Intermittent positive pressure ventilation increases diastolic pulmonary arterial pressure in advanced COPD

ObjectivesTo measure the impact of intermittent positive pressure ventilation (IPPV) on diastolic pulmonary arterial pressure (dPAP) and pulmonary pulse pressure in patients with advanced COPD.BackgroundThe physiological effects of raised intrathoracic pressures upon the pulmonary circulation have not been fully established.Methods22 subjects with severe COPD receiving IPPV were prospectively assessed with pulmonary and radial arterial catheterization. Changes in dPAP were assessed from end-expiration to early inspiration during low and high tidal volume ventilation.ResultsInspiration during low tidal volume IPPV increased the median [IQR] dPAP by 3.9 [2.5–4.8] mm Hg (P < 0.001). During high tidal volume, similar changes were observed. The IPPV-associated change in dPAP was correlated with baseline measures of PaO2 (rho = 0.65, P = 0.005), pH (rho = 0.64, P = 0.006) and right atrial pressure (rho = −0.53, P = 0.011).ConclusionsIn severe COPD, IPPV increases dPAP and reduces pulmonary pulse pressure during inspiration.