Clinical Outcomes of Lung Transplantation: Experience at Asan Medical Center

Design and evaluation of a Mobile-Based decision support system to enhance lung transplant candidate assessment and management: knowledge translation integrated with clinical workflow

BACKGROUND

Accurate and timely decision-making in lung transplantation (LTx) programs is critical. The main objective of this study was to develop a mobile-based evidence-based clinical decision support system (CDSS) to enhance the management of lung transplant candidates.

METHOD

An iterative participatory software development process was employed to develop the ImamLTx CDSS. This study was accomplished in three phases. First, required data and standard clinical workflow were identified according to the literature review and expert consensus. Second, a rule-based knowledge-based CDSS application was developed. In the third phase, this CDSS was evaluated. The evaluation was done using the standard Post-Study System Usability Questionnaire (PSSUQ 18.3) and ten usability heuristics factors for user interface design.

RESULTS

According to expert consensus, fifty-five data items were identified as essential data sets using the Content Validity Ratio (CVR) formula. By integrating information flow in clinical practices with clinical protocols, more than 450 rules and 500 knowledge statements were extracted. This CDSS provides clinical decision support on an Android platform regarding inclusion and exclusion referral criteria, optimum transplant time based on the type of lung disease, findings of initial assessment, and the overall evaluation of lung transplant candidates. Evaluation results showed high usability ratings due to the fact provided accuracy and sensitivity of this lung transplant CDSS with the information quality domain receiving the highest score (6.305 from 7).

CONCLUSION

Through a stepwise approach, the ImamLTx CDSS was developed to provide LTx programs with timely patient data access via a mobile platform. Our results suggest integration with existing workflow to support clinical decision-making and provide patient-specific recommendations.

Association of Chest CT-Based Quantitative Measures of Muscle and Fat with Post-Lung Transplant Survival and Morbidity: A Single Institutional Retrospective Cohort Study in Korean Population

OBJECTIVE

Abnormal body composition is an important modifiable risk factor in lung transplantation. Therefore, precise quantification of different body components, including muscle and fat, may play an important role in optimizing outcomes in lung transplant patients. The purpose of the study was to investigate the prognostic significance of muscle and subcutaneous fat mass measured on chest CT with regard to lung transplantation survival and other post-transplant outcomes.

MATERIALS AND METHODS

The study population included 45 consecutive adult lung transplant recipients (mean age of 47.9 ± 12.1 years; 31 males and 14 females) between 2011 and 2017. Preoperative cross-sectional areas of muscle and subcutaneous fat were semi-automatically measured on axial CT images at the level of the 12th thoracic vertebra (T12). Additional normalized indexed parameters, adjusted for either height or weight, were obtained. Associations of quantitative parameters with survival and various other post-transplant outcomes were evaluated.

RESULTS

Of the 45 patients included in the present study, 10 mortalities were observed during the follow-up period. Patients with relative sarcopenia (RS) classified based on height-adjusted muscle area with a cut-off value of 28.07 cm²/m² demonstrated worse postoperative survival (log-rank test, p = 0.007; hazard ratio [HR], 6.39:1) despite being adjusted for age, sex, and body mass index (HR, 8.58:1; p = 0.022). Weight-adjusted parameters of muscle area were negatively correlated with duration of ventilator support (R = -0.54, p < 0.001) and intensive care unit (ICU) stay (R = -0.33, p = 0.021).

CONCLUSION

Patients with RS demonstrate worse survival after lung transplantation that those without RS. Additionally, quantitative parameters of muscles measured at the T12 level on chest CT were associated with the duration of post-lung transplant ventilator support and duration of stay in the ICU.

Characteristics of Lung Allocation and Outcomes of Lung Transplant according to the Korean Urgency Status

PURPOSE

We investigated the characteristics of lung allocation and outcomes of lung transplant (LTx) according to the Korean urgency status.

MATERIALS AND METHODS

LTx registration in the Korean Organ Transplantation Registry (KOTRY) began in 2015. From 2015 to June 2017, 86 patients who received LTx were enrolled in KOTRY. After excluding one patient who received a heart-lung transplant, 85 were included. Subjects were analyzed according to the Korean urgency status.

RESULTS

Except for Status 0, urgency status was classified based on partial pressure of oxygen in arterial blood gas analysis and functional status in 52 patients (93%). The wait time for lung allograft was well-stratified by urgency (Status 0, 46.5±59.2 days; Status 1, 104.4±98.2 days; Status 2 or 3, 132.2±118.4 days, p=0.009). Status 0 was associated with increased operative times and higher intraoperative blood transfusion. Status 0 was associated with prolonged extracorporeal membrane oxygenation use, postoperative bleeding, and longer mechanical ventilation after operation. Survival of Status 0 patients seemed worse than that of non-Status 0 patients, although differences were not significant.

CONCLUSION

The Korean urgency classification for LTx is determined by using very limited parameters and may not be a true reflection of urgency. Status 0 patients seem to have poor outcomes compared to the other urgency status patients, despite having the highest priority for donor lungs. Further multi-center and nationwide studies are needed to revise the lung allocation system to reflect true urgency and provide the best benefit of lung transplantation.

The lung allocation score could evaluate allocation systems in countries that do not use the score

BACKGROUND

Evaluating allocation system effects on lung transplantation and determining systemic flaws is difficult. The purpose of this study was to assess the Korean urgency-based lung allocation system using the lung allocation score.

METHODS

We reviewed transplantation patients retrospectively. Candidates were classified into groups based on urgency. Status 0 designated hospitalized patients requiring ventilator and/or extracorporeal life support. The lung allocation score was calculated based on the recipient's condition at transplantation.

RESULTS

One-hundred-twenty-three Status 0, 1, and 2/3 patients (40, 71, and 12, respectively) were enrolled. The median waiting time was 68 days. Nineteen Status 0 patients who received lung transplants deteriorated from non-Status 0 (median, 64 days). The lung allocation score showed a bimodal distribution (peaks around 45 and 90, corresponding with non-Status 0 and Status 0, respectively). Status 0 and the lung allocation score were independent risk factors for poor survival after adjustment for confounders (Status 0, hazard ratio, 2.788, p = 0.001; lung allocation score, hazard ratio, 1.025, p < 0.001). The lung allocation score cut-off for survival was 44. On dividing the non-Status 0 patients into 2 groups using the cut-off values and regrouping into Status 0, non-Status 0 with high lung allocation score (> 44), and non-Status 0 with low lung allocation score (< 44), we observed that non-Status 0 with high lung allocation score patients had better survival than Status 0 patients (p = 0.020) and poorer survival than non-Status 0 with low lung allocation score patients (p = 0.018).

CONCLUSIONS

The LAS demonstrated the characteristics of LTx recipients in Korea and the Korean allocation system needs to be revised to reduce the number of patients receiving LTx in Status 0. The LAS system could be used as a tool to evaluate lung allocation systems in countries that do not use the LAS system.

Long-Term Outcomes of Adult Lung Transplantation Recipients: A Single-Center Experience in South Korea

Background

Recently, the number of lung transplants in South Korea has increased. However, the long-term outcome data is limited. In this study, we aimed to investigate the long-term outcomes of adult lung transplantation recipients.

Methods

Among the patients that underwent lung transplantation at a tertiary referral center in South Korea between 2008 and 2017, adults patient who underwent deceased-donor lung transplantation with available follow-up data were enrolled. Their medical records were retrospectively reviewed.

Results

Through eligibility screening, we identified 60 adult patients that underwent lung (n=51) or heart-lung transplantation (n=9) during the observation period. Idiopathic pulmonary fibrosis (46.7%, 28/60) was the most frequent cause of lung transplantation. For all the 60 patients, the median follow-up duration for post-transplantation was 2.6 years (range, 0.01–7.6). During the post-transplantation follow-up period, 19 patients (31.7%) died at a median duration of 194 days. The survival rates were 75.5%, 67.6%, and 61.8% at 1 year, 3 years, and 5 years, respectively. Out of the 60 patients, 8 (13.3%) were diagnosed with chronic lung allograft dysfunction (CLAD), after a mean duration of 3.3±2.8 years post-transplantation. The CLAD development rate was 0%, 17.7%, and 25.8% at 1 year, 3 years, and 5 years, respectively. The most common newly developed post-transplantation comorbidity was the chronic kidney disease (CKD; 54.0%), followed by diabetes mellitus (25.9%).

Conclusion

Among the adult lung transplantation recipients at a South Korea tertiary referral center, the long-term survival rates were favorable. The proportion of patients who developed CLAD was not substantial. CKD was the most common post-transplantation comorbidity.

The First Living-Donor Lobar Lung Transplantation in Korea: a Case Report

Lung transplantation is the only treatment for end-stage lung disease, but the problem of donor shortage is unresolved issue. Herein, we report the first case of living-donor lobar lung transplantation (LDLLT) in Korea. A 19-year-old woman patient with idiopathic pulmonary artery hypertension received her father's right lower lobe and her mother's left lower lobe after pneumonectomy of both lungs in 2017. The patient has recovered well and is enjoying normal social activity. We think that LDLLT could be an alternative approach to deceased donor lung transplantation to overcome the shortage of lung donors.

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.