Automatic adjustment of noninvasive pressure support with a bilevel home ventilator in patients with acute respiratory failure: a feasibility study.
OBJECTIVE
To test the feasibility of applying noninvasive ventilation (NIV) using a prototype algorithm implemented in a bilevel ventilation device designed to adjust pressure support (PS) to maintain a clinician-set alveolar ventilation in patients with acute respiratory failure after initial stabilization.


METHODS
Prospective crossover interventional study in an intensive care unit, university hospital.


METHODS
19 patients receiving NIV for acute hypercapnic respiratory failure (13 men, 6 women; mean age 70+/-11 years).


METHODS
The same bilevel ventilator was used with manually adjusted PS and with the automated algorithm (autoPS), set to maintain the same alveolar ventilation as in PS. Sequence (measurements at end of each period): (a) prior to initiating NIV (baseline 1); (b) 45 min with manually set PS; (c) 60 min without NIV; (d) 45 min with autoPS; (e) 60 min without NIV; (f) 45 min with manually set PS.


RESULTS
The magnitude of decrease in PaCO(2) and increase in pH with autoPS was comparable to that of conventional PS, with the same alveolar ventilation and level of PS. No technical problem occurred in autoPS mode, and no NIV trial had to be discontinued because of patient discomfort.


CONCLUSIONS
These results suggest that the alveolar ventilation based automatic control of PS during NIV with a bilevel device is feasible and leads to beneficial effects in patients with acute respiratory failure comparable to those of manually set PS. Further studies should now explore the potential of this system over longer periods in patients with acute and chronic respiratory failure.
Battisti
Anne
A
Department of Intensive Care, University Hospital, 1211, Geneva 14, Switzerland.
Tassaux
Didier
D
Bassin
David
D
Jolliet
Philippe
P
D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D001794:Blood Pressure; D018592:Cross-Over Studies; D005240:Feasibility Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D012121:Respiration, Artificial / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000628:therapy*