Cerebral oxygenation and regional cerebral perfusion responses with resistance breathing during central hypovolemia

Victoria L. Kay, Justin D. Sprick, Caroline Alice Rickards

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)

Abstract

Resistance breathing improves tolerance to central hypovolemia induced by lower body negative pressure (LBNP), but this is not related to protection of anterior cerebral blood flow [indexed by mean middle cerebral artery velocity (MCAv)]. We hypothesized that inspiratory resistance breathing improves tolerance to central hypovolemia by maintaining cerebral oxygenation (ScO2), and protecting cerebral blood flow in the posterior cerebral circulation [indexed by posterior cerebral artery velocity (PCAv)]. Eight subjects (4 male/4 female) completed two experimental sessions of a presyncopal-limited LBNP protocol (3 mmHg/min onset rate) with and without (Control) resistance breathing via an impedance threshold device (ITD). ScO2 (via near-infrared spectroscopy), MCAv and PCAv (both via transcranial Doppler ultrasound), and arterial pressure (via finger photoplethysmography) were measured continuously. Hemodynamic responses were analyzed between the Control and ITD condition at baseline (T1) and the time representing 10 s before presyncope in the Control condition (T2). While breathing on the ITD increased LBNP tolerance from 1,506 ± 75 s to 1,704 ± 88 s (P = 0.003), both mean MCAv and mean PCAv were similar between conditions at T2 (P ≥ 0.46), and decreased by the same magnitude with and without ITD breathing (P ≥ 0.53). ScO2 also decreased by ~9% with or without ITD breathing at T2 (P = 0.97), and there were also no differences in deoxygenated (dHb) or oxygenated hemoglobin (HbO2) between conditions at T2 (P ≥ 0.43). There was no evidence that protection of regional cerebral blood velocity (i.e., anterior or posterior cerebral circulation) nor cerebral oxygen extraction played a key role in the determination of tolerance to central hypovolemia with resistance breathing.

Original languageEnglish
Pages (from-to)R132-R139
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume313
Issue number2
DOIs
StatePublished - 1 Jan 2017

Fingerprint

Hypovolemia
Cerebrovascular Circulation
Respiration
Perfusion
Electric Impedance
Central Tolerance
Lower Body Negative Pressure
Posterior Cerebral Artery
Middle Cerebral Artery
Equipment and Supplies
Photoplethysmography
Doppler Ultrasonography
Near-Infrared Spectroscopy
Syncope
Fingers
Arterial Pressure
Hemoglobins
Hemodynamics
Oxygen

Keywords

  • Hemodynamic oscillations
  • Hemorrhage
  • Inspiratory threshold device
  • Lower body negative pressure
  • Middle cerebral artery
  • Posterior cerebral artery

Cite this

@article{a2884b42fb2043029f77ab3d8bf7f8ca,
title = "Cerebral oxygenation and regional cerebral perfusion responses with resistance breathing during central hypovolemia",
abstract = "Resistance breathing improves tolerance to central hypovolemia induced by lower body negative pressure (LBNP), but this is not related to protection of anterior cerebral blood flow [indexed by mean middle cerebral artery velocity (MCAv)]. We hypothesized that inspiratory resistance breathing improves tolerance to central hypovolemia by maintaining cerebral oxygenation (ScO2), and protecting cerebral blood flow in the posterior cerebral circulation [indexed by posterior cerebral artery velocity (PCAv)]. Eight subjects (4 male/4 female) completed two experimental sessions of a presyncopal-limited LBNP protocol (3 mmHg/min onset rate) with and without (Control) resistance breathing via an impedance threshold device (ITD). ScO2 (via near-infrared spectroscopy), MCAv and PCAv (both via transcranial Doppler ultrasound), and arterial pressure (via finger photoplethysmography) were measured continuously. Hemodynamic responses were analyzed between the Control and ITD condition at baseline (T1) and the time representing 10 s before presyncope in the Control condition (T2). While breathing on the ITD increased LBNP tolerance from 1,506 ± 75 s to 1,704 ± 88 s (P = 0.003), both mean MCAv and mean PCAv were similar between conditions at T2 (P ≥ 0.46), and decreased by the same magnitude with and without ITD breathing (P ≥ 0.53). ScO2 also decreased by ~9{\%} with or without ITD breathing at T2 (P = 0.97), and there were also no differences in deoxygenated (dHb) or oxygenated hemoglobin (HbO2) between conditions at T2 (P ≥ 0.43). There was no evidence that protection of regional cerebral blood velocity (i.e., anterior or posterior cerebral circulation) nor cerebral oxygen extraction played a key role in the determination of tolerance to central hypovolemia with resistance breathing.",
keywords = "Hemodynamic oscillations, Hemorrhage, Inspiratory threshold device, Lower body negative pressure, Middle cerebral artery, Posterior cerebral artery",
author = "Kay, {Victoria L.} and Sprick, {Justin D.} and Rickards, {Caroline Alice}",
year = "2017",
month = "1",
day = "1",
doi = "10.1152/ajpregu.00385.2016",
language = "English",
volume = "313",
pages = "R132--R139",
journal = "American Journal of Physiology - Regulatory Integrative and Comparative Physiology",
issn = "0363-6119",
publisher = "American Physiological Society",
number = "2",

}

Cerebral oxygenation and regional cerebral perfusion responses with resistance breathing during central hypovolemia. / Kay, Victoria L.; Sprick, Justin D.; Rickards, Caroline Alice.

In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 313, No. 2, 01.01.2017, p. R132-R139.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Cerebral oxygenation and regional cerebral perfusion responses with resistance breathing during central hypovolemia

AU - Kay, Victoria L.

AU - Sprick, Justin D.

AU - Rickards, Caroline Alice

PY - 2017/1/1

Y1 - 2017/1/1

N2 - Resistance breathing improves tolerance to central hypovolemia induced by lower body negative pressure (LBNP), but this is not related to protection of anterior cerebral blood flow [indexed by mean middle cerebral artery velocity (MCAv)]. We hypothesized that inspiratory resistance breathing improves tolerance to central hypovolemia by maintaining cerebral oxygenation (ScO2), and protecting cerebral blood flow in the posterior cerebral circulation [indexed by posterior cerebral artery velocity (PCAv)]. Eight subjects (4 male/4 female) completed two experimental sessions of a presyncopal-limited LBNP protocol (3 mmHg/min onset rate) with and without (Control) resistance breathing via an impedance threshold device (ITD). ScO2 (via near-infrared spectroscopy), MCAv and PCAv (both via transcranial Doppler ultrasound), and arterial pressure (via finger photoplethysmography) were measured continuously. Hemodynamic responses were analyzed between the Control and ITD condition at baseline (T1) and the time representing 10 s before presyncope in the Control condition (T2). While breathing on the ITD increased LBNP tolerance from 1,506 ± 75 s to 1,704 ± 88 s (P = 0.003), both mean MCAv and mean PCAv were similar between conditions at T2 (P ≥ 0.46), and decreased by the same magnitude with and without ITD breathing (P ≥ 0.53). ScO2 also decreased by ~9% with or without ITD breathing at T2 (P = 0.97), and there were also no differences in deoxygenated (dHb) or oxygenated hemoglobin (HbO2) between conditions at T2 (P ≥ 0.43). There was no evidence that protection of regional cerebral blood velocity (i.e., anterior or posterior cerebral circulation) nor cerebral oxygen extraction played a key role in the determination of tolerance to central hypovolemia with resistance breathing.

AB - Resistance breathing improves tolerance to central hypovolemia induced by lower body negative pressure (LBNP), but this is not related to protection of anterior cerebral blood flow [indexed by mean middle cerebral artery velocity (MCAv)]. We hypothesized that inspiratory resistance breathing improves tolerance to central hypovolemia by maintaining cerebral oxygenation (ScO2), and protecting cerebral blood flow in the posterior cerebral circulation [indexed by posterior cerebral artery velocity (PCAv)]. Eight subjects (4 male/4 female) completed two experimental sessions of a presyncopal-limited LBNP protocol (3 mmHg/min onset rate) with and without (Control) resistance breathing via an impedance threshold device (ITD). ScO2 (via near-infrared spectroscopy), MCAv and PCAv (both via transcranial Doppler ultrasound), and arterial pressure (via finger photoplethysmography) were measured continuously. Hemodynamic responses were analyzed between the Control and ITD condition at baseline (T1) and the time representing 10 s before presyncope in the Control condition (T2). While breathing on the ITD increased LBNP tolerance from 1,506 ± 75 s to 1,704 ± 88 s (P = 0.003), both mean MCAv and mean PCAv were similar between conditions at T2 (P ≥ 0.46), and decreased by the same magnitude with and without ITD breathing (P ≥ 0.53). ScO2 also decreased by ~9% with or without ITD breathing at T2 (P = 0.97), and there were also no differences in deoxygenated (dHb) or oxygenated hemoglobin (HbO2) between conditions at T2 (P ≥ 0.43). There was no evidence that protection of regional cerebral blood velocity (i.e., anterior or posterior cerebral circulation) nor cerebral oxygen extraction played a key role in the determination of tolerance to central hypovolemia with resistance breathing.

KW - Hemodynamic oscillations

KW - Hemorrhage

KW - Inspiratory threshold device

KW - Lower body negative pressure

KW - Middle cerebral artery

KW - Posterior cerebral artery

UR - http://www.scopus.com/inward/record.url?scp=85026887764&partnerID=8YFLogxK

U2 - 10.1152/ajpregu.00385.2016

DO - 10.1152/ajpregu.00385.2016

M3 - Article

VL - 313

SP - R132-R139

JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology

JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology

SN - 0363-6119

IS - 2

ER -