Journal article
Hypoxic Pulmonary Vasoconstriction Does Not Explain All Regional Perfusion Redistribution in Asthma
American journal of respiratory and critical care medicine, Vol.196(7), pp.834-844
10/01/2017
DOI: 10.1164/rccm.201612-2438OC
PMCID: PMC5649975
PMID: 28644040
Abstract
Regional hypoventilation in bronchoconstricted patients with asthma is spatially associated with reduced perfusion, which is proposed to result from hypoxic pulmonary vasoconstriction (HPV).
To determine the role of HPV in the regional perfusion redistribution in bronchoconstricted patients with asthma.
Eight patients with asthma completed positron emission tomographic/computed tomographic lung imaging at baseline and after bronchoconstriction, breathing either room air or 80% oxygen (80% O
) on separate days. Relative perfusion, specific ventilation (sV), and gas fraction (Fgas) in the 25% of the lung with the lowest specific ventilation (sV
) and the remaining lung (sV
) were quantified and compared.
In the sV
region, bronchoconstriction caused a significant decrease in sV under both room air and 80% O
conditions (baseline vs. bronchoconstriction, mean ± SD, 1.02 ± 0.20 vs. 0.35 ± 0.19 and 1.03 ± 0.20 vs. 0.32 ± 0.16, respectively; P < 0.05). In the sV
region, relative perfusion decreased after bronchoconstriction under room air conditions and also, to a lesser degree, under 80% O
conditions (1.02 ± 0.19 vs. 0.72 ± 0.08 [P < 0.001] and 1.08 ± 0.19 vs. 0.91 ± 0.12 [P < 0.05], respectively). The Fgas increased after bronchoconstriction under room air conditions only (0.99 ± 0.04 vs. 1.00 ± 0.02; P < 0.05). The sV
subregion analysis indicated that some of the reduction in relative perfusion after bronchoconstriction under 80% O
conditions occurred as a result of the presence of regional hypoxia. However, relative perfusion was also significantly reduced in sV
subregions that were hyperoxic under 80% O
conditions.
HPV is not the only mechanism that contributes to perfusion redistribution in bronchoconstricted patients with asthma, suggesting that another nonhypoxia mechanism also contributes. We propose that this nonhypoxia mechanism may be either direct mechanical interactions and/or unidentified intercellular signaling between constricted airways, the parenchyma, and the surrounding vasculature.
Details
- Title: Subtitle
- Hypoxic Pulmonary Vasoconstriction Does Not Explain All Regional Perfusion Redistribution in Asthma
- Creators
- Vanessa J Kelly - Pulmonary and Critical Care AssociatesKathryn A Hibbert - Pulmonary and Critical Care AssociatesPuja Kohli - Pulmonary and Critical Care AssociatesMamary Kone - Pulmonary and Critical Care AssociatesElliot E Greenblatt - Massachusetts General HospitalJose G Venegas - Harvard UniversityTilo Winkler - Massachusetts General HospitalR Scott Harris - Pulmonary and Critical Care Associates
- Resource Type
- Journal article
- Publication Details
- American journal of respiratory and critical care medicine, Vol.196(7), pp.834-844
- DOI
- 10.1164/rccm.201612-2438OC
- PMID
- 28644040
- PMCID
- PMC5649975
- NLM abbreviation
- Am J Respir Crit Care Med
- ISSN
- 1073-449X
- eISSN
- 1535-4970
- Grant note
- T32 HL007874 / NHLBI NIH HHS F32 HL128026 / NHLBI NIH HHS R01 HL086717 / NHLBI NIH HHS
- Language
- English
- Date published
- 10/01/2017
- Academic Unit
- Anesthesia
- Record Identifier
- 9985141863702771
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