Short-term effect of controlled instead of assisted noninvasive ventilation in chronic respiratory failure due to chronic obstructive pulmonary disease.
BACKGROUND
Noninvasive positive-pressure ventilation (NPPV) unloads respiratory muscles. Spontaneous-breathing ventilation modes require patient effort to trigger the ventilator, whereas controlled modes potentially economize on patient triggering effort and thus achieve more complete respiratory muscle rest. Data on controlled NPPV have not been published to date. We hypothesize that controlled ventilation is feasible in patients with hypercapnic chronic obstructive pulmonary disease.


METHODS
We measured blood gas values, respiratory muscle strength, spontaneous breathing pattern, and lung function before and after a 3-month period of NPPV in 305 patients (213 male, mean +/- SD age 61.3 +/- 8.6 y). The subjects used a controlled NPPV mode when they could tolerate it.


RESULTS
Ninety-one percent of the patients were able to adapt to a controlled NPPV mode. In those patients, daytime P(CO(2)) decreased from 56.7 +/- 7.5 mm Hg to 47.5 +/- 6.6 mm Hg (p < 0.001) and P(O(2)) increased from 49.2 +/- 8.8 mm Hg to 56.2 +/- 8.5 mm Hg (p < 0.001). Their mean maximum inspiratory pressure increased from 42.3 +/- 16.9 cm H(2)O to 48.4 +/- 18.0 cm H(2)O (p < 0.001). Their mean vital capacity increased from 1.89 +/- 0.62 L to 1.99 +/- 0.67 L (p = 0.004). And their spontaneous breathing pattern became less rapid and shallow.


CONCLUSIONS
Controlled NPPV is feasible in patients with hypercapnic chronic obstructive pulmonary disease. We observed improved blood gas values, lung function, and inspiratory muscle strength.
Dellweg
Dominic
D
Zentrum für Pneumologie, Beatmung, und Schlafmedizin Allergologie, Fachkrankenhaus Kloster Grafschaft, Annostrasse 1, 57392 Schmallenberg, Germany. d.dellweg@fkkg.de
Schonhofer
Bernd
B
Haidl
Peter M
PM
Barchfeld
Thomas
T
Wenzel
Markus D
MD
Appelhans
Patrick
P
Kohler
Dieter
D
D000368:Aged; D002908:Chronic Disease; D005858:Germany; D006801:Humans; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D011175:Positive-Pressure Respiration / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000628:therapy*; D012131:Respiratory Insufficiency / Q000209:etiology*