Prognostic factors in lung transplantation: the Santa Casa de Porto Alegre experience

Survival Tree Provides Individualized Estimates of Survival After Lung Transplant

INTRODUCTION

Identifying contributors to lung transplant survival is vital in mitigating mortality. To enhance individualized mortality estimation and determine variable interaction, we employed a survival tree algorithm utilizing recipient and donor data.

METHODS

United Network Organ Sharing data (2000-2021) were queried for single and double lung transplants in adult patients. Graft survival time <7 d was excluded. Sixty preoperative and immediate postoperative factors were evaluated with stepwise logistic regression on mortality; final model variables were included in survival tree modeling. Data were split into training and testing sets and additionally validated with 10-fold cross validation. Survival tree pruning and model selection was based on Akaike information criteria and log-likelihood values. Estimated survival probabilities and log-rank pairwise comparisons between subgroups were calculated.

RESULTS

A total of 27,296 lung transplant patients (8175 single; 19,121 double lung) were included. Stepwise logistic regression yielded 47 significant variables associated with mortality. Survival tree modeling returned six significant factors: recipient age, length of stay from transplant to discharge, recipient ventilator duration post-transplant, double lung transplant, recipient reintubation post-transplant, and donor cytomegalovirus status. Eight subgroups consisting of combinations of these factors were identified with distinct Kaplan-Meier survival curves.

CONCLUSIONS

Survival trees provide the ability to understand the effects and interactions of covariates on survival after lung transplantation. Individualized survival probability with this technique found that preoperative and postoperative factors influence survival after lung transplantation. Thus, preoperative patient counseling should acknowledge a degree of uncertainty given the influence of postoperative factors.

Which strategy is better for lung transplantation: Cardiopulmonary bypass or extracorporeal membrane oxygenation?

Background: In lung transplantation surgery, extracorporeal life support (ECLS) is essential for safety. Various support methods, including cardiopulmonary bypass (CPB) and off-pump techniques, are used, with extracorporeal membrane oxygenation (ECMO) gaining prominence. However, consensus on the best support strategy is lacking.Purpose: This article reviews risks, benefits, and outcomes of different support strategies in lung transplantation. By consolidating knowledge, it aims to clarify selecting the most appropriate ECLS modality.Research Design: A comprehensive literature review examined CPB, off-pump techniques, and ECMO outcomes in lung transplantation, including surgical results and complications.Study Sample: Studies, including clinical trials and observational research, focused on ECLS in lung transplantation, both retrospective and prospective, providing a broad evidence base.Data Collection and/or Analysis: Selected studies were analyzed for surgical outcomes, complications, and survival rates associated with CPB, off-pump techniques, and ECMO to assess safety and effectiveness.Results: Off-pump techniques are preferred, with ECMO increasingly vital as a bridge to transplant, overshadowing CPB. However, ECMO entails hidden risks and higher costs. While safer than CPB, optimizing ECMO postoperative use and monitoring is crucial for success.Conclusions: Off-pump techniques are standard, but ECMO's role is expanding. Despite advantages, careful ECMO management is crucial due to hidden risks and costs. Future research should focus on refining ECMO use and monitoring to improve outcomes, emphasizing individualized approaches for LT recipients.

Relationship of Exercise Capacity, Physical Function, and Frailty Measures With Clinical Outcomes and Healthcare Utilization in Lung Transplantation: A Scoping Review

Measures of exercise capacity, frailty, and physical function are commonly used in lung transplant candidates and recipients to evaluate their physical limitations and the effects of exercise training and to select candidates for transplantation. It is unclear how these measures are related to clinical outcomes and healthcare utilization before and after lung transplantation. The purpose of this scoping review was to describe how measures of exercise capacity, physical function, and frailty are related to pre- and posttransplant outcomes.

Methods

We considered studies of any design that included performance-based tests of exercise capacity, physical function, and frailty in adult lung transplant candidates or recipients. Outcomes of interest were clinical outcomes (eg, mortality, quality of life) and healthcare utilization.

Results

Seventy-two articles met the inclusion criteria. The 6-min walk test (6MWT) was shown to be related to mortality on the waiting list with different distance values as cutoffs points. There were inconsistent results regarding the relationship of the 6MWT with other clinical outcomes. Few studies have examined the relationship between the cardiopulmonary exercise test or the short physical performance battery and clinical outcomes, although some studies have shown relationship with survival posttransplant and quality of life. Few studies examined the relationship between the tests of interest and healthcare utilization' and the results were inconsistent.

Conclusions

Except for the relationship between the 6MWT and mortality on the waiting list, there is limited evidence regarding the relationship of performance-based measures of exercise capacity, frailty, and physical function with clinical outcomes or healthcare utilization.

Preoperative risk factors for successful extubation or not after lung transplantation

Background

The purpose of this study was to uncover preoperative risk factors for extubation failure or re-intubation for patients undergoing lung transplant (LTx).

Methods

We performed a retrospective case-control study of LTx from our center between January 2017 and March 2019. Demographic and preoperative characteristics were collected for all included patients. Univariable analysis and multivariable logistic regression were used to analyze risk factors of postoperative unsuccessful extubation following LTx.

Results

Among 107 patients undergoing first LTx investigated, 74 (69.16%) patients who were successfully liberated from mechanical ventilation (MV), and 33 (30.84%) patients who were unsuccessful extubation, which 18 (16.82%) patients suffered from reintubation. associated preoperative factors for unsuccessful extubation following LTx included preoperative extracorporeal membrane oxygenation (ECMO) support [OR =4.631, 95% confidence interval (CI): 1.403–15.286, P=0.012], the preoperative ability of independent expectoration (OR =4.517, 95% CI: 1.498–13.625, P=0.007), the age older than 65-year-old (OR =4.039, 95% CI: 1.154–14.139, P=0.029), and receiving the double lung and heart-LTx (OR =3.390, 95% CI: 0.873–13.162, P=0.078; and OR =16.579, 95% CI: 2.586–106.287, P=0.012, respectively). Further, we investigated the preoperative predicted factors for reintubation. Only the preoperative ECMO remained a significant predictor of re-intubation (OR =4.69, 95% CI: 1.56–15.286, P=0.012).

Conclusions

Preoperative independent sputum clearance, preoperative ECMO, older than 65-year-old, and double lung or heart-LTx were four independent risk factors for unsuccessful extubation. Moreover, preoperative ECMO was the only independent risk factor for reintubation.

Comparison of mechanical cardiopulmonary support strategies during lung transplantation

INTRODUCTION

Lung transplantation outcomes are influenced by the intraoperative mechanical cardiopulmonary support strategy used. This surgery was historically done either on cardiopulmonary bypass (CPB) or off pump. Recently, there has been increased interest in intraoperative support with veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO). However, there is a lack of consensus on the relative risks, benefits and indications for each intraoperative support strategy.

AREAS COVERED

This review includes information from cohort studies, case-control studies, and case series that compare morbidity and/or mortality of two or more intraoperative cardiopulmonary support strategies during lung transplantation.

EXPERT OPINION

The optimal strategy for intraoperative cardiopulmonary support during lung transplantation remains an area of debate. Current data suggest that off pump is associated with better outcomes and could be considered whenever feasible. ECMO is generally associated with preferable outcomes to CPB, but the data supporting this association is not robust. Interestingly, whether CPB is unplanned or prolonged might influence outcomes more than the use of CPB itself. These observations can help guide surgical teams in their approach for intraoperative mechanical support strategy during lung transplantation and should serve as the basis for further investigations.

Acute Kidney Injury after Lung Transplantation: A Systematic Review and Meta-Analysis

Background: Lung transplantation has been increasingly performed worldwide and is considered an effective therapy for patients with various causes of end-stage lung diseases. We performed a systematic review to assess the incidence and impact of acute kidney injury (AKI) and severe AKI requiring renal replacement therapy (RRT) in patients after lung transplantation. Methods: A literature search was conducted utilizing Ovid MEDLINE, EMBASE, and Cochrane Database from inception through June 2019. We included studies that evaluated the incidence of AKI, severe AKI requiring RRT, and mortality risk of AKI among patients after lung transplantation. Pooled incidence and odds ratios (ORs) with 95% confidence interval (CI) were obtained using random-effects meta-analysis. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42019134095). Results: A total of 26 cohort studies with a total of 40,592 patients after lung transplantation were enrolled. Overall, the pooled estimated incidence rates of AKI (by standard AKI definitions) and severe AKI requiring RRT following lung transplantation were 52.5% (95% CI: 45.8–59.1%) and 9.3% (95% CI: 7.6–11.4%). Meta-regression analysis demonstrated that the year of study did not significantly affect the incidence of AKI (p = 0.22) and severe AKI requiring RRT (p = 0.68). The pooled ORs of in-hospital mortality in patients after lung transplantation with AKI and severe AKI requiring RRT were 2.75 (95% CI, 1.18–6.41) and 10.89 (95% CI, 5.03–23.58). At five years, the pooled ORs of mortality among patients after lung transplantation with AKI and severe AKI requiring RRT were 1.47 (95% CI, 1.11–1.94) and 4.79 (95% CI, 3.58–6.40), respectively. Conclusion: The overall estimated incidence rates of AKI and severe AKI requiring RRT in patients after lung transplantation are 52.5% and 9.3%, respectively. Despite advances in therapy, the incidence of AKI in patients after lung transplantation does not seem to have decreased. In addition, AKI after lung transplantation is significantly associated with reduced short-term and long-term survival.

What is expected in lung function after lung transplantation due to end-stage pulmonary silicosis?

In this study, we aimed to determine the impact of lung transplantation (LTx) on pulmonary function tests (PFTs) and survival among patients with end-stage silicosis. We included patients with end-stage silicosis on the wait list for LTx, between January 1989 and July 2015 (N = 26). Sixteen of these patients received LTx; 10 were eligible, but did not undergo LTx (non-LTx) during the study period. Retrospective information on PFTs (spirometry [volumes and flows], 6-minute walking test [6MWT], and DLCO) was retrieved from patients' medical charts, including baseline information for all patients and follow-up information for the LTx. At baseline, most patients presented with spirometric and 6MWT values that were suggestive of severe disease (FEV₁ /FVC 76.5 ± 29.7; 6MWT 267.4 ± 104.5 m). Significant increases in these values were observed at follow-up in the LTx (P = .036 and .151, respectively). The overall median survival of patients in the LTx and non-LTx was 3.35 years (95% CI: 0.16-14.38) and 0.78 years (95% confidence interval [CI]: 0.12-3.65) (P = 0.002), respectively. For patients with end-stage silicosis, LTx offers significant benefits regarding pulmonary function and survival when compared to non-LTx, and is a reliable tool to help this critical population of patients, whose only treatment option is LTx.

Pattern and Predictors of Hospital Readmission During the First Year After Lung Transplantation

Hospital readmission after lung transplantation negatively affects quality of life and resource utilization. A secondary analysis of data collected prospectively was conducted to identify the pattern of (incidence, count, cumulative duration), reasons for and predictors of readmission for 201 lung transplant recipients (LTRs) assessed at 2, 6, and 12 mo after discharge. The majority of LTRs (83.6%) were readmitted, and 64.2% had multiple readmissions. The median cumulative readmission duration was 19 days. The main reasons for readmission were other than infection or rejection (55.5%), infection only (25.4%), rejection only (9.9%), and infection and rejection (0.7%). LTRs who required reintubation (odds ratio [OR] 1.92; p = 0.008) or were discharged to care facilities (OR 2.78; p = 0.008) were at higher risk for readmission, with a 95.7% cumulative incidence of readmission at 12 mo. Thirty-day readmission (40.8%) was not significantly predicted by baseline characteristics. Predictors of higher readmission count were lower capacity to engage in self-care (incidence rate ratio [IRR] 0.99; p = 0.03) and discharge to care facilities (IRR 1.45; p = 0.01). Predictors of longer cumulative readmission duration were older age (arithmetic mean ratio [AMR] 1.02; p = 0.009), return to the intensive care unit (AMR 2.00; p = 0.01) and lower capacity to engage in self-care (AMR 0.99; p = 0.03). Identifying LTRs at risk may assist in optimizing predischarge care, discharge planning and long-term follow-up.

Functional improvement in patients with idiopathic pulmonary fibrosis undergoing single lung transplantation

Objective:

To evaluate the changes in lung function in the first year after single lung transplantation in patients with idiopathic pulmonary fibrosis (IPF).

Methods:

We retrospectively evaluated patients with IPF who underwent single lung transplantation between January of 2006 and December of 2012, reviewing the changes in the lung function occurring during the first year after the procedure.

Results:

Of the 218 patients undergoing lung transplantation during the study period, 79 (36.2%) had IPF. Of those 79 patients, 24 (30%) died, and 11 (14%) did not undergo spirometry at the end of the first year. Of the 44 patients included in the study, 29 (66%) were men. The mean age of the patients was 57 years. Before transplantation, mean FVC, FEV₁, and FEV₁/FVC ratio were 1.78 L (50% of predicted), 1.48 L (52% of predicted), and 83%, respectively. In the first month after transplantation, there was a mean increase of 12% in FVC (400 mL) and FEV₁ (350 mL). In the third month after transplantation, there were additional increases, of 5% (170 mL) in FVC and 1% (50 mL) in FEV₁. At the end of the first year, the functional improvement persisted, with a mean gain of 19% (620 mL) in FVC and 16% (430 mL) in FEV₁.

Conclusions:

Single lung transplantation in IPF patients who survive for at least one year provides significant and progressive benefits in lung function during the first year. This procedure is an important therapeutic alternative in the management of IPF.

Idiopathic pulmonary fibrosis in BRIC countries: the cases of Brazil, Russia, India, and China

Idiopathic pulmonary fibrosis (IPF), the prototype of interstitial lung diseases, has the worst prognosis and is the only interstitial lung disease for which approved pharmacological treatments are available. Despite being considered a rare disease, IPF patients pose major challenges to both physicians and healthcare systems. It is estimated that a large number of IPF patients reside in BRIC countries (Brazil, Russia, India, and China) given their overall total population of approximately 3 billion inhabitants. Nevertheless, the limited availability of chest imaging in BRIC countries is considered a chief obstacle to diagnosis, since high-resolution computed tomography of the chest is the key diagnostic test for IPF. Further, obtaining reliable lung function tests and providing treatment access is difficult in the more rural areas of these countries. However, IPF might represent an opportunity for BRIC countries: the exponentially increasing demand for the enrollment of IPF patients in clinical trials of new drugs is predicted to face a shortage of patients - BRIC countries may thus play a crucial role in advancing towards a cure for IPF.

Lung transplantation: a treatment option in end-stage lung disease

BACKGROUND

Lung transplantation is the final treatment option in the end stage of certain lung diseases, once all possible conservative treatments have been exhausted. Depending on the indication for which lung transplantation is performed, it can improve the patient's quality of life (e.g., in emphysema) and/ or prolong life expectancy (e.g., in cystic fibrosis, pulmonary fibrosis, and pulmonary arterial hypertension). The main selection criteria for transplant candidates, aside from the underlying pulmonary or cardiopulmonary disease, are age, degree of mobility, nutritional and muscular condition, and concurrent extrapulmonary disease. The pool of willing organ donors is shrinking, and every sixth candidate for lung transplantation now dies while on the waiting list.

METHOD

We reviewed pertinent articles (up to October 2013) retrieved by a selective search in Medline and other German and international databases, including those of the International Society for Heart and Lung Transplantation (ISHLT), Eurotransplant, the German Institute for Applied Quality Promotion and Research in Health-Care (Institut für angewandte Qualitätsförderung und Forschung im Gesundheitswesen, AQUA-Institut), and the German Foundation for Organ Transplantation (Deutsche Stiftung Organtransplantation, DSO).

RESULTS

The short- and long-term results have markedly improved in recent years: the 1-year survival rate has risen from 70.9% to 82.9%, and the 5-year survival rate from 46.9% to 59.6%. The 90-day mortality is 10.0%. The postoperative complications include acute (3.4%) and chronic (29.0%) transplant rejection, infections (38.0%), transplant failure (24.7%), airway complications (15.0%), malignant tumors (15.0%), cardiovascular events (10.9%), and other secondary extrapulmonary diseases (29.8%). Bilateral lung transplantation is superior to unilateral transplantation (5-year survival rate 57.3% versus 47.4%).

CONCLUSION

Seamless integration of the various components of treatment will be essential for further improvements in outcome. In particular, the follow-up care of transplant recipients should always be provided in close cooperation with the transplant center.

The immediate post-operative period following lung transplantation: mapping of nursing interventions

OBJECTIVES:

to investigate the principle nursing interventions/actions, prescribed in the immediate post-operative period for patients who receive lung transplantation, recorded in the medical records, and to map these using the Nursing Interventions Classification (NIC) taxonomy.

METHOD:

retrospective documental research using 183 medical records of patients who received lung transplantation (2007/2012). The data of the patients' profile were grouped in accordance with the variables investigated, and submitted to descriptive analysis. The nursing interventions prescribed were analyzed using the method of cross-mapping with the related interventions in the NIC. Medical records which did not contain nursing prescriptions were excluded.

RESULTS:

the majority of the patients were male, with medical diagnoses of pulmonary fibrosis, and underwent lung transplantation from a deceased donor. A total of 26 most frequently-cited interventions/actions were found. The majority (91.6%) were in the complex and basic physiological domains of the NIC. It was not possible to map two actions prescribed by the nurses.

CONCLUSIONS:

it was identified that the main prescriptions contained general care for the postoperative period of major surgery, rather than prescriptions individualized to the patient in the postoperative period following lung transplantation. Care measures related to pain were underestimated in the prescriptions. The mapping with the taxonomy can contribute to the elaboration of the care plan and to the use of computerized systems in this complex mode of therapy.

Lung transplantation in idiopathic pulmonary fibrosis: a systematic review of the literature

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a distinct form of interstitial pneumonia with unknown origin and poor prognosis. Current pharmacologic treatments are limited and lung transplantation is a viable option for appropriate patients. The aim of this review was to summarize lung transplantation survival in IPF patients overall, between single (SLT) vs. bilateral lung transplantation (BLT), pre- and post Lung Allocation Score (LAS), and summarize wait-list survival.

METHODS

A systematic review of English-language studies published in Medline or Embase between 1990 and 2013 was performed. Eligible studies were those of observational design reporting survival post-lung transplantation or while on the wait list among IPF patients.

RESULTS

Median survival post-transplantation among IPF patients is estimated at 4.5 years. From ISHLT and OPTN data, one year survival ranged from 75% - 81%; 3-year: 59% - 64%; and 5-year: 47% - 53%. Post-transplant survival is lower for IPF vs. other underlying pre-transplant diagnoses. The proportion of IPF patients receiving BLT has steadily increased over the last decade and a half. Unadjusted analyses suggest improved long-term survival for BLT vs. SLT; after adjustment for patient characteristics, the differences tend to disappear. IPF patients account for the largest proportion of patients on the wait list and while wait list time has decreased, the number of transplants for IPF patients has increased over time. OPTN data show that wait list mortality is higher for IPF patients vs. other diagnoses. The proportion of IPF patients who died while awaiting transplantation ranged from 14% to 67%. While later transplant year was associated with increased survival, no significant differences were noted pre vs. post LAS implementation; however a high LAS vs low LAS was associated with decreased one-year survival.

CONCLUSIONS

IPF accounts for the largest proportion of patients awaiting lung transplants, and IPF is associated with higher wait-list and post-transplant mortality vs. other diagnoses. Improved BLT vs. SLT survival may be the result of selection bias. Survival pre- vs. post LAS appears to be similar except for IPF patients with high LAS, who have lower survival compared to pre-LAS. Data on post-transplant morbidity outcomes are sparse.