Patient controlled pressure support ventilation

Introduction

Pressure support ventilation is mostly used in weaning from mechanical ventilaton in acute respiratory failure. There are no data regarding the optimal level of assistance for each patient in different clinical conditions. We approach a new method that allows patients to set their own PSV level by a remote control connected to the ventilator.

Materials and methods

In 9 awake intubated patients (age 57 ± 17 years, BMI 24 ± 3 kg/m², PaO₂/FiO₂ 283 ± 51, Ramsey 1.9 ± 0.4) we measured the breathing pattern (V_T, RR), the work of breathing (WOB J/min, estimated from a modified Campbell diagram [1]) and the dyspnea sensation using the Borg visual scale [2]. Patients were studied at three fixed levels of PSV (5-15-25 cmH₂O). At the end of each step we gave the patient the possibility to change the level of PSV using the remote control. Patients were previously instructed by attendant physician about the use of the remote control.

Results

See Table and Figure. It appears that increasing the pressure support level, the patient work of breathing decreases while the Borg dyspnea scale shows no significant differences.

Figure

The dyspnea sensation when patient is allowed to set the pressure support level.

Table

Conclusions

Patient controlled PSV could be a useful technique in ventilatory management of critically ill awake patients.