Incidence and variables associated with 30-day mortality after lung transplantation

Analysis of Perioperative Factors Leading to Postoperative Pulmonary Complications, Graft Injury and Increased Postoperative Mortality in Lung Transplantation

OBJECTIVES

Postoperative complications such as postoperative pulmonary complications (PPCs) and other organ complications are associated with increased morbidity and mortality after successful lung transplantation and have a detrimental effect on patient recovery. The aim of this study was to investigate perioperative risk factors for in-hospital mortality and postoperative complications with a focus on PPC and graft injury in patients undergoing lung transplantation DESIGN: Single-center retrospective cohort study of 173 patients undergoing lung transplantation SETTING: University Hospital, Medical Center Freiburg.

MAIN RESULTS

In the stepwise multivariate regression analysis, donor age >60 years (odds ratio [OR], 1.85; 95% confidence interval [CI], 1.27-2.81), intraoperative extracorporeal membrane oxygenation (OR, 2.4; 95% CI, 1.7-3.3), transfusion of >4 red blood cell concentrates (OR, 3.1; 95% CI, 1.82-5.1), mean pulmonary artery pressure of >30 mmHg at the end of surgery (OR, 3.5; 95% CI, 2-6.3), the occurrence of postoperative graft injury (OR, 4.1; 95% CI, 2.8-5.9), PPCs (OR, 2.1; 95% CI, 1.7-2.6), sepsis (OR, 4.5; 95% CI, 2.8-7.3), and Kidney disease Improving Outcome grading system stage 3 acute renal failure (OR, 4.3; 95% CI, 2.4-7.7) were associated with increased in hospital mortality, whereas patients with chronic obstructive pulmonary disease had a lower in-hospital mortality (OR, 1.6; 95% CI, 1.4-1.9). The frequency and number of PPCs correlated with postoperative mortality.

CONCLUSIONS

Clinical management and risk stratification focusing on the underlying identified factors that could help to improve patient outcomes.

Lung donor bronchoalveolar lavage positivity: Incidence, risk factors, and lung transplant recipients' outcome

BACKGROUND

Inconsistent data exists regarding the risk factors for bronchoalveolar lavage (BAL) positivity in lung donors, the incidence of donor-derived infections (DDI), and the effect of BAL positivity on lung transplant (LuTx) recipients' outcome.

METHODS

A retrospective analysis was conducted on consecutive LuTx at a single center from January 2016 to December 2022. Donors' data, including characteristics, graft function and BAL samples were collected pre-procurement. Recipients underwent BAL before LuTx and about the 3rd, 7th and 14th day after LuTx. A DDI was defined as BAL positivity (bacterial growth ≥104 colony forming units) for identical bacterial species between donor and recipient. Recipients' pre-operative characteristics, intra-operative management, and post-operative outcomes were assessed. Two recipient cohorts were identified based on lung colonization status before undergoing LuTx.

RESULTS

Out of 188 LuTx procedures performed, 169 were analyzed. Thirty-six percent of donors' BAL tested positive. Donors' characteristics and graft function at procurement were not associated with BAL positivity. Fourteen DDI were detected accounting for 23% of recipients receiving a graft with a positive BAL. Only among uncolonized recipients, receiving a graft with positive BAL is associated with higher likelihood of requiring invasive ventilation at 72 hours after LuTx on higher positive end-expiratory pressure levels having lower PaO2/FiO2, prolonged duration of mechanical ventilation and longer ICU stay. No difference in hospital length of stay was observed.

CONCLUSIONS

Receiving a graft with a positive BAL, which is poorly predicted by donors' characteristics, carries the risk of developing a DDI and is associated to a worse early graft function among uncolonized recipients.

Predictors of early mortality after lung transplantation for idiopathic pulmonary arterial hypertension

Lung transplantation remains an important therapeutic option for idiopathic pulmonary arterial hypertension (IPAH), yet short-term survival is the poorest among the major diagnostic categories. We sought to develop a prediction model for 90-day mortality using the United Network for Organ Sharing database for adults with IPAH transplanted between 2005 and 2021. Variables with a p value ≤ 0.1 on univariate testing were included in multivariable analysis to derive the best subset model. The cohort comprised 693 subjects, of whom 71 died (10.2%) within 90 days of transplant. Significant independent predictors of early mortality were: extracorporeal circulatory support and/or mechanical ventilation at transplant (OR: 3; CI: 1.4-5), pulmonary artery diastolic pressure (OR: 1.3 per 10 mmHg; CI: 1.07-1.56), forced expiratory volume in the first second percent predicted (OR: 0.8 per 10%; CI: 0.7-0.94), recipient total bilirubin >2 mg/dL (OR: 3; CI: 1.4-7.2) and ischemic time >6 h (OR: 1.7, CI: 1.01-2.86). The predictive model was able to distinguish 25% of the cohort with a mortality of ≥20% from 49% with a mortality of ≤5%. We conclude that recipient variables associated with increasing severity of pulmonary vascular disease, including pretransplant advanced life support, and prolonged ischemic time are important risk factors for 90-day mortality after lung transplant for IPAH.

Impact of delayed veno-venous extracorporeal membrane oxygenation weaning on postoperative rehabilitation of lung transplantation: a single-center comparative study

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a reliable and effective extracorporeal life support during lung transplantation (LTx). However, the clinical benefit of delayed VV-ECMO weaning remains unclear. The current study aims to investigate whether delayed weaning of VV-ECMO is more beneficial to the rehabilitation for lung transplant patients. Patients who underwent LTx with VV-ECMO between January 2017 and January 2019 were included. Enrollment of patients was suitable for weaning off ECMO immediately after surgery. Randomization was performed in the operating room. Postoperative outcomes were compared between the two groups. Besides, univariate and multivariable logistic regressions were performed to estimate risk of postoperative complications. Compared to VV-ECMO weaning immediately after LTx, delayed weaning was associated with shorter hospital length of stay (days, 31 vs. 46; P < 0.05), lower incidence of noninvasive ventilation (4.3% vs. 24.4%; P < 0.05), primary graft dysfunction (PGD) (6.4% vs. 29.3%; P < 0.05), atrial fibrillation (AF) (4.3% vs. 22%, P < 0.05), and respiratory failure (4.3% vs. 19.5%; P < 0.05). Multivariable logistic regressions revealed that VV-ECMO weaning after LTx was independently correlated with increased risk of developing PGD [odds ratio (OR), 5.97, 95% CI 1.16-30.74], AF (OR, 6.87, 95% CI 1.66-28.47) and respiratory failure (OR, 6.02, 95% CI 1.12-32.49) by comparison of delayed VV-ECMO weaning. Patients with delayed VV-ECMO weaning are associated with lower complications and short hospital length of stay, while it relates to longer mechanical ventilation. These findings suggest that delayed VV-ECMO after LTx can facilitate rehabilitation.

Textbook Outcome: Definition and Analysis of a Novel Quality Measure in Lung Transplantation

OBJECTIVE

To define textbook outcome (TO) for lung transplantation (LTx) using a contemporary cohort from a high-volume institution.

SUMMARY BACKGROUND DATA

TO is a standardized, composite quality measure based on multiple postoperative endpoints representing the ideal "textbook" hospitalization.

METHODS

Adult patients who underwent LTx at our institution between 2016 and 2019 were included. TO was defined as freedom from intraoperative complication, postoperative reintervention, 30-day intensive care unit or hospital readmission, length of stay >75th percentile of LTx patients, 90 day mortality, 30-day acute rejection, grade 3 primary graft dysfunction at 48 or 72 hours, postoperative extracorporeal membrane oxygenation, tracheostomy within 7 days, inpatient dialysis, reintubation, and extubation >48 hours post-transplant. Recipient, operative, financial characteristics, and post-transplant outcomes were recorded from institutional data and compared between TO and non-TO groups.

RESULTS

Of 401 LTx recipients, 97 (24.2%) achieved TO. The most common reason for TO failure was extubation >48 hours post-transplant (N = 119, 39.1%); the least common was mortality (N = 15, 4.9%). Patient and graft survival were improved among patients who achieved versus failed TO (patient survival: log-rank P < 0.01; graft survival: log-rank P < 0.01). Rejection-free and chronic lung allograft dysfunction-free survival were similar between TO and non-TO groups (rejection-free survival: log-rank P = 0.07; chronic lung allograft dysfunction-free survival: log-rank P = 0.3). On average, patients who achieved TO incurred approximately $638,000 less in total inpatient charges compared to those who failed TO.

CONCLUSIONS

TO in LTx was associated with favorable post-transplant outcomes and significant cost-savings. TO may offer providers and patients new insight into transplant center quality of care and highlight areas for improvement.

Extracorporeal Membrane Oxygenation as a Bridge to Lung Transplant

Extracorporeal membrane oxygenation (ECMO) is a cardiopulmonary technology capable of supporting cardiac and respiratory function in the presence of end-stage lung disease. Initial experiences using ECMO as a bridge to lung transplant (ECMO-BTLT) were characterized by high rates of ECMO-associated complications and poor posttransplant outcomes. More recently, ECMO-BTLT has garnered success in preserving patients' physiologic condition and candidacy prior to lung transplant due to technological advances and improved management. Despite recent growth, clinical practice surrounding use of ECMO-BTLT remains variable, with little data to inform optimal patient selection and management. Although many questions remain, the use of ECMO-BTLT has shown promising outcomes suggesting that ECMO-BTLT can be an effective strategy to ensure that complex and rapidly decompensating patients with end-stage lung disease can be safely transplanted with good outcomes. Further studies are needed to refine and inform practice patterns, management, and lung allocation in this high-risk and fragile patient population.

Donor ventilation parameters as predictors for length of mechanical ventilation after lung transplantation: Results of a prospective multicenter study

BACKGROUND

The evaluation of donor lungs heavily depends on the subjective judgment of the retrieval surgeon. As a consequence, acceptance rates vary significantly among transplant centers. We aimed to determine donor ventilation parameters in a prospective study and test if they could be used as objective quality criteria during organ retrieval.

METHODS

A prospective evaluation of lung donors was performed in 3 transplant centers. Ventilation parameters were collected at the time of retrieval using a standardized ventilation protocol. Recipient length of mechanical ventilation (LMV) was defined as the primary end point, and collected data was used to build linear models predicting LMV.

RESULTS

In total, 166 donors were included in this study. Median LMV after transplantation was 32 hours (interquartile range: 20-63 hours). Peak inspiratory pressure and dynamic compliance (C_dyn) at the time of retrieval, but not the partial pressure of oxygen/fraction of inspired oxygen (P/F) ratio, correlated with recipient LMV in Spearman correlations (r = 0.280, p = 0.002; r = -0.245, p = 0.003; and r = 0.064, p = 0.432, respectively). Linear models were built to further evaluate the impact of donor ventilation parameters on LMV. The first model was based on donor P/F ratio, donor age, donor intubation time, donor smoking history, donor partial pressure of carbon dioxide, aspiration, chest trauma, and pathologic chest X-ray. This model performed poorly (multiple R-squared = 0.063). In a second model, donor ventilation parameters were included, and C_dyn was identified as the strongest predictor for LMV. The third model was extended by recipient factors, which significantly improved the robustness of the model (multiple R-squared = 0.293).

CONCLUSION

In this prospective evaluation of donor lung parameters, currently used donor quality criteria poorly predicted recipient LMV. Our data suggest that C_dyn is a strong donor-bound parameter to predict short-term graft performance; however, recipient factors are similarly relevant.

Lung allocation for transplant: The European perspective

Since the first successful lung transplants in humans were done in the 1980s, lung transplantation has become an established treatment for end-stage pulmonary disease. Because the access to transplantable organs is limited and unpredictable, rules that guide the allocation of lungs for transplants have emerged. Such rules are governed not only by medical and bioethical necessities, but also by local traditions, legislation, and practical circumstances. Therefore, there may be significant differences between the organ allocation practices in various parts of the world. In this brief communication, the European perspective on lung allocation is presented, also adding a very brief description of other parts of the world.

Noteworthy Literature Published in 2018 for Thoracic Organ Transplantation

Publications of note from 2018 are reviewed for the cardiothoracic transplant anesthesiologist. Strategies to expand the availability of donor organs were highlighted, including improved donor management, accumulating experience with increased-risk donors, ex vivo perfusion techniques, and donation after cardiac death. A number of reports examined posttransplant outcomes, including outcomes other than mortality, with new data-driven risk models. Use of extracorporeal support in cardiothoracic transplantation was a prominent theme. Major changes in adult heart allocation criteria were implemented, aiming to improve objectivity and transparency in the listing process. Frailty and prehabilitation emerged as targets of comprehensive perioperative risk mitigation programs.