TY - JOUR
T1 - Inflammatory Activity in Atelectatic and Normally Aerated Regions During Early Acute Lung Injury
AU - Hinoshita, Takuga
AU - Ribeiro, Gabriel Motta
AU - Winkler, Tilo
AU - de Prost, Nicolas
AU - Tucci, Mauro R.
AU - Costa, Eduardo Leite Vieira
AU - Wellman, Tyler J.
AU - Hashimoto, Soshi
AU - Zeng, Congli
AU - Carvalho, Alysson R.
AU - Melo, Marcos Francisco Vidal
N1 - Publisher Copyright:
© 2020 The Association of University Radiologists
PY - 2020/12
Y1 - 2020/12
N2 - Rationale and Objectives: Pulmonary atelectasis presumably promotes and facilitates lung injury. However, data are limited on its direct and remote relation to inflammation. We aimed to assess regional 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) kinetics representative of inflammation in atelectatic and normally aerated regions in models of early lung injury. Materials and Methods: We studied supine sheep in four groups: Permissive Atelectasis (n = 6)—16 hours protective tidal volume (VT) and zero positive end-expiratory pressure; Mild (n = 5) and Moderate Endotoxemia (n = 6)- 20–24 hours protective ventilation and intravenous lipopolysaccharide (Mild = 2.5 and Moderate = 10.0 ng/kg/min), and Surfactant Depletion (n = 6)—saline lung lavage and 4 hours high VT. Measurements performed immediately after anesthesia induction served as controls (n = 8). Atelectasis was defined as regions of gas fraction <0.1 in transmission or computed tomography scans. 18F-FDG kinetics measured with positron emission tomography were analyzed with a three-compartment model. Results: 18F-FDG net uptake rate in atelectatic tissue was larger during Moderate Endotoxemia (0.0092 ± 0.0019/min) than controls (0.0051 ± 0.0014/min, p = 0.01). 18F-FDG phosphorylation rate in atelectatic tissue was larger in both endotoxemia groups (0.0287 ± 0.0075/min) than controls (0.0198 ± 0.0039/min, p = 0.05) while the 18F-FDG volume of distribution was not significantly different among groups. Additionally, normally aerated regions showed larger 18F-FDG uptake during Permissive Atelectasis (0.0031 ± 0.0005/min, p < 0.01), Mild (0.0028 ± 0.0006/min, p = 0.04), and Moderate Endotoxemia (0.0039 ± 0.0005/min, p < 0.01) than controls (0.0020 ± 0.0003/min). Conclusion: Atelectatic regions present increased metabolic activation during moderate endotoxemia mostly due to increased 18F-FDG phosphorylation, indicative of increased cellular metabolic activation. Increased 18F-FDG uptake in normally aerated regions during permissive atelectasis suggests an injurious remote effect of atelectasis even with protective tidal volumes.
AB - Rationale and Objectives: Pulmonary atelectasis presumably promotes and facilitates lung injury. However, data are limited on its direct and remote relation to inflammation. We aimed to assess regional 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) kinetics representative of inflammation in atelectatic and normally aerated regions in models of early lung injury. Materials and Methods: We studied supine sheep in four groups: Permissive Atelectasis (n = 6)—16 hours protective tidal volume (VT) and zero positive end-expiratory pressure; Mild (n = 5) and Moderate Endotoxemia (n = 6)- 20–24 hours protective ventilation and intravenous lipopolysaccharide (Mild = 2.5 and Moderate = 10.0 ng/kg/min), and Surfactant Depletion (n = 6)—saline lung lavage and 4 hours high VT. Measurements performed immediately after anesthesia induction served as controls (n = 8). Atelectasis was defined as regions of gas fraction <0.1 in transmission or computed tomography scans. 18F-FDG kinetics measured with positron emission tomography were analyzed with a three-compartment model. Results: 18F-FDG net uptake rate in atelectatic tissue was larger during Moderate Endotoxemia (0.0092 ± 0.0019/min) than controls (0.0051 ± 0.0014/min, p = 0.01). 18F-FDG phosphorylation rate in atelectatic tissue was larger in both endotoxemia groups (0.0287 ± 0.0075/min) than controls (0.0198 ± 0.0039/min, p = 0.05) while the 18F-FDG volume of distribution was not significantly different among groups. Additionally, normally aerated regions showed larger 18F-FDG uptake during Permissive Atelectasis (0.0031 ± 0.0005/min, p < 0.01), Mild (0.0028 ± 0.0006/min, p = 0.04), and Moderate Endotoxemia (0.0039 ± 0.0005/min, p < 0.01) than controls (0.0020 ± 0.0003/min). Conclusion: Atelectatic regions present increased metabolic activation during moderate endotoxemia mostly due to increased 18F-FDG phosphorylation, indicative of increased cellular metabolic activation. Increased 18F-FDG uptake in normally aerated regions during permissive atelectasis suggests an injurious remote effect of atelectasis even with protective tidal volumes.
KW - Acute lung injury
KW - Atelectasis
KW - Endotoxin
KW - F-FDG PET
KW - Mechanical ventilation
UR - https://www.scopus.com/pages/publications/85081893539
UR - https://www.scopus.com/pages/publications/85081893539#tab=citedBy
U2 - 10.1016/j.acra.2019.12.022
DO - 10.1016/j.acra.2019.12.022
M3 - Article
C2 - 32173290
AN - SCOPUS:85081893539
SN - 1076-6332
VL - 27
SP - 1679
EP - 1690
JO - Academic Radiology
JF - Academic Radiology
IS - 12
ER -