Microcirculatory dysfunction and dead-space ventilation in early ARDS: a hypothesis-generating observational study
| Autor: | Alejandro Bruhn, Gustavo A. Ospina-Tascón, Juan David Valencia, Humberto J. Madriñán, Daniel De Backer, Diego F. Bautista, Edgardo Quiñones, Luis Eduardo Calderón-Tapia, Glenn Hernandez, William F. Bermudez |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
medicine.medical_specialty
ARDS Dead-space ventilation Ventilation perfusion mismatch Hemodynamics Respiratory physiology Microcirculatory blood flow Critical Care and Intensive Care Medicine 03 medical and health sciences 0302 clinical medicine V D/V T Internal medicine Medicine Respiratory system Ventilation/perfusion mismatch VD/VT Acute respiratory distress syndrome business.industry Research Microcirculation lcsh:Medical emergencies. Critical care. Intensive care. First aid 030208 emergency & critical care medicine lcsh:RC86-88.9 Blood flow Oxygenation medicine.disease 030228 respiratory system Breathing Cardiology Economie business |
| Zdroj: | Annals of intensive care, 10 (1 Annals of Intensive Care Annals of Intensive Care, Vol 10, Iss 1, Pp 1-11 (2020) |
| Popis: | Background: Ventilation/perfusion inequalities impair gas exchange in acute respiratory distress syndrome (ARDS). Although increased dead-space ventilation (VD/VT) has been described in ARDS, its mechanism is not clearly understood. We sought to evaluate the relationships between dynamic variations in VD/VT 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 VD/VT 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. VD/VT was calculated from the CO2 production (VCO2) and CO2 exhaled fraction (FECO2) 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 VD/VT at baseline (Spearman’s rho = − 0.76 and − 0.63, p < 0.001; R2 = 0.63, and 0.48, p < 0.001, respectively) and 24 h after (Spearman’s rho = − 0.71, and − 0.65; p < 0.001; R2 = 0.66 and 0.60, p < 0.001, respectively). Other respiratory, macro-hemodynamic and oxygenation parameters did not correlate with VD/VT. Variations in PPV between baseline and 24 h were inverse and significantly related to simultaneous changes in VD/VT (Spearman’s rho = − 0.66, p < 0.001; R2 = 0.67, p < 0.001). Conclusion: Increased heterogeneity of microcirculatory blood flow evaluated at sublingual mucosa seems to be related to increases in VD/VT, 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. SCOPUS: ar.j info:eu-repo/semantics/published |
| Databáze: | OpenAIRE |
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