Journal of critical care
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Journal of critical care · Jun 2011
Changes of heart and respiratory rate dynamics during weaning from mechanical ventilation: a study of physiologic complexity in surgical critically ill patients.
The aim of the study was to investigate heart rate (HR) and respiratory rate (RR) complexity in patients with weaning failure or success, using both linear and nonlinear techniques. ⋯ We suggest that nonlinear analysis of cardiorespiratory dynamics has increased prognostic impact upon weaning outcome in surgical patients.
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Journal of critical care · Jun 2011
Increased pulmonary artery systolic storage associated with improved ventilation-to-perfusion ratios in acute respiratory distress syndrome.
The possibility that the increased pulmonary artery systolic storage (PASS) correlates with an improved distribution of ventilation/perfusion (V(A)/Q) and hence benefits gas exchange in acute respiratory distress syndrome (ARDS) was examined. Pulmonary artery systolic storage is the fraction of stroke volume stored in PA during systole and then discharged to the capillaries. The increased PASS can augment the diastolic pulmonary capillary blood flow (PCBF), which can then increase capillary blood volume participating in gas diffusion. We examined this by assessing the correlation between PASS and physiologic dead space to tidal volume (VD/VT) ratio. ⋯ Our data indicate that the increased PASS correlates with an improved distribution of V(A)/Q and hence benefits gas exchange in ARDS.