Dataset Information

Microcirculatory dysfunction and dead-space ventilation in early ARDS: a hypothesis-generating observational study.

ABSTRACT:

Background

Ventilation/perfusion inequalities impair gas exchange in acute respiratory distress syndrome (ARDS). Although increased dead-space ventilation (V_D/V_T) has been described in ARDS, its mechanism is not clearly understood. We sought to evaluate the relationships between dynamic variations in V_D/V_T and extra-pulmonary microcirculatory blood flow detected at sublingual mucosa hypothesizing that an altered microcirculation, which is a generalized phenomenon during severe inflammatory conditions, could influence ventilation/perfusion mismatching manifested by increases in V_D/V_T fraction during early stages of ARDS.

Methods

Forty-two consecutive patients with early moderate and severe ARDS were included. PEEP was set targeting the best respiratory-system compliance after a PEEP-decremental recruitment maneuver. After 60 min of stabilization, hemodynamics and respiratory mechanics were recorded and blood gases collected. V_D/V_T was calculated from the CO₂ production ([Formula: see text]) and CO₂ exhaled fraction ([Formula: see text]) measurements by volumetric capnography. Sublingual microcirculatory images were simultaneously acquired using a sidestream dark-field device for an ulterior blinded semi-quantitative analysis. All measurements were repeated 24 h after.

Results

Percentage of small vessels perfused (PPV) and microcirculatory flow index (MFI) were inverse and significantly related to V_D/V_T at baseline (Spearman's rho?=?- 0.76 and - 0.63, p?2?=?0.63, and 0.48, p?2?=?0.66 and 0.60, p?D/V_T. Variations in PPV between baseline and 24 h were inverse and significantly related to simultaneous changes in V_D/V_T (Spearman's rho?=?- 0.66, p?2?=?0.67, p?ConclusionIncreased heterogeneity of microcirculatory blood flow evaluated at sublingual mucosa seems to be related to increases in V_D/V_T, while respiratory mechanics and oxygenation parameters do not. Whether there is a cause-effect relationship between microcirculatory dysfunction and dead-space ventilation in ARDS should be addressed in future research.

SUBMITTER: Ospina-Tascon GA

PROVIDER: S-EPMC7093634 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Microcirculatory dysfunction and dead-space ventilation in early ARDS: a hypothesis-generating observational study.

Ospina-Tascón Gustavo A GA Bautista Diego F DF Madriñán Humberto J HJ Valencia Juan D JD Bermúdez William F WF Quiñones Edgardo E Calderón-Tapia Luis Eduardo LE Hernandez Glenn G Bruhn Alejandro A De Backer Daniel D

Annals of intensive care 20200324 1

<h4>Background</h4>Ventilation/perfusion inequalities impair gas exchange in acute respiratory distress syndrome (ARDS). Although increased dead-space ventilation (V<sub>D</sub>/V<sub>T</sub>) has been described in ARDS, its mechanism is not clearly understood. We sought to evaluate the relationships between dynamic variations in V<sub>D</sub>/V<sub>T</sub> and extra-pulmonary microcirculatory blood flow detected at sublingual mucosa hypothesizing that an altered microcirculation, which is a gen ...[more]

PMID: 32211957

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Dataset Information

Microcirculatory dysfunction and dead-space ventilation in early ARDS: a hypothesis-generating observational study.

Background

Methods

Results

Publications

Microcirculatory dysfunction and dead-space ventilation in early ARDS: a hypothesis-generating observational study.

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