The present study was designed to analyze the mean pressures and the amount of respiratory work done by the patient and by the respiratory support during assisted intermittent positive pressure (IPPV-ASS) and assisted spontaneous breathing (ASB). During IPPV-ASS the dynamic pressure in the aiways (Paw) overcomes the static pressure (Prs) in every instant of the inspiratory phase, as it occurs during normal IPPV and a very small part of the work is produced by the patient. During ASB the Paw is always lower than the Prs. A large part of the total respiratory work can be substituted by the patient. During IPPV-ASS the mean airway pressure obtained was 10.68 ± 1.99 cm H2O whilst during ASB the same patients showed a value of 2.26 ± 0.35 cm H2O. The difference was statistically significant (t = -9.31; P <0.001). For similar values of end-expiratory pressure the two different methods provide different values in mean intrapulmonary pressure, according to the respiratory work actively done by the patient. The larger the work sustained by the patient the lower the mean intrathoracic pressure.
|Number of pages||2|
|Journal||IRCS Medical Science|
|Publication status||Published - 1984|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)