Effects of frequency and inspiratory plateau pressure during recruitment manoeuvres on lung and distal organs in acute lung injury.
OBJECTIVE
To evaluate the effects of frequency and inspiratory plateau pressure (Pplat) during recruitment manoeuvres (RMs) on lung and distal organs in acute lung injury (ALI).


METHODS
We studied paraquat-induced ALI rats. At 24 h, rats were anesthetized and RMs were applied using continuous positive airway pressure (CPAP, 40 cmH(2)O/40 s) or three-different sigh strategies: (a) 180 sighs/h and Pplat = 40 cmH(2)O (S180/40), (b) 10 sighs/h and Pplat = 40 cmH(2)O (S10/40), and (c) 10 sighs/h and Pplat = 20 cmH(2)O (S10/20).


RESULTS
S180/40 yielded alveolar hyperinflation and increased lung and kidney epithelial cell apoptosis as well as type III procollagen (PCIII) mRNA expression. S10/40 resulted in a reduction in epithelial cell apoptosis and PCIII expression. Static elastance and alveolar collapse were higher in S10/20 than S10/40.


CONCLUSIONS
The reduction in sigh frequency led to a protective effect on lung and distal organs, while the combination with reduced Pplat worsened lung mechanics and histology.
Steimback
Paula W
PW
Laboratory of Pulmonary Investigation, Instituto de Biofísica Carlos Chagas Filho, C.C.S., Universidade Federal do Rio de Janeiro, Ilha do Fundão, Rio de Janeiro, RJ 21941-902, Brazil.
Oliveira
Gisele P
GP
Rzezinski
Andréia F
AF
Silva
Pedro L
PL
Garcia
Cristiane S N B
CS
Rangel
Graziela
G
Morales
Marcelo M
MM
Lapa E Silva
José R
JR
Capelozzi
Vera L
VL
Pelosi
Paolo
P
Rocco
Patricia R M
PR
D055371:Acute Lung Injury / Q000139:chemically induced*; D000825:Animal Structures / Q000293:injuries*; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D017063:Outcome Assessment, Health Care; D011650:Pulmonary Alveoli / Q000473:pathology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D011999:Recruitment, Neurophysiological / Q000502:physiology*; D015656:Respiratory Mechanics; D055397:Ventilator-Induced Lung Injury