P. Neumann et al., EFFECT OF DIFFERENT PRESSURE LEVELS ON THE DYNAMICS OF LUNG COLLAPSE AND RECRUITMENT IN OLEIC-ACID-INDUCED LUNG INJURY, American journal of respiratory and critical care medicine, 158(5), 1998, pp. 1636-1643
Citations number
22
Categorie Soggetti
Emergency Medicine & Critical Care","Respiratory System
The effects of different inspiratory and expiratory airway pressures (
Paw) on the dynamics of lung collapse and recruitment were studied in
14 anesthetized, mechanically ventilated, pigs with oleic-cid-induced
lung injury. Repetitive CT scans of the same slice were obtained every
0.8 s during different inspiration and expiration hold procedures. Th
e mean lung density and amount of atelectasis were measured in each sc
an. Inspiration to a Paw of 15 cm H2O above PEEP resulted in recruitme
nt of collapsed lung tissue, mainly within 1.4 s. During expiration lu
ng density increased rapidly and at an almost even rate within the fir
st 1.4 s, whereas a rapid increase of atelectasis occurred after an in
itial delay period of 0.6 s with PEEP = 10 or 15 cm H2O. PEEP of 20 or
25 cm H2O almost prevented lung collapse during expiration. Thus, in
order to avoid cyclic alveolar collapse during mechanical ventilation
in oleic-acid-induced lung injury, a PEEP level greater than or equal
to 20 cmH(2)O or an expiration time less than or equal to 0.6 s is req
uired. Long inspiratory time intervals, as used in inverse ratio venti
lation, seem to be of minor importance for the recruitment of collapse
d lung tissue in this experimental model.