Data di Pubblicazione:
2006
Citazione:
KEY ROLE OF THE POTENTIALLY RECRUITABLE LUNG ON THE MECHANICAL EFFECTS
OF PEEP DURING ARDS / P. Caironi, M. Cressoni, D. Chiumello, V.M. Ranieri, M. Quintel, R. Cornejo, G. Bugedo, L. Gattinoni. - In: INTENSIVE CARE MEDICINE. - ISSN 0342-4642. - 32:suppl 1(2006), pp. S97-S97. (Intervento presentato al 19. convegno European Society of Intensive Care Medicine, Annual Congress tenutosi a Barcelona nel 2006).
Abstract:
INTRODUCTION. In acute respiratory distress syndrome (ARDS), the effect of high level of positive
end-expiratory pressure (PEEP) on outcome likely depends on the balance between its beneficial and
detrimental effects (reduction of intra-tidal lung opening-closing [O/C] vs. increase of alveolar strain).
We hypothesized that these effects may extensively vary according to the amount of the potentially
recruitable lung (PRL) of each patient.
METHODS. Sixty-eight patients underwent a whole lung CT-scan at 5 and 15 cmH2O PEEP, and
at airway plateau pressure of 45 cmH2O. End-inspiratory non-aerated lung tissue was estimated from
the CT pressure-volume curve. Intra-tidal lung O/C was defined as the difference between the endexpiratory
and end-inspiratory non-aerated lung tissue at each PEEP step, while keeping tidal-volume
(VT) constant (8-10ml/kg). Alveolar strain was calculated as the ratio between the end-inspiratory lung
inflation and end-expiratory lung volume. The amount of PRL was defined as the proportion of lung
tissue regaining aeration between 5 and 45 cmH2O airway pressures.
RESULTS. Patients were divided into those with a lower- and those with a higher-PRL, according to its
median value (9 percent). At 5 cmH2O PEEP, lung O/C in patients with a higher-PRL was greater than
that of patients with a lower-PRL (141±85 [SD] vs. 20±22 gr, P<0.01), which was almost negligible
(2±2% of the lung weight). In contrast, alveolar strain was identical in the two groups (0.38±0.17 vs.
0.41±0.15). Increasing PEEP to 15 cmH2O reduced the lung O/C only in patients with a higher-PRL
(down to 63±87 gr, P<0.01), and increased the alveolar strain at the same extent in both groups (up
to 0.68±0.33 and 0.84±0.26, respectively, P<0.01 for both). Regardless the same VT (9±2 vs. 9±2
ml/kg) and PEEP (12±3 vs. 11±3 cmH2O) clinically employed, patients with a higher-PRL showed a
greater clinical lung O/C (200±106 vs. 36±26 gr, P<0.01), and a higher mortality rate at ICU discharge
(41 vs. 15%, P=0.02), than patients with a lower-PRL.
CONCLUSION. The use of high level of PEEP appears to be physiologically advantageous only in
patients with a higher-PRL, where the beneficial effects may exceed the harmful ones.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Acute Respiratory Distress Syndrome
Elenco autori:
P. Caironi, M. Cressoni, D. Chiumello, V.M. Ranieri, M. Quintel, R. Cornejo, G. Bugedo, L. Gattinoni
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