Cardio-respiratory interactions in acute asthma

Figures

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  FIGURE 1. The increase in pulmonary vascular resistances (PVR) from Zone west 3 to zone West 1. in the upper zones (zones 1 of West), the alveolar pressure (Palv) is higher than the intravascular pressure (PAP and PVP) and occludes the intra-alveolar vessels, in the lower zones (zones 3 of West) the intravascular pressure is higher than the alveolar pressure and the vascular resistances are weak. The regimen is intermediate in the middle zones (zones 2 of West).

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  FIGURE 2. Reproduced with permission of the © ERS 2023: European Respiratory Journal December 2013, 42 (6) 1,696–1,705; DOI: 10.1183/09031936.00138912). Relationships between pulmonary vascular resistances and lung volume (see text for detailed explanations). FRC, functional residual capacity; TLC, total lung capacity; RV, residual volume.

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  FIGURE 3. Reproduced with permission of the © ERS 2023: European Respiratory Journal December 2013, 42 (6) 1,696–1,705; DOI: 10.1183/09031936.00138912. Recording of arterial pressure measured using an arterial catheter in a patient with acute exacerbation of airway obstruction. Pulsus paradoxus is present as the decrease in systolic arterial pressure is >10 mmHg (about 17 mmHg). Note that the arterial pulse pressure also decreases at inspiration suggesting that LV stroke volume decreases at inspiration. The grey areas indicate the inspiratory phases (Insp).