Utilization of the lower inflection point of the pressure-volume curve results in protective conventional ventilation comparable to high frequency oscillatory ventilation in an animal model of acute respiratory distress syndrome
Clinics
;
63(2): 237-244, 2008. graf, tab
Article
in English
| LILACS
| ID: lil-481054
ABSTRACT
INTRODUCTION:
Studies comparing high frequency oscillatory and conventional ventilation in acute respiratory distress syndrome have used low values of positive end-expiratory pressure and identified a need for better recruitment and pulmonary stability with high frequency.OBJECTIVE:
To compare conventional and high frequency ventilation using the lower inflection point of the pressure-volume curve as the determinant of positive end-expiratory pressure to obtain similar levels of recruitment and alveolar stability.METHODS:
After lung lavage of adult rabbits and lower inflection point determination, two groups were randomized conventional (positive end-expiratory pressure = lower inflection point; tidal volume=6 ml/kg) and high frequency ventilation (mean airway pressures= lower inflection point +4 cmH2O). Blood gas and hemodynamic data were recorded over 4 h. After sacrifice, protein analysis from lung lavage and histologic evaluation were performed.RESULTS:
The oxygenation parameters, protein and histological data were similar, except for the fact that significantly more normal alveoli were observed upon protective ventilation. High frequency ventilation led to lower PaCO2 levels.DISCUSSION:
Determination of the lower inflection point of the pressure-volume curve is important for setting the minimum end expiratory pressure needed to keep the airways opened. This is useful when comparing different strategies to treat severe respiratory insufficiency, optimizing conventional ventilation, improving oxygenation and reducing lung injury.CONCLUSIONS:
Utilization of the lower inflection point of the pressure-volume curve in the ventilation strategies considered in this study resulted in comparable efficacy with regards to oxygenation and hemodynamics, a high PaCO2 level and a lower pH. In addition, a greater number of normal alveoli were found after protective conventional ventilation in an animal model of acute respiratory distress syndrome.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Respiratory Distress Syndrome
/
High-Frequency Ventilation
/
Positive-Pressure Respiration
/
Disease Models, Animal
Type of study:
Prognostic study
Limits:
Animals
Language:
English
Journal:
Clinics
Journal subject:
Medicine
Year:
2008
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
São Paulo University/BR
Similar
MEDLINE
...
LILACS
LIS