Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O2

Ann R. Elliott; Abhilash S. Kizhakke Puliyakote; Vincent Tedjasaputra; Beni Pazár; Harrieth Wagner; S. Rui C.; Jeremy E. Orr; G. Kim Prisk; Peter D. Wagner; Susan R. Hopkins

doi:10.14814/phy2.14488

Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O₂

Ann R. Elliott^*, Abhilash S. Kizhakke Puliyakote, Vincent Tedjasaputra, Beni Pazár, Harrieth Wagner, S. Rui C., Jeremy E. Orr, G. Kim Prisk, Peter D. Wagner, Susan R. Hopkins

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

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Abstract

Proton magnetic resonance (MR) imaging to quantify regional ventilation–perfusion ((Formula presented.)) ratios combines specific ventilation imaging (SVI) and separate proton density and perfusion measures into a composite map. Specific ventilation imaging exploits the paramagnetic properties of O₂, which alters the local MR signal intensity, in an F_IO₂-dependent manner. Specific ventilation imaging data are acquired during five wash-in/wash-out cycles of breathing 21% O₂ alternating with 100% O₂ over ~20 min. This technique assumes that alternating F_IO₂ does not affect (Formula presented.) heterogeneity, but this is unproven. We tested the hypothesis that alternating F_IO₂ exposure increases (Formula presented.) mismatch in nine patients with abnormal pulmonary gas exchange and increased (Formula presented.) mismatch using the multiple inert gas elimination technique (MIGET).The following data were acquired (a) breathing air (baseline), (b) breathing alternating air/100% O₂ during an emulated-SVI protocol (eSVI), and (c) 20 min after ambient air breathing (recovery). MIGET heterogeneity indices of shunt, deadspace, ventilation versus (Formula presented.) ratio, LogSD (Formula presented.), and perfusion versus (Formula presented.) ratio, LogSD (Formula presented.) were calculated. LogSD (Formula presented.) was not different between eSVI and baseline (1.04 ± 0.39 baseline, 1.05 ± 0.38 eSVI, p =.84); but was reduced compared to baseline during recovery (0.97 ± 0.39, p =.04). There was no significant difference in LogSD (Formula presented.) across conditions (0.81 ± 0.30 baseline, 0.79 ± 0.15 eSVI, 0.79 ± 0.20 recovery; p =.54); Deadspace was not significantly different (p =.54) but shunt showed a borderline increase during eSVI (1.0% ± 1.0 baseline, 2.6% ± 2.9 eSVI; p =.052) likely from altered hypoxic pulmonary vasoconstriction and/or absorption atelectasis. Intermittent breathing of 100% O₂ does not substantially alter (Formula presented.) matching and if SVI measurements are made after perfusion measurements, any potential effects will be minimized.

Original language	English
Article number	e14488
Number of pages	11
Journal	Physiological Reports
Volume	8
Issue number	13
Early online date	7 Jul 2020
DOIs	https://doi.org/10.14814/phy2.14488
Publication status	Published - Jul 2020
Externally published	Yes

Keywords

hyperoxia
magnetic resonance imaging
pulmonary perfusion distribution
pulmonary ventilation distribution
specific ventilation imaging
ventilation-perfusion ratio

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10.14814/phy2.14488Licence: CC BY

NRL_44628Final published version, 1.09 MBLicence: CC BY

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Elliott, A. R., Kizhakke Puliyakote, A. S., Tedjasaputra, V., Pazár, B., Wagner, H., Rui C., S., Orr, J. E., Prisk, G. K., Wagner, P. D., & Hopkins, S. R. (2020). Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O₂. Physiological Reports, 8(13), Article e14488. https://doi.org/10.14814/phy2.14488

@article{c5c17890b6224a5eb2318c93ccc32f37,

title = "Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100\% O2",

abstract = "Proton magnetic resonance (MR) imaging to quantify regional ventilation–perfusion ((Formula presented.)) ratios combines specific ventilation imaging (SVI) and separate proton density and perfusion measures into a composite map. Specific ventilation imaging exploits the paramagnetic properties of O2, which alters the local MR signal intensity, in an FIO2-dependent manner. Specific ventilation imaging data are acquired during five wash-in/wash-out cycles of breathing 21\% O2 alternating with 100\% O2 over \textasciitilde{}20 min. This technique assumes that alternating FIO2 does not affect (Formula presented.) heterogeneity, but this is unproven. We tested the hypothesis that alternating FIO2 exposure increases (Formula presented.) mismatch in nine patients with abnormal pulmonary gas exchange and increased (Formula presented.) mismatch using the multiple inert gas elimination technique (MIGET).The following data were acquired (a) breathing air (baseline), (b) breathing alternating air/100\% O2 during an emulated-SVI protocol (eSVI), and (c) 20 min after ambient air breathing (recovery). MIGET heterogeneity indices of shunt, deadspace, ventilation versus (Formula presented.) ratio, LogSD (Formula presented.), and perfusion versus (Formula presented.) ratio, LogSD (Formula presented.) were calculated. LogSD (Formula presented.) was not different between eSVI and baseline (1.04 ± 0.39 baseline, 1.05 ± 0.38 eSVI, p =.84); but was reduced compared to baseline during recovery (0.97 ± 0.39, p =.04). There was no significant difference in LogSD (Formula presented.) across conditions (0.81 ± 0.30 baseline, 0.79 ± 0.15 eSVI, 0.79 ± 0.20 recovery; p =.54); Deadspace was not significantly different (p =.54) but shunt showed a borderline increase during eSVI (1.0\% ± 1.0 baseline, 2.6\% ± 2.9 eSVI; p =.052) likely from altered hypoxic pulmonary vasoconstriction and/or absorption atelectasis. Intermittent breathing of 100\% O2 does not substantially alter (Formula presented.) matching and if SVI measurements are made after perfusion measurements, any potential effects will be minimized.",

keywords = "hyperoxia, magnetic resonance imaging, pulmonary perfusion distribution, pulmonary ventilation distribution, specific ventilation imaging, ventilation-perfusion ratio",

author = "Elliott, \{Ann R.\} and \{Kizhakke Puliyakote\}, \{Abhilash S.\} and Vincent Tedjasaputra and Beni Paz{\'a}r and Harrieth Wagner and \{Rui C.\}, S. and Orr, \{Jeremy E.\} and Prisk, \{G. Kim\} and Wagner, \{Peter D.\} and Hopkins, \{Susan R.\}",

year = "2020",

month = jul,

doi = "10.14814/phy2.14488",

language = "English",

volume = "8",

journal = "Physiological Reports",

issn = "2051-817X",

publisher = "Blackwell Publishing",

number = "13",

}

Elliott, AR, Kizhakke Puliyakote, AS, Tedjasaputra, V, Pazár, B, Wagner, H, Rui C., S, Orr, JE, Prisk, GK, Wagner, PD & Hopkins, SR 2020, 'Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O₂', Physiological Reports, vol. 8, no. 13, e14488. https://doi.org/10.14814/phy2.14488

TY - JOUR

T1 - Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O2

AU - Elliott, Ann R.

AU - Kizhakke Puliyakote, Abhilash S.

AU - Tedjasaputra, Vincent

AU - Pazár, Beni

AU - Wagner, Harrieth

AU - Rui C., S.

AU - Orr, Jeremy E.

AU - Prisk, G. Kim

AU - Wagner, Peter D.

AU - Hopkins, Susan R.

PY - 2020/7

Y1 - 2020/7

N2 - Proton magnetic resonance (MR) imaging to quantify regional ventilation–perfusion ((Formula presented.)) ratios combines specific ventilation imaging (SVI) and separate proton density and perfusion measures into a composite map. Specific ventilation imaging exploits the paramagnetic properties of O2, which alters the local MR signal intensity, in an FIO2-dependent manner. Specific ventilation imaging data are acquired during five wash-in/wash-out cycles of breathing 21% O2 alternating with 100% O2 over ~20 min. This technique assumes that alternating FIO2 does not affect (Formula presented.) heterogeneity, but this is unproven. We tested the hypothesis that alternating FIO2 exposure increases (Formula presented.) mismatch in nine patients with abnormal pulmonary gas exchange and increased (Formula presented.) mismatch using the multiple inert gas elimination technique (MIGET).The following data were acquired (a) breathing air (baseline), (b) breathing alternating air/100% O2 during an emulated-SVI protocol (eSVI), and (c) 20 min after ambient air breathing (recovery). MIGET heterogeneity indices of shunt, deadspace, ventilation versus (Formula presented.) ratio, LogSD (Formula presented.), and perfusion versus (Formula presented.) ratio, LogSD (Formula presented.) were calculated. LogSD (Formula presented.) was not different between eSVI and baseline (1.04 ± 0.39 baseline, 1.05 ± 0.38 eSVI, p =.84); but was reduced compared to baseline during recovery (0.97 ± 0.39, p =.04). There was no significant difference in LogSD (Formula presented.) across conditions (0.81 ± 0.30 baseline, 0.79 ± 0.15 eSVI, 0.79 ± 0.20 recovery; p =.54); Deadspace was not significantly different (p =.54) but shunt showed a borderline increase during eSVI (1.0% ± 1.0 baseline, 2.6% ± 2.9 eSVI; p =.052) likely from altered hypoxic pulmonary vasoconstriction and/or absorption atelectasis. Intermittent breathing of 100% O2 does not substantially alter (Formula presented.) matching and if SVI measurements are made after perfusion measurements, any potential effects will be minimized.

AB - Proton magnetic resonance (MR) imaging to quantify regional ventilation–perfusion ((Formula presented.)) ratios combines specific ventilation imaging (SVI) and separate proton density and perfusion measures into a composite map. Specific ventilation imaging exploits the paramagnetic properties of O2, which alters the local MR signal intensity, in an FIO2-dependent manner. Specific ventilation imaging data are acquired during five wash-in/wash-out cycles of breathing 21% O2 alternating with 100% O2 over ~20 min. This technique assumes that alternating FIO2 does not affect (Formula presented.) heterogeneity, but this is unproven. We tested the hypothesis that alternating FIO2 exposure increases (Formula presented.) mismatch in nine patients with abnormal pulmonary gas exchange and increased (Formula presented.) mismatch using the multiple inert gas elimination technique (MIGET).The following data were acquired (a) breathing air (baseline), (b) breathing alternating air/100% O2 during an emulated-SVI protocol (eSVI), and (c) 20 min after ambient air breathing (recovery). MIGET heterogeneity indices of shunt, deadspace, ventilation versus (Formula presented.) ratio, LogSD (Formula presented.), and perfusion versus (Formula presented.) ratio, LogSD (Formula presented.) were calculated. LogSD (Formula presented.) was not different between eSVI and baseline (1.04 ± 0.39 baseline, 1.05 ± 0.38 eSVI, p =.84); but was reduced compared to baseline during recovery (0.97 ± 0.39, p =.04). There was no significant difference in LogSD (Formula presented.) across conditions (0.81 ± 0.30 baseline, 0.79 ± 0.15 eSVI, 0.79 ± 0.20 recovery; p =.54); Deadspace was not significantly different (p =.54) but shunt showed a borderline increase during eSVI (1.0% ± 1.0 baseline, 2.6% ± 2.9 eSVI; p =.052) likely from altered hypoxic pulmonary vasoconstriction and/or absorption atelectasis. Intermittent breathing of 100% O2 does not substantially alter (Formula presented.) matching and if SVI measurements are made after perfusion measurements, any potential effects will be minimized.

KW - hyperoxia

KW - magnetic resonance imaging

KW - pulmonary perfusion distribution

KW - pulmonary ventilation distribution

KW - specific ventilation imaging

KW - ventilation-perfusion ratio

UR - https://www.scopus.com/pages/publications/85087661566

U2 - 10.14814/phy2.14488

DO - 10.14814/phy2.14488

M3 - Article

C2 - 32638530

AN - SCOPUS:85087661566

SN - 2051-817X

VL - 8

JO - Physiological Reports

JF - Physiological Reports

IS - 13

M1 - e14488

ER -

Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O₂

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