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Decelerating inspiratory flow waveform improves lung mechanics and gas exchange in patients on intermittent positive-pressure ventilation

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Abstract

The effects of two inspiratory flow waveforms (WFs), decelerating and constant have been studied in 14 patients undergoing intermittent positive-pressure ventilation (IPPV). With tidal volume (VT), inspiratory time, inspiratory-expiratory (I/E) ratio and frequency being kept constant, the decelerating waveform produced statistically significant reduction of peak pressure, total respiratory resistance, work of inspiration, ratio of dead space to tidal volume (VD/VT) and alveolar-arterial gradient for oxygen (A-a)PO2. There was significant increase in total static and kinetic compliances and PaO2, with no significant changes in PaCO2, in cardiac output (CO) and in other haemodynamic measurements.

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Al-Saady, N., Bennett, E.D. Decelerating inspiratory flow waveform improves lung mechanics and gas exchange in patients on intermittent positive-pressure ventilation. Intensive Care Med 11, 68–75 (1985). https://doi.org/10.1007/BF00254777

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Key words

  • IPPV
  • Inspiratory WFs
  • VD/VT ratio
  • PaO2
  • (A-a)PO2 and CO