PT  - JOURNAL ARTICLE
AU  - B Schonhofer
AU  - M Sonneborn
AU  - P Haidl
AU  - H Bohrer
AU  - D Kohler
TI  - Comparison of two different modes for noninvasive mechanical ventilation in chronic respiratory failure: volume versus pressure controlled device
AID  - 10.1183/09031936.97.10010184
DP  - 1997 Jan 01
TA  - European Respiratory Journal
PG  - 184--191
VI  - 10
IP  - 1
4099  - http://erj.ersjournals.com/content/10/1/184.short
4100  - http://erj.ersjournals.com/content/10/1/184.full
SO  - Eur Respir J1997 Jan 01; 10
AB  - The most commonly used mode of noninvasive mechanical ventilation (NMV) is volume-controlled intermittent positive pressure ventilation (IPPV). Pressure support ventilation has recently become increasingly popular, but its merits have not been clearly defined. In an open, nonrandomized follow-up study, we evaluated two modes of NMV, volume-controlled (IPPV) and pressure-controlled ventilation (PCV) over 6 months in 30 consecutive patients (24 males and 6 females, aged 49 +/- 19 yrs) with chronic respiratory failure (CRF). The baseline assessments comprised both physiological and subjective data. In all cases, nasal IPPV was initially administered for 1 month, followed by a second month of nasal PCV. Thereafter, responders or nonresponders to PCV were defined according to the patients' subjective symptom score and/or the recurrence of hypercapnia. During the IPPV phase, in all but two patients the subjective and objective parameters improved significantly. During the following 1 month PCV phase, stabilization was maintained in 18 patients ("responders"), while 10 patients were defined as "nonresponders". In nonresponders, hypercapnia increased (arterial carbon dioxide tension (Pa,CO2): 5.7 +/- 0.4 to 6.6 +/- 0.5 kPa; p < 0.05) and symptom scores decreased. Compared with responders, nonresponders had a lower mean nocturnal arterial oxygen saturation (Sa,O2) (p < 0.05) and a higher daytime Pa,CO2 (p < 0.05) at baseline. We con clude that the majority of patients suffering from chronic respiratory failure who are initially satisfactorily ventilated with intermittent positive pressure ventilation may also be adequately maintained with pressure-controlled ventilation. However, there is a subgroup with more severe chronic respiratory failure at baseline, in whom pressure-controlled ventilation is inadequate. After 4 weeks of treatment with pressure-controlled ventilation, the subjective scores and the arterial carbon dioxide tension values reliably distinguished between long-term responders and nonresponders to pressure-controlled ventilation.