Comparison of mask and nasal continuous positive airway pressure after extubation and mechanical ventilation.
OBJECTIVE
To examine the effects of continuous positive airway pressure applied via face masks and nose masks on the change in functional residual capacity and gas exchange.


METHODS
Descriptive and prospective study.


METHODS
Intensive care unit of a university hospital.


METHODS
Ten patients with acute lung injury who had required mechanical ventilation.


METHODS
Continuous positive airway pressure at a level of 10 cm H2O applied in random order via face and nose masks.


RESULTS
Both continuous positive airway pressure methods resulted in an almost identical increase of functional residual capacity. During nasal continuous positive airway pressure, the increase in functional residual capacity was 294 +/- 82 mL. During mask continuous positive airway pressure, the increase in functional residual capacity was 290 +/- 85 mL. PaO2 increased and the alveolar-arterial oxygen tension/alveolar oxygen tension quotient decreased significantly during mask continuous positive airway pressure and nasal continuous positive airway pressure at a level of 10 cm H2O. Two patients showed a periodic change in their breathing patterns; they took a few breaths at an increased lung volume, followed by one deep expiration caused by mouth opening. Change in mask pressure was negligible in these two patients. Using a visual analog scale (10 = highly comfortable; 0 = severely uncomfortable), the patients rated nasal continuous positive airway pressure (8.6 +/- 0.9) significantly more comfortable than mask continuous positive airway pressure (2.6 +/- 0.8).


CONCLUSIONS
The major advantages of continuous positive airway pressure (the improvement of functional residual capacity and oxygen transfer) can also be achieved with nasal continuous positive airway pressure in the postextubation period in patients who have been mechanically ventilated for acute lung injury.
Putensen
C
C
Clinic of Anesthesia and Intensive Care Medicine, University of Innsbruck, Austria.
Hörmann
C
C
Baum
M
M
Lingnau
W
W
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000403:Airway Resistance; D005260:Female; D005652:Functional Residual Capacity; D006801:Humans; D007442:Intubation, Intratracheal; D055370:Lung Injury; D008297:Male; D008397:Masks; D009104:Multiple Trauma; D011175:Positive-Pressure Respiration / Q000379:methods*; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial