Intercostal muscle oxygenation during expiratory load breathing at rest
Authors: Aurélien Pichon
Claire de Bisschop
Quentin Bretonneau
Journal: Respiratory Physiology & Neurobiology (2019)
Discipline: CLINICAL MEDICINE
Keywords: Airway obstruction; Expiratory resistance; Healthy subjects; NIRS; Respiratory muscle oxygenation.
Affiliations: Laboratoire 'MOVE', EA 6314 - Université de Poitiers, Faculté des Sciences du Sport, 8, allée Jean Monnet, 86000 Poitiers, France., Laboratoire 'MOVE', EA 6314 - Université de Poitiers, Faculté des Sciences du Sport, 8, allée Jean Monnet, 86000 Poitiers, France. Electronic address: .

Abstract:  Background: During acute bronchial obstruction, despite a higher work of breathing, blood supply and oxygen availability may be reduced in intercostal muscles because of mechanical constraints. This hypothesis was assessed in healthy subjects breathing with and without expiratory load (ETL). Methods: Eleven men (24 ± 2 years) breathed at rest for 5 min in unloaded condition and for 20 min through a 20-cmH2O ETL. Tissue saturation index (TSI) and changes (Δ) in concentration of total and oxy-haemoglobin ([tHb] and [O2Hb]) were measured in the seventh intercostal space by near-infrared spectroscopy. Results: [tHb] and [O2Hb] decreased with ETL (-5.16 μM and -3.54 μM; p &lt; 0.05). TSI did not vary. Negative correlations were observed between Δ[O2Hb] and changes in expiratory flow rate (ΔVt/Te) and between ΔTSI and Δ V˙E (r = -0.78 and -0.74; p ≤ 0.01). Conclusion: Despite decreases in Hb concentrations, saturation in oxygen was not reduced with ETL in intercostal muscles, suggesting a satisfactory ventilatory and/or hemodynamic arrangement. 

Retracted: No

PubPeer comments:
 The study is described as a prospective research in humans, performed in France: The study has been performed on healthy volunteers, medical parameters and anthropometric measures were collected. The measurement list are provided here: - Anthropometry - Pulmonary function tests - Respiratory muscle oxygenation - Respiratory pattern and gas exchanges - Dyspnea - Pulse oximetry - Cardiovascular parameters As a consequence, It is definitely a prospective research in human (RIPH) with regards of the french law. According the [SmartReg Tool from the Girci] , the anthropometric measurement is sufficient to define this study as an RIPH. There is few hesitation here on the definition of this study as a RIPH. In France, all RIPHs (whatever the level) require the approval from a CPP before to start the recruitment of participants. Starting a prospective research in humans in France without a CPP is a serious breach to the Health French Law. The ethic statement of this study is described as follows: * The protocol was fully and explicitly presented, and the signed consent form was returned prior to the beginning of the study, which was approved by the CERSTAPS ethical committee (2018-25-01-22) * The CERSTAPS is not a Comitu00e9 de Protection des Personnes (CPP). As mentioned on the [CERSTAPS website] itself, a prospective research in humans in France MUST obtain an approval from a CPP before to start. The ethics statement do not provide any information related to a CPP approval. Can the authors clarify: - If they obtain a CPP approval before to start the recruitment? - If they request a CPP approval? In this case, what was the answer of the CPP ? If a CPP provides a waiver for the approval, the article should mention it and detail the waiver in order to raise any question on ethics procedure. However, if the CPP approval or a waiver from a CPP has not been obtained, this is a major infringement to the Health French Law and the Declaration of Helsinki (article 23). ,