Ex Vivo Lung Perfusion of Cardiac-death Donor Lung in Pigs

Background : Lung transplantation (LTx) is a life-saving treatment for patients with end-stage lung disease; however, the shortage of donor lungs has been a major limiting factor to increasing the number of LTx. Growing experience following LTx using donor lungs after cardiac death (DCD) has been promising, although concerns remain. The purpose of this study was to develop a DCD lung harvest model using an ex vivo lung perfusion (EVLP) system and to assess the function of presumably damaged lungs harvested from the DCD donor in pigs. Methods : The 40 kg pigs were randomly divided into the control group with no ischemic lung injury (n=5) and the study group (n=5), which had 1 hour of warm ischemic lung injury after cardiac arrest. Harvested lungs were placed in the EVLP circuit and oxygen capacities (OC), pulmonary vascular resistance (PVR), and peak airway pressure (PAP) were evaluated every hour for 4 hours. At the end of EVLP, specimens were excised for pathologic review and wet/dry ratio. Results : No statistically significant difference in OC (P=0.353), PVR (P=0.951), and PAP (P=0.651) was observed in both groups. Lung injury severity score (control group vs. study group: 0.700±0.303 vs. 0.870±0.130; P=0.230) and wet/dry ratio (control group vs. study group: 5.89±0.97 vs. 6.20±0.57; P=0.560) also showed no statistically significant difference between the groups. Conclusions : The function of DCD lungs assessed using EVLP showed no difference from that of control lungs without ischemic injury; therefore, utilization of DCD lungs can be a new option to decrease the number of deaths on the waiting list.ope

Perioperative factors associated with 1-year mortality after lung transplantation: a single-center experience in Korea

Background: Most studies about the risk factors of 1-year mortality after lung transplantation were performed on non-Asians. This study aimed to evaluate the perioperative factors related to the 1-year mortality after lung transplantation in Korea. Methods: Sixty-eight consecutive patients who underwent lung transplantation without preoperative extracorporeal membrane oxygenation treatment at 1 tertiary hospital in South Korea between October 24, 2012, and October 16, 2015, were analyzed retrospectively. Results: Forty-four patients (64.7%) lived for >1 year after lung transplantation. The median age of all patients was 55 years (range, 16-75 years), and men accounted for 57.4%. The major cause of lung transplantation was idiopathic pulmonary fibrosis (48.5%); the other causes were interstitial lung disease related to connective tissue disease (17.6%) and bronchiolitis obliterans after stem cell transplantation (14.7%). In univariate analysis, higher median age (52 vs. 61.5 years, P5.5 higher than the preoperative DNI (22.7% vs. 70.8%, P<0.001) were significantly related to 1-year mortality. After adjustments, old age, postoperative increased DNI, and need for RRT after transplantation were the independent perioperative risk factors for 1-year mortality after lung transplantation. Conclusions: Recipients with advanced age should be carefully selected, and patients who need RRT or with increased DNI after transplantation should be managed accordingly.ope

Permissive fluid volume in adult patients undergoing extracorporeal membrane oxygenation treatment

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a cardiorespiratory support technique for patients with circulatory or pulmonary failure. Frequently, large-volume fluid resuscitation is needed to ensure sufficient extracorporeal blood flow in patients initiating ECMO. However, excessive overhydration is known to increase mortality in critically ill patients. Therefore, in order to define a tolerant volume range in patients undergoing ECMO treatment, the association between cumulative fluid balance (CFB) and outcome was evaluated in patients undergoing ECMO. METHODS: This retrospective multicenter cohort study was conducted with 723 patients who underwent ECMO in three tertiary care hospitals between 2005 and 2016. CFB was calculated as total fluid input minus total fluid output during the first 3 days from ECMO initiation. The patients were divided into groups that initiated ECMO owing to cardiovascular disease (CVD)-related or non-cardiovascular disease (non-CVD)-related causes. The primary endpoint was mortality within 90 days after ECMO commencement. RESULTS: Totals of 406 and 317 patients were included in the CVD and non-CVD groups, respectively. In the CVD group, the mean age was 58.4 ± 17.7 years, and 68.2% were male. The mean age was 55.7 ± 15.7 years, and 65.3% were male in the non-CVD group. The median CFB values were 64.7 and 53.5 ml/kg in the CVD and non-CVD groups, respectively. Multivariable analysis using Cox proportional hazards models revealed a significantly increased risk of 90-day mortality in patients with higher CFB values in both the CVD and non-CVD groups. However, the risks were elevated only in the two CFB quartile groups with the largest CFB amounts. Cubic spline models showed that mortality risk began to increase significantly when CFB was 82.3 ml/kg in the CVD group. In patients with respiratory diseases, the mortality risk increase was significant for those with CFB levels above 189.6 ml/kg. CONCLUSIONS: Mortality risk did not increase until a certain level of fluid overload was reached in patients undergoing ECMO. Adequate fluid resuscitation is critical to improving outcomes in these patients.ope

Comparison of short-term outcomes for connective tissue disease-related interstitial lung disease and idiopathic pulmonary fibrosis after lung transplantation

Background: Pulmonary involvement is common in connective tissue disease (CTD), and respiratory failure is a major cause of morbidity and mortality in CTD-related interstitial lung disease (CTD-ILD). Lung transplantation is thus important for these patients. However, survival, outcomes, and management of these patients after transplantation have been debated. The aim of this study was to evaluate the outcomes for CTD-ILD compared to those for idiopathic pulmonary fibrosis (IPF) after lung transplantation. Methods: We performed a single-centre retrospective study of 62 patients with CTD-ILD or IPF who underwent lung transplantation at a tertiary hospital in South Korea between October 2012 and October 2016. Results: Patients with CTD-ILD (n=15) were younger (46 vs. 60 years, P=0.001) and were less likely to be male (33.3% vs. 76.6%, P=0.004) than were patients with IPF (n=47). The 1-year cumulative survival rate was 80.0% for CTD-ILD and 59.6% for IPF (log-rank P=0.394). There was no difference in the cumulative survival rate (log-rank P=0.613) of age- and sex-matched patients with CTD-ILD (n=15) and IPF (n=15). The incidence of primary graft dysfunction was similar (P=0.154), and 2 (18.2%) patients developed possible CTD flare. Conclusions: Patients with CTD-ILD and those with IPF who underwent lung transplantation had similar survival rates.ope

Implications of Plasma Renin Activity and Plasma Aldosterone Concentration in Critically Ill Patients with Septic Shock

Background : The renin-angiotensin-aldosterone system is closely associated with volume status and vascular tone in septic shock. The present study aimed to assess whether plasma renin activity (PRA) and plasma aldosterone concentration (PAC) measurements compared with conventional severity indicators are associated with mortality in patients with septic shock. Methods : We evaluated 105 patients who were admitted for septic shock. Plasma levels of the biomarkers PRA and PAC, the PAC/PRA ratio, C-reactive protein (CRP) level, and cortisol level on days 1, 3, and 7 were serially measured. During the intensive care unit stay, relevant clinical information and laboratory results were recorded. Results : Patients were divided into two groups according to 28-day mortality: survivors (n = 59) and non-survivors (n = 46). The survivor group showed lower PRA, PAC, Acute Physiologic and Chronic Health Evaluation (APACHE) II score, and Sequential Organ Failure Assessment (SOFA) score than did the non-survivor group (all P < 0.05). The SOFA score was positively correlated with PRA (r = 0.373, P < 0.001) and PAC (r = 0.316, P = 0.001). According to receiver operating characteristic analysis, the areas under the curve of PRA and PAC to predict 28-day mortality were 0.69 (95% confidence interval [CI], 0.58 to 0.79; P = 0.001) and 0.67 (95% CI, 0.56 to 0.77; P = 0.003), respectively, similar to the APACHE II scores and SOFA scores. In particular, the group with PRA value ≥3.5 ng ml-1 h-1 on day 1 showed significantly greater mortality than did the group with PRA value <3.5 ng ml-1 h-1 (log-rank test, P < 0.001). According to multivariate analysis, SOFA score (hazard ratio, 1.11; 95% CI, 1.01 to 1.22), PRA value ≥3.5 ng ml-1 h-1 (hazard ratio, 3.25; 95% CI, 1.60 to 6.60), previous history of cancer (hazard ratio, 3.44; 95% CI, 1.72 to 6.90), and coronary arterial occlusive disease (hazard ratio, 2.99; 95% CI, 1.26 to 7.08) were predictors of 28-day mortality. Conclusions : Elevated PRA is a useful biomarker to stratify the risk of critically ill patients with septic shock and is a prognostic predictor of 28-day mortality.ope

Clinical implications of the plasma EphA2 receptor level in critically ill patients with septic shock

The Eph/ephrin receptor ligand system is known to play a role in inflammation induced by infection, injury, and inflammatory diseases. The present study aimed to evaluate plasma EphA2 receptor levels in critically ill patients with sepsis. This study was a prospective cohort study evaluating samples and clinical data from the medical intensive care unit (MICU) of a 2000-bed university tertiary referral hospital in South Korea. Positive correlations of the plasma EphA2 receptor level with the acute physiology and chronic health evaluation (APACHE) II score and the sequential organ failure assessment (SOFA) score were observed. The area under the curve (AUC) for the plasma EphA2 receptor level on a receiver operating characteristic curve was 0.690 (95% confidence interval [CI], 0.608-0.764); the AUCs for the APACHE II score and SOFA scores were 0.659 (95% CI, 0.576-0.736) and 0.745 (95% CI, 0.666-0.814), respectively. A Cox proportional hazard model identified an association between an increased plasma EphA2 receptor level (>51.5 pg mL-1) and increased risk of 28-day mortality in the MICU (hazard ratio = 3.22, 95% CI, 1.709-6.049). An increased plasma EphA2 receptor level was associated with sepsis severity and 28-day mortality among sepsis patients.ope

Prevalence of pre-transplant anti-HLA antibodies and their impact on outcomes in lung transplant recipients

BACKGROUND: Previous studies have suggested that antibodies against human leukocyte antigen (HLA) are associated with worse outcomes in lung transplantation. However, little is known about the factors associated with outcomes following lung transplantation in Asia. Accordingly, we investigated the prevalence of anti-HLA antibodies in recipients before transplantation and assessed their impact on outcomes in Korea. METHODS: A single-center retrospective study was conducted. The study included 76 patients who received a lung transplant at a tertiary hospital in South Korea between January 2010 and March 2015. RESULTS: Nine patients (11.8%) had class I and/or class II panel-reactive antibodies greater than 50%. Twelve patients (15.8%) had anti-HLA antibodies with a low mean fluorescence intensity (MFI, 1000-3000), 7 (9.2%) with a moderate MFI (3000-5000), and 12 (15.8%) with a high MFI (> 5000). Ten patients (13.2%) had suspected donor-specific antibodies (DSA), and 60% (6/10) of these patients had antibodies with a high MFI. In an analysis of outcomes, high-grade (>/=2) primary graft dysfunction (PGD) was more frequent in patients with anti-HLA antibodies with moderate-to-high MFI values than in patients with low MFI values (39.4% vs. 14.0%, p = 0.011). Of 20 patients who survived longer than 2 years and evaluated for pBOS after transplant, potential bronchiolitis obliterans syndrome (pBOS) or BOS was more frequent in patients with anti-HLA antibodies with moderate-to-high MFI than in patients with low MFI, although this difference was not statistically significant (50.0% vs. 14.3%, p = 0.131). CONCLUSIONS: The prevalence of anti-HLA antibodies with high MFI was not high in Korea. However, the MFI was relatively high in patients with DSA. Anti-HLA antibodies with moderate-to-high MFI values were related to high-grade PGD. Therefore, recipients with high MFI before lung transplantation should be considered for desensitization and close monitoring.ope

Pneumocystis jirovecii pneumonia (PCP) PCR-negative conversion predicts prognosis of HIV-negative patients with PCP and acute respiratory failure

BACKGROUND: Pneumocystis jirovecii pneumonia (PCP) is often fatal in human immunodeficiency (HIV)-negative patients and typically presents with respiratory insufficiency. Predicting treatment failure is challenging. This study aimed to identify prognostic factors and examine PCP polymerase chain reaction (PCR)-negative conversion in non-HIV PCP patients with respiratory failure. METHOD: We retrospectively enrolled 81 non-HIV patients diagnosed with and treated for PCP with respiratory failure in the intensive care unit at a tertiary hospital over a 3-year period. PCP was diagnosed via nested PCR-mediated detection of Pneumocystis jirovecii in induced sputum samples, endotracheal aspirates, and bronchoalveolar lavage fluids. PCP PCR was performed weekly to check for negative conversion. RESULTS: The overall survival rate was 35.8%. Seventy-four patients (91.3%) required mechanical ventilation, and 6 (7.4%) required high-flow nasal oxygen treatment. The PCP PCR-negative conversion rate was 70.5% (survivors, 97%; non-survivors, 63.5%); the median time to conversion was 10 (7.0-14.0) days. On univariate analysis, the APACHE II score (p < 0.001), renal failure requiring renal replacement therapy (p = 0.04), PCP PCR-negative conversion (p = 0.003), and the PaO2/FiO2 ratio (first 24 hours) (p < 0.001) significantly correlated with mortality. On multivariate analysis, PCP PCR-negative conversion (hazard ratio, 0.433; 95% confidence interval, 0.203-0.928; p = 0.031) and the PaO2/FiO2 ratio (first 24 hours) (hazard ratio, 0.988; 95% confidence interval, 0.983-0.993; p < 0.001) independently predicted prognosis. CONCLUSIONS: Determination of PCP PCR-negative conversion and PaO2/FiO2 ratios may help physicians predict treatment failure and mortality in non-HIV PCP patients with respiratory failure.ope

Association of serum ferritin levels with smoking and lung function in the Korean adult population: analysis of the fourth and fifth Korean National Health and Nutrition Examination Survey

BACKGROUND: Iron-catalyzed oxidative stress contributes to lung injury after exposure to various toxins, including cigarette smoke. An oxidant/antioxidant imbalance is considered to play a critical role in the pathogenesis of COPD. Ferritin is a key protein in iron homeostasis, and its capacity to oxidize and sequester the metal preventing iron prooxidant activity implicates its possible role in the alteration of antioxidant imbalance. We investigated the relationship among cigarette smoking, lung function, and serum ferritin concentration in a large cohort representative of the Korean adult population. MATERIALS AND METHODS: Among 50,405 participants of the Korean National Health and Nutrition Examination Survey from 2010 to 2014, 15,239 adult subjects older than 40 years with serum ferritin levels and spirometric data were selected for this study. RESULTS: The mean age was 56.5 years for men (43%) and 56.9 years for women (57%). The prevalence of airway obstruction was 13.4%, which was significantly higher in men than in women, and increased in former or current smokers. The median levels of serum ferritin were highest in the airway obstruction group, followed by the restrictive pattern group, and lowest in the normal lung function group. The median ferritin levels were increased by smoking status and amounts in each spirometric subgroup. In multivariable regression analysis, serum ferritin was positively associated with forced expiratory volume in 1 second and forced expiratory volume in 1 second/forced vital capacity, whereas the smoking amount was negatively associated with the adjustment with age, sex, height, and weight. CONCLUSION: Serum ferritin levels were increased in former or current smokers and were increased with smoking amount in all subgroups of participants categorized according to spirometric results. The result was also evident in the subgroups divided by obstructive severity. While smoking amount was inversely related to lung function, higher levels of serum ferritin were associated with enhanced spirometric results in a representative sample of the general Korean adult population. Future prospective studies will be needed to clarify the causality between serum ferritin and lung functions and their role in COPD morbidity.ope

Feasibility of Immediate in-Intensive Care Unit Pulmonary Rehabilitation after Lung Transplantation: A Single Center Experience

Background Physical function may influence perioperative outcomes of lung transplantation. We investigated the feasibility of a pulmonary rehabilitation program initiated in the immediate postoperative period at an intensive care unit (ICU) for patients who underwent lung transplantation. Methods We retrospectively evaluated 22 patients who received pulmonary rehabilitation initiated in the ICU within 2 weeks after lung transplantation at our institution from March 2015 to February 2016. Levels of physical function were graded at the start of pulmonary rehabilitation and then weekly throughout rehabilitation according to criteria from our institutional pulmonary rehabilitation program: grade 1, bedside (G1); grade 2, dangling (G2); grade 3, standing (G3); and grade IV, gait (G4). Results The median age of patients was 53 years (range, 25 to 73 years). Fourteen patients (64%) were males. The initial level of physical function was G1 in nine patients, G2 in seven patients, G3 in four patients, and G4 in two patients. Patients started pulmonary rehabilitation at a median of 7.5 days (range, 1 to 29 days) after lung transplantation. We did not observe any rehabilitation-related complications during follow-up. The final level of physical function was G1 in six patients, G3 in two patients, and G4 in 14 patients. Fourteen of the 22 patients were able to walk with or without assistance, and 13 of them maintained G4 until discharge; the eight remaining patients never achieved G4. Conclusions Our results suggest the feasibility of early pulmonary rehabilitation initiated in the ICU within a few days after lung transplantation.ope