TY - JOUR
T1 - Lung regional metabolic activity and gas volume changes induced by tidal ventilation in patients with acute lung injury
AU - Bellani, Giacomo
AU - Guerra, Luca
AU - Musch, Guido
AU - Zanella, Alberto
AU - Patroniti, Nicolò
AU - Mauri, Tommaso
AU - Messa, Cristina
AU - Pesenti, Antonio
PY - 2011/5/1
Y1 - 2011/5/1
N2 - Rationale: During acute lung injury (ALI), mechanical ventilation can aggravate inflammation by promoting alveolar distension and cyclic recruitment-derecruitment. As an estimate of the intensity of inflammation,metabolic activity can bemeasured by positrone-mission tomography imaging of [18F]fluoro-2-deoxy-D-glucose. Objectives: To assess the relationship between gas volume changes induced by tidal ventilation and pulmonary metabolic activity in patients with ALI. Methods: In 13 mechanically ventilated patients with ALI and relatively high positive end-expiratory pressure, we performed a positron emission tomography scan of the chest and three computed tomography scans: at mean airway pressure, end-expiration, and end-inspiration. Metabolicactivitywasmeasuredfromthe[18F]fluoro-2-deoxy-D-glucose uptake rate. The computed tomography scans were used to classify lung regions as derecruited throughout the respiratory cycle, undergoing recruitment-derecruitment, and normally aerated. Measurements and Main Results: Metabolic activity of normally aerated lung was positively correlated both with plateau pressure, showing a pronounced increase above 26 to 27 cm H2O, and with regional VT normalized by end-expiratory lung gas volume. This relationship did not appear to be caused by a higher underlying parenchymal metabolic activity in patients with higher plateau pressure. Regions undergoing cyclic recruitment-derecruitment did not have higher metabolic activity than those collapsed throughout the respiratory cycle. Conclusions: In patients with ALI managed with relatively high end-expiratory pressure, metabolic activity of aerated regions was associated with both plateau pressure and regional VT normalized by end-expiratory lung gas volume, whereas no association was found between cyclic recruitment- derecruitment and increased metabolic activity.
AB - Rationale: During acute lung injury (ALI), mechanical ventilation can aggravate inflammation by promoting alveolar distension and cyclic recruitment-derecruitment. As an estimate of the intensity of inflammation,metabolic activity can bemeasured by positrone-mission tomography imaging of [18F]fluoro-2-deoxy-D-glucose. Objectives: To assess the relationship between gas volume changes induced by tidal ventilation and pulmonary metabolic activity in patients with ALI. Methods: In 13 mechanically ventilated patients with ALI and relatively high positive end-expiratory pressure, we performed a positron emission tomography scan of the chest and three computed tomography scans: at mean airway pressure, end-expiration, and end-inspiration. Metabolicactivitywasmeasuredfromthe[18F]fluoro-2-deoxy-D-glucose uptake rate. The computed tomography scans were used to classify lung regions as derecruited throughout the respiratory cycle, undergoing recruitment-derecruitment, and normally aerated. Measurements and Main Results: Metabolic activity of normally aerated lung was positively correlated both with plateau pressure, showing a pronounced increase above 26 to 27 cm H2O, and with regional VT normalized by end-expiratory lung gas volume. This relationship did not appear to be caused by a higher underlying parenchymal metabolic activity in patients with higher plateau pressure. Regions undergoing cyclic recruitment-derecruitment did not have higher metabolic activity than those collapsed throughout the respiratory cycle. Conclusions: In patients with ALI managed with relatively high end-expiratory pressure, metabolic activity of aerated regions was associated with both plateau pressure and regional VT normalized by end-expiratory lung gas volume, whereas no association was found between cyclic recruitment- derecruitment and increased metabolic activity.
KW - Acute lung injury
KW - Artificial
KW - Positron emission tomography
KW - Respiration
KW - Tomography
KW - X-ray computed
UR - http://www.scopus.com/inward/record.url?scp=79955490275&partnerID=8YFLogxK
U2 - 10.1164/rccm.201008-1318OC
DO - 10.1164/rccm.201008-1318OC
M3 - Article
C2 - 21257791
AN - SCOPUS:79955490275
VL - 183
SP - 1193
EP - 1199
JO - American Journal of Respiratory and Critical Care Medicine
JF - American Journal of Respiratory and Critical Care Medicine
SN - 1073-449X
IS - 9
ER -