A positive donor gram stain does not predict outcome following lung transplantation

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Impact of perioperative airway pathogens on living-donor lobar lung transplantation outcomes

PURPOSE

To elucidate the clinical impact of pathogenic organism (PO) positivity early after transplantation, we evaluated the impact of perioperative airway POs on outcomes after living-donor lobar lung transplantation (LDLLT), where the graft airway is supposed to be sterile from a healthy donor.

METHOD

A retrospective review of 67 adult LDLLT procedures involving 132 living donors was performed. Presence of POs in the recipients' airways was evaluated preoperatively and postoperatively in intensive-care units.

RESULTS

POs were detected preoperatively in 13 (19.4%) recipients. No POs were isolated from the donor airways at transplantation. POs were detected in 39 (58.2%) recipients postoperatively; most were different from the POs isolated preoperatively. Postoperative PO isolation was not associated with short-term outcomes other than prolonged postoperative ventilation. The 5-year overall survival was significantly better in the PO-negative group than in the PO-positive group (89.1% vs. 63.7%, P = 0.014). In the multivariate analysis, advanced age (hazard ratio [HR]: 1.041 per 1-year increase, P = 0.033) and posttransplant PO positivity in the airway (HR: 3.684, P = 0.019) significantly affected the survival.

CONCLUSIONS

The airways of the living-donor grafts were microbiologically sterile. PO positivity in the airway early after transplantation negatively impacted long-term outcomes.

Evaluation of Donor Lungs for Transplantation: The Efficacy of Screening Bronchoscopy for Detecting Donor Aspiration and Its Relationship to the Resulting Allograft Function in Corresponding Recipients

BACKGROUND

Potential organ donors often have suffered anoxic and/or traumatic brain injury during which they may have experienced aspiration of gastric material (AGM). Evaluation of such donors typically includes a screening bronchoscopic examination during which determinations of aspiration are made. The efficacy of this visual screening and its relationship to post-transplant allograft function are unknown.

METHODS

Before procurement, bronchoscopy was performed on donors in which both bronchoalveolar lavage fluid (BALF) was collected and a visual inspection made. As a marker of AGM, BALF specimens were analyzed for the presence of bile salts. Data collected on the corresponding recipients included primary graft dysfunction (PGD) score, post-transplant spirometry, acute rejection scores (ARS), and overall survival.

RESULTS

Of 31 donors evaluated, bronchoscopies revealed only 2 with visual evidence of AGM, whereas BALF analysis for bile salts indicated AGM in 14. As such, screening bronchoscopy had a sensitivity of only 7.1%. Visual detection of AGM via bronchoscopy was not associated with any resulting grade of PGD (χ2 = 2.96, P = .23); however, AGM defined by detection of bile salts was associated (χ2 = 7.56, P = .02). Over the first post-transplant year, the corresponding recipients experienced a similar improvement in allograft function (χ2 = 1.63, P = .69), ARS (P = .69), and survival (P = .24).

CONCLUSION

Visual inspection during a single bronchoscopic examination of lung donors underestimates the prevalence of AGM. The detection of bile salts in donor BALF is associated with early allograft dysfunction in the corresponding recipients but not with later allograft proficiency, acute rejection responses, or 1-year post-transplant survival.

Expanding Donor Options for Lung Transplant: Extended Criteria, Donation After Circulatory Death, ABO Incompatibility, and Evolution of Ex Vivo Lung Perfusion

Only using brain-dead donors with standard criteria, the existing donor shortage has never improved in lung transplantation. Currently, clinical efforts have sought the means to use cohorts of untapped donors, such as extended criteria donors, donation after circulatory death, and donors that are ABO blood group incompatible, and establish the evidence for their potential contribution to the lung transplant needs. Also, technical maturation for using those lungs may eliminate immediate concerns about the early posttransplant course, such as primary graft dysfunction or hyperacute rejection. In addition, recent clinical and preclinical advances in ex vivo lung perfusion techniques have allowed the safer use of lungs from high-risk donors and graft modification to match grafts to recipients and may improve posttransplant outcomes. This review summarizes recent trends and accomplishments and future applications for expanding the donor pool in lung transplantation.

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.

Organ Donation, the Non-Perfect Lung Donor, and Variability in Conversion to Transplant

Rates of lung donation have increased over the past several years. This has been accomplished through the utilization of donors with extended criteria, the creation of donor hospitals or centers, and the optimization of lungs through the implementation of donor management protocols. These measures have resulted in augmenting the pool of available donors thereby decreasing the wait time for lung transplantation candidates. Although transplant programs vary significantly in their acceptance rates of these organs, studies have not shown any difference in the incidence of primary graft dysfunction or overall mortality for the recipient when higher match-run sequence organs are accepted. Yet, the level of comfort in accepting these donors varies among transplant programs. This deviation in practice results in these organs going to lower-priority candidates thereby increasing the waitlist time of other recipients and ultimately has a deleterious effect on an institution's waitlist mortality.

Bronchial Culture Growth From the Donor and Recipient as Predictive Factors in the Detection of Primary Graft Dysfunction and Pneumonia After Lung Transplant

OBJECTIVES

In this study, our aim was to investigate whether bacterial culture growth from donors and recipients is related to early posttransplant complications and to analyze its role in primary graft dysfunction and posttransplant pneumonia in lung transplant recipients.

MATERIALS AND METHODS

This retrospective cohort study included patients diagnosed with end-stage lung disease who received a lung transplant for treatment. We examined relationships between donor bronchial lavage, pretransplant recipient sputum, and recipient posttransplant serial bronchial lavage culture results, as well as the development of both primary graft dysfunction and pneumonia after lung transplant during the early posttransplant period.

RESULTS

Our study included 77 patients with median age of 48 years (25%-75% IQR, 34-56 years) and who were mostly men (79.2%; n = 61). Donor culture positivity was 62.3% (n = 48), and the positivity of sputum culture from patients before transplant was 20.8% (n = 16). Compared with that shown in those without versus those with primary graft dysfunction, there were significantly more positive sputum cultures from patients before transplant (P = .003). Recipients with donor culture growth had a longer duration of invasive mechanical ventilation (median of 4 days [IQR, 2-13 days] vs 1 day [IQR, 1-2 days]; P = .001, respectively) than those without. Multivariate logistic analysis identified both donor culture positivity (odds ratio: 3.391; 95% CI, 1.12-20.46; P = .0028) and sputum culture positivity in pretransplant recipient candidates (odds ratio: 6.494; 95% CI, 1.80-36.27; P = .004) as independent predictors of primary graft dysfunction.

CONCLUSIONS

Bacterial growth shown in donor bronchial lavage and sputum culture positivity in patients before transplant were found to be independent predictors of primary graft dysfunction in the early posttransplant period. Organism growth in both the donor and the recipient during the pretransplant period are important determinants for the development of primary graft dysfunction.

Infectious Complications in Lung Transplant Recipients

Infection remains a common cause of death throughout the lifespan of a lung transplant recipient. The increased susceptibility of lung transplant recipients is multifactorial including exposure of the graft to the external environment, impaired mucociliary clearance, and high levels of immunosuppression. Long-term outcomes in lung transplant recipients remain poor compared with other solid organ transplants largely due to deaths from infections and chronic allograft dysfunction. Antibacterial, antifungal, and antiviral prophylaxis may be used after lung transplantation to target a number of different opportunistic infections for varying durations of time. The first-month posttransplant is most commonly characterized by nosocomial infections and donor-derived infections. Following the first month to the first 6 months after transplant-a period of intense immunosuppression-is associated with opportunistic infections. While immunosuppression is reduced after the first year posttransplant, infection remains a risk with community-acquired and rarer infectious agents. Clinicians should be vigilant for infection at all time points after transplant. The use of patient-tailored prophylaxis and treatments help ensure graft and patient survival.

Management of the Potential Lung Donor

The use of donor management protocols has significantly improved recovery rates; however, the inherent instability of lungs after death results in low utilization rates of potential donor lungs. Donor lungs are susceptible to direct trauma, aspiration, neurogenic edema, ventilator-associated barotrauma, and ventilator-associated pneumonia. After irreversible brain injury and determination of futility of care, the goal of medical management of the donor shifts to maintaining hemodynamic stability and maximizing the likelihood of successful organ recovery.

Donor selection for lung transplant in Turkey: Is it necessary to wait for an ideal donor?

Background

The aim of this study was to evaluate the donor criteria used in lung transplantation in our clinic.

Methods

A total of 55 cadaveric donors who were accepted for lung transplantation in our clinic between December 2016 and January 2019 were retrospectively analyzed according to ideal donor criteria. The donors were divided into two groups as ideal and non-ideal ones according to their age, partial pressure of oxygen in arterial blood, history of smoking, and ventilation day. Donor data, recipient characteristics and survival outcomes were evaluated.

Results

Of 55 donors accepted for lung transplantation, 24 (43.7%) were ideal and 31 (56.3%) were non-ideal donors. The 90-day mortality and one-year survival rates were not significantly different between the two groups. The 90-day mortality was 25% in the ideal group and 22.6% in the non-ideal group (p=0.834). The one-year survival rates after lung transplantation were 64.5% versus 70.6% in the ideal and non-ideal groups, respectively (p=0.444).

Conclusion

The whole clinical picture should be evaluated before accepting or rejecting donors for lung transplantation. The use of lung donors that do not meet the ideal criteria does not impair short- and mid-term results, compared to ideal lung donors. Strict implementation of donor criteria may prevent using suitable donors for lung transplantation. Use of non-ideal donors can reduce waiting list mortality.

Donor lung management: Changing perspectives

Worldwide, lung transplantation has been a therapeutic option for select end-stage lung disease patients who are on optimized medical regimens, but the underlying clinical condition continues to progress. For any successful lung transplantation program, it is important to have a robust donor lung management program. Lungs are commonly affected by the various factors related to trauma or neurogenic in brain stem death donors. This article would focus on the basic protocols to optimize donor lungs which would help in increasing donor pool. It would also elaborate COVID-specific points for donor lung evaluation. This article would also describe the criteria for ideal as well as marginal donor lungs. A comprehensive literature search was performed using PubMed to review various articles related to donor lung management.

Bacterial products in donor airways prevent the induction of lung transplant tolerance

Although postoperative bacterial infections can trigger rejection of pulmonary allografts, the impact of bacterial colonization of donor grafts on alloimmune responses to transplanted lungs remains unknown. Here, we tested the hypothesis that bacterial products present within donor grafts at the time of implantation promote lung allograft rejection. Administration of the toll-like receptor 2 (TLR2) agonist Pam₃ Cys₄ to Balb/c wild-type grafts triggered acute cellular rejection after transplantation into B6 wild-type recipients that received perioperative costimulatory blockade. Pam₃ Cys₄ -triggered rejection was associated with an expansion of CD8⁺ T lymphocytes and CD11c⁺ CD11b^hi MHC (major histocompatibility complex) class II⁺ antigen-presenting cells within the transplanted lungs. Rejection was prevented when lungs were transplanted into TLR2-deficient recipients but not when MyD88-deficient donors were used. Adoptive transfer of B6 wild-type monocytes, but not T cells, following transplantation into B6 TLR2-deficient recipients restored the ability of Pam₃ Cys₄ to trigger acute cellular rejection. Thus, we have demonstrated that activation of TLR2 by a bacterial lipopeptide within the donor airways prevents the induction of lung allograft tolerance through a process mediated by recipient-derived monocytes. Our work suggests that donor lungs harboring bacteria may precipitate an inflammatory response that can facilitate allograft rejection.

Effectiveness of short vs long-course perioperative antibiotics in lung transplant recipients with donor positive respiratory cultures

Lung transplant recipients are at increased risk for infection in the early postoperative phase, thus perioperative antibiotics are employed. This retrospective study evaluated the efficacy of short- vs long-course perioperative antibiotics in lung transplant patients. Lung transplant patients with donor positive cultures between August 2013 and September 2019 were evaluated, excluding those with cystic fibrosis, death within 14 days and re-transplants. The primary outcome was 30-day freedom from donor-derived respiratory infection. A total of 147 patients were included (57 short vs 90 long-course). Median perioperative antibiotic duration was 6 days in the short-course vs 14 days in the long-course group (P < .0001). Thirty-day freedom from donor-derived respiratory infection was present in 56 (98%) patients in the short-course vs 85 (94%) patients in the long-course group (P = .41). There was no difference in development of Clostridioides difficile infections (P = .41), while cumulative ventilator time and time to post-op extubation were longer in the long-course group (P = .001 and .004, respectively). Among lung transplant recipients with positive donor respiratory cultures, short-course perioperative antibiotics were as effective as long-course antibiotics in preventing donor-derived bacterial respiratory infections.

Effects of Multidrug-resistant Bacteria in Donor Lower Respiratory Tract on Early Posttransplant Pneumonia in Lung Transplant Recipients Without Pretransplant Infection

BACKGROUND

Multidrug-resistant (MDR) bacteria in the lower respiratory tracts of allografts may be risk factors for early posttransplant pneumonia (PTP) that causes detrimental outcomes in lung transplant recipients (LTRs). We evaluated the effects of immediate changes in MDR bacteria in allografts on early PTP and mortality rates in LTRs.

METHODS

We reviewed 90 adult bilateral LTRs without pretransplant infections who underwent lung transplantation between October 2012 and May 2018. Quantitative cultures were performed with the bronchoalveolar lavage fluids of the allografts preanastomosis and within 3 days posttransplant. The International Society for Heart and Lung Transplantation consensus defines early PTP as pneumonia acquired within 30 days posttransplant and not associated with acute rejection.

RESULTS

MDR Acinetobacter baumannii (11/34, 32.4%) and Staphylococcus aureus (9/34, 26.5%) were identified in 24.4% (22/90) of the preanastomosis allografts. Four LTRs had the same MDR bacteria in allografts preanastomosis and posttransplant. Allograft MDR bacteria disappeared in 50% of the LTRs within 3 days posttransplant. Early PTP and all-cause in-hospital mortality rates were not different between LTRs with and without preanastomosis MDR bacteria (P = 0.75 and 0.93, respectively). MDR bacteria ≥10 CFU/mL in the lungs within 3 days posttransplant was associated with early PTP (odds ratio, 5.8; 95% confidence interval, 1.3-27.0; P = 0.03).

CONCLUSIONS

High levels of preexisting MDR bacteria in allografts did not increase early PTP and mortality rates in LTRs. Despite the small and highly selective study population, lung allografts with MDR bacteria may be safely transplanted with appropriate posttransplant antibiotic therapy.

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.

Ex vivo lung CT findings may predict the outcome of the early phase after lung transplantation

Purpose

We developed an ex vivo lung CT (EVL-CT) technique that allows us to obtain detailed CT images and morphologically assess the retrieved lung from a donor for transplantation. After we recovered the lung graft from a brain-dead donor, we transported it to our hospital and CT images were obtained ex vivo before lung transplant surgery. The objective of this study was to investigate the correlation between the EVL-CT findings and post-transplant outcome in patients who underwent bilateral lung transplantation (BLT) or single lung transplantation (SLT).

Methods

We retrospectively reviewed the records of 70 patients with available EVL-CT data who underwent BLT (34 cases) or SLT (36 cases) in our hospital between October 2007 and September 2017. The recipients were divided into 2 groups (control group, infiltration group) according to the findings of EVL-CT of the lung graft in BLT and SLT, respectively. Recipients in the control group were transplanted lung grafts without any infiltrates (BLT control group, SLT control group). Recipients in the infiltration group received lung grafts with infiltrates (BLT infiltration group, SLT infiltration group).

Results

The recipients in the BLT infiltration group showed significantly slower recovery from primary graft dysfunction and a longer mechanical ventilation period and ICU stay period than those in the BLT control group. The mechanical ventilation period was significantly longer in the recipients in the SLT infiltration group than those in the SLT control group.

Conclusion

EVL-CT may predict the outcome of the early phase after lung transplantation.

Airway bacteria of the recipient but not the donor are relevant to post-lung transplant pneumonia

BACKGROUND

Optimal management of early airway infection is essential for the survival of lung transplant (LTx) recipients during the first 12 months after transplantation. This study aimed to explore the main cause of post-lung transplant pneumonia (PLTP) within 30 days after LTx.

METHODS

Forty LTx patients were retrospectively analyzed. Sputum sampling from donors' and recipients' airways was performed pretransplant and posttransplant daily for the first 30 days after LTx. Organisms in the recipient's and donor's original airways were compared to pathogens responsible for PLTP. Patients with and without PLTP were also compared to identify relevant risk factors.

RESULTS

Seventeen (42.5%) patients developed pneumonia (PLTP group) and 23 had no episode of pneumonia (Non-PLTP group) during the first 30 days. In the PLTP group, median time from LTx to PLTP onset was 6 days. A significantly higher incidence of PLTP was caused by recipient's rather than donor's original airway bacteria (62% vs 13%, p < 0.01). Smoking history of the donor and pretransplant airway bacterial colonization of the recipient were independent risk factors of PLTP which was associated with prolonged posttransplant mechanical ventilation with longer intensive care unit stay and worse survival outcomes.

CONCLUSIONS

The recipient's original airway microflora rather than the donor's, was highly associated with PLTP. A combination of donor smoking history and recipient airway infection should be avoided, while evidence of donor lung infection is not a contraindication for LTx.

Reasons for Donor Lungs Unsuitability After Radiographic Selection

OBJECTIVES

Deceased lung donation requires optimum donor care, with lung viability greatly affected by the progress of the disease leading to brain death. In this study, we searched for causes of lung unsuitability for transplant in both primary and secondary evaluations.

MATERIALS AND METHODS

Primary lung evaluations included chest radiography, oxygen challenge test, and donor clinical and history examination. Secondary evaluations for lungs that passed the first step included fiberoptic bronchoscopy and donor-recipient matching.

RESULTS

From 2012 to 2017, there were 1020 potential deceased organ donors in our center. Primary evaluations showed that the most prominent reason for lung donation unsuitability was low oxygen challenge result (n = 433, 42.5%). Other reasons were abnormal chest radiograph (n = 378, 38%), history of heavy smoking and inhaled drugs addiction (n = 112, 11%), prolonged intubation (n = 28, 2.7%), and lung disease history (n = 69, 6.7%). There were 104 (10.1%) potential donors to undergo fiberoptic bronchoscopy for further lung evaluation, with 47 (45.2%) selected for final lung donation. Five lungs (4.8%) with bronchoscopic confirmation for suitability were not retrieved due to lack of instruments and resources. Among the 57 (54.8%) rejected potential lung donations, the greatest factor impacting suitability was observation of purulent secretions in bronchoscopy (n = 24, 23%), evidence of aspiration (n = 10, 9.6%), infiltration (n = 7, 6.7%), and tracheitis.

CONCLUSIONS

The most common cause of lung rejection after primary evaluation is observation of purulent secretions in tracheobronchial tree. Therefore, implementation of appropriate strategies to prevent respiratory infection in the intensive care unit is needed to expand the lung donor pool.

Impact of donor lung pathogenic bacteria on patient outcomes in the immediate post-transplant period

BACKGROUND

Patient outcomes post-lung transplant remain inferior to other types of solid organ transplantation. We investigated whether the presence of potentially pathogenic bacteria (PPB) in donor lung bronchial cultures was associated with adverse outcomes postoperatively.

METHODS

All patients who underwent lung transplantation between August 2015 and April 2017 at the University of Kentucky Medical Center were retrospectively reviewed. Retransplants, patients with bronchiectasis (including cystic fibrosis), and individuals who received organs from donation after cardiac death (DCD) donors were excluded. The remaining subjects were separated into two groups: individuals whose donor bronchial cultures grew PPB, and those whose cultures either returned negative for PPB or were sterile. 30-day mortality rates as well as the incidence of grade 3 primary graft dysfunction (PGD) and acute kidney injury (AKI) at both 24 and 72 hours post-transplant were calculated. The duration of mechanical ventilation postoperatively was also recorded.

RESULTS

Thirty two subjects comprised the study population. 20 patients (63%) had growth of PPB on donor cultures, while 12 (37%) did not. Patients with PPB had a significantly greater number of days on the ventilator postoperatively compared to those with no PPB (mean = 11.3 and median = 5.0 vs mean = 5.8 and median = 3.0, respectively, P = 0.0232). Subsequent regression analysis revealed this association to not be influenced by recipient lung allocation score (LAS), donor age, donor smoking history, recipient mean pulmonary artery pressure (mPAP) value, and/or use of cardiopulmonary bypass at the time of transplantation. Neither 30-day survival nor incidence of Grade 3 PGD and AKI at 24 or 72 hours post-transplant differed between the two groups (P > 0.05).

CONCLUSION

The recovery of PPB in donor lung cultures was associated with a longer duration of mechanical ventilation postoperatively in lung transplant recipients.

Infective endocarditis due to Burkholderia cepacia in a neonate: a case report

Background

Burkholderia is a pathogen that is rarely seen in clinical cases. However, this organism is being found more commonly in hospitals.

Case presentation

A female Indonesian newborn was referred to our neonatal intensive care unit because of respiratory distress. The newborn had been delivered the previous night via cesarean section. A physical examination revealed intercostal retractions and weak cry. The newborn’s gestational history was preterm, small for gestational age, and preterm premature ruptured membrane for 14 hours. Continuous positive airway pressure was administered. A multiple-antibiotic regimen consisting of ampicillin-sulbactam, gentamicin, meropenem, and ceftriaxone was initiated. Insertion of a central catheter was performed. The patient’s laboratory results were low blood albumin and globulin, anemia, and leukopenia. A blood culture revealed Burkholderia cepacia that was resistant to multiple antimicrobial agents. A chest x-ray showed infiltrate on both lung fields. Echocardiography showed two vegetations on the tricuspid valve.

Conclusions

B. cepacia is a rare cause of infective endocarditis. With its capability to colonize water and grow on microbicides, the presence of B. cepacia in a patient’s blood warrants further investigation in institutions providing care. This might not be the first publication on this topic.

Evaluation and Management of the Potential Lung Donor

The expansion of the donor lung pool has involved an evidence-driven redefinition of acceptable donors. Proceeding with transplantation with an acceptable rather than ideal donor depends on specific patient-related and organ-related risk factors as well as the severity of recipient illness. Although the physiologic optimization of brain-dead donors has not changed significantly in recent years, the use of donor management protocols has improved procurement rates. Ex vivo lung perfusion is an increasingly viable strategy to recondition lungs that would otherwise fall below the acceptable threshold for transplant. Ex vivo perfusion trials for preservation of standard donor lungs are ongoing.

Bacterial Infection during Adult Donor Care

Assessment, prevention, and treatment of bacterial infection in donors are critically important to the welfare of grafts and recipients after transplantation. Transmission of bacterial, viral, fungal, and protozoan infections from a donor to recipient(s) has been documented to have serious or fatal consequences. This article reviews issues of bacterial infection only. The organ procurement coordinator, supported by guidelines developed and prospectively modified by the organ procurement organization, must assess the donor for the presence and severity of bacterial tissue invasion and administer appropriate antimicrobial agents during donor care. Continuation of infection control measures, obtaining serial or surveillance samples for culture, review of antibiotic sensitivity data, initiation of empiric treatment, and modification of medications or their dosing are components of this important responsibility during donor care.

Lung donor selection criteria

The criteria that define acceptable physiologic and social parameters for lung donation have remained constant since their empiric determination in the 1980s. These criteria include a donor age between 25-40, a arterial partial pressure of oxygen (PaO2)/FiO2 ratio greater than 350, no smoking history, a clear chest X-ray, clean bronchoscopy, and a minimal ischemic time. Due to the paucity of organ donors, and the increasing number of patients requiring lung transplant, finding a donor that meets all of these criteria is quite rare. As such, many transplants have been performed where the donor does not meet these stringent criteria. Over the last decade, numerous reports have been published examining the effects of individual acceptance criteria on lung transplant survival and graft function. These studies suggest that there is little impact of the historical criteria on either short or long term outcomes. For age, donors should be within 18 to 64 years old. Gender may relay benefit to all female recipients especially in male to female transplants, although results are mixed in these studies. Race matched donor/recipients have improved outcomes and African American donors convey worse prognosis. Smoking donors may decrease recipient survival post transplant, but provide a life saving opportunity for recipients that may otherwise remain on the transplant waiting list. No specific gram stain or bronchoscopic findings are reflected in recipient outcomes. Chest radiographs are a poor indicator of lung donor function and should not adversely affect organ usage aside for concerns over malignancy. Ischemic time greater than six hours has no documented adverse effects on recipient mortality and should not limit donor retrieval distances. Brain dead donors and deceased donors have equivalent prognosis. Initial PaO2/FiO2 ratios less than 300 should not dissuade donor organ usage, although recruitment techniques should be implemented with intent to transplant.

Lung transplant infection

Lung transplantation has become an accepted therapeutic procedure for the treatment of end‐stage pulmonary parenchymal and vascular disease. Despite improved survival rates over the decades, lung transplant recipients have lower survival rates than other solid organ transplant recipients. The morbidity and mortality following lung transplantation is largely due to infection‐ and rejection‐related complications. This article will review the common infections that develop in the lung transplant recipient, including the general risk factors for infection in this population, and the most frequent bacterial, viral, fungal and other less frequent opportunistic infections. The epidemiology, diagnosis, prophylaxis, treatment and outcomes for the different microbial pathogens will be reviewed. The effects of infection on lung transplant rejection will also be discussed.

Late respiratory infection after lung transplantation

BACKGROUND

Aiming to improve outcome of lung transplantation (LTx) patients, we reviewed risk factors and treatment practices for the LTx recipients who experienced respiratory infection in the late post-LTx period (>1 month after LTx).

METHODS

We analyzed the clinical data of 48 recipients and donors from 61 LTx, who experienced late respiratory infections. Late respiratory infections were classified according to the etiology, time of occurrence, and frequency of donor-to-host transmission or colonization of the recipient prior to transplantation.

RESULTS

During the period of observation, 42 episodes of respiratory infections occurred. The organisms most frequently involved were gram (-) bacteria: Acinetobacter baumannii (n=13, 31.0%), Pseudomonas aeruginosa (n=7, 16.7%), and Klebsiella pneumoniae (n=4, 10.0%). Among the 42 episodes recorded, 14 occurred in the late post-LTx period. These were bacterial (n=6, 42.9%), fungal (n=2, 14.3%), viral (n=4, 28.5%), and mycobacterial (n=2, 14.3%) infections. Of 6 bacterial infections, 2 were from multidrug-resistant (MDR) A. baumannii and one from each of MDR P. aeruginosa, extended spectrum β-lactamase (+) K. pneumoniae, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae. Infection-related death occurred in 6 of the 14 episodes (43%).

CONCLUSION

Although the frequency of respiratory infection decreased sharply in the late post-LTx period, respiratory infection was still a major cause of mortality. Gram (-) MDR bacteria were the agents most commonly identified in these infections.

Cough reflex in lung transplant recipients

Lung transplantation has become the standard of care for particular individuals with advanced lung disease. However, this surgical procedure involves interruption of the lower vagal nerve fibers which leads to loss of the protective cough reflex. Injury of the neural pathways involved with the sensory limb of the cough reflex is associated with an increased risk of complications involving the allograft. While loss of the cough reflex was once considered permanent, recent evidence indicates functional and structural restoration is a time-dependent process that occurs 6-12 months after lung transplantation. The implication that the cough reflex may be reestablished in lung transplant recipients provides insight into the dynamic response to airway neural injury that may lead to improvements in allograft tissue repair.

Elevated plasma long pentraxin-3 levels and primary graft dysfunction after lung transplantation for idiopathic pulmonary fibrosis

Primary graft dysfunction (PGD) after lung transplantation may result from ischemia reperfusion injury (IRI). The innate immune response to IRI may be mediated by Toll-like receptor and IL-1-induced long pentraxin-3 (PTX3) release. We hypothesized that elevated PTX3 levels were associated with PGD. We performed a nested case control study of lung transplant recipients with idiopathic pulmonary fibrosis (IPF) or chronic obstructive pulmonary disease (COPD) from the Lung Transplant Outcomes Group cohort. PTX3 levels were measured pretransplant, and 6 and 24 h postreperfusion. Cases were subjects with grade 3 PGD within 72 h of transplantation and controls were those without grade 3 PGD. Generalized estimating equations and multivariable logistic regression were used for analysis. We selected 40 PGD cases and 79 non-PGD controls. Plasma PTX3 level was associated with PGD in IPF but not COPD recipients (p for interaction < 0.03). Among patients with IPF, PTX3 levels at 6 and 24 h were associated with PGD (OR = 1.6, p = 0.02 at 6 h; OR = 1.4, p = 0.008 at 24 h). Elevated PTX3 levels were associated with the development of PGD after lung transplantation in IPF patients. Future studies evaluating the role of innate immune activation in IPF and PGD are warranted.

Microbial pattern of bronchoalveolar lavage in brain dead donors

BACKGROUND

We assessed bronchoalveolar lavage (BAL) cultures of brain dead donors seeking to achieve better donor management and decrease transplant complications. Determining the most common source of some postoperative infections causing morbidity and mortality among lung recipients would help to reach this goal.

MATERIALS AND METHODS

This prospective study was performed on 80 brain dead donors from August 2008 to August 2009. Donors with partial pressure of arterial O2 to the fraction of inspired O2 (PaO2/FIO2)>300 mm Hg and a normal chest x-ray underwent bronchoscopy to obtain a BAL.

FINDINGS

The mean donor age was 30±14 years and 50 (63%) were males with 21 (26%) showing a positive history for smoking and 32 (40%) with turbid tracheal secretions. Chest x-ray was abnormal in 49 (61%). Positive culture BAL results were observed among 30 (38%) patients: there were 17 (90%) bacterial and 6 (22%) fungal. Finally, 16 donors (20%) were considered suitable lung donors, allowing 10 lung transplantations.

CONCLUSION

Only 20% of donors had acceptable lungs for transplantation. The high rates of positive bacterial and fungal BAL cultures in donors suggest the need for more aggressive critical care management and antibiotic therapy which may be beneficial to prevent future infections in recipients. Further prospective studies are needed to assess the correlation between donor BAL results and posttransplant morbidity and mortality.

Recommendations for the use of extended criteria donors in lung transplantation

Selection criteria for lung donation were based on initial experiences with lung transplantation without further studies to improve them, thereby guaranteeing the best use of donated organs. A definition of an extended criteria donor is therefore required to obtain more lungs to meet the demands of patients awaiting transplantation. Studies have been reviewed for the impact on survival and morbidity of age ranges, oxygen fraction, cause of death, smoking habits, x-ray findings, infection, hepatitis serology and non-heart-beating status, seeking to support physicians to make decisions regarding the use of marginal organs.

Special issues in the management and selection of the donor for lung transplantation

Lung transplantation is a viable treatment option for select patients with end-stage lung disease. Two issues hamper progress in transplantation: first, donor shortage is a major limitation to increasing the number of transplants performed. Secondly, recipient outcomes remain disappointing when compared with other solid organ transplant results. Outcomes are limited by primary graft dysfunction (PGD), the posttransplant acute lung injury that increases both short-and long-term mortality. Attempts to overcome donor shortage have included aggressively managing solid organ donors to increase the number of donor lungs suitable for transplantation. Yet, the quality of the lung donor is likely to be related to the probability of the recipient experiencing PGD. PGD is the culmination of a series of insults, hemodynamic, metabolic, and inflammatory, that begin with the brain dead donor and result in poor recipient outcomes. Understanding the mechanism of donor lung injury resulting from brain death and the possible treatment strategies for its inhibition could help to increase the number of usable lungs and decrease the rate of PGD in the recipient. Here we present a review of the key pathways which result in donor lung injury, and follow this with a brief review of recent biomarkers that are proving to be instrumental to our ability to predict truly unsuitable lungs, and our ability to predict and hopefully prevent or treat recipients with subsequent lung injury.

Brain death and its influence on the lungs of the donor: how is it prevented?

The need for lung grafts is currently greater than ever. Unfortunately, the availability of grafts is insufficient for this demand. So we are forced to request organs for transplantation in the "waste bin." One possible solution to this problem may be the use of grafts from brain-dead patients. Sadly brain death is followed by devastating hemodynamic, inflammatory, and neurohumoral reactions in the potential donor which not only inflict direct damage, but also induce activation of the immune system which can cause rejection or even graft failure. Therefore, various groups have examined measures to prevent this outcome. In this review, we attempt to reconstruct the events that follow brain death, suggesting an algorithm to prevent a brain-dead patient's lungs from further damage. Finally, we are proposing potential measures of graft's protection of further investigation.

Extended donor criteria in lung transplantation

PURPOSE OF REVIEW

Despite improvements in respiratory care and lung transplant organ allocation algorithms, waiting lists continue to grow worldwide. Attempts at improving organ donation rates have generally had little impact on the increase in the number of transplants performed. Improved use of the available pool of cadaveric organ donors, therefore, represents one of few immediately available strategies to alleviate organ shortages.

RECENT FINDINGS

The once-strict lung donor selection criteria have, of necessity, been relaxed and, in many instances, this situation has been to no apparent detrimental effect on posttransplant outcome. There is, however, some evidence that extension of donor acceptability in some respects leads to poorer early outcomes, mainly by increasing the rate of early graft dysfunction. The extension of selection criteria to allow the maximum number of safe lung transplants, coupled with aggressive and appropriate donor management is, therefore, of particular current relevance to the lung transplantation community.

SUMMARY

Although the available evidence for and against the commonly used lung donor selection criteria leaves many questions unanswered, it can help decrease the large number of uncertainties that be falls the practice of lung donor selection and recipient matching.

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.

Pulmonary infections in transplantation pathology

CONTEXT

Pulmonary infections are common and often life-threatening in solid organ and stem cell transplant recipients. Understanding their pathology is critical to making improvements in care and survival as well as in surgical techniques, immunosuppression management, prophylaxis, and treatment. Pulmonary infections are particularly common and serious in the susceptible population of lung transplant recipients.

OBJECTIVE

To summarize recent updates in the field for opportunistic infections and some common pathogens, and to consider the role of the diagnostic pulmonary histopathologist as well as advances in molecular diagnosis.

DATA SOURCES

This work is based on a selected review of the relevant medical and scientific literature, with emphasis on lung transplantation experience gained during 2 decades of practice.

CONCLUSIONS

Pulmonary infections in transplant recipients present a diagnostic challenge and are a continuing source of mortality and morbidity despite improvement in prophylaxis and treatment. Accurate diagnosis requires multidisciplinary input from clinicians, radiologists, and pathology disciplines as well as complementary molecular methods.

Surgical therapies for pulmonary arterial hypertension

Surgical therapies for the treatment of pulmonary arterial hypertension typically are reserved for patients who are deemed to be refractory to medical therapy and have evidence of progressive right-sided heart failure. Atrial septostomy, a primarily palliative procedure, may stave off hemodynamic collapse from right-sided heart failure long enough to permit a more definitive surgical treatment such as lung or combined heart-lung transplantation. This article discusses indications for and results of atrial septostomy and lung and heart-lung transplantation in patients who have pulmonary arterial hypertension.

Marginal Lung Donors: A Diminishing Margin of Safety?

Lung donor shortages have resulted in the critical appraisal of cadaveric donor acceptability criteria and the gradual relaxation of once strict guidelines. Many centers have reported their results with these "extended criteria" donors and an increasing number of multicenter registry studies have also been published. The results have been contradictory and leave many questions unanswered. Important new data has however come to light since the last review of the subject by the International Society for Heart and Lung Transplantation Pulmonary Council. We review the current literature focusing on recent developments in the pursuit of an expanded lung donor pool with acceptable outcomes.

Ex Vivo Evaluation of Nonacceptable Donor Lungs

BACKGROUND

Only a minority of the potential candidates for lung donation are considered suitable, using current evaluation methods. A new method for ex vivo evaluation, with the potential for reconditioning of marginal and nonacceptable lungs, has been developed. This is a report of the ex vivo evaluation of six donor lungs deemed nonacceptable (arterial oxygen pressure less than 40 kPa) by the Scandiatransplant, Eurotransplant, and UK transplant organizations.

METHODS

The lungs are perfused ex vivo with Steen solution, a lung evaluation-preservation solution, mixed with red blood cells to a hematocrit of 15%. This extracellular solution is designed to have an optimal colloid osmotic pressure so that physiologic pressure and flow can be maintained without development of pulmonary edema. An oxygenator connected to the extracorporeal circuit maintains a normal mixed venous blood gas level in the perfusate. The lungs are ventilated and evaluated through analyses of pulmonary vascular resistance, oxygenation capacity, and arterial carbon dioxide pressure minus end-tidal carbon dioxide difference.

RESULTS

The arterial oxygen pressure (inspired oxygen fraction, 1.0) increased from 27 kPa (range, 17 to 34 kPa) in situ in the organ donor at the referring hospital to 57 kPa (range, 39 to 66 kPa) during the ex vivo evaluation. The pulmonary vascular resistance varied from 3.2 to 5.7 Wood units, and the arterial carbon dioxide pressure minus end-tidal carbon dioxide difference was in the range of 1 to 2.5 kPa.

CONCLUSIONS

The arterial oxygen pressure improves significantly in this model. This ex vivo evaluation model is a valuable addition to the armamentarium in finding acceptable lungs in a donor population with inferior arterial oxygen pressure values.