. Systolic, diastolic and mean blood flows were measured in the eighth dorsal intercostal space during free and loaded breathing using the ED technique. Flows were calculated as the product of the artery intraluminal surface and blood velocity. Ten healthy subjects (42 ± 13·6 years) were included. Integrated electromyogram (iEMG), arterial pressure, cardiac frequency and breathing pattern were also recorded. Mean blood flows were 3·5 ± 1·2 ml min−1 at rest, 6 ± 2·6 ml min−1 while breathing through a combined inspiratory and expiratory resistance and 4·0 ± 1·3 ml min−1 1 min after unloading. Diastolic blood flow was about one‐third the systolic blood flow. The changes in blood flows were consistent with those in iEMG. No change in mean blood flow was observed between inspiration and expiration, suggesting a balance in the perfusion of external and internal muscles during breathing. In conclusion, ED is a feasible technique for non‐invasive, real‐time measurement of intercostal blood flow in humans. In healthy subjects, mean blood flow appeared tightly matched to iEMG activity. This technique may provide a way to assess the vascular adaptations induced by diseases in which respiratory work is increased or cardiac blood flow altered.