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Fig. 1 | Critical Care

Fig. 1

From: Estimation of transpulmonary driving pressure during synchronized mechanical ventilation using a single lower assist maneuver (LAM) in rabbits: a comparison to measurements made with an esophageal balloon

Fig. 1

Sample waveforms during neurally adjusted ventilatory assist (NAVA) and volume control (VC) to demonstrate protocol steps and analysis. Signals were obtained in one animal breathing spontaneously in the NAVA mode (first three breaths), or passively ventilated in VC mode (far right), both shown with resistive load, NAVA level 1.5 cm H2O/uV. From top to bottom, single breath waveforms are presented for ventilator pressure (PVENT), esophageal pressure (PES), transpulmonary pressure (PL), flow and volume (VOL), and electrical activity of the diaphragm (Edi). The first three breaths (left to right) are NAVA breaths during spontaneous breathing. The third breath is a low assist maneuver (LAM), shown in red. The respective waveforms from the LAM (red) were superimposed on the NAVA breaths (green) to demonstrate matching of Edi values. The fourth breath, on the far right, was taken during neuromuscular (NM) blockade, so the subject is not activating their respiratory muscles (Edi is flat) and ventilation is passive (PES goes positive for the breath) during Volume Control mode (blue lines). We superimposed the assisted breath with the CMV breath to demonstrate the matching of volume and flow for spontaneous (green) and passive (blue) breaths

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Critical Care

ISSN: 1364-8535