The societal impact of single versus bilateral lung transplantation for chronic obstructive pulmonary disease

Single vs Double Lung Transplantation in Older Adults: A Propensity-Matched Analysis

BACKGROUND

Single lung transplantation (SLT) is associated with worse long-term outcomes than bilateral lung transplantation (BLT), but often is performed in older adults at risk of not tolerating BLT.

RESEARCH QUESTION

How do the outcomes of SLT and BLT compare among older adult recipients?

STUDY DESIGN AND METHODS

The Scientific Registry of Transplant Recipients database (2005-2022) was queried for lung transplant recipients 65 years of age or older. Patients were stratified by whether they underwent BLT or SLT and were propensity matched. Baseline characteristics and morbidity were compared with frequentist statistics. Survival was analyzed via Kaplan-Meier estimation. Risk factors for mortality were identified with Cox regression.

RESULTS

Of 9,904 included patients, 4,829 patients (48.8%) underwent SLT. Patients who underwent SLT had lower lung allocation scores (39.6 vs 40.6; P < .001), more interstitial lung disease (74.4% vs 64.6%; P < .001), and lower rates of bridging (0.7% vs 2.4%; P < .001). Groups did not differ significantly by sex, BMI, or donor characteristics. Propensity matching resulted in 2,539 patients in each group. On matched analysis, patients undergoing SLT had shorter lengths of stay (14 days vs 18 day), lower reintubation rates (14.7% vs 19.8%), and less postoperative dialysis use (4.2% vs 6.4%; P < .001 for all). Patients who underwent SLT had comparable survival at 30 days (97.6% vs 97.3%; P = .414) and 1 year (85.5% vs 86.3%; P = .496), but lower survival at 5 years (45.4% vs 53.4%; P < .001) on matched analysis. SLT was a risk factor for 5-year mortality (adjusted hazard ratio, 1.19; P < .001).

INTERPRETATION

In older adults, SLT is associated with less morbidity and comparable early survival relative to BLT, but lower 5-year survival. SLT is reasonable to perform in older adults at high risk of not tolerating BLT.

Double lung transplantation is better than single lung transplantation for end-stage chronic obstructive pulmonary disease: a meta-analysis

BACKGROUND

Lung transplantation is one of the most common treatment options for patients with end-stage chronic obstructive pulmonary disease. However, the choice between single and double lung transplantation for these patients remains a matter of debate. Therefore, we performed a systematic search of medical databases for studies on single lung transplantation, double lung transplantation, and chronic obstructive pulmonary disease.

METHODS

The rate ratio and hazard ratio of survival were analyzed. The meta-analysis included 15 case-control and retrospective registry studies.

RESULTS

The rate ratios of the 3-year survival (0.937 and P = 0.041) and 5-year survival (0.775 and P = 0.000) were lower for single lung transplantation than for double lung transplantation. However, the hazard ratio did not differ significantly between the two.

CONCLUSIONS

Double lung transplantation was found to provide better benefits than single lung transplantation in terms of the long-term survival in patients with chronic obstructive pulmonary disease.

Spirometry testing for extracorporeal membrane oxygenation (ECMO) bridge to transplant patients

PURPOSE

ECMO can provide a bridge to transplantation and improve survival for patients with advanced lung disease. Although pulmonary function testing (PFT) is an important component of the lung allocation score (LAS), it is not always feasible on patients requiring ECMO. While generally safe, PFT testing has contraindications and is not recommended in unstable patients. Currently there are no recommendations regarding the performance of spirometry in ECMO patients.

STUDY DESIGN

and Methods: We reviewed data on five patients with advanced lung disease requiring ECMO-bridge to transplant. After careful consideration of the theoretical physiologic risks associated with forced expiratory maneuvers, bedside spirometry was performed in order to update the patients' LAS.

RESULTS

All patients successfully completed three forced expiratory maneuvers in the seated position with a bedside spirometer. Vital signs and ECMO flow were stable during testing and without complication. In 2 patients who had both a LAS pre and post spirometry, the LAS increased by 3-5 points.

CONCLUSION

Spirometry results are pivotal to organ allocation under current organ sharing protocols. This case series demonstrates that bedside spirometry testing may be performed safely in patients on ECMO awaiting lung transplantation without appreciable side effects, leading to a more accurate LAS score.

Lung Transplant Type & Donor Age in Idiopathic Pulmonary Fibrosis: A Single Center Study

BACKGROUD

Idiopathic pulmonary fibrosis (IPF) accounts for a marked proportion of diagnoses on the US lung transplant (LTx) list. The effects of single (SLT) versus double LTx (DLT) and lung donor age on survival in IPF remain unclear and were investigated in this study.

METHODS

We retrospectively assessed survival of LTx recipients with IPF at a single institution from February 2012-March 2020. Survival was analyzed and compared between LTx types (SLT and DLT), donor ages, and the combined groups (LTx type & donor age) using Kaplan-Meier survival analysis and compared by log-rank test. P-values less than 0.05 were considered significant.

RESULTS

Of 744 LTx patients at our institution, 307 (41.3%) were diagnosed with IPF, of which 208 (67.8%) were SLT, and 97 (31.6%) were DLT (2 excluded patients underwent heart-lung transplantation). There was no significant difference in survival due to LTx type (P = 0.41) or for patients with donor age <50 or ≥50 y (P = 0.46). Once stratified by both LTx type and donor age, analysis showed no significant difference in survival between the four groups (P = 0.69).

CONCLUSIONS

With ethical consideration for organ allocation, as the average age of the US population increases, donor lungs aged ≥50 are an increasingly useful resource in LTx. Our findings suggest donor age and LTx type do not significantly affect survival. Therefore, SLT, and donor lungs aged ≥50 ought to be more readily considered as non-inferior options for LTx in patients with IPF.

Postoperative Management of Hyperinflated Native Lung in Single-Lung Transplant Recipients with Chronic Obstructive Pulmonary Disease: A Review Article

End-stage chronic obstructive pulmonary disease (COPD) is the most common indication for single- or double-lung transplantation. Acute native lung hyperinflation (ANLH) is a unique postoperative complication of single-lung transplantation for COPD patients, with incidence varying in the medical literature from 15 to 30%. The diagnosis is made radiographically by contralateral mediastinal shift and ipsilateral diaphragmatic flattening. ANLH can deteriorate into hemodynamic instability, and respiratory impairment can result from compression of the allograft, which can precipitate atelectasis, hypoxemia, and hypercapnia, necessitating specific ventilatory intervention or volume reduction surgery. Currently, there is consensus for a therapeutic role of noninvasive positive pressure ventilation (NIPPV) in acute respiratory failure after lung transplantation as a well-tolerated measure to avoid re-intubation. This manuscript presents a concise review on the diagnosis and treatment of ANLH following unilateral lung transplant, along with a management algorithm created by the authors.

Right single lung transplantation or double lung transplantation compared with left single lung transplantation in chronic obstructive pulmonary disease

BACKGROUND

Although single and double lung transplantation outcomes for chronic obstructive pulmonary disease (COPD) have been investigated, right and left single lung transplants have never been rigorously compared to evaluate disease-specific differences. Single lung transplants for COPD often have hyperinflation of the contralateral native lung, which may be more pronounced in left lung transplants.

METHODS

Using the United Network for Organ Sharing registry, we conducted a retrospective cohort study of 5,585 adults who underwent lung transplantation for COPD from May 4, 2005 to June 30, 2017. Subjects were followed until March 2019. Post-transplant survival was compared using Cox proportional hazards and Royston and Parmar's flexible parametric survival models. We adjusted for donor and recipient factors with known or plausible associations with survival.

RESULTS

Lung transplant recipients who received a left single lung transplant for COPD had an increased risk of post-transplant death when compared with those who received a right single lung transplant for COPD (hazard ratio [HR]: 1.24, 95% CI: 1.08-1.48, p = 0.002). Survival did not differ significantly between double lung transplant and right single lung transplant recipients (HR: 0.88, 95% CI: 0.77-1.02, p = 0.086). Adjusted 5-year survival was 57.8% (95% CI: 55.7-60.1) for double lung recipients, 56.7% (95% CI: 55.4-58.0) for right single lung recipients, and 50.9% (95% CI: 47.2-55.0) for left single lung recipients.

CONCLUSIONS

In COPD, right single lung transplantation was associated with improved post-transplant survival compared with left single lung transplantation, and no significant difference in post-transplant survival compared with double lung transplantation was found. In light of the ongoing donor lung shortage, preferential allocation of right single lungs to patients with COPD should be considered.

Procedure Preference and Intention-to-Treat Outcomes after Listing for Lung Transplantation among U.S. Adults. A Cohort Study

RATIONALE

Bilateral lung transplantation is widely used to treat chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD), on the basis of an expectation of improved survival after transplantation. Yet, waiting list mortality is higher while awaiting bilateral transplantation. The net effect of procedure preference on overall survival is unknown.

OBJECTIVES

To determine whether an unrestricted procedure preference is associated with improved overall outcomes after listing for lung transplantation.

METHODS

We performed a retrospective cohort study of 12,155 adults with COPD or ILD listed for lung transplantation in the United States between May 4, 2005, and December 31, 2014. We defined a "restricted" procedure preference as listing for "bilateral transplantation only" and an "unrestricted" procedure preference as listing for any combination of bilateral or single lung transplantation. We used a composite "intention-to-treat" primary outcome that included events both before and after transplantation, defined as the number of days between listing and death, removal from the list for clinical deterioration, or retransplantation.

RESULTS

In adjusted analyses, an unrestricted procedure preference was associated with a 3% lower rate of the primary intention-to-treat outcome in COPD (adjusted hazard ratio [aHR], 0.97; 95% confidence interval [CI], 0.89-1.07) and a 1% higher rate in ILD (aHR, 1.01; 95% CI, 0.94-1.08). There was no convincing evidence that these associations varied by age, disease severity, or the use of mechanical support. Among those with ILD and concomitant severe pulmonary hypertension, an unrestricted preference was associated with a 17% increased rate of the primary outcome (aHR, 1.17; 95% CI, 0.99-1.39). An unrestricted preference was consistently associated with lower rates of death or removal from the list for clinical deterioration and with higher rates of transplantation. Graft failure rates were similar among those listed with restricted and unrestricted preferences.

CONCLUSION

When considering outcomes both before and after transplantation, we found no evidence that patients with COPD or ILD benefit from listing for bilateral lung transplantation compared with listing for a more liberal procedure preference. An unrestricted listing strategy for suitable candidates may increase the number of transplants performed without impacting overall survival.

Lung transplantation for chronic obstructive pulmonary disease: past, present, and future directions

PURPOSE OF REVIEW

Lung transplantation offers an effective treatment modality for patients with end-stage chronic obstructive pulmonary disease (COPD). The exact determination of when to refer, list, and offer transplant as well as the preferred transplant procedure type remains unclear. Additionally, there are special considerations specific to patients with COPD being considered for lung transplantation, including the implications of single lung transplantation on lung cancer risk, native lung hyperinflation, and overall survival.

RECENT FINDINGS

The International Society for Heart and Lung Transplantation's most recent recommendations rely on an assessment of COPD severity based on BODE index. Despite the lack of evidence supporting a mortality benefit of bilateral over single lung transplantation for COPD patients, the majority of transplants performed in this population remain bilateral. Some of the concerns specific to single lung transplantation remain the possibility of de novo native lung cancer and the hemodynamic and physiologic implications of acute native lung hyperinflation.

SUMMARY

COPD remains the most common worldwide indication for lung transplantation. Ongoing study is still required to assess the overall survival benefit of lung transplantation and assess the overall quality of life impact on the COPD patient population.

Controversies and emerging topics in lung transplantation

Lung transplantation provides a realistic hope of improved survival and enhanced quality of life. However, outcomes can be disappointing, meaning many decisions are highly controversial. Practice is largely based on expert opinion and there is a dearth of high-level evidence. Not surprisingly, this leads to centre-specific practices that may vary considerably in controversial areas. The aim of this review, therefore, is to explore some of those domains and present the available evidence. As the science of lung transplantation approaches its fifth decade, we are only now reaching a critical mass of clinicians and scientific researchers to enable adequately powered studies to assist in informing our approach to some of these controversies.

Lung transplantation provides a realistic hope of improved survival and enhanced quality of life. However, outcomes can be disappointing, meaning many decisions are highly controversial. Better evidence is desperately needed.http://ow.ly/Dl4N30maYV9

Bilateral versus single lung transplantation: are two lungs better than one?

There is a long-standing debate over whether single or bilateral lung transplant provides better short and long-term clinical outcomes. We performed a detailed PubMed search on relevant clinical research publications on single (SLT) and bilateral lung transplantation (BLT). We included studies that were published before and after the implementation of the lung allocation score (LAS). We reviewed disease-specific short- and long-term outcomes associated with each transplantation technique. The majority of published studies are retrospective cohort studies that use institutional data or large patient registries. Outcomes associated with transplantation technique vary by disease specific indication, age, and patient severity. Over the past decade, the relative proportion of bilateral lung transplantation has increased. Increasing adoption of bilateral lung transplant likely reflects the general acceptance of several advantages associated with the technique. However, making a clear, evidence-based decision is difficult in light of the fact that there has never been and probably never will be a randomized trial. Our institutional preference is bilateral lung transplant. However, consideration for the technique should still be made on a case-by-case basis.

Single lung transplantation for lymphangioleiomyomatosis: a single-center experience in Japan

PURPOSE

Lung transplantation is accepted as an effective modality for patients with end-stage pulmonary lymphangioleiomyomatosis (LAM). Generally, bilateral lung transplantation is preferred to single lung transplantation (SLT) for LAM because of native lung-related complications, such as pneumothorax and chylothorax. It remains controversial whether SLT is a suitable surgical option for LAM. The objective of this study was to evaluate the morbidity, mortality and outcome after SLT for LAM in a lung transplant center in Japan.

METHODS

We reviewed the records of 29 patients who underwent SLT for LAM in our hospital between March, 2000 and November, 2017. The data collected included the pre-transplant demographics of recipients, surgical characteristics, complications, morbidity, mortality and survival after SLT for LAM.

RESULTS

The most common complication after SLT for LAM was contralateral pneumothorax (n = 7; 24.1%). Six of these recipients were treated successfully with chest-tube placement and none required surgery for the pneumothorax. The second-most common complication was chylous pleural effusion (n = 6; 20.7%) and these recipients were all successfully treated by pleurodesis. The 5-year survival rate after SLT for LAM was 79.5%.

CONCLUSION

LAM-related complications after SLT for this disease can be managed. SLT is a treatment option and may improve access to lung transplantation for patients with end-stage LAM.

High emergency organ allocation rule in lung transplantation: a simulation study

The scarcity of suitable organ donors leads to protracted waiting times and mortality in patients awaiting lung transplantation. This study aims to assess the short- and long-term effects of a high emergency organ allocation policy on the outcome of lung transplantation.

We developed a simulation model of lung transplantation waiting queues under two allocation strategies, based either on waiting time only or on additional criteria to prioritise the sickest patients. The model was informed by data from the United Network for Organ Sharing. We compared the impact of these strategies on waiting time, waiting list mortality and overall survival in various situations of organ scarcity.

The impact of a high emergency allocation strategy depends largely on the organ supply. When organ supply is sufficient (>95 organs per 100 patients), it may prevent a small number of early deaths (1 year survival: 93.7% against 92.4% for waiting time only) without significant impact on waiting times or long-term survival. When the organ/recipient ratio is lower, the benefits in early mortality are larger but are counterbalanced by a dramatic increase of the size of the waiting list. Consequently, we observed a progressive increase of mortality on the waiting list (although still lower than with waiting time only), a deterioration of patients’ condition at transplant and a decrease of post-transplant survival times.

High emergency organ allocation is an effective strategy to reduce mortality on the waiting list, but causes a disruption of the list equilibrium that may have detrimental long-term effects in situations of significant organ scarcity.

High emergency organ allocation is effective to reduce waiting list mortality when organ supply is sufficienthttp://ow.ly/KD1930fPs8I

Single-lung transplantation in emphysema: Retrospective study analyzing survival and waiting list mortality

AIM: To performed remains a subject of debate and is the principal aim of the study.

METHODS: This retrospective analysis included 73 patients with emphysema (2000-2012). The outcomes of patients undergoing single-lung transplantation (SL) (n = 40) or double-lung transplant (DL) (n = 33) were compared in a Cox multivariate analysis to study the impact of the technique, postoperative complications and acute and chronic rejection on survival rates. Patients were selected for inclusion in the waiting list according to the International Society of Heart Lung Transplantation criteria. Pre and postoperative rehabilitation and prophylaxis, surgical technique and immunosuppressive treatment were similar in every patients. Lung transplantation waiting list information on a national level and retrospective data on emphysema patient survival transplanted in Spain during the study period, was obtained from the lung transplantation registry managed by the National Transplant Organization (ONT).

RESULTS: Both groups were comparable in terms of gender and clinical characteristics. We found significant differences in the mean age between the groups, the DL patients being younger as expected from the inclusion criteria. Perioperative complications occurred in 27.6% SL vs 54% DL (P = 0.032). Excluding perioperative mortality, median survival was 65.3 mo for SL and 59.4 mo for DL (P = 0.96). Bronchiolitis obliterans and overall 5-year survival were similar in both groups. Bacterial respiratory infection, cytomegalovirus and fungal infection rates were higher but not significant in SL. No differences were found between type of transplant and survival (P = 0.48). To support our results, national data on all patients with emphysema in waiting list were obtained (n = 1001). Mortality on the waiting list was 2.4% for SL vs 6.2% for DL. There was no difference in 5 year survival between 235 SL and 430 DL patients transplanted (P = 0.875).

CONCLUSION: Our results suggest that SL transplantation in emphysema produce similar survival than DL with less postoperative complication and significant lower mortality in waiting list.

A global perspective of lung transplantation: Part 1 - Recipient selection and choice of procedure

Lung transplantation has grown considerably in recent years and its availability has spread to an expanding number of countries worldwide. Importantly, survival has also steadily improved, making this an increasingly viable procedure for patients with end-stage lung disease and limited life expectancy. In this first of a series of articles, recipient selection and type of transplant operation are reviewed. Pulmonary fibrotic disorders are now the most indication in the U.S., followed by chronic obstructive pulmonary disease and cystic fibrosis. Transplant centers have liberalized criteria to include older and more critically ill candidates. A careful, systematic, multi-disciplinary selection process is critical in identifying potential barriers that may increase risk and optimize long-term outcomes.

Rapamycin Combined with Immature Dendritic Cells Attenuates Obliterative Bronchiolitis in Trachea Allograft Rats by Regulating the Balance of Regulatory and Effector T Cells

BACKGROUND

Obliterative bronchiolitis (OB) ranks as the major obstacle for long-term survival of lung transplantation patients. Rapamycin (Rapa) has recently been confirmed as an immunosuppressant for antirejection due to its suppressive role in T cell activation. Here, we explore the effect of Rapa combined with immature dendritic cells (imDCs) on OB in trachea allograft rats.

METHODS

The effect of bone marrow-derived imDCs or Rapa-imDCs on lymphocyte cells and CD4+ T cells were evaluated by methyl thiazolyl tetrazolium and flow cytometry. Tracheal transplantation was performed from Lewis rats to Wistar recipients. Recipient rats received Rapa+imDCs for 10 consecutive days after implantation. Allograft rejection was assessed by micro-CT image, hematoxylin/eosinHE staining and flow cytometry. The underlying mechanism was also investigated.

RESULTS

Rapa-imDCs inhibited lymphocyte and CD4+ T cell growth. Furthermore, Rapa-imDC treatment induced T cell hyporesponsiveness by attenuating T cell differentiation into IFN-x03B3;-producing T cells (Th1), but increased CD4+CD25+Foxp3+ T cell (Treg) contents. Importantly, Rapa-imDC administration ameliorated airway obliteration symptoms and CD4+ and CD8+ T cell infiltration. Furthermore, the proinflammatory factor levels of IL-6, TNF-α, IFN-x03B3; and IL-17 were decreased, concomitant with the upregulation of immunosuppressive cytokines IL-10 and TGF-β1. Further analysis confirmed that Rapa-imDC treatment attenuated the amounts of infiltrated IL-17+CD4+ T cells (Th17 cells) and Th1 cells, but increased Treg contents in the spleens of recipients.

CONCLUSIONS

This research may corroborate a protective role of Rapa-imDCs in OB by regulating the balance between effector T cells and Tregs, suggesting a potential applicable strategy to treat OB after lung transplantation.

Continued Utility of Single-Lung Transplantation in Select Populations: Chronic Obstructive Pulmonary Disease

BACKGROUND

The use of single lung transplantation (SLTx) for chronic obstructive pulmonary disease is often viewed as inferior therapy compared with bilateral lung transplantation (BLTx). We hypothesized from our experience that subpopulations of recipients with emphysema exist in which SLTx represents therapy that is equivalent to BLTx, therefore allowing more patients access to transplantation.

METHODS

Consecutive patients undergoing LTx for emphysema between 1992 and 2012 at a single institution were identified and analyzed retrospectively. A similar cohort from the United Network of Organ Sharing (UNOS) national database was identified for comparison. Five-year survival in patients receiving SLTx and those receiving BLTx were compared using Kaplan-Meier survival curves and log-rank tests.

RESULTS

Two hundred thirty-six patients meeting criteria were identified from our institution. Two hundred six underwent SLTx, and 30 underwent BLTx. Five-year survival for single-center SLTx (53.2% ± 3.6%) and BLTx (56.7% ± 10.2%) was not significantly different (p = 0.753). The national database included 7,256 patients meeting selection criteria, with 4,408 undergoing SLTx and 2,848 undergoing BLTx. Five-year survival among the national cohorts was lower for SLTx (46.4% ± 0.8%) compared with BLTx (55.9% ± 1.1%) (p < 0.0001). However, 5-year survival for our single-center SLTx experience (53.2% ± 3.6%) was comparable to the national BLTx cohort (55.9% ± 1.1%) (p = 0.539).

CONCLUSIONS

Five-year survival after SLTx for emphysema was comparable to that for BLTx in cohorts from our institution and from the UNOS national database. Further study should focus on the mechanism behind these improved outcomes. Given the potential for a larger number of life-years saved, SLTx should continue to be considered a therapeutic option in appropriately selected patients with chronic obstructive pulmonary disease (COPD).

An Official American Thoracic Society/European Respiratory Society Statement: Research questions in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity, mortality, and resource use worldwide. The goal of this Official American Thoracic Society (ATS)/European Respiratory Society (ERS) Research Statement is to describe evidence related to diagnosis, assessment, and management; identify gaps in knowledge; and make recommendations for future research. It is not intended to provide clinical practice recommendations on COPD diagnosis and management.

METHODS

Clinicians, researchers, and patient advocates with expertise in COPD were invited to participate. A literature search of Medline was performed, and studies deemed relevant were selected. The search was not a systematic review of the evidence. Existing evidence was appraised and summarized, and then salient knowledge gaps were identified.

RESULTS

Recommendations for research that addresses important gaps in the evidence in all areas of COPD were formulated via discussion and consensus.

CONCLUSIONS

Great strides have been made in the diagnosis, assessment, and management of COPD as well as understanding its pathogenesis. Despite this, many important questions remain unanswered. This ATS/ERS Research Statement highlights the types of research that leading clinicians, researchers, and patient advocates believe will have the greatest impact on patient-centered outcomes.

An official American Thoracic Society/European Respiratory Society statement: research questions in COPD

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity, mortality, and resource use worldwide. The goal of this official American Thoracic Society (ATS)/European Respiratory Society (ERS) research statement is to describe evidence related to diagnosis, assessment and management; identify gaps in knowledge; and make recommendations for future research. It is not intended to provide clinical practice recommendations on COPD diagnosis and management.

Clinicians, researchers, and patient advocates with expertise in COPD were invited to participate. A literature search of Medline was performed, and studies deemed relevant were selected. The search was not a systematic review of the evidence. Existing evidence was appraised and summarised, and then salient knowledge gaps were identified.

Recommendations for research that addresses important gaps in the evidence in all areas of COPD were formulatedviadiscussion and consensus.

Great strides have been made in the diagnosis, assessment and management of COPD, as well as understanding its pathogenesis. Despite this, many important questions remain unanswered. This ATS/ERS research statement highlights the types of research that leading clinicians, researchers, and patient advocates believe will have the greatest impact on patient-centred outcomes.

Single-lung transplantation in the United States: what happens to the other lung?

BACKGROUND

This study assessed treatment patterns and examined organ utilization in the setting of single-lung transplantation (SLT).

METHODS

The United Network for Organ Sharing database was queried for all SLTs performed from 1987 to 2011. Trends in utilization of the second donor lung were assessed, both from recipient and donor perspectives. Donors were stratified into 2 groups: those donating both lungs and those donating only 1 lung. Independent predictors of using only 1 donor lung were identified using multivariable logistic regression.

RESULTS

We identified 10,361 SLTs originating from 7,232 unique donors. Of these donors, both lungs were used in only 3,129 (43.3%), resulting in more than 200 second donor lungs going unused annually since 2005, with no significant increase in use over time (p = 0.95). After adjustment, donor characteristics predicting the second donor lung going unused included B/AB blood groups (adjusted odds ratio [AOR]: 1.69 and 2.62, respectively; p < 0.001), smaller body surface area (AOR, 1.30; p = 0.02), lower donor partial pressure of arterial oxygen (AOR, 0.90 per 50 mm Hg increase; p < 0.001), pulmonary infection (AOR, 1.15; p = 0.04), extended criteria donor status (AOR, 1.66; p < 0.001), and death caused by head trauma (AOR, 1.57; p < 0.001) or anoxia (AOR, 1.53; p = 0.001).

CONCLUSIONS

Among donors for SLT, less than half of all cases led to use of the second donor lung. Although anatomic, infectious, or other pathophysiologic issues prohibit 100% utilization, more aggressive donor matching efforts may be a simple method of increasing the utilization of this scarce resource, particularly for less common blood types.

Deceased organ donation consent rates among racial and ethnic minorities and older potential donors

OBJECTIVES

We sought to assess consent rates for organ donation from potential brain-dead donors, and to identify factors associated with variation in consent for donation that could guide the development of targeted interventions to increase organ consent rates.

DESIGN, SETTING, AND SUBJECTS

We used data provided by the Organ Procurement and Transplantation Network to analyze the 35,823 organ procurement organization-reported eligible deaths (potential brain-dead donors ≤ 70 yr of age) from January 1, 2008, to October 31, 2011.

MEASUREMENTS AND MAIN RESULTS

Excluding cases where donation authorization was based on prior patient documentation (e.g., donor registry), consent was obtained on 21,601 (68.9%), not obtained on 8,727 (27.8%), and not requested on 1,080 (3.4%) eligible deaths. There were substantial differences in consent rates among racial/ethnic groups (77.0% in whites, 67.5% in Hispanics, 54.9% in blacks, and 48.1% in Asians) and organ procurement organizations (median [interquartile range]: 72.4% [67.5-87.3]). In generalized estimating equation models, with whites and patients ages 18-39 yr as the respective reference groups, consent for donation was less likely to be obtained among Hispanics (odds ratio 0.54; 95% confidence interval 0.44-0.65), blacks (odds ratio 0.35; 95% confidence interval 0.31-0.39), Asians (odds ratio 0.31; 95% confidence interval 0.25-0.37), and eligible donors ages 55-64 (odds ratio 0.72; 95% confidence interval 0.67-0.77), and ≥ 65 yr (odds ratio 0.58; 95% confidence interval 0.52-0.64).

CONCLUSIONS

In presenting the first published analyses of consent rates among all eligible deaths, this study confirms smaller and regional studies that showed significant differences in consent rates between whites and racial/ethnic minorities (blacks, Hispanics, and Asians). The study also identifies considerable variation in consent rates between age groups and between organ procurement organizations. Critical care physicians are usually the front-line providers for potential brain-dead donors and their next-of-kin, and these data highlight the need for further research to identify the causes of variation in consent rates and mechanisms to increase rates where appropriate.

Twenty-four-hour intensivist staffing in teaching hospitals: tensions between safety today and safety tomorrow

There is an inherent tension between the training needs of inexperienced clinicians and the safety of the patients for whom they are responsible. Our society has accepted this tension as a necessary trade-off to maintain a competent workforce of physicians year after year. However, recent trends in medical education have diminished resident autonomy in favor of the safety of current patients. One dramatic example is the rapid increase in the number of academic ICUs that provide coverage by attending physicians at all hours. The potential benefits of this staffing model have strong face validity: improved quality and efficiency from the constant involvement of experienced intensivists, increased family and staff satisfaction from the immediate availability of attending physicians, and reduced burn-out among intensivists from reduced on-call responsibilities. Thus, many hospitals have moved toward 24-h coverage by attending intensivist physicians without evidence that these benefits actually accrue and perhaps without full consideration of possible unintended consequences. In this article, we discuss the potential benefits and risks of nocturnal intensivist staffing, considering the needs of current and future patients. Furthermore, we suggest that there remains sufficient uncertainty about these benefits and risks that it is both necessary and ethical to study the effects in earnest.

Cardiopulmonary exercise testing in lung transplantation: a review

There has been an increase in lung transplantation in the USA. Lung allocation is guided by the lung allocation score (LAS), which takes into account one measure of exercise capacity, the 6-minute walk test (6MWT). There is a paucity of data regarding the role and value of cardiopulmonary stress test (CPET) in the evaluation of lung transplant recipients while on the transplant waiting list and after lung transplantation. While clearly there is a need for further prospective investigation, the available literature strongly suggests a potential role for CPET in the setting of lung transplant.