scholarly journals Mechanical Power Correlates With Lung Inflammation Assessed by Positron-Emission Tomography in Experimental Acute Lung Injury in Pigs

2021 ◽  
Vol 12 ◽  
Author(s):  
Martin Scharffenberg ◽  
Jakob Wittenstein ◽  
Xi Ran ◽  
Yingying Zhang ◽  
Anja Braune ◽  
...  

Background: Mechanical ventilation (MV) may initiate or worsen lung injury, so-called ventilator-induced lung injury (VILI). Although different mechanisms of VILI have been identified, research mainly focused on single ventilator parameters. The mechanical power (MP) summarizes the potentially damaging effects of different parameters in one single variable and has been shown to be associated with lung damage. However, to date, the association of MP with pulmonary neutrophilic inflammation, as assessed by positron-emission tomography (PET), has not been prospectively investigated in a model of clinically relevant ventilation settings yet. We hypothesized that the degree of neutrophilic inflammation correlates with MP.Methods: Eight female juvenile pigs were anesthetized and mechanically ventilated. Lung injury was induced by repetitive lung lavages followed by initial PET and computed tomography (CT) scans. Animals were then ventilated according to the acute respiratory distress syndrome (ARDS) network recommendations, using the lowest combinations of positive end-expiratory pressure and inspiratory oxygen fraction that allowed adequate oxygenation. Ventilator settings were checked and adjusted hourly. Physiological measurements were conducted every 6 h. Lung imaging was repeated 24 h after first PET/CT before animals were killed. Pulmonary neutrophilic inflammation was assessed by normalized uptake rate of 2-deoxy-2-[18F]fluoro-D-glucose (KiS), and its difference between the two PET/CT was calculated (ΔKiS). Lung aeration was assessed by lung CT scan. MP was calculated from the recorded pressure–volume curve. Statistics included the Wilcoxon tests and non-parametric Spearman correlation.Results: Normalized 18F-FDG uptake rate increased significantly from first to second PET/CT (p = 0.012). ΔKiS significantly correlated with median MP (ρ = 0.738, p = 0.037) and its elastic and resistive components, but neither with median peak, plateau, end-expiratory, driving, and transpulmonary driving pressures, nor respiratory rate (RR), elastance, or resistance. Lung mass and volume significantly decreased, whereas relative mass of hyper-aerated lung compartment increased after 24 h (p = 0.012, p = 0.036, and p = 0.025, respectively). Resistance and PaCO2 were significantly higher (p = 0.012 and p = 0.017, respectively), whereas RR, end-expiratory pressure, and MP were lower at 18 h compared to start of intervention.Conclusions: In this model of experimental acute lung injury in pigs, pulmonary neutrophilic inflammation evaluated by PET/CT increased after 24 h of MV, and correlated with MP.

2006 ◽  
Vol 32 (11) ◽  
pp. 1889-1894 ◽  
Author(s):  
Jean-Christophe Richard ◽  
Didier Le Bars ◽  
Nicolas Costes ◽  
Fabienne Bregeon ◽  
Christian Tourvieille ◽  
...  

1996 ◽  
Vol 39 ◽  
pp. 222-222
Author(s):  
Haresh Kirpalani ◽  
Kabir Abubakar ◽  
Claude Nahmias ◽  
Derek deSa ◽  
Geoffrey Coates ◽  
...  

2011 ◽  
Vol 14 (5) ◽  
pp. 283 ◽  
Author(s):  
Andre Plass ◽  
Maximilian Y. Emmert ◽  
Oliver Gaemperli ◽  
Hatem Alkadhi ◽  
Philipp Kaufmann ◽  
...  

<p><b>Background:</b> We evaluated how comprehensive assessment of coronary artery lesions and their hemodynamic relevance by means of hybrid positron emission tomography (PET) and computed tomography (CT) imaging would affect decision-making in coronary artery bypass surgery (CABG), compared with using invasive coronary angiography (ICA) alone.</p><p><b>Methods:</b> After undergoing ICA, 27 patients (21 men and 6 women; mean SD age, 66 � 10 years) planned for cardiac surgery were scheduled for myocardial perfusion stress/rest evaluation with [13N]ammonia PET and CT coronary angiography. Only ICA was available to the surgeon. Postoperatively, the performed CABG was compared with the hypothetical strategy based on hybrid PET/CT findings (regional coronary flow reserve [CFR], myocardial perfusion defects). Procedures included CABG (n = 18) alone, CABG combined with valve replacement (n = 6), and CABG combined with isolated valve replacement (n = 3). A total of 56 bypass grafts (28 venous and 28 arterial) and 66 distal anastomoses were placed.</p><p><b>Results:</b> CT evaluation showed 93% concordance (66/71) with ICA regarding significant stenoses, with sensitivity, specificity, positive predictive value, and negative predictive value of 93.1%, 98.7%, 94.4%, and 98.4%, respectively. In the PET scan, 16 patients had 1 ischemic region, and 12 patients had 1 scar region, including 5 patients who presented with mixed conditions (scar and ischemia). One patient had a completely normal myocardium. Compared with the performed surgery, PET/CT fusion evaluation showed that of the performed anastomoses, 48% had documented ischemia (with a CFR <2 in 86%), 38% were nonischemic (although a CFR value <2 was found in 78%), and 14% had scar tissue (fixed perfusion defect).</p><p><b>Conclusions:</b> Although <50% of bypasses were placed to areas with myocardial ischemia, the CFR was low in the majority of nonischemic regions, a finding that may have important prognostic relevance. PET/CT fusion imaging could potentially influence planning for CABG and provide incremental prognostic information.</p>


Oncology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Ahmed Abdelhakeem ◽  
Madhavi Patnana ◽  
Xuemei Wang ◽  
Jane E. Rogers ◽  
Mariela Blum Murphy ◽  
...  

<b><i>Background:</i></b> The value of baseline fluorodeoxyglucose-positron emission tomography-computed tomography (PET-CT) remains uncertain once gastroesophageal cancer is metastatic. We hypothesized that assessment of detailed PET-CT parameters (maximum standardized uptake value [SUVmax] and/or total lesion glycolysis [TLG]), and the extent of metastatic burden could aid prediction of probability of response or prognosticate. <b><i>Methods:</i></b> We retrospectively analyzed treatment-naive patients with stage 4 gastroesophageal cancer (December 2002–August 2017) who had initial PET-CT for cancer staging at MD Anderson Cancer Center. SUVmax and TLG were compared with treatment outcomes for the full cohort and subgroups based on metastatic burden (≤2 or &#x3e;2 metastatic sites). <b><i>Results:</i></b> We identified 129 patients with metastatic gastroesophageal cancer who underwent PET-CT before first-line therapy. The median follow-up time was 61 months. The median overall survival (OS) was 18.5 months; the first progression-free survival (PFS) was 5.5 months. SUVmax or TLG of the primary tumor or of all metastases combined had no influence on OS or PFS, whether the number of metastases was ≤2 or &#x3e;2. Overall response rates (ORRs) to first-line therapy were 48% and 45% for patients with ≤2 and &#x3e;2 metastases, respectively (nonsignificant). ORR did not differ based on low or high values of SUVmax or TLG. <b><i>Conclusions:</i></b> This is the first assessment of a unique set of PET-CT data and its association with outcomes in metastatic gastroesophageal cancer. In our large cohort of patients, detailed analyses of PET-CT (by SUVmax and/or TLG) did not discriminate any parameters examined. Thus, baseline PET-CT in untreated metastatic gastroesophageal cancer patients has limited or no utility.


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