Ventilatory response to head‐down‐tilt in healthy human subjects
| Title: | Ventilatory response to head‐down‐tilt in healthy human subjects |
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| Authors: | Abdulaziz Alsharifi, Niamh Carter, Akbar Irampaye, Charlotte Stevens, Elisa Mejia, Joerg Steier, Gerrard F. Rafferty |
| Source: | Experimental Physiology, Vol 109, Iss 12, Pp 2134-2146 (2024) |
| Publisher Information: | Wiley, 2024. |
| Publication Year: | 2024 |
| Collection: | LCC:Physiology |
| Subject Terms: | baroreceptors, cerebral blood flow, chemoreceptors, head‐down tilt, respiratory control, Trendelenburg position, Physiology, QP1-981 |
| More Details: | Abstract Postural fluid shifts may directly affect respiratory control via a complex interaction of baro‐ and chemo‐reflexes, and cerebral blood flow. Few data exist concerning the steady state ventilatory responses during head‐down tilt. We examined the cardiorespiratory responses during acute 50° head‐down tilt (HDT) in 18 healthy subjects (mean [SD] age 27 [10] years). Protocol 1 (n = 8, two female) was 50° HDT from 60° head‐up posture sustained for 10 min, while exposed to normoxia, normoxic hypercapnia (5% CO2), hypoxia (12% inspired O2) or hyperoxic hypercapnia (95% O2, 5% CO2). Protocol 2 (n = 10, four female) was 50° HDT from supine, sustained for 10 min, while breathing either medical air or normoxic hypercapnic (5% CO2) gas. Ventilation (V̇E, pneumotachograph), end‐tidal O2 and CO2 concentration and blood pressure (Finapres) were measured continuously throughout each protocol. Middle cerebral artery blood flow velocity (MCAv; transcranial Doppler) was also measured during protocol 2. Ventilation increased significantly (P |
| Document Type: | article |
| File Description: | electronic resource |
| Language: | English |
| ISSN: | 1469-445X 0958-0670 56974345 |
| Relation: | https://doaj.org/toc/0958-0670; https://doaj.org/toc/1469-445X |
| DOI: | 10.1113/EP092014 |
| Access URL: | https://doaj.org/article/adf09d90acdc4be2b56974345bc17d76 |
| Accession Number: | edsdoj.f09d90acdc4be2b56974345bc17d76 |
| Database: | Directory of Open Access Journals |
| ISSN: | 1469445X 09580670 56974345 |
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| DOI: | 10.1113/EP092014 |
| Published in: | Experimental Physiology |
| Language: | English |