[Pressure versus volume constant ventilation in chronic ventilatory insufficiency].
BACKGROUND
Volume controlled intermittent ventilation (IPPV) via face mask is a treatment of proven efficacy for chronic respiratory failure (CRF). Pressure support ventilation has recently been introduced in the treatment of CRF. In this study we investigated whether pressure constant ventilation (PCV) via face mask could be an adequate long term alternative to IPPV.


METHODS
We studied 30 (24 male, age: 52.2 +/- 15.9 years) patients with CRF. We measured the following parameters at baseline, after 1, 2 and 6 months, respectively: blood gas analysis, oxygen saturation, vital capacity, forced exspiratory volume, breathing frequency, tidal volume, inspiratory mouth occlusion pressure, maximal inspiratory pressure, subjective symptom scores and ventilator acceptance scores. In all patients, we attempted to treat with IPPV over 1 month, followed by 1 month's trial of PCV. If PCV, compared to IPPV, was adequate, PCV was continued for a follow-up period of 4 months' duration. If patients deteriorated after PCV they were treated the following 4 months with IPPV.


RESULTS
In 28 out of 30 patients CRF improved concerning subjective and objective parameters. After IPPV 18 out of 28 patients changed to PCV, with an equal quality of treatment (PCV-responder). Ten patients were PCV-nonresponders since compared to IPPV the subjective scores deteriorated and the PaCO2 increased again. In all patients of either therapy group, subjective and objective parameters remained constant for another 4 months period. At baseline the PCV-nonresponders had significantly higher degree of hypercapnia and oxygen desaturation; no other parameters were found to be of predictive value concerning the efficacy of PCV.


CONCLUSIONS
PCV proved to be an alternative to IPPV in the treatment of chronic respiratory insufficiency in approximately 60% of the patients with CRF. However there is a subgroup with more severe CRF at baseline in whom PCV is inadequate.
Sonneborn
M
M
Krankenhaus Kloster Grafschaft, Zentrum für Pneumologie, Beatmungs- und Schlafmedizin, Schmallenberg-Grafschaft.
Schönhofer
B
B
Haidl
P
P
Böhrer
H
H
Köhler
D
D
D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007385:Intermittent Positive-Pressure Ventilation / Q000379:methods*; D008134:Long-Term Care; D008173:Lung Diseases, Obstructive / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D011650:Pulmonary Alveoli / Q000503:physiopathology; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*
D002245:Carbon Dioxide
Druck- versus volumenkonstante Beatmung bei der chronisch ventilatorischen Insuffizienz.