Strategies to optimize the use of currently available lung donors

Anti-inflammatory effect of thalidomide in an experimental lung donor model of brain death

Lung transplantation stands as a vital treatment for severe lung diseases, primarily sourcing organs from donors with brain death (BD). This research delved into the potential anti-inflammatory effects of thalidomide in rats with BD-induced lung complications. In this study twenty-four Wistar rats were divided into three groups: the control (CTR), brain death (BD) and brain death + thalidomide (TLD) groups. Post specific procedures, a 360 min monitoring period ensued. Comprehensive analyses of blood and heart-lung samples were conducted. Elevated IL-6 levels characterized both BD and TLD groups relative to the CTR (p = 0.0067 and p = 0.0137). Furthermore, TNF-α levels were notably higher in the BD group than both CTR and TLD (p = 0.0152 and p = 0.0495). Additionally, IL-1β concentrations were significantly pronounced in both BD and TLD compared to CTR, with the BD group surpassing TLD (p = 0.0256). Immunohistochemical assessments revealed augmented NF-ĸB expression in the BD group in comparison to both CTR and TLD (p = 0.0006 and p = 0.0005). With this study we can conclude that BD induced acute pulmonary inflammation, whereas thalidomide manifested a notable capability in diminishing key inflammatory markers, indicating its prospective therapeutic significance in lung transplantation scenarios.

Interventional pulmonology techniques in lung transplantation

Lung transplantation is a key therapeutic option for several end-stage lung diseases. Interventional pulmonology techniques, mostly bronchoscopy, play a key role throughout the whole path of lung transplantation, from donor evaluation to diagnosis and management of post-transplant complications. We carried out a non-systematic, narrative literature review aimed at describing the main indications, contraindications, performance characteristics and safety profile of interventional pulmonology techniques in the context of lung transplantation. We highlighted the role of bronchoscopy during donor evaluation and described the debated role of surveillance bronchoscopy (with bronchoalveolar lavage and transbronchial biopsy) to detect early rejection, infections and airways complications. The conventional (transbronchial forceps biopsy) and the new techniques (i.e. cryobiopsy, biopsy molecular assessment, probe-based confocal laser endomicroscopy) can detect and grade rejection. Several endoscopic techniques (e.g. balloon dilations, stent placement, ablative techniques) are employed in the management of airways complications (ischemia and necrosis, dehiscence, stenosis and malacia). First line pleural interventions (i.e. thoracentesis, chest tube insertion, indwelling pleural catheters) may be useful in the context of early and late pleural complications occurring after lung transplantation. High quality studies are advocated to define endoscopic standard protocols and thus help improving long-term prognostic outcomes of lung transplant recipients.

Lung Transplantation in India: a Brief Review, Landmarks, Indian Scenario, and our Experience

Lung transplantation is gaining widespread acceptance as the preferred therapeutic option for selected cases of end-stage lung disease in India. The indications of lung transplantation are increasing, with better post-operative survival, including the COVID affected lung, if we choose our patients well. The national acceptance of expanded criteria in lung donation, streamlining of the process of lung transplantation by governmental, and non-governmental organizations and significant increase in the number of organ donations in India have strengthened the lung transplantation program within the country. Through this article, we describe a brief history, the process, and our experience of lung transplantation since we started our program in 2017 until date.

International Society for Heart and Lung Transplantation consensus statement for the standardization of bronchoalveolar lavage in lung transplantation

Bronchoalveolar lavage (BAL) is a key clinical and research tool in lung transplantation (LTx). However, BAL collection and processing are not standardized across LTx centers. This International Society for Heart and Lung Transplantation-supported consensus document on BAL standardization aims to clarify definitions and propose common approaches to improve clinical and research practice standards. The following 9 areas are covered: (1) bronchoscopy procedure and BAL collection, (2) sample handling, (3) sample processing for microbiology, (4) cytology, (5) research, (6) microbiome, (7) sample inventory/tracking, (8) donor bronchoscopy, and (9) pediatric considerations. This consensus document aims to harmonize clinical and research practices for BAL collection and processing in LTx. The overarching goal is to enhance standardization and multicenter collaboration within the international LTx community and enable improvement and development of new BAL-based diagnostics.

Impact of Recruitment Maneuvers to Cover Adverse Effects of Donor Transfer

OBJECTIVES

Our aim was to investigate the negative effects of transferring brain-dead donors to the intensive care unit on the ratio of PaO₂ to inspired oxygen fraction and the benefits of recruitment maneuvers on its reversal.

MATERIALS AND METHODS

In this randomized trial, we assigned 30 brain-dead donors to an intervention group and a control group. After transfer to the intensive care unit, donors in the intervention group received a lung recruitment maneuver according to protocol for 1 hour, whereas the control group did not receive this intervention. Arterial blood gas was drawn before transfer, immediately aftertransfer, and 3 hours after transfer.

RESULTS

Before transfer to immediately after transfer, the PaO₂-to-inspired oxygen fraction ratio decreased from 281.30 ± 100.33 to 225.03 ± 95.72 mm Hg (P < .01). At 3 hours aftertransfer,the PaO₂-to-inspired oxygen fraction ratio in the intervention and control groups was 280.4 ± 120.4 and 213.4 ± 75.5 mm Hg (P = .017), respectively. The absolute difference in PaO₂-to-inspired oxygen fraction ratio from before to 3 hours after transfer was -16.9 ± 44.1 and 51.8 ± 61.4 mm Hg (P < .001), in the intervention and control groups,respectively. Increasing central venous pressure and/or transfer time further potentiated the decrease ofthe PaO₂-to-inspired oxygen fraction ratio.

CONCLUSIONS

The PaO₂-to-inspired oxygen fraction ratio decreased after transfer of brain-dead donors to the intensive care unit. This was partially reversible by standardized recruitment maneuvers.

Increasing donor sequence number is not associated with inferior outcomes in lung transplantation

BACKGROUND

Donor sequence number (DSN) represents the number of recipients to whom an organ has been offered. The impact of seeing numerous prior refusals may potentially influence the decision to accept an organ. We sought to determine if DSN was associated with inferior posttransplant outcomes.

METHODS

Using the United Network for Organ Sharing database, a retrospective analysis was performed on 22 361 patients who received a lung transplant between 2005 and 2017. Patients were grouped into low DSN (1-24, n = 16 860) and high DSN (>24, n = 5501) categories. Baseline characteristics and posttransplant outcomes were analyzed. An institutional subgroup was also analyzed to compare rates of primary graft dysfunction (PGD) posttransplant.

RESULTS

The DSN ranged from 1 to 1735 (median, 7; interquartile range, 2-24). A total of 18 507 recipients received an organ with at least one prior refusal. Recipients of donors with a higher DSN were older (58 vs 55 years; P < .01) but had lower lung allocation scores (43.5 vs 47.5; P < .01). On adjusted analysis, high DSN was not associated with increased mortality (hazard ratio, 0.99; 95% confidence interval, 0.94-1.04; P = .77). There was no difference in the incidence of graft failure (P = .37) or retransplantation (P = .24). Recipient subgroups who received donors with an increasing DSN >50 and >75 also demonstrated no difference in mortality when compared with a low DSN (P = .86 and P = .97). There was no difference in PGD for patients with a low vs a high DSN at any time posttransplant.

CONCLUSIONS

DSN is not associated with increased mortality in patients undergoing lung transplantation and should not negatively influence the decision to accept a lung for transplant.

Effect of hypertonic saline in the pretreatment of lung donors with hemorrhagic shock

BACKGROUND

Hemorrhagic shock-induced lung edema and inflammation are two of the main reasons for the rejection of lungs donated for transplantation. Hypertonic saline (HS) induces intravascular volume expansion and has considerable immunomodulating effects that might minimize edema. Our hypothesis is based on the use of a hypertonic solution for treatment of donors who are in shock in an attempt to increase the supply of lungs for transplantation.

METHODS

A total of 80 rats were allocated to four groups: one group was given an infusion of normal saline (NS; n = 20), one group received HS; n = 20, a sham group (n = 20), and a Shock group (n = 20). Half of the lungs from each group were evaluated in an ex vivo perfusion system, and the other half was used for measurements of cytokine levels and neutrophil counts.

RESULTS

In the ex vivo perfusion assessment, the pulmonary artery pressures of the animals in the NS and HS groups did not exhibit significant differences compared with those in the sham group (P > 0.05) but were lower than those in the Shock group (P < 0.01). Furthermore, the tumor necrosis factor-α levels and neutrophil counts were lower in the HS group than those in the Shock group (P < 0.01) and did not exhibit significant differences compared with those in either the NS and Sham groups (P > 0.05).

CONCLUSIONS

We showed that HS was equivalent to isotonic saline and contributed to the treatment of lungs subjected to hemorrhagic shock.

Starting a lung transplant program: a roadmap for long-term excellence

Lung transplantation is an effective therapy for many patients with end-stage lung disease. Few centers across the United States offer this therapy, as a successful lung transplant program requires significant institutional resources and specialized personnel. Analysis of the United Network of Organ Sharing database reveals that the failure rate of new programs exceeds 40%. These data suggest that an accurate assessment of program viability as well as a strategy to continuously assess defined quality measures is needed. As part of strategic planning, regional availability of recipient and donors should be assessed. Additionally, analysis of institutional expertise at the physician, support staff, financial, and administrative levels is necessary. In May of 2007, we started a new lung transplant program at the University of Iowa Hospitals and Clinics and have performed 101 transplants with an average recipient 1-year survival of 91%, placing our program among the top in the country for the past 5 years. Herein, we review internal and external factors that impact the viability of a new lung transplant program. We discuss the use of four prospectively identified quality measures: volume, recipient outcomes, financial solvency, and academic contribution as one approach to achieve programmatic excellence.

Method of isolated ex vivo lung perfusion in a rat model: lessons learned from developing a rat EVLP program

The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. As this technology expands and improves, the ability to potentially evaluate and improve the quality of substandard lungs prior to transplant is a critical need. In order to more rigorously evaluate these approaches, a reproducible animal model needs to be established that would allow for testing of improved techniques and management of the donated lungs as well as to the lung-transplant recipient. In addition, an EVLP animal model of associated pathologies, e.g., ventilation induced lung injury (VILI), would provide a novel method to evaluate treatments for these pathologies. Here, we describe the development of a rat EVLP lung program and refinements to this method that allow for a reproducible model for future expansion. We also describe the application of this EVLP system to model VILI in rat lungs. The goal is to provide the research community with key information and “pearls of wisdom”/techniques that arose from trial and error and are critical to establishing an EVLP system that is robust and reproducible.

Interim report of the Japanese original donor evaluation and management system: the medical consultant system

PURPOSE

Lung transplantation (LTx) is an established therapy for end-stage lung failure. However, in Japan, the donor organ shortage is extremely severe compared with other developed countries, because of the strict Japanese Organ Transplantation Law. To maximize LTx opportunities in Japan, we have established a special donor evaluation and management system termed the medical consultant (MC) system.

METHODS

Data from 171 lung donor candidates registered in Japan from May 1998 to May 2012 were obtained and investigated in a retrospective manner. The candidates were separated into the non-MC-intervened and MC-intervened groups, and then data regarding the PaO2/FiO2 ratio, donation rate and organ survival rate were analyzed and compared between the groups.

RESULTS

The PaO2/FiO2 ratio of the MC-intervened group was ameliorated from the time of first brain death diagnosis to organ harvest. Although the base condition of the MC-intervened group was significantly worse than that of the non-MC-intervened group, the donation rates showed no significant difference (0.64 and 0.66, respectively; p = 0.89). There was a difference in the organ survival rate between the non-MC and MC-intervened groups (5-year survival rates of 67.2 and 88.3 %, respectively; p = 0.16).

CONCLUSION

The MC system used for organ donor evaluation and management in Japan has achieved acceptable interim results.

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.

Clinical neurology in lung transplantation

Lung transplantation is the only established therapeutic option for several end-stage respiratory diseases. Limited mostly by lack of suitable allografts, the results have measurably improved over the last decade. Numerous surgical and pharmaceutical improvements have had positive impact on outcomes. The potential for critical care issues and the need for interdisciplinary management remains paramount. Cardiac, renal, and metabolic complications are frequently encountered in the acute postoperative phase. Allograft rejection and infectious diseases as well as problems related to immunosuppressive regimen are seen later after lung transplantation. Neurologic manifestations with a range of etiologies are discussed here in this context.

Donor age and early graft failure after lung transplantation: a cohort study

Lungs from older adult organ donors are often unused because of concerns for increased mortality. We examined associations between donor age and transplant outcomes among 8860 adult lung transplant recipients using Organ Procurement and Transplantation Network and Lung Transplant Outcomes Group data. We used stratified Cox proportional hazard models and generalized linear mixed models to examine associations between donor age and both 1-year graft failure and primary graft dysfunction (PGD). The rate of 1-year graft failure was similar among recipients of lungs from donors age 18-64 years, but severely ill recipients (Lung Allocation Score [LAS] >47.7 or use of mechanical ventilation) of lungs from donors age 56-64 years had increased rates of 1-year graft failure (p-values for interaction = 0.04 and 0.02, respectively). Recipients of lungs from donors <18 and ≥65 years had increased rates of 1-year graft failure (adjusted hazard ratio [HR] 1.23, 95% CI 1.01-1.50 and adjusted HR 2.15, 95% CI 1.47-3.15, respectively). Donor age was not associated with the risk of PGD. In summary, the use of lungs from donors age 56 to 64 years may be safe for adult candidates without a high LAS and the use of lungs from pediatric donors is associated with a small increase in early graft failure.

Donor evaluation for lung transplantation in Korea

Lung transplantation for end-stage lung disease results in prolonged survival and improved pulmonary function. However, the shortage of donor lungs has been a major limiting factor in Korea. We sought to investigate the number and utilization of donor lungs by the five institutions performing LTx in Korea, retrospectively reviewing outcomes of organs registered in the Korean Network for Organ Sharing from January to December, 2010. Lungs were offered from 270 brain-dead patients (189 males and 81 females) of mean age of 45.2 ± 14.2 years (range, 12 to 77 years). The most common cause of brain death was hemorrhage (n = 219, 81%). Only 18 (6.7%) donor lungs were used, which was low compared with kidney (93.3%), liver (86.3%), heart (26.7%), and pancreas (11.1%) use. The mean age of donors of transplanted lungs was 35.7 years (range, 14 to 51 years) compared with 45.9 years for other organs (P = .003). The characteristics of utilized donor lungs were: mean partial pressure of oxygen (PaO(2)), 300.9 mm Hg; mean smoking history, as 2.7 pack-years; and mean body mass index, 21.2 kg/m(2). The causes of refusal were medical ineligibility (n = 129) including poor PaO(2), abnormal chest x-ray, long smoking history, older age (n = 46), no properly matched recipient (n = 46), unknown (n = 17), and family withdrawal (n = 14). Only 8 (33.3%) were transplanted from standard criteria and 10 from the lungs that did not satisfy these criteria. An efficient utilization system is needed to improve lung transplantations.

Benefit of a single recruitment maneuver after an apnea test for the diagnosis of brain death

Introduction

Many potential lung transplants are lost because of hypoxemia during donor management. We hypothesized that the apnea test, necessary to confirm the diagnosis of brain death in potential lung donors, was involved in the decrease in the ratio of partial pressure of arterial O₂ to fraction of inspired O₂ (PaO₂/FiO₂) and that a single recruitment maneuver performed just after the apnea test can reverse this alteration.

Methods

In this case-control study, we examined the effectiveness of the recruitment maneuver with a comparison cohort of brain dead patients who did not receive the maneuver. Patients were matched one-to-one on the basis of initial PaO₂/FiO₂ and on the duration of mechanical ventilation before the apnea test. PaO₂/FiO₂ was measured before (T1), at the end (T2) and two hours after apnea test (T3).

Results

Twenty-seven patients were included in each group. The apnea test was associated with a significant decrease in PaO₂/FiO₂ from 284 ± 98 to 224 ± 104 mmHg (P < 0.001). The decrease in PaO₂/FiO₂ between T1 and T3 was significantly lower in the recruitment maneuver group than in the control group (-4 (-68-57) vs -61 (-110--18) mmHg, P = 0.02). The number of potential donors with PaO₂/FiO₂ > 300 mmHg decreased by 58% (95% CI: 28-85%) in the control group vs 0% (95% CI: 0-34%) in the recruitment maneuver group (P < 0.001).

Conclusions

The apnea test induced a decrease in PaO₂/FiO₂ in potential lung donors. A single recruitment maneuver performed immediately after the apnea test can reverse this alteration and may prevent the loss of potential lung donors.

Donation after cardiac death lung transplantation outcomes

PURPOSE OF REVIEW

Lung transplantation is now a well established treatment option for several end-stage respiratory diseases. Survival after lung transplantation has significantly improved over the last decade. The primary limitation to increased utilization of lung transplantation remains donor scarcity. Suitable allografts have been procured from donors after determination of neurologic death and from donors after determination of cardiac death (DDCD or DCD). Historically, the first human lung transplantation performed, utilized an allograft procured after cardiovascular death, also referred to as nonheart-beating donor.The experience at University of Wisconsin in 1993 reintroduced DCD lung transplantation with the first successful clinical case.

RECENT FINDINGS

A potential additional lung allograft source, DCD lung transplantation has been established with very acceptable outcomes observed by several centers. We provide the relevant background for the rationale of donor allograft expansion to include DCD lungs from controlled (Maastricht category III donors).

SUMMARY

This review considers the available evidence for DCD lung transplantation and compares reported primary graft dysfunction rates and current survival data available.

Histologic and functional evaluation of lungs reconditioned by ex vivo lung perfusion

BACKGROUND

Only about 15% of donor lungs are considered suitable for transplantation (LTx). Ex vivo lung perfusion (EVLP) has been developed as a method to reassess and repair damaged lungs. We report our experience with EVLP in non-acceptable donor lungs and evaluate its ability to recondition these lungs.

METHODS

We studied lungs from 16 brain-dead donors rejected for LTx. After harvesting, the lungs were stored at 4°C for 10 hours and subjected to normothermic EVLP with Steen Solution (Vitrolife, Göteborg, Sweden) for 60 minutes. For functional evaluation, the following variables were assessed: partial pressure of arterial oxygen (Pao(2)), pulmonary vascular resistance (PVR), and lung compliance (LC). For histologic assessment, lung biopsy was done before harvest and after EVLP. Tissue samples were examined under light microscopy. To detect and quantify apoptosis, terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling assay was used.

RESULTS

Thirteen lung donors were refused for having impaired lung function. The mean Pao(2) obtained in the organ donor at the referring hospital was 193.7 mm Hg and rose to 489 mm Hg after EVLP. During EVLP, the mean PVR was 652.5 dynes/sec/cm(5) and the mean LC was 48 ml/cm H(2)O. There was no significant difference between the mean Lung Injury Score before harvest and after EVLP. There was a trend toward a reduction in the median number of apoptotic cells after EVLP.

CONCLUSIONS

EVLP improved lung function (oxygenation capacity) of organs considered unsuitable for transplantation. Lung tissue structure did not deteriorate even after 1 hour of normothermic perfusion.

Modelo experimental ex vivo com bloco pulmonar dividido

Modelos de recondicionamento pulmonar ex vivo têm sido avaliados desde sua proposição. Quando são utilizados pulmões humanos descartados para transplante, a grande variabilidade entre os casos pode limitar o desenvolvimento de alguns estudos. No intuito de reduzir esse problema, desenvolvemos uma técnica de separação do bloco pulmonar em direito e esquerdo com posterior reconexão, permitindo que um lado sirva de caso e o outro de controle.

Advancing donor management research: design and implementation of a large, randomized, placebo-controlled trial

BACKGROUND

Given the persistent shortage of organs for transplantation, new donor management strategies to improve both organ utilization and quality of procured organs are needed. Current management protocols for the care of the deceased donor before organ procurement are based on physiological rationale, experiential reasoning, and retrospective studies without rigorous testing. Although many factors contribute to the lack of controlled clinical trials in donor management, a major factor is the unique challenges posed by research in the brain-dead organ donor.

METHODS AND RESULTS

This article describes the study design and the challenges faced during implementation of the Beta-agonists for Oxygenation in Lung Donors (BOLD) study, a randomized, placebo-controlled clinical trial of nebulized albuterol vs. placebo in 500 organ donors. The study design and implementation are described with emphasis on aspects of the study that are unique to research in brain-dead organ donors.

CONCLUSIONS

Experience gained during the design and implementation of the BOLD study should be useful for investigators planning future clinical trials in the brain-dead donor population and for intensivists who are involved in the care of the brain-dead organ donor.

Intensivtherapie nach Transplantation solider Organe

Der Intensivmedizin kommt eine zentrale Bedeutung in Rahmen der Transplantationsmedizin zu. Aufgrund ihrer marginalen Organfunktion benötigen die Patienten nicht selten bereits im Vorfeld der Transplantation eine intensivmedizinische Versorgung, zu der dann auch die Evaluation und Listung sowie die Koordination des zeitkritischen Transplantationsablaufs gehören können. Die direkte postoperative Betreuung nach komplexen Organtransplantationen bedarf fast ausschließlich der Versorgung im Rahmen von Überwachungsstationen, in denen sowohl direkt transplantationsassoziierte Komplikationen als auch Nebenerkrankungen eine intensivmedizinische Behandlungen notwendig machen. Sie zielt auf die Stabilisierung der Organfunktion, Behandlung begleitender Organdysfunktionen, adäquate Induktion der Immunsuppression und die möglichst frühe Wiedererlangung der Eigenständigkeit des Transplantierten ab.

Ex vivo lung perfusion: early report of Brazilian experience

INTRODUCTION

Only about 15% of the potential candidates for lung donation are considered suitable for transplantation. A new method for ex vivo lung perfusion (EVLP) can be used to evaluate and recondition "marginal," nonacceptable lungs. We have herein described an initial experience with ex vivo perfusion of 8 donor lungs deemed nonacceptable.

MATERIALS AND METHODS

After harvesting, the lungs were perfused ex vivo with Steen Solution, an extracellular matrix with high colloid osmotic pressure. A membrane oxygenator connected to the circuit received gas from a mixture of nitrogen and carbon dioxide, maintaining a normal mixed venous blood gas level in the perfusate. The lungs were gradually rewarmed, reperfused, and ventilated for evaluation through analyses of oxygenation capacity, pulmonary vascular resistance (PVR), lung compliance (LC), and biopsy.

RESULTS

The arterial oxygen pressure (with inspired oxygen fraction of 100%) increased from a mean of 206 mm Hg in the organ donor at the referring hospital to a mean of 498 mm Hg during the ex vivo evaluation. After 1 hour of EVLP, PVR varied from 440-1454 dynes/sec/cm(5); LC was in the range of 26-90 mL/cmH(2)O. There was no histological deterioration after 10 hours of cold ischemia and 1 hour of EVLP.

CONCLUSIONS

The ex vivo evaluation model can improve oxygenation capacity of "marginal" lungs rejected for transplantation. It has great potential to increase lung donor availability and, possibly, reduce time on the waiting list.

Ex vivo lung perfusion: initial Brazilian experience

In the last 20 years, lung transplantation has become the standard treatment for patients with end-stage lung disease. However, less than 20% of the donor lungs available for transplant are actually usable. This disparity between the growing number of recipients and the small number of donors has resulted in increased mortality among lung transplant candidates on waiting lists. Strategies such as the utilization of organs from marginal donors have proven ineffective in increasing the number of transplants. In 2000, a new method for reconditioning human lungs that had been previously rejected for transplantation was developed in Sweden. We describe our initial experience with ex vivo lung perfusion.

Increasing organ yield through a lung management protocol

Gift of Life Michigan determined that the largest gap between the number of organ donors and the number of organs transplanted has been in the number of lungs transplanted. The literature was reviewed for lung donor management strategies and other organ procurement organizations were surveyed for existing donor management guidelines to improve lung function. On the basis of pulmonary physiology and the knowledge gained from the literature search, Gift of Life Michigan developed a lung donor management protocol that has been very effective. In 4 years, the number of lungs transplanted has increased from 37 to 135, representing a 265% improvement.

Lung transplantation in the United States, 1999-2008

This article highlights trends and changes in lung and heart-lung transplantation in the United States from 1999 to 2008. While adult lung transplantation grew significantly over the past decade, rates of heart-lung and pediatric lung transplantation have remained low. Since implementation of the lung allocation score (LAS) donor allocation system in 2005, decreases in the number of active waiting list patients, waiting times for lung transplantation and death rates on the waiting list have occurred. However, characteristics of recipients transplanted in the LAS era differed from those transplanted earlier. The proportion of candidates undergoing lung transplantation for chronic obstructive pulmonary disease decreased, while increasing for those with pulmonary fibrosis. In the LAS era, older, sicker and previously transplanted candidates underwent transplantation more frequently compared with the previous era. Despite these changes, when compared with the pre-LAS era, 1-year survival after lung transplantation did not significantly change after LAS inception. The long-term effects of the change in the characteristics of lung transplant recipients on overall outcomes for lung transplantation remain unknown. Continued surveillance and refinements to the LAS system will affect the distribution and types of candidates transplanted and hopefully lead to improved system efficiency and outcomes.

Pulmonary recruitment protocol for organ donors: a new strategy to improve the rate of lung utilization

Because lung transplantation is the only effective therapy for terminal respiratory failure, the demand for donor lungs has increased steadily. However, the number of donors has remained fairly constant over the years, which results in an increasing duration of waiting for lung transplantation. To overcome the lack of organs, various strategies have been developed by transplant centers including use of marginal donors. To increase the lung utilization rate in multiorgan donors, we implemented a simple lung recruitment protocol involving a brief period of controlled sustained inflation. In 2005, the lung utilization rate in the transplant program at our institution was only 20% in multiorgan donors. With the lung recruitment protocol, the rate of lung utilization for transplantation increased to 33%, in 2006, 24% in 2007, and 24% in 2008. Following the lung recruitment protocol, the arterial oxygen tension/fraction of inspired oxygen ratio increased to greater than 15% in more than 40% of donors. We were able to improve gas exchange sufficiently that as many as two-thirds of the lungs were suitable for transplantation. During the protocol, no complications were reported, and no patient became hemodynamically unstable, precluding organ procurement. We believe that optimization of multiorgan donor management with simple interventions may improve oxygenation, reducing the number of inadequate donor lungs and increasing the overall donor pool and organ availability.

Effects of administration of intravenous naloxone on gas exchange in brain-dead lung donors

OBJECTIVE

To observe the effect of naloxone on the lung function of potential lung transplant donors with neurogenic pulmonary edema.

DESIGN AND INTERVENTIONS

Donors aged 16 to 55 years without any factors to contraindicate lung donation (pneumonia, pulmonary contusion, etc) were included. Ventilator settings were standardized to a tidal volume of 10 to 12 mL/kg, an FIO2 of 0.40, and a respiratory rate that kept PCO2 between 35 and 45 mm Hg. Chest physiotherapy, nebulizer treatments, and frequent suctioning were undertaken. Baseline arterial blood gas analysis and an oxygen challenge were performed. The patients were then given 8 to 10 mg of naloxone. Oxygen challenges and arterial blood gas analyses were repeated every 4 to 6 hours. The data were analyzed by using a paired t test, and each patient served as his or her own control.

SETTING

These interventions were performed on the 19 LifeQuest donors who met the set criteria from July 2002 to July 2004.

RESULTS

The PaO2 on the oxygen challenge immediately after administration of naloxone increased from 329 (SD 177) to 363 (SD 191) mm Hg, although the increase from baseline was not significant. The PaO2 from the second oxygen challenge (median time, 7 hours after administration of naloxone) increased to 413 (SD 177) mm Hg (P<.01).

[Hormone modulation of organ donor. Utility of the steroids]

Recently, the work group made up of the National Transplant Organization (Organización Nacional de Trasplantes, ONT), Spanish Society of Intensive, Critical Medicine and Coronary Units (Sociedad Española de Medicina Intensiva, Crítica y de Unidades Coronarias, SEMICYUC) and other Scientific Societies have recommended using 15 mg/kg of methyl prednisolone during the management of lung donors after brain death. This recommendation is based on descriptive and retrospective studies. However, the review of different experimental and clinical studies also suggests a potential benefit of using steroids in either thoracic or abdominal organ donors during management strategies. In brain death management, early steroid administration may decrease cytokine production and also may prevent alterations induced by proinflammatoy mediators, stabilize cell membranes, reduce expression of cell surface adhesion molecules and avoid lipid peroxidation after the ischemic period. This could be beneficial in increasing number and quality of organs harvested and in decreasing rejection episodes after transplant. It would be very recommendable to carry out prospective and comparative studies to demonstrate these potential utilities. Meanwhile and knowing the deleterious effects of inflammatory activity arising during and after brain death, we recommend using 15 mg/kg of methyl prednisolone in the organ donor management, as soon as possible. The potential benefit of its immunomodulation effects, its low cost and the absence of major side effects can justify this recommendation.

Effects of Administration of Intravenous Naloxone on Gas Exchange in Brain-Dead Lung Donors

Objective

To observe the effect of naloxone on the lung function of potential lung transplant donors with neurogenic pulmonary edema.

Design and Interventions

Donors aged 16 to 55 years without any factors to contraindicate lung donation (pneumonia, pulmonary contusion, etc) were included. Ventilator settings were standardized to a tidal volume of 10 to 12 mL/kg, an FiO2 of 0.40, and a respiratory rate that kept PCO2 between 35 and 45 mm Hg. Chest physiotherapy, nebulizer treatments, and frequent suctioning were undertaken. Baseline arterial blood gas analysis and an oxygen challenge were performed. The patients were then given 8 to 10 mg of naloxone. Oxygen challenges and arterial blood gas analyses were repeated every 4 to 6 hours. The data were analyzed by using a paired t test, and each patient served as his or her own control.

Setting

These interventions were performed on the 19 LifeQuest donors who met the set criteria from July 2002 to July 2004.

Results

The PaO2 on the oxygen challenge immediately after administration of naloxone increased from 329 (SD 177) to 363 (SD 191) mm Hg, although the increase from baseline was not significant. The PaO2 from the second oxygen challenge (median time, 7 hours after administration of naloxone) increased to 413 (SD 177) mm Hg ( P < .01).

[Lung transplantation. Indications, long-term results and special impact of follow-up care]

Die Lungentransplantation ist bei weit fortgeschrittenen Lungenerkrankungen nach Ausschöpfung aller Therapiemöglichkeiten eine Therapieoption, welche die Lebensqualität und – bei bestimmten Indikationen (zystische Fibrose, Lungenfibrose, pulmonal arterielle Hypertonie) – Lebenserwartung verbessert. Die Anzahl verfügbarer Spenderorgane ist so gering, dass jeder 6. Patient auf der Warteliste verstirbt. Bei der Auswahl geeigneter Kandidaten sind neben der ursächlichen Lungen- oder Herz-Lungenerkrankung, das Alter, vorhandene Mobilität, Ernährungs- und Muskelstatus und extrapulmonale Begleiterkrankungen entscheidende Kriterien. Postoperative Komplikationen können durch die Operation bedingt, durch eine Transplantatabstoßung (akut oder chronisch), Atemwegskomplikationen, Infektionen und extrapulmonale Folgeerkrankungen auftreten. Die Nachsorge erfolgt immer in Kooperation mit dem Transplantationszentrum und hat in großen Zentren zu einer spürbaren Verbesserung der Langzeitergebnisse geführt.

Management of the pediatric organ donor to optimize lung donation

Lung transplantation in childhood is a highly specialized clinical practice confined to a few centers around the world. Organ availability remains an important limiting factor in extending the application of this procedure to more infants, children and adolescents. The lungs are the organ most vulnerable to injury, infection and dysfunction among transplantable organs in the brain dead deceased donor. In this manuscript, we review the pathophysiology of the most common and important disease states that affect the lungs in potential donors. Furthermore, we herein provide recommendations for optimal management of the pediatric organ donor with an emphasis on strategies to improve the opportunity for the lungs to be placed in candidates on the transplant list.

Update on lung transplantation

Lung transplantation is a suitable treatment to improve the quality of life and the prognosis of patients with various end-stage pulmonary diseases. There is a shortage of organs and the number of patients on waiting list is exceeding the number of transplants per year approximately two-fold in most countries. Strategies to increase the donor pool are therefore crucial. The long-term prognosis after lung transplantation is not yet as good as for other transplantation procedures and special complications should be taken into account. Aside from infections chronic organ dysfunction is the main cause of death and the most important prognosis limiting factor. Other typical problems are rejection, bronchus complications, and primary transplant dysfunction. However, the results of large centers show promising improvements in recent years.

Perfil do doador de pulmão disponibilizado no estado de São Paulo, Brasil, em 2006

OBJETIVO: Analisar a taxa de aproveitamento de pulmões disponibilizados em São Paulo no ano de 2006, bem como caracterizar o perfil dos doadores de pulmão deste período. MÉTODOS: Estudo retrospectivo de 497 prontuários de doadores de pulmão, no período de janeiro a dezembro de 2006. RESULTADOS: Não houve oferta de doação de pulmões para transplante em 149 (30%) dos prontuários analisados, sendo excluídos do estudo. A idade média dos 348 doadores eleitos para o estudo foi de 37,4 ± 16,1 anos, e 56,9% deles eram do sexo masculino. As principais causas da morte cerebral dos doadores foram: acidente vascular cerebral (40,5%); trauma cranioencefálico (34,2%); e hemorragia subaracnóidea (10,9%). A grande maioria dos doadores recebia drogas vasoativas (90,5%), sendo que 13,5% haviam apresentado parada cárdio-respiratória. Do ponto de vista infeccioso, o leucograma médio foi de 15.008 ± 6.467 células/mm³, 67,8% recebiam antibioticoterapia e 26,1% apresentavam infecção pulmonar. Quase 40% dos doadores apresentavam alterações radiográficas. Apenas 4,9% dos doadores foram aceitos, representando 28 pulmões (taxa de aproveitamento de órgãos de 4%). Os motivos de recusa foram: alteração gasométrica (30,1%); infecção (23,7%); e distância (10,9%). CONCLUSÕES: A taxa de aproveitamento de pulmões em nosso meio é baixa quando comparada às taxas médias de aproveitamento mundial. Além disso, mais de 50% das recusas deveram-se à gasometria arterial inadequada e infecção pulmonar. Aliar melhor cuidado ao potencial doador à menor rigidez nos critérios de seleção poderia aumentar a utilização dos órgãos doados.

Lung transplantation

PURPOSE OF REVIEW

To describe recent advances in lung transplantation relevant to anesthesiologists.

RECENT FINDINGS

There is recent literature describing medical, surgical, anesthetic and critical care of lung transplant recipients.

SUMMARY

There have been substantial changes in preoperative selection and preparation of lung transplant recipients; these include donation after cardiac death, and improved lung-preservation solutions. Newer immunosuppression regimens have been successfully evaluated in clinical trials. Particular advances in anesthesia include endorsement of fluid restriction in thoracic surgery, greater use of transesophageal echocardiography, and postoperative extracorporeal membrane oxygenation.

Unilateral radiographic abnormalities after bilateral lung transplantation: exclusion from the definition of primary graft dysfunction?

OBJECTIVES

Unilateral infiltrates on chest x-ray films are occasionally seen after bilateral lung transplantation. In the primary graft dysfunction grading system, the presence or absence of a radiographic abnormality is crucial in determining the incidence and severity of primary graft dysfunction. However, no consideration is given as to whether unilateral infiltrates have the same impact and relevance as bilateral infiltrates. This study aims to describe the incidence, features, and outcomes of posttransplant unilateral infiltrates and their effect on the novel primary graft dysfunction grading system.

METHODS

Depending on posttransplant radiographic appearance, 144 patients who underwent bilateral lung transplantation were divided into 3 groups: no infiltrates (clear), unilateral infiltrates (unilateral), or bilateral infiltrates (bilateral).

RESULTS

Radiographic abnormalities were seen in 43% of donors and 61% of posttransplant recipients (sensitivity = 76%, specificity = 50%). The percentage of recipients in the unilateral, clear, and bilateral groups was 26%, 39%, and 35%, respectively. Lower posttransplant oxygenation (P < .05), longer intubation hours, and more intensive care unit days (P < .0001) were seen in the bilateral compared with the unilateral and the clear groups. A significant difference in the prevalence of primary graft dysfunction (P < .0001) was seen, depending on whether unilateral infiltrates were included or excluded from the primary graft dysfunction grading.

CONCLUSIONS

The incidence of unilateral infiltrates is relatively high after bilateral lung transplantation. The early posttransplant outcome of the unilateral infiltrates is similar to that in the group having a clear chest x-ray film and significantly better than that in those with bilateral infiltrates. In bilateral lung transplantation, only bilateral infiltrates should be used as part of the definition of primary graft dysfunction.

Feasibility and Utility of a Lung Donor Score: Correlation With Early Post-Transplant Outcomes

BACKGROUND

A lung donor score may provide a numerical value of overall donor lung "quality" to allow comparison among different organizations and research protocols. This study aims to develop a simple scoring system and investigate its applicability on predicting donor selection and early post-lung-transplant (LTx) outcomes.

METHODS

Data of all donors referred to our institution in 2001 were initially analyzed to create a LTx donor score. Five domains, age, smoking history, chest X-ray, secretions, and arterial blood gas results, were included. A larger cohort of transplant recipients (years 2002 to 2005) was analyzed to validate the score against early post-LTx outcomes.

RESULTS

In the initial 2001 cohort, 36 of 87 (41%) donors were used for 41 LTx (used group) and 51 (59%) were declined for medical (lung-exclusion group, n = 31) and general (general-exclusion group, n = 20) reasons. The median donor scores in the used, general-exclusion, and lung-exclusion groups were 2.0, 2.0, and 10.0, respectively (p < 0.0001). In multivariate analysis of the validation cohort, the donor score in bilateral LTx was significantly associated with post-transplant ratio of arterial oxygen tension and inspired oxygen fraction (coefficient = -16.19, p = 0.002), primary graft dysfunction grade (coefficient = 0.21, p < 0.0001), and intubation hours (coefficient = 0.05, p = 0.04); however, a significant association was not seen in single LTx.

CONCLUSIONS

A proposed simple donor scoring system, based on five major donor variables available at the time of donor selection, may be useful for data comparison between specific centers, quality control, evaluative research, and clinical decision making in donor selection and management in LTx.

Definitions of primary graft dysfunction after lung transplantation: differences between bilateral and single lung transplantation

OBJECTIVE

The primary graft dysfunction definition has been applied to both bilateral lung transplantation and single lung transplantation. However, the differences between bilateral and single lung transplantation in terms of primary graft dysfunction remain unknown. This study aims to investigate the features and utility of the new primary graft dysfunction grading system by comparing early outcomes from bilateral and single lung transplantation.

METHODS

The primary graft dysfunction grade of 228 consecutive lung transplants (149 bilateral and 79 single lung transplants) at multiple postoperative time points was analyzed. Subgroup analysis with chronic obstructive pulmonary disease was performed to further validate the difference between bilateral lung transplantation and single lung transplantation.

RESULTS

The percentage of grade 3 primary graft dysfunction in bilateral and single lung transplants was 32% and 37% at 0 hours (T0), 9% and 33% at 12 hours (T12), 7% and 26% at 24 hours (T24), and 9% and 18% at 72 hours (T72), respectively. The prevalence of the grade 3 primary graft dysfunction (T24) was significantly different between those undergoing bilateral lung transplantation and those undergoing single lung transplantation (P = .02). The primary graft dysfunction grade (T0) significantly correlated with the duration of intubation in both bilateral (r = 0.35, P < .0001) and single (r = 0.42, P = .001) lung transplantation and length of intensive care unit stay in both bilateral (r = 0.31, P = .0002) and single (r = 0.33, P = .006) lung transplantation. These differences were validated by the subgroup analysis.

CONCLUSIONS

The prevalence of primary graft dysfunction grade is different between bilateral and single lung transplantation and varies with time. Although the primary graft dysfunction grade correlated with the early posttransplantation outcomes, for the purposes of description and further studies, primary graft dysfunction in bilateral and single lung transplantation should be considered separately.

Update of early respiratory failure in the lung transplant recipient

PURPOSE OF REVIEW

Respiratory failure remains the most common complication in the perioperative period after lung transplantation. Consequently it is important to develop an approach to diagnosis and the treatment of respiratory failure in this population. This review highlights the advances made in the understanding and treatment of lung transplant patients in the early postoperative phase. Owing to its relative importance, advances in the understanding and treatment of ischaemia-reperfusion injury are highlighted.

RECENT FINDINGS

The causes of respiratory failure and the complications seen after transplantation are time dependent, with ischaemia-reperfusion, infection, technical problems and acute rejection being the most common in the early perioperative phase, and obliterative bronchiolitis, rejection, and infections secondary to bacteria, fungi, and viruses becoming more prevalent after 3 months. The advances in lung preservation and postoperative care may be overshadowed by an increase in the complexity of the recipients and the use of more marginal organs. An improved mechanistic understanding of ischaemia-reperfusion injury has translated into potential therapeutic targets. The development of prospective clinical trials, however, is hampered by a relatively small sample of patients and a significant degree of heterogeneity in the lung transplant population.

SUMMARY

Many advances have been made in the understanding of ischaemia-reperfusion injury. Owing to the acute and long-term implications of this complication, interventions that reduce the risk of developing ischaemia-reperfusion need to be evaluated in prospective clinical trials.

Lung Transplantation: Current Status and Challenges

The lung is an anatomically complex vital organ whose normal physiology depends on actively regulated ventilation and perfusion, and maintenance of a delicate blood-air barrier over a huge surface area in direct contact with a potentially hostile environment. Despite significant progress over the past 25 years, both short- and long-term outcomes remain significantly inferior for lung recipients relative to other "solid" organs. This review summarizes the current status of lung transplantation so as to frame the principle challenges currently facing end-stage lung-failure patients and the practitioners who care for them.

Techniques of Reconstruction for Inadequate Donor Left Atrial Cuff in Lung Transplantation

BACKGROUND

An inadequate donor left atrial (LA) cuff due to an anatomical abnormality of the pulmonary vasculature or technical errors at the time of procurement can exclude the lungs from transplant. This study aims to describe the incidence, efficacy, and various techniques of LA cuff reconstruction in lung transplantation.

METHODS

A total of 637 pulmonary venous anastomosis in 405 consecutive lung transplants from January 1995 to July 2005 were reviewed. Comparison between the patients who required LA cuff reconstruction (reconstruction group) or who did not (no-reconstruction group) was made in posttransplant outcomes.

RESULTS

An overall incidence of requirement of LA cuff reconstruction was 2.7% (4% on the right, 1% on the left, p = 0.03). Seventy-one percent of LA inadequacy was corrected using a pericardial patch on the anterior LA cuff wall; the remainder required complicated reconstruction for separated/short pulmonary veins to create a new LA cuff. There was no significant difference between the reconstruction and no-reconstruction groups, respectively, in oxygenation (329 +/- 28, 337 +/- 10, p = 0.81), duration of intubation and intensive care unit stay (p = 0.54, p = 0.89, respectively), 30-day mortality (12%, 6%, p = 0.30), and 5-year survival (57%, 52%, p = 0.80).

CONCLUSIONS

Inadequate donor LA cuff is an infrequent but potentially serious complication in lung transplantation. Donor LA cuff reconstruction using donor pericardium or pulmonary artery remnant is a useful technique to salvage surgically marginal lungs without affecting early and late posttransplant outcomes. These lungs should not be excluded from transplantation.