Outcome of alveolar hemorrhage in hematopoietic stem cell transplant recipients

Epidemiology of Diffuse Alveolar Hemorrhage in Pediatric Allogeneic Hematopoietic Cell Transplantation Recipients

Diffuse alveolar hemorrhage (DAH) is a life-threatening pulmonary toxicity that can arise after hematopoietic cell transplantation (HCT). Risk factors and outcomes are not well understood owing to a sparsity of cases spread across multiple centers. The objectives of this epidemiologic study were to characterize the incidence, outcomes, transplantation-related risk factors and comorbid critical care diagnoses associated with post-HCT DAH. Retrospective analysis was performed in a multicenter cohort of 6995 patients age ≤21 years who underwent allogeneic HCT between 2008 and 2014 identified through the Center for International Blood and Marrow Transplant Research registry and cross-matched with the Virtual Pediatric Systems database to obtain critical care characteristics. A multivariable Cox proportional hazard model was used to determine risk factors for DAH. Logistic regression models were used to determine critical care diagnoses associated with DAH. Survival outcomes were analyzed using both a landmark approach and Cox regression, with DAH as a time-varying covariate. DAH occurred in 81 patients at a median of 54 days post-HCT (interquartile range, 23 to 160 days), with a 1-year post-transplantation cumulative incidence probability of 1.0% (95% confidence interval [CI], .81% to 1.3%) and was noted in 7.6% of all pediatric intensive care unit patients. Risk factors included receipt of transplantation for nonmalignant hematologic disease (reference: malignant hematologic disease; hazard ratio [HR], 1.98; 95% CI, 1.22 to 3.22; P = .006), use of a calcineurin inhibitor (CNI) plus mycophenolate mofetil (MMF) as graft-versus-host disease (GVHD) prophylaxis (referent: CNI plus methotrexate; HR, 1.89; 95% CI, 1.07 to 3.34; P = .029), and grade III-IV acute GVHD (HR, 2.67; 95% CI, 1.53-4.66; P < .001). Critical care admitted patients with DAH had significantly higher rates of systemic hypertension, pulmonary hypertension, pericardial disease, renal failure, and bacterial/viral/fungal infections (P < .05) than those without DAH. From the time of DAH, median survival was 2.2 months, and 1-year overall survival was 26% (95% CI, 17% to 36%). Among all HCT recipients, the development of DAH when considered was associated with a 7-fold increase in unadjusted all-cause post-HCT mortality (HR, 6.96; 95% CI, 5.42 to 8.94; P < .001). In a landmark analysis of patients alive at 2 months post-HCT, patients who developed DAH had a 1-year overall survival of 33% (95% CI, 18% to 49%), compared to 82% (95% CI, 81% to 83%) for patients without DAH (P < .001). Although DAH is rare, it is associated with high mortality in the post-HCT setting. Our data suggest that clinicians should have a heightened index of suspicion of DAH in patients with pulmonary symptoms in the context of nonmalignant hematologic indication for HCT, use of CNI + MMF as GVHD prophylaxis, and severe acute GVHD. Further investigations and validation of modifiable risk factors are warranted given poor outcomes.

Intrapulmonary administration of recombinant activated factor VII in pediatric, adolescent, and young adult oncology and hematopoietic cell transplant patients with pulmonary hemorrhage

Introduction

Diffuse alveolar hemorrhage (DAH) is a devastating disease process with 50-100% mortality in oncology and hematopoietic cell transplant (HCT) recipients. High concentrations of tissue factors have been demonstrated in the alveolar wall in acute respiratory distress syndrome and DAH, along with elevated levels of tissue factor pathway inhibitors. Activated recombinant factor VII (rFVIIa) activates the tissue factor pathway, successfully overcoming the tissue factor pathway inhibitor (TFPI) inhibition of activation of Factor X. Intrapulmonary administration (IP) of rFVIIa in DAH is described in small case series with successful hemostasis and minimal complications.

Methods

We completed a single center retrospective descriptive study of treatment with rFVIIa and outcomes in pediatric oncology and HCT patients with pulmonary hemorrhage at a quaternary hematology/oncology hospital between 2011 and 2019. We aimed to assess the safety and survival of patients with pulmonary hemorrhage who received of IP rFVIIa.

Results

We identified 31 patients with pulmonary hemorrhage requiring ICU care. Thirteen patients received intrapulmonary rFVIIa, while eighteen patients did not. Overall, 13 of 31 patients (41.9%) survived ICU discharge. ICU survival (n=6) amongst those in the IP rFVIIa group was 46.2% compared to 38.9% (n=7) in those who did not receive IP therapy (p=0.69). Hospital survival was 46.2% in the IP group and 27.8% in the non-IP group (p=0.45). There were no adverse events noted from use of IP FVIIa.

Conclusions

Intrapulmonary rFVIIa can be safely administered in pediatric oncology patients with pulmonary hemorrhage and should be considered a viable treatment option for these patients.

Pulmonary Hemorrhage in Pediatric Hematopoietic Stem Cell Transplant Recipients: A Single-Center Retrospective Study

OBJECTIVES

Pulmonary hemorrhage (PH) is a serious complication posthematopoietic stem cell transplant (HSCT). In view of limited available pediatric data, we performed a retrospective study to describe epidemiology, management, and outcomes of PH post-HSCT in children in our national center.

DESIGN

Retrospective study.

SETTING

Academic children's hospital (2000-2015).

SUBJECTS

Children (< 18 yr) with PH and requiring PICU care post-HSCT.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The historical prevalence of PH in our center was 2.7% (31/1,148). Twenty patients had a concomitant infection, 15 had bacterial infection, 8 had viral infection, and 3 patients had a fungal infection. With a median follow-up time of 60 months, 7 of 31 patients were alive. Early PH (< 40 d post-HSCT) was associated with improved survival (6/15 vs 1/16, p = 0.035). Patients who received high-dose pulsed corticosteroid had improved survival when compared with those who did not (7/22 vs 0/9, p = 0.0012); this also applied to the subgroup of patients with a concomitant infection (5/15 vs 0, p = 0.001). None of the patients who survived had measurable respiratory sequelae.

CONCLUSIONS

PH is a rare but serious complication after HSCT. Corticosteroids were associated with improved survival even in patients with a concomitant infection.

Diffuse Alveolar Hemorrhage in Hematopoietic Cell Transplantation

Diffuse alveolar hemorrhage (DAH) is a morbid syndrome that occurs after autologous and allogeneic hematopoietic cell transplantation in children and adults. DAH manifests most often in the first few weeks following transplantation. It presents with pneumonia-like symptoms and acute respiratory failure, often requiring high levels of oxygen supplementation or mechanical ventilatory support. Hemoptysis is variably present. Chest radiographs typically feature widespread alveolar filling, sometimes with peripheral sparing and pleural effusions. The diagnosis is suspected when serial bronchoalveolar lavages return increasingly bloody fluid. DAH is differentiated from infectious causes of alveolar hemorrhage when extensive microbiological testing reveals no pulmonary pathogens. The cause is poorly understood, though preclinical and clinical studies implicate pretransplant conditioning regimens, particularly those using high doses of total-body-irradiation, acute graft-versus-host disease (GVHD), medications used to prevent GVHD, and other factors. Treatment consists of supportive care, systemic corticosteroids, platelet transfusions, and sometimes includes antifibrinolytic drugs and topical procoagulant factors. Therapeutic blockade of tumor necrosis factor-α showed promise in observational studies, but its benefit for DAH remains uncertain after small clinical trials. Even with these treatments, mortality from progression and relapse is high. Future investigational therapies could target the vascular endothelial cell biology theorized to contribute to alveolar bleeding and pathways that contribute to susceptibility, inflammation, cellular resilience, and tissue repair. This review will help clinicians navigate through the limited evidence to diagnose and treat DAH, counsel patients and families, and plan for future research.

Management of diffuse alveolar hemorrhage in the hematopoietic stem cell transplantation population: A systematic review

Pulmonary complications post-hematopoietic stem cell transplantation (HSCT) such as diffuse alveolar hemorrhage (DAH) can occur in 2% to 14% of HSCT patients and have a mortality greater than 80%. Diffuse alveolar hemorrhage is considered to be an inflammatory response; therefore, HSCT patients are primarily treated with different types of systemic corticosteroids with varying dosages. Other treatments currently reported in the literature in conjunction with corticosteroids include aminocaproic acid, recombinant factor VIIa (rFVIIa), and etanercept. This review highlights appropriate frontline and adjunctive treatment options for HSCT patients with DAH and outcomes for each intervention. To perform the review, the PubMed database was searched from inception through March 19, 2021, to identify potential studies using the search terms DAH and HSCT, DAH and hematopoietic cell transplant (HCT), DAH and stem cell, lung injury and HSCT, and lung injury and HCT. When applicable, references from articles identified in the search were also reviewed for inclusion. Much of the data identified were limited to retrospective cohort studies and case series. Based on the data available, the treatment approach should consist of corticosteroid therapy with a suggested methylprednisolone dose of 250 mg daily followed by a 50% taper every 3 days. Intrapulmonary administration of rFVIIa and intravenous administration of aminocaproic acid could be considered as adjunctive agents in those patients who do not promptly respond to corticosteroid therapy. Due to a lack of data specific to HSCT patients who develop DAH and the risk of infectious complications, etanercept should be avoided. Future studies should be designed as randomized controlled trials and examine the use of adjunctive therapies in the upfront setting for HSCT patients with DAH.

Pulmonary Complications in Hematopoietic Stem Cell Transplant Recipients-A Clinician Primer

Hematopoietic stem cell transplants (HSCT) are becoming more widespread as a result of optimization of conditioning regimens and prevention of short-term complications with prophylactic antibiotics and antifungals. However, pulmonary complications post-HSCT remain a leading cause of morbidity and mortality and are a challenge to clinicians in both diagnosis and treatment. This comprehensive review provides a primer for non-pulmonary healthcare providers, synthesizing the current evidence behind common infectious and non-infectious post-transplant pulmonary complications based on time (peri-engraftment, early post-transplantation, and late post-transplantation). Utilizing the combination of timing of presentation, clinical symptoms, histopathology, and radiographic findings should increase rates of early diagnosis, treatment, and prognostication of these severe illness states.

Treatment of Diffuse Alveolar Hemorrhage: Controlling Inflammation and Obtaining Rapid and Effective Hemostasis

Diffuse alveolar hemorrhage (DAH) is a life-threatening pulmonary complication in patients with hematologic malignancies or systemic autoimmune disorders. Pathologic findings show pulmonary capillaritis, bland hemorrhage, diffuse alveolar damage, and hemosiderin-laden macrophages, but in the majority of cases, pathogenesis remains unclear. Despite the severity and high mortality, the current treatment options for DAH remain empirical. Systemic treatment to control inflammatory activity including high-dose corticosteroids, cyclophosphamide, and rituximab and supportive care have been applied, but largely unsuccessful in critical cases. Activated recombinant factor VII (FVIIa) can achieve rapid local hemostasis and has been administered either systemically or intrapulmonary for the treatment of DAH. However, there is no randomized controlled study to evaluate the efficacy and safety, and the use of FVIIa for DAH remains open to debate. This review discusses the pathogenesis, diverse etiologies causing DAH, diagnosis, and treatments focusing on hemostasis using FVIIa. In addition, the risks and benefits of the off-label use of FVIIa in pediatric patients will be discussed in detail.

Epidemiology, Risk Factors, and Outcomes of Diffuse Alveolar Hemorrhage After Hematopoietic Stem Cell Transplantation

BACKGROUND

Diffuse alveolar hemorrhage (DAH) is an uncommon complication of hematopoietic stem cell transplantation (HCT) that carries high morbidity and mortality. Limited contemporary data are available regarding the incidence, outcomes, and risk factors for DAH.

RESEARCH QUESTION

What are the incidence, outcomes, and risk factors for DAH developing after HCT?

METHODS

This was a single-center retrospective cohort study of patients who underwent HCT between January 1, 2005, and December 31, 2016. The incidence and outcomes of DAH development were evaluated. A multivariate logistic regression model was used to analyze differences between survivors and nonsurvivors.

RESULTS

Of 4,350 patients undergoing first-time HCT, DAH was diagnosed in 99 (2.3%). DAH was seen in 40 of 3,536 autologous HCT recipients (1.1%) and 59 of 814 allogeneic HCT recipients (7.2%). Mean age was 53 ± 13 years, and median time of DAH diagnosis was 126 days (interquartile range, 19-349 days) after HCT. In-hospital mortality and mortality 1 year after DAH diagnosis were 55.6% and 76.8%, respectively. DAH diagnosis more than 30 days after transplantation (OR, 7.06; 95% CI, 1.65-30.14), low platelet count (OR, 0.98; 95% CI, 0.96-1.0; P = .02), elevated international normalized ratio (INR; OR, 4.08; 95% CI, 0.64-25.88; P = .046) and need for invasive mechanical ventilation (OR, 8.18; 95% CI, 1.9-35.21) were associated with higher in-hospital mortality. Steroid treatment did not alter mortality (P = .80) or length of stay (P = .65). However, among those who received steroids, survival was higher in whose who received modest-dose steroids (< 250 mg methylprednisolone equivalent/d) compared with those who received high-dose steroids (≥ 250 mg methylprednisolone equivalent/d; OR, 0.21; 95% CI, 0.07-0.72).

INTERPRETATION

The mortality of DAH after HCT remains high, and DAH can occur long after transplantation. Later development of DAH (>30 days after HCT), need for invasive mechanical ventilation, thrombocytopenia, and elevated INR are all associated with worse outcomes.

Critical Care of Hematopoietic Stem Cell Transplant Patients

Life-threatening complications are frequent after hematopoietic stem cell transplant (HSCT), and optimum critical care is essential to ensuring good outcomes. The immunologic consequences of HSCT result in a markedly different host response to critical illness. Infection is the most common cause of critical illness but noninfectious complications are frequent. Respiratory failure or sepsis are the typical presentations but the sequelae of HSCT can affect nearly any organ system. Pattern recognition can facilitate anticipation and early intervention in post-HSCT critical illness. HSCT critical care is a multidisciplinary endeavor. Continued investigation and focus on process improvement will continue to improve outcomes.

Diffuse Alveolar Hemorrhage After Pediatric Hematopoietic Stem Cell Transplantation

Pulmonary complications are common following hematopoietic cell transplantation (HCT) and contribute significantly to its morbidity and mortality. Diffuse alveolar hemorrhage is a devastating non-infectious complication that occurs in up to 5% of patients post-HCT. Historically, it carries a high mortality burden of 60–100%. The etiology remains ill-defined but is thought to be due to lung injury from conditioning regimens, total body irradiation, occult infections, and other comorbidities such as graft vs. host disease, thrombotic microangiopathy, and subsequent cytokine release and inflammation. Clinically, patients present with hypoxemia, dyspnea, and diffuse opacities consistent with an alveolar disease process on chest radiography. Diagnosis is most commonly confirmed with bronchoscopy findings of progressively bloodier bronchoalveolar lavage or the presence of hemosiderin-laden macrophages on microscopy. Treatment with glucocorticoids is common though dosing and duration of therapy remains variable. Other agents, such as aminocaproic acid, tranexamic acid, and activated recombinant factor VIIa have also been tried with mixed results. We present a review of diffuse alveolar hemorrhage with a focus on its pathogenesis and treatment options.

Use of intrapulmonary administration of thrombin in hematological malignancy patients with alveolar haemorrhage: A case series

INTRODUCTION

Alveolar hemorrhage (AH) is characterized by the acute onset of alveolar bleeding and hypoxemia and can be fatal. Thrombin has been widely used to achieve coagulation and hemostasis. However, the efficacy of thrombin in patients with AH is unclear. Thus, this study aimed to evaluate the efficacy of thrombin administration in patients with hematological malignancy and AH.

PATIENT CONCERNS AND DIAGNOSES

This retrospective study included 15 hematological malignancy patients (8 men and 7 women; mean age 47.7 ± 17.3 years) with AH who were administered intrapulmonary thrombin between March 2013 and July 2018.

INTERVENTIONS AND OUTCOMES

All patients received bovine-origin thrombin (1000 IU/ml, Reyon Pharmaceutical Co., Ltd., Seoul, Korea) via a fiberoptic bronchoscope. A maximum of 15 ml of thrombin was injected via the working channel to control bleeding. The ability of thrombin to control bleeding was assessed. Additionally, the change in the PaO2/FiO2 (PF) ratio after intrapulmonary thrombin administration was evaluated. Intrapulmonary thrombin was administered a minimum of 3 days after starting mechanical ventilation in all patients, and it immediately controlled the active bleeding in 13 of 15 patients (86.7%). However, AH relapse was noted in 3 of the 13 patients (23.1%). The PF ratio improved in 10 of 15 patients (66.6%), and the mean PF ratio was significantly higher after thrombin administration than before administration (P = .03). No adverse thromboembolic complications or systemic adverse events were observed.

CONCLUSION

Thrombin administration was effective in controlling bleeding in hematological malignancy patients with AH. Intrapulmonary thrombin administration might be a good therapeutic option for treating AH.

ICU Complications of Hematopoietic Stem Cell Transplant, Including Graft vs Host Disease

Hematopoietic stem cell transplant (HSCT) is an essential treatment modality for many malignant and non-malignant hematologic diseases. Advances in HSCT techniques have dramatically decreased peri-transplant morbidity and mortality, but it remains a high-risk procedure, and a significant number of patients will require critical care during the transplant process. Complications of HSCT are both infectious and non-infectious, and the intensivist must be familiar with common infections, the management of neutropenic sepsis and septic shock, the management of respiratory failure in the immunocompromised host, and a plethora of HSCT-specific complications. Survival from critical illness after HSCT is improving, but the mortality rate remains unacceptably high. Continued research and optimization of critical care provision in this population should continue to improve outcomes.

Diffuse alveolar hemorrhage is most often fatal and is affected by graft source, conditioning regimen toxicity, and engraftment kinetics

Diffuse alveolar hemorrhage after hematopoietic stem cell transplantation is a frequently fatal complication with no standard therapy. Although significant changes in supportive and intensive care measures for patients undergoing hematopoietic stem cell transplantation have been made over the past decades, the impact of these changes on the incidence and outcome of patients with diffuse alveolar hemorrhage has not been examined. We analyzed 1228 patients who underwent allogeneic hematopoietic stem cell transplantation between 2008-2015 at the University of Minnesota to study the incidence, risk factors, and outcomes of diffuse alveolar hemorrhage. Diffuse alveolar hemorrhage developed in 5% of allogeneic hematopoietic stem cell transplant recipients, at a median of 30 days (range +3 to +168 days) after transplantation. The incidence of diffuse alveolar hemorrhage was significantly greater in recipients of umbilical cord blood than peripheral blood or bone marrow grafts (HR: 2.08, 95% CI: 1.16-3.74; P=0.01). In multivariate analysis, delayed neutrophil engraftment or primary graft failure was a risk factor for diffuse alveolar hemorrhage following peripheral blood or bone marrow hematopoietic stem cell transplants (HR: 5.51, 95% CI: 1.26-24; P=0.02) and delayed platelet engraftment was associated with significantly increased diffuse alveolar hemorrhage in umbilical cord blood transplant recipients (HR: 6.96, 95% CI: 2.39-20.29; P<0.05). Myeloablative regimens including total body irradiation were also risk factors for diffuse alveolar hemorrhage (HR: 1.8, 95% CI: 1.03-3.13, P=0.05) in both peripheral blood or bone marrow and umbilical cord blood hematopoietic stem cell transplants (HR: 1.87, 95% CI: 0.95-3.71). Patients with diffuse alveolar hemorrhage had an inferior 6-month treatment-related mortality (HR: 6.09, 95% CI: 4.33-8.56, P<0.01) and 2-year overall survival (HR: 4.16, 95% CI: 3.06-5.64; P<0.01) using either graft source. The etiology of diffuse alveolar hemorrhage is multifactorial, involving lung injury influenced by high-dose total body irradiation, graft source, and delayed engraftment or graft failure. The survival of patients with diffuse alveolar hemorrhage after hematopoietic stem cell transplantation remains poor. Clinical interventions or experimental studies (e.g., cell expansion for umbilical cord blood transplants or thrombopoietin use) that modulate these risk factors may limit the incidence and improve the outcomes of diffuse alveolar hemorrhage.

Pneumonia After Hematopoietic Stem Cell Transplantation

Pneumonia is the main cause of morbidity and mortality after hematopoietic stem cell transplantation. Two thirds of pneumonias observed after both autologous and allogeneic stem cell transplantations are of infectious origin, and coinfections are frequent. One third is due to noninfectious process, such as alveolar hemorrhage, alveolar proteinosis, or alloimmune pulmonary complications such as bronchiolitis obliterans or idiopathic interstitial pneumonitis. Most of these noninfectious complications may require treatment with corticosteroids which may be deleterious in infection. On the other hand, these complications either mimic or may be complicated with infections. Therefore, a precise diagnosis of pneumonia is of crucial importance to decide of the optimal treatment. CT scan is the best procedure for imaging of the lung. Although several indirect biomarkers, such as serum or plasma galactomannan or (1-3) β(beta)-G-glucan, can help in the etiological diagnosis, only direct invasive investigations provide the best chance to identify the cause(s) of pneumonia. Bronchoalveolar lavage (BAL) under fiberoptic bronchoscopy is the procedure of choice to identify the cause of pulmonary infection. It is safe and reproducible, and its diagnostic yield is around 50 % if the BAL fluid is processed at the laboratory according to a prespecified protocol established between the transplanter, the infectious diseases’ specialist, the pneumologist, and the laboratory, allowing the identification of the most likely hypotheses. Transbronchial biopsy does not provide significant additional information to BAL in most cases and more often complicates with bleeding and pneumothorax. In case of a noncontributory BAL, the decision to proceed to a second BAL, a transthoracic biopsy, or a surgical biopsy should be cautiously weighted in a multidisciplinary approach in regard to the benefits and risks of invasive procedures versus empirical treatment.

Noninfectious Generalized Bronchiolitis in the Setting of Allogeneic Stem Cell Transplantation: A Potential Mimic of Lower Respiratory Tract Infection

RATIONALE AND OBJECTIVES

To describe a little-known therapy-related small-airway phenomenon presumably caused by mucosal irritation in patients undergoing allogeneic stem cell transplantation (allo-SCT).

MATERIALS AND METHODS

Retrospective database search at our institution identified 739 hematologic patients who underwent chemotherapy + allo-SCT between September 2004 and March 2014. After infectious pulmonary complications were excluded, 75 patients (female = 24; male = 51; median age = 47 years) with signs of generalized bronchiolitis (GB) on chest high-resolution computed tomography were identified. Computed tomography (CT) was performed proximate to chemotherapy onset; 92% had follow-up CT (mean, 1.9 weeks). The presence of centrilobular nodules, bronchial wall thickening (BWT), tree-in-bud (distributed diffuse vs. focal), ground-glass opacity, airspace opacification, luminal impactions, and air trapping was correlated with occurrence and duration of oral mucositis and therapy characteristics. Intensity of tree-in-bud and centrilobular nodules was graded absent (grade = 0), moderate (grade = 1), or marked (grade = 2).

RESULTS

Overall incidence of GB among allo-SCT patients was 10.14%. GB was diagnosed at the time point of transplantation with a mean duration of CT findings of 4 weeks (±2.7). Tree-in-bud (17% [grade 2] and 83% [grade 1]) and BWT were present in 100% of the patients. Centrilobular nodules diffusely distributed were found in 45.5% of patients (20% [grade 2], 24% [grade 1], and 56% [none]). Air trapping and mosaic pattern were found in 13% and 16% of the patients, respectively. Resolution of GB was spontaneous. GB and its severity correlated with the temporal course and grade of oral mucositis; frequency and degree were not significantly influenced by the chemotherapy regimen. The incidence of GB in high-resolution computed tomography was statistically and significantly higher in patients with oral mucositis (P < 0.035).

CONCLUSIONS

GB is frequent during chemotherapy for allo-SCT and is characterized by an even distribution of tree-in-bud, BWT, centrilobular nodules, mild clinical symptoms, and spontaneous resolution.

Bronchoalveolar lavage and lung biopsy in patients with cancer and hematopoietic stem-cell transplantation recipients: a systematic review and meta-analysis

PURPOSE

The objective of this study was to describe the diagnostic yield and complication rate of bronchoalveolar lavage (BAL) and lung biopsy in the evaluation of pulmonary lesions in patients with cancer and recipients of hematopoietic stem-cell transplantation (HSCT).

METHODS

We conducted a systematic literature review and performed electronic searches of Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials. Studies were included if patients had cancer or were recipients of HSCT, and if they underwent BAL or lung biopsy for the evaluation of pulmonary lesions. Only English language publications were included.

RESULTS

In all, 14,148 studies were screened; 72 studies of BAL and 31 of lung biopsy were included. The proportion of procedures leading to any diagnosis was similar by procedure type (0.53 v 0.54; P = .94) but an infectious diagnosis was more common with BAL compared with lung biopsy (0.49 v 0.34; P < .001). Lung biopsy more commonly led to a noninfectious diagnosis (0.43 v 0.07; P < .001) and was more likely to change how the patient was managed (0.48 v 0.31; P = .002) compared with BAL. However, complications were more common with lung biopsy (0.15 v 0.08; P = .006), and procedure-related mortality was four-fold higher for lung biopsy (0.0078) compared with BAL (0.0018).

CONCLUSION

BAL may be the preferred diagnostic modality for the evaluation of potentially infectious pulmonary lesions because of lower complication and mortality rates; thus, choice of procedure depends on clinical suspicion of infection. Guidelines to promote consistency in the approach to the evaluation of lung infiltrates may improve clinical care of patients.

Diffuse pulmonary hemorrhage: clues to the diagnosis

Diffuse pulmonary hemorrhage (DPH) refers to an uncommon but significant condition of bleeding into the alveolar space. Anemia and hemoptysis are important clinical features, but they may be absent. Although the radiographic and computed tomography findings are often varied and nonspecific, the imaging manifestations of pulmonary hemorrhage and the associated findings in the thorax often provide important diagnostic information that may lead to a specific diagnosis. DPH significantly influences patient management and has important prognostic implications. This review article explores the imaging findings in DPH and its differential diagnosis, highlighting important clues to this diagnosis and to its underlying etiology. DPH is an uncommon condition characterized by bleeding into the alveolar space that, when recognized on imaging, provides important diagnostic and prognostic information.

Low-, medium- and high-dose steroids with or without aminocaproic acid in adult hematopoietic SCT patients with diffuse alveolar hemorrhage

Diffuse alveolar hemorrhage (DAH) is a poorly understood complication of transplantation carrying a high mortality. Patients commonly deteriorate and require intensive care unit (ICU) admission. Treatment with high-dose steroids and aminocaproic acid (ACA) has been suggested. The current study examined 119 critically ill adult hematopoietic transplant patients treated for DAH. Patients were subdivided into low-, medium- and high-dose steroid groups with or without ACA. All groups had similar baseline characteristics and severity of illness scores. Primary objectives were 30, 60, 100 day, ICU and hospital mortality. Overall mortality (n=119) on day 100 was high at 85%. In the steroids and ACA cohort (n=82), there were no significant differences in 30, 60, 100, day, ICU and hospital mortality between the dosing groups. In the steroids only cohort (n=37), the low-dose steroid group had a lower ICU and hospital mortality (P=0.02). Adjunctive treatment with ACA did not produce differences in outcomes. In the multivariate analysis, medium- and high-dose steroids were associated with a higher ICU mortality (P=0.01) as compared with the low-dose group. Our data suggest that treatment strategies may need to be reanalyzed to avoid potentially unnecessary and potentially harmful therapies.

Infections Caused by Stenotrophomonas maltophilia in Recipients of Hematopoietic Stem Cell Transplantation

Stenotrophomonas maltophilia (S. maltophilia) is a globally emerging Gram-negative bacillus that is widely spread in environment and hospital equipment. Recently, the incidence of infections caused by this organism has increased, particularly in patients with hematological malignancy and in recipients of hematopoietic stem cell transplantation (HSCT) having neutropenia, mucositis, diarrhea, central venous catheters or graft versus host disease and receiving intensive cytotoxic chemotherapy, immunosuppressive therapy, or broad-spectrum antibiotics. The spectrum of infections in HSCT recipients includes pneumonia, urinary tract and surgical site infection, peritonitis, bacteremia, septic shock, and infection of indwelling medical devices. The organism exhibits intrinsic resistance to many classes of antibiotics including carbapenems, aminoglycosides, most of the third-generation cephalosporins, and other β-lactams. Despite the increasingly reported drug resistance, trimethoprim-sulfamethoxazole is still the drug of choice. However, the organism is still susceptible to ticarcillin-clavulanic acid, tigecycline, fluoroquinolones, polymyxin-B, and rifampicin. Genetic factors play a significant role not only in evolution of drug resistance but also in virulence of the organism. The outcome of patients having S. maltophilia infections can be improved by: using various combinations of novel therapeutic agents and aerosolized aminoglycosides or colistin, prompt administration of in vitro active antibiotics, removal of possible sources of infection such as infected indwelling intravascular catheters, and application of strict infection control measures.

Recombinant human factor VIIa for alveolar hemorrhage following allogeneic stem cell transplantation

The mortality rate of alveolar hemorrhage (AH) after allogeneic hematopoietic stem cell transplantation is greater than 60% with supportive care and high-dose steroid therapy. We performed a retrospective cohort analysis to assess the benefits and risks of recombinant human factor VIIa (rFVIIa) as a therapeutic adjunct for AH. Between 2005 and 2012, 57 episodes of AH occurred in 37 patients. Fourteen episodes (in 14 patients) were treated with steroids alone, and 43 episodes (in 23 patients) were treated with steroids and rFVIIa. The median steroid dose was 1.9 mg/kg/d (interquartile range [IQR], 0.8 to 3.5 mg/kg/d; methylprednisolone equivalents) and did not differ statistically between the 2 groups. The median rFVIIa dose was 41 μg/kg (IQR, 39 to 62 μg/kg), and a median of 3 doses (IQR, 2 to 17) was administered per episode. Concurrent infection was diagnosed in 65% of the episodes. Patients had moderately severe hypoxia (median PaO2/FiO2, 193 [IQR, 141 to 262]); 72% required mechanical ventilation, and 42% survived to extubation. The addition of rFVIIa did not alter time to resolution of AH (P = .50), duration of mechanical ventilation (P = .89), duration of oxygen supplementation (P = .55), or hospital mortality (P = .27). Four possible thrombotic events (9% of 43 episodes) occurred with rFVIIa. rFVIIa in combination with corticosteroids did not confer clear clinical advantages compared with corticosteroids alone. In patients with AH following hematopoietic stem cell transplantation, clinical factors (ie, worsening infection, multiple organ failure, or recrudescence of primary disease) may be more important than the benefit of enhanced hemostasis from rFVIIa.

An update on pulmonary complications of hematopoietic stem cell transplantation

The indications for hematopoietic stem cell transplantation (HSCT) continue to expand. However, the risk for pulmonary complications post-HSCT continues to be high. Early recognition and treatment of pulmonary complications may improve outcomes. This is an overview of diagnosis, manifestations, and treatment of the most common infectious and noninfectious pulmonary complications post-HSCT. Knowing the patient's timeframe post-HSCT (preengraftment, postengraftment, late), type of HSCT (allogeneic vs autologous), radiographic findings, and clinical presentation can help to differentiate between the many pulmonary complications. This article will also address pretransplantation evaluation and infectious and noninfectious complications in the patient post-HSCT. While mortality post-HSCT continues to improve, respiratory failure continues to be the leading cause of ICU admissions for patients who have undergone HSCT. Mechanical ventilation is a predictor of poor outcomes in these patients, and further research is needed regarding their critical care management, treatment options for noninfectious pulmonary complications, and mortality prediction models posttransplantation.

Diffuse alveolar hemorrhage in patients with hematological malignancies: HRCT patterns of pulmonary involvement and disease course

OBJECTIVE

To analyze high-resolution computed tomography (HRCT) patterns of lung involvement and disease course in patients with hematological malignancies experiencing diffuse alveolar hemorrhage (DAH) after chemotherapy ± allogeneic stem cell transplantation (allo-SCT).

MATERIALS AND METHODS

Sixteen patients experiencing DAH after chemotherapy ± allo-SCT were enrolled. A total of 74 computed tomography (CT) scans obtained before, during, and after onset of DAH were evaluated retrospectively.

RESULTS

CT features of DAH are each, by oneself, nonspecific. However, conjoint bilateral, diffuse, and dependent ground glass opacity ± crazy paving, accompanied by airspace bronchograms, should suggest this complication. The HRCT course comprises a wide range of trends that are not predictive for patient's outcome, but progression of parenchymal consolidations at follow up was more often detrimental.

High-dose cyclophosphamide therapy associated with diffuse alveolar hemorrhage after allogeneic hematopoietic stem cell transplantation

BACKGROUND

The occurrence of diffuse alveolar hemorrhage (DAH) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rare but severe. There are few reports that have examined the correlation between pre-HSCT chemotherapeutic exposure and DAH.

OBJECTIVES

We examine the role of pre-HSCT chemotherapeutic exposure, conditioning regimens, pre-HSCT comorbidities and transplant-related complications in the development of DAH after allo-HSCT and evaluate the effect of the high-dose corticosteroid strategy on DAH.

METHODS

A retrospective nested case-control study was designed. Cases with DAH and controls matched for year of allo-HSCT and length of follow-up were identified from a cohort of 597 patients who underwent allo-HSCT between 2006 and 2011 for acute leukemia.

RESULTS

Twenty-two patients suffered from DAH; the mean age at the time of presentation was 30.4 years (±12.9) and the mean time to presentation was 7.8 months (±8.1) post-HSCT. The pre-HSCT cyclophosphamide exposure and the cumulative cyclophosphamide dose were significantly higher among the DAH cases compared with the controls, and the cumulative cyclophosphamide dose of ≥5 g/m(2) was independently associated with DAH (OR = 3.4, p = 0.030). High-dose corticosteroid treatment did not significantly improve survival.

CONCLUSIONS

From these results we can identify patients who are at a higher risk of developing DAH after allo-HSCT, and we found that high-dose corticosteroid therapy may not alter the poor outcome associated with this syndrome.

Platelets in pulmonary vascular physiology and pathology

Almost a trillion platelets pass through the pulmonary circulation every minute, yet little is known about how they support pulmonary physiology or contribute to the pathogenesis of lung diseases. When considering this conundrum, three questions jump out: Does platelet production in the lungs occur? Why does severe thrombocytopenia—which undercuts the principal physiological role of platelets to effect hemostasis—not lead to pulmonary hemorrhage? Why does atherothrombosis—which platelets initiate, maintain, and trigger is other critically important arterial beds—not develop in the pulmonary artery? The purpose of this review is to explore these and derivative questions by providing data within a conceptual framework that begins to organize a subject that is largely unassembled.

Stenotrophomonas maltophilia infection in hematopoietic SCT recipients: high mortality due to pulmonary hemorrhage

To clarify the clinical features and outcome of Stenotrophomonas maltophilia infection among hematopoietic SCT (HCT) recipients, we retrospectively reviewed the records of 1085 consecutive HCT recipients and identified 42 episodes in 31 HCT recipients with S. maltophilia infection. We compared these recipients with 30 non-HCT patients with S. maltophilia infection. The mortality rate in HCT recipients was significantly higher than that in non-HCT patients (relative risk 5.7, P=0.04), and we identified seven patients with pulmonary hemorrhage due to S. maltophilia, exclusively in the HCT cohort. Six of these latter seven patients died within 1 day from the onset of hemorrhage and the isolate was identified after death in most cases; one patient, who received empiric therapy for S. maltophilia and granulocyte transfusion, survived for more than 2 weeks. The patients with pulmonary hemorrhage had a more severe and longer duration of neutropenia, persistent fever despite of the use of broad-spectrum antibiotics, complication by pneumonia and higher C-reactive protein levels than those without pulmonary hemorrhage. In conclusion, S. maltophilia was associated with fulminant and fatal pulmonary hemorrhage in HCT recipients. Empiric therapy with antibiotics before the onset of pulmonary hemorrhage may be effective in HCT recipients who carry the conditions identified.

Utility of early versus late fiberoptic bronchoscopy in the evaluation of new pulmonary infiltrates following hematopoietic stem cell transplantation

Pulmonary infiltrates frequently complicate hematopoietic SCT (HSCT). The utility of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) in the evaluation of new pulmonary infiltrates, particularly as it relates to optimal timing of the procedure, is unclear. Based on this, we retrospectively reviewed 501 consecutive, adult, nonintubated patients who underwent 598 BALs for evaluation of new pulmonary infiltrates during the first 100 days following HSCT to determine whether diagnostic yields for infection, subsequent antimicrobial treatment modifications and patient outcomes differed following early vs late referrals for the procedure. The overall yield of BAL for clinically significant pathogens was 55%. Notably, the yield was 2.5-fold higher among FOBs performed within the first 4 days of presentation (early FOB) compared to those performed late, and highest (75%) when performed within 24 h of clinical presentation. Rates of FOB-guided adjustments in antimicrobial therapy (51%) did not differ significantly between early and late examinations. However, late FOB-related antibiotic adjustments were associated with 30-day pulmonary-associated deaths that were threefold higher (6 vs 18%, P=0.0351). Major FOB-related complications occurred in only three (0.6%) patients. We conclude that early referral for FOB in this patient setting is associated with higher diagnostic yields and may favorably impact survival.

Severe respiratory failure due to diffuse alveolar hemorrhage: clinical characteristics and outcome of intensive care

BACKGROUND

The aim of this study was to characterize patients and report outcome of diffuse alveolar hemorrhage (DAH) requiring intensive care unit support.

PATIENTS AND METHODS

Thirty-seven patients were identified. Clinical characteristics and outcome were determined by chart review.

RESULTS

Eighty-nine percent of patients presented with shortness of breath, 23% with cough, and 3% with hemoptysis. In 9% of patients, a diagnosis of DAH was suspected on admission. Diagnosis was confirmed by finding a progressively hemorrhagic bronchoalveolar lavage fluid in 89% and by a positive iron stain in 11% of patients. Vasculitis was causative in 19%, drug toxicity in 11%, thrombocytopenia in 27%, stem-cell transplantation in 5%, sepsis-associated lung injury in 22%, and unknown mechanisms in 16%. Thirty-two patients were mechanically ventilated, 4 received noninvasive ventilation, and 1 received supplemental oxygen therapy. Overall, 18 (49%) of 37 patients survived the intensive care unit stay. Survival was markedly different between patients with an immunologic/unknown etiology (82%) and patients with thrombocytopenia and/or sepsis (22%).

DISCUSSION

Diffuse alveolar hemorrhage should be considered in all patients with persistent pulmonary infiltrates. Both bronchoalveolar lavage fluid and iron stain are mandatory diagnostic means. Patients with an immunologic/idiopathic pathogenetic mechanism have a relatively good prognosis, whereas the outcome in individuals with DAH secondary to cancer therapy or sepsis is poor.