RT Journal Article
SR Electronic
T1 Physiological changes during low and high “intensity “ noninvasive ventilation
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP erj00561-2011
DO 10.1183/09031936.00056111
A1 J. Lukácsovits
A1 A. Carlucci
A1 N. Hill
A1 P. Ceriana
A1 L. Pisani
A1 A. Schreiber
A1 P. Pierucci
A1 G. Losonczy
A1 S. Nava
YR 2011
UL http://erj.ersjournals.com/content/early/2011/09/01/09031936.00056111.abstract
AB In a physiological randomized cross-over study, performed in stable hypercapnic COPD patients, we have assessed the short term effects of two settings of non-invasive ventilation, one aimed at maximally reducing Pa,CO2 level (Hi-NPPV:27.6±2.1 cmH2O of IPAP, 4±0 cmH2O of EPAP and respiratory rate of 22·min−1) and one according to the usual parameters used in earlier studies (Li-NPPV:17.7±1.6 cmH2O of IPAP, 4±0 cmH2O of EPAP and respiratory rate of 12·min−1). Both modes of ventilation significantly improved gas exchange compared to spontaneous breathing (SB), but to a greater extent using Hi-NPPV (PCO2:59.3±7.5, 55.2±6.9 and 49.4±7.8 mmHg, for SB, Li-NPPV and Hi-NPPV respectively). Similarly Hi-NPPV induced a greater reduction in the Pressure Time Product of the diaphragm per minute from 323±149 cmH2O*sec·min−1 during SB to 132±139 cmH2O*sec·min−1 during Li-NPPV and 40±69 cmH2O*sec·min−1 during Hi-NPPV, while in 9/15 patients completely abolished spontaneous breathing activity. Hi-NPPV also induced a marked reduction in cardiac output measured noninvasively with a Finometer, compared to Li-NPPV. We conclude that while Hi-NPPV is more effective than Li-NPPV in improving gas exchange and in reducing inspiratory effort, it induces a marked reduction in cardiac output, which needs to be considered when Hi-NPPV is applied to patients with pre-existing cardiac disease.