dead space ventilation in cardiaovascular disease cpet

Dead space (Vd) is the portion of each tidal volume that does not take part in gas exchange and includes: anatomical dead space (Vd aw), that is the part of airways that do not contribute to gas exchange (nose, pharynx, conduction airways and ventilator equipment if mechanical ventilation is present) and alveolar dead space (Vd alv) or alveoli which are well-ventilated but poorly perfused ( 1, 2). Physiological gas exchange occurs only in presence of ventilation and perfusion (V/Q) homogeneity nevertheless an easy and accurate indicator that can measure V/Q alterations is far from being available. Keywords: Dead space acute respiratory distress syndrome (ARDS) volumetric capnography lung recruitment Different capnographic indices can be useful to evaluate therapeutic interventions or setting mechanical ventilation. Dead space measurement is a reliable method that provides important clinical and prognostic information. Different patterns of ventilation affect also CO 2 elimination in fact, end-inspiratory pause prolongation reduces dead space, increasing respiratory system compliance plateau pressure and consequently driving pressure increase accordingly. Dead space guided recruitment allows avoiding regional overdistension or reduction in cardiac output in critical care patients with ALI or ARDS.

Lung recruitment is a dynamic process that combines recruitment manoeuvres (RMs) with positive end expiratory pressure (PEEP) and low Vt to recruit collapsed alveoli. Different dead space indices can provide useful information in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) patients, where changes in microvasculature are the main determinants for the increase in dead space and consequently a worsening of the outcome. Dead space is not routinely measured in critical care practice, because the difficulties in in interpreting capnograms and the different methods of calculations. Policy of Dealing with Allegations of Research MisconductĪbstract: Dead space is the portion of each tidal volume that does not take part in gas exchange and represents a good global index of the efficiency of the lung function.Policy of Screening for Plagiarism Process.

Dead space ventilation in cardiaovascular disease cpet