Using Pressure Support Ventilation

In pressure support ventilation, the patient determines the respiratory rate & the duration of inspiration. You set the PEEP and inspiratory pressure (pressure support level). Remember that the peak/plateau pressure is the PS plus the PEEP. On newer ventilators it is possible to adjust the inspiratory slope, to tailor the inspiratory flow rate to patient demands, and the point at which the ventilator cycles off (as a percentage of peak flow). For most patients such adjustments are unnecessary. If the patient requires positive pressure only to overcome the resistance to breathing through an endotracheal tube, consider using automatic tube compensation.

Set PEEP as  in protocol (click here)

Start with pressure support 20cmH20 and adjust to tidal volume 5-6ml/kg (start high and work down - this will recruit collapsed lung units)

Watch lung compliance: increase PS if compliance reduces (decreased tidal volumes) decrease PS if compliance improves (tidal volumes >6ml/kg).

Look at pressure waveform, adjust inspiratory flow (slope) to optimal setting.

Address patient sedation (tachypnea in PSV is often from inadequate sedation)

Patrick Neligan 2002