A Novel Large Animal Model of Acute Respiratory Distress Syndrome Induced by Mitochondrial Products.

OBJECTIVE: We aimed to create a reproducible lung injury model utilizing injection of mitochondrial damage-associated molecular products. Our goal was to characterize the pathophysiologic response to damage-associated molecular pattern mediated organ injury. SUMMARY BACKGROUND DATA: There remain significant gaps in our understanding of acute respiratory distress syndrome, in part due to the lack of clinically applicable animal models of this disease. Animal models of noninfectious, tissue damage-induced lung injury are needed to understand the signals and responses associated with this injury. METHODS: Ten pigs (35-45 kg) received an intravenous dose of disrupted mitochondrial products and were followed for 6 hours under general anesthesia. These animals were compared to a control group (n = 5) and a model of lung injury induced by bacterial products (lipopolysaccharide n = 5). RESULTS: Heart rate and temperature were significantly elevated in the mitochondrial product (204 ±â€Š12 and 41 ±â€Š1) and lipopolysaccharide groups (178 ±â€Š18 and 42 ±â€Š0.5) compared with controls (100 ±â€Š13 and 38 ±â€Š0.5) (P <0.05). Lung oxygenation (PaO2/FiO2) was significantly lower 6 hours after injection in the mitochondrial products and lipopolysaccharide groups compared with controls (170 ±â€Š39, 196 ±â€Š27, and 564 ±â€Š75 mm Hg respectively, P = 0.001). Lung injury scoring of histological sections was significantly worse in mitochondrial and lipopolysaccharide groups compared with controls (mitochondrial-64 ±â€Š6, lipopolysaccharide-54 ±â€Š8, control-14 ±â€Š1.5, P= 0.002). CONCLUSIONS: Our data demonstrated that the presence of mitochondrial products in the circulation leads to systemic inflammatory response and lung injury. In its acute phase lung injury induced by tissue or bacterial products is clinically indistinguishable.

Survival of Lung Transplant Candidates With COPD: BODE Score Reconsidered.

BACKGROUND: The BMI, obstruction, dyspnea, and exercise capacity (BODE) score is used to inform prognostic considerations for lung transplantation for COPD, but it has not been validated in this context. A large proportion of mortality in COPD is attributable to comorbidities that could preclude transplant candidacy. We hypothesized that patients with COPD who are selected as transplant candidates experience better survival than traditional interpretation of BODE scores might indicate. METHODS: We performed a retrospective analysis of survival according to the BODE score for patients with COPD in the United Network of Organ Sharing (UNOS) database of lung transplantation candidates (n = 4,377) compared with the cohort of patients with COPD in which the BODE score was validated (n = 625). RESULTS: Median survival in the fourth quartile of BODE score was 59 months (95% CI, 51-77 months) in the UNOS cohort and 37 months (95% CI, 29-42 months) in the BODE validation cohort. In models controlling for BODE score and incorporating lung transplantation as a competing end point, the risk of death was higher in the BODE validation cohort (subhazard ratio, 4.8; 95% CI, 4.0-5.7; P < .001). The risk difference was greatest in the fourth quartile of BODE scores (SHR, 6.1; 95% CI, 4.9-7.6; P < .001). CONCLUSIONS: Extrapolation of prognosis based on the BODE score overestimates mortality risk in lung transplantation candidates with COPD. This is likely due to a lower prevalence of comorbid conditions attributable to the lung transplantation evaluation screening process.

The use of extended criteria donors decreases one-year survival in high-risk lung recipients: A review of the United Network of Organ Sharing Database.

OBJECTIVE: The study objective was to investigate the impact of matching donor quality to recipient severity on survival after lung transplant. METHODS: By using the Organ Procurement and Transplantation Network/United Network for Organ Sharing dataset, we analyzed lung transplant recipients from May 4, 2005, to December 31, 2012. By using adjusted Cox regressions, we identified extended criteria donors as those who had 1 or more of the following: age 65 years or more, smoking history of 20 pack-years or more, diabetes mellitus, or African-American race. All other donors were considered standard donors. Recipients were categorized by lung allocation score: lung allocation score less than 70 and lung allocation score 70 or greater. Our primary outcome was 1-year survival after lung transplantation. RESULTS: Of the 10,995 lung recipients, 3792 (34%) received extended criteria donor organs. Extended criteria donors were associated with an increased hazard of death (hazard ratio [HR], 1.41; 95% confidence interval [CI], 1.26-1.56; P < .001). One-year survival was 87% and 82% (P < .001) for recipients with a lung allocation score less than 70 and 80% and 72% (P = .017) for recipients with a lung allocation score 70 or greater who received standard donor and extended criteria donor organs, respectively. In Cox regression models, the hazard of death was increased for recipients with a lung allocation score less than 70 + extended criteria donor (HR, 1.42; 95% CI, 1.27-1.60; P < .001), recipients with a lung allocation score 70 or greater + standard donor (HR, 1.37; 95% CI, 1.10-1.71; P = .005), and was the highest for recipients with a lung allocation score 70 or greater + extended criteria donor (HR, 1.81; 95% CI, 1.40-2.33; P < .001) compared with recipients with a lung allocation score less than 70 + standard donor. CONCLUSIONS: Extended criteria donors are associated with reduced 1-year survival, and recipients with a lung allocation score 70 or greater who receive extended criteria donor organs have the lowest survival.