Donor selection and management

Lung Transplantation, Pulmonary Endothelial Inflammation, and Ex-Situ Lung Perfusion: A Review

Lung transplantation (LTx) is the gold standard treatment for end-stage lung disease; however, waitlist mortality remains high due to a shortage of suitable donor lungs. Organ quality can be compromised by lung ischemic reperfusion injury (LIRI). LIRI causes pulmonary endothelial inflammation and may lead to primary graft dysfunction (PGD). PGD is a significant cause of morbidity and mortality post-LTx. Research into preservation strategies that decrease the risk of LIRI and PGD is needed, and ex-situ lung perfusion (ESLP) is the foremost technological advancement in this field. This review addresses three major topics in the field of LTx: first, we review the clinical manifestation of LIRI post-LTx; second, we discuss the pathophysiology of LIRI that leads to pulmonary endothelial inflammation and PGD; and third, we present the role of ESLP as a therapeutic vehicle to mitigate this physiologic insult, increase the rates of donor organ utilization, and improve patient outcomes.

Safe Lung Flush Technique During Recovery From Donors After Circulatory Death

Donation after circulatory death is defined as donation after cardiac arrest and circulatory cessation. The number of circulatory death donors is growing and significantly increases the organ donor pool. Shortening the warm ischemia time is pivotal in the outcomes and survival after transplant. We describe simplified and safe technique for lung flush during lung recovery from donors after circulatory death.

Critical Care before Lung Transplantation

Lung transplantation is widely accepted as the only viable treatment option for patients with end-stage lung disease. However, the imbalance between the number of suitable donor lungs available and the number of possible candidates often results in intensive care unit (ICU) admission for the latter. In the ICU setting, critical care is essential to keep these patients alive and to successfully bridge to lung transplantation. Proper management in the ICU is also one of the key factors supporting long-term success following transplantation. Critical care includes the provision of respiratory support such as mechanical ventilation (MV) and extracorporeal life support (ECLS). Accordingly, a working knowledge of the common critical care issues related to these unique patients and the early recognition and management of problems that arise before and after transplantation in the ICU setting are crucial for long-term success. In this review, we discuss the management and selection of candidates for lung transplantation as well as existing respiratory support strategies that involve MV and ECLS in the ICU setting.

Short- and Long-term Outcomes After Lung Transplantation From Circulatory-Dead Donors: A Single-Center Experience

BACKGROUND

Donation after cardiac death (DCD) to overcome the donor organ shortage is well accepted in the clinical setting, although long-term outcome after DCD lung transplantation (LTx) remains largely unknown.

METHODS

In this retrospective study, DCD LTx recipients (n = 59) were compared with a cohort of donation after brain death (DBD) LTx recipients (n = 331) transplanted between February 2007 and September 2013; follow-up was until January 1, 2016. Short-term (duration of mechanical ventilation, intensive care unit stay, hospital stay, and highest primary graft dysfunction score within 72 hours) and long-term (chronic lung allograft dysfunction-free and overall survival) follow-up were compared over a median follow-up of 50.5 (±3.7) months for DCD and 66.8 (±1.5) months for DBD.

RESULTS

There were no differences between groups with regard to patient characteristics: age (P = 0.78), underlying disease (P = 0.30) and type of type of LTx (P = 0.10), except sex where more males were transplanted with a DCD donor (62.7%) vs (48.3%, P = 0.048). There was no difference in time on mechanical ventilation (P = 0.59), intensive care unit stay (P = 0.74), highest primary graft dysfunction score (P = 0.67) and hospital stay (P = 0.99). Moreover, chronic lung allograft dysfunction-free (P = 0.86) and overall survival (P = 0.15) did not differ between the DBD and DCD groups.

CONCLUSIONS

In our experience, both short- and long-term outcomes in DCD lung recipients are comparable to that of DBD lung recipients. Therefore, DCD LTx can be considered a safe strategy that significantly increased our transplant activity.

The impact of alteplase on pulmonary graft function in donation after circulatory death - An experimental study

Objective

Lung transplantation is hampered by the lack of organs resulting in deaths on the waiting list. The usage of donation after circulatory death (DCD) lungs would dramatically increase donor availability. The most optimal organ preservation method, and the need for antithrombotic and fibrinolytic treatment to prevent thrombosis in the donor lungs is currently on debate. The present study investigated, in a simulated clinical DCD situation, whether the addition of alteplase in the flush-perfusion solution at the time of pulmonary graft harvesting could prevent thrombosis in the donor lung and thereby improve pulmonary graft function.

Methods

Twelve Swedish domestic pigs were randomized into two groups. All animals underwent ventricular fibrillation and were then left untouched for 1 h after declaration of death. None of the animals received heparin. The lungs were then harvested and flush-perfused with Perfadex^® solution and the organs were then stored at 8 °C for 4 h. In one group alteplase was added to the Perfadex^® solution (donation after cardiac death with alteplase (DCD-A)) and in the other, it was not (DCD). Lung function was evaluated, using ex vivo lung perfusion (EVLP), with blood gases at different oxygen levels, pulmonary vascular resistance (PVR), lung weight, and macroscopic appearance.

Results

During EVLP, there were no significant differences between groups in PaO₂ at any investigated FiO₂ level (1.0, 0.5, or 0.21). At FiO₂ 1.0, the PaO₂ in the DCD and DCD-A was 51.7 ± 2.05 kPa and 60.3 ± 3.67 kPa, respectively (p = 0.1320). There were no significant differences between groups PVR levels, in the DCD (372 ± 31 dyne x s/cm⁵) and in the DCD-A (297 ± 37 dyne x s/cm⁵) groups (p = 0.1720). There was no significant difference between groups in macroscopic appearance.

Conclusions

All the lungs showed excellent blood gases after EVLP, and they all meet the criteria's for clinical lung transplantation. The use of alteplase did not seem to have any obvious benefit to the donor lungs in a DCD situation. The donor lungs treated with alteplas showed slightly better blood gases and slightly lower PVR compared to the group without alteplas, however the difference was not significant. DCD appears to be a safe and effective method to expand the donor pool.

Guidelines for the assessment and acceptance of potential brain-dead organ donors

Organ transplantation is the only alternative for many patients with terminal diseases. The increasing disproportion between the high demand for organ transplants and the low rate of transplants actually performed is worrisome. Some of the causes of this disproportion are errors in the identification of potential organ donors and in the determination of contraindications by the attending staff. Therefore, the aim of the present document is to provide guidelines for intensive care multi-professional staffs for the recognition, assessment and acceptance of potential organ donors.

Longer Versus Shorter Duration of Supervised Rehabilitation After Lung Transplantation: A Randomized Trial

OBJECTIVE

To investigate the effects of a supervised longer- (14wk) versus shorter-duration (7wk) rehabilitation program after lung transplantation (LTX).

DESIGN

Randomized controlled trial.

SETTING

Outpatient rehabilitation gym setting.

PARTICIPANTS

Post-LTX patients aged ≥18 years (N=66; 33 women; mean age, 51±13y) who had undergone either single LTX or bilateral LTX.

INTERVENTION

Outpatient rehabilitation program consisting of thrice-weekly sessions with cardiovascular training on bike ergometer and treadmill plus upper and lower limb strength training.

MAIN OUTCOME MEASURES

Measures were taken at baseline, 7 weeks, 14 weeks, and 6 months by assessors who were blinded to group allocation. Functional exercise capacity was measured by the 6-minute walk test (6MWT). Strength of quadriceps and hamstrings was measured on an isokinetic dynamometer and recorded as average peak torque of 6 repetitions for both muscles. Quality of life (QOL) was assessed with the Medical Outcomes Study 36-Item Short-Form Health Survey.

RESULTS

Of the participants, 86% had bilateral LTX and 41% had primary diagnosis of chronic obstructive pulmonary disease. The 6MWT increased in both groups with no significant difference between groups at any time point (mean 6mo 6MWD: short, 590±85m vs long, 568±127m; P=0.5). Similarly, at 6 months, there was no difference between groups in quadriceps average peak torque (mean, 115±38Nm vs 114±40Nm, respectively; P=.59), hamstring average peak torque (57±18Nm vs 52±19Nm, respectively; P=.36), or mental or physical health domains of quality of life.

CONCLUSIONS

Shorter duration (7wk) of rehabilitation achieves comparable outcomes with 14 weeks of supervised rehabilitation for functional exercise capacity, lower limb strength, and quality of life at 6 months after LTX.

Lung transplantation from donation after cardiocirculatory death: a systematic review and meta-analysis

BACKGROUND

Lung transplantation (LTx) can extend life expectancy and enhance the quality of life for select patients with end-stage lung disease. In the setting of donor lung shortage and waiting list mortality, the interest in donation after cardiocirculatory death (DCD) is increasing. We performed a systematic review and meta-analysis to compare outcomes between DCD and conventional donation after brain death (DBD).

METHODS

PubMed, CINAHL, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and ClinicalTrials.gov were searched. We identified original research studies with 1-year post-transplant survival data involving >5 DCD transplants. We performed meta-analyses examining 1-year survival, primary graft dysfunction, and acute rejection after LTx.

RESULTS

We identified 519 citations; 11 observational cohort studies met our inclusion criteria for systematic review, and 6 met our inclusion criteria for meta-analysis. There were no differences found in 1-year mortality after LTx between DCD and DBD cohorts in individual studies or in the meta-analysis (DCD [n = 271] vs DBD [n = 2,369], relative risk [RR] 0.88, 95% confidence interval [CI] 0.59-1.31, p = 0.52, I(2) = 0%). There was also no difference between DCD and DBD in a pooled analysis of 5 studies reporting on primary graft dysfunction (RR 1.09, 95% CI 0.68-1.73, p = 0.7, I(2) = 0%) and 4 studies reporting on acute rejection (RR 0.72, 95% CI 0.49-1.05, p = 0.09, I(2) = 0%).

CONCLUSIONS

Survival after LTx from DCD is comparable to survival after LTx from DBD in observational cohort studies. DCD appears to be a safe and effective method to expand the donor pool.

Critical care management of the lung transplant recipient

Lung transplantation provides the prospect of improved survival and quality of life for patients with end stage lung and pulmonary vascular diseases. Given the severity of illness of such patients at the time of surgery, lung transplant recipients require particular attention in the immediate post-operative period to ensure optimal short-term and long-term outcomes. The management of such patients involves active involvement of a multidisciplinary team versed in common post-operative complications. This review provides an overview of such complications as they pertain to the practitioners caring for post-operative lung transplant recipients. Causes and treatment of conditions affecting early morbidity and mortality in lung transplant recipients will be detailed, including primary graft dysfunction, cardiovascular and surgical complications, and immunologic and infectious issues. Additionally, lung donor management issues and bridging the critically ill potential lung transplant recipient to transplantation will be discussed.