Dual Oxygenation in the Treatment of Hypoxemic Respiratory Failure: A Retrospective Cohort Study.

BACKGROUND: At the beginning of the coronavirus disease 2019 (COVID-19) pandemic, many patients presented with acute hypoxemic respiratory failure, requiring ventilatory support. One treatment method was the addition of a reservoir mask to a high flow nasal cannula (HFNC) (dual oxygenation). OBJECTIVES: To evaluate the clinical outcomes of combining reservoir mask on top of a high-flow nasal cannula. METHODS: A retrospective cohort of adult patients who were admitted due to COVID-19 during the first year of the pandemic to Rambam Health Care Campus. The primary endpoint was 30-day mortality. Secondary endpoints were incidence of invasive positive pressure ventilation initiation and admission to the intensive care unit (ICU). Patients who received positive pressure ventilation for reasons other than hypoxemic respiratory failure or who were transferred to another facility while still on HFNC were excluded. RESULTS: The final analysis included 333 patients; 166 were treated with dual oxygenation and 167 with HFNC only (controls). No significant differences in baseline characteristics were noted between the groups. The dual oxygenation group was slightly older (69.2 ± 14.8 years vs. 65.6 ± 15.5 years, P = 0.034). The 30-day mortality (24.1% vs. 36.5%, P = 0.013), rates of invasive positive pressure ventilation (47% vs. 59.3%, P = 0.024), and ICU admissions (41.6% vs. 52.7%, P = 0.042) were all significantly lower in the dual oxygenation group. CONCLUSIONS: The addition of reservoir masks to HFNC may improve the oxygenation and overall prognosis in patients with severe hypoxemia due to COVID-19.

Chronic lung allograft dysfunction phenotype and prognosis by machine learning CT analysis.

BACKGROUND: Chronic lung allograft dysfunction (CLAD) is the principal cause of graft failure in lung transplant recipients and prognosis depends on CLAD phenotype. We used a machine learning computed tomography (CT) lung texture analysis tool at CLAD diagnosis for phenotyping and prognostication compared with radiologist scoring. METHODS: This retrospective study included all adult first double lung transplant patients (January 2010-December 2015) with CLAD (censored December 2019) and inspiratory CT near CLAD diagnosis. The machine learning tool quantified ground-glass opacity, reticulation, hyperlucent lung and pulmonary vessel volume (PVV). Two radiologists scored for ground-glass opacity, reticulation, consolidation, pleural effusion, air trapping and bronchiectasis. Receiver operating characteristic curve analysis was used to evaluate the diagnostic performance of machine learning and radiologist for CLAD phenotype. Multivariable Cox proportional hazards regression analysis for allograft survival controlled for age, sex, native lung disease, cytomegalovirus serostatus and CLAD phenotype. RESULTS: 88 patients were included (57 bronchiolitis obliterans syndrome (BOS), 20 restrictive allograft syndrome (RAS)/mixed and 11 unclassified/undefined) with CT a median 9.5 days from CLAD onset. Radiologist and machine learning parameters phenotyped RAS/mixed with PVV as the strongest indicator (area under the curve (AUC) 0.85). Machine learning hyperlucent lung phenotyped BOS using only inspiratory CT (AUC 0.76). Radiologist and machine learning parameters predicted graft failure in the multivariable analysis, best with PVV (hazard ratio 1.23, 95% CI 1.05-1.44; p=0.01). CONCLUSIONS: Machine learning discriminated between CLAD phenotypes on CT. Both radiologist and machine learning scoring were associated with graft failure, independent of CLAD phenotype. PVV, unique to machine learning, was the strongest in phenotyping and prognostication.

SARS-CoV-2 and seasonal influenza: similarities and disparities.

This report describes the differences in disease severity and clinical presentation between hospitalized patients with coronavirus disease 2019 (COVID-19) and others with seasonal influenza. A total of 136 influenza and 152 COVID-19 patients were included. Patients with influenza more frequently had dyspnea (p = 0.004), hypoxemia (p < 0.001), underlying diseases (p = 0.046), and elevated liver enzymes (p = 0.028). In contrast, patients with COVID-19 were overweight (p < 0.001), lymphopenic (p < 0.001), had elevated CRP (p = 0.011), and radiological abnormalities (p < 0.001). Patients with influenza were more severely ill on admission (NEWS > 5) (p < 0.001). However, length of hospital stay, ventilatory support, and 30-day-mortality were similar. Despite differences in clinical presentation and disease severity between influenza and COVID-19 patients, both groups had similar clinical outcomes.

Significance of phenotype change after chronic lung allograft dysfunction onset.

Definitions for chronic lung allograft dysfunction (CLAD) phenotypes were recently revised (2019 ISHLT consensus). Post-CLAD onset phenotype transition may occur as a result of change in obstruction, restriction, or RAS-like opacities (RLO). We aimed to assess the prevalence and prognostic implications of these transitions. This was a single-center, retrospective cohort study of bilateral lung transplants performed in 2009-2015. CLAD phenotypes were determined per ISHLT guidelines. CLAD phenotype transition was defined as a sustained change in obstruction, restriction or RLO. We specifically focused on phenotype changes based on RLO emergence. Association of RLO development with time to death or retransplant were assessed using Kaplan-Meier and Cox proportional hazards models. Among 211 patients with CLAD, 47 (22.2%) experienced a phenotype transition. Nineteen patients developed RLO. Development of RLO phenotype after CLAD onset was associated with a shorter time to death/retransplant when considering the entire CLAD patient cohort (HR = 4.00, CI 2.74-5.83, P < 0.001) and also when restricting the analysis to only patients with a Non-RLO phenotype at CLAD onset (HR 9.64, CI 5.52-16.84, P < 0.0001). CLAD phenotype change based on emergence of RAS-like opacities implies a worse outcome. This highlights the clinical importance of imaging follow-up to monitor for phenotype transitions after CLAD onset.

Invasive Pulmonary Aspergillosis in Multiple Myeloma patients: A sizeable diagnosis in the era of novel anti-myeloma therapies.

BACKGROUND: Advances in treatment for multiple myeloma (MM) patients entail a high risk for opportunistic infections such as invasive pulmonary aspergillosis (IPA). OBJECTIVES: This study was conducted to describe the patient's profile, clinical manifestations, diagnosis and outcome of MM patients with IPA, in our large haemato-oncology centre. PATIENTS/METHODS: We retrospectively analysed patients with MM who underwent Broncho alveolar lavage for pneumonia at Rambam Hospital during a 13-year period from July 2005 to February 2018. We focused on those with Aspergillus pneumonia. RESULTS: Of the 669 patients with multiple myeloma, mean age 62.6 (±7.6) years, forty-two patients (6.2%) were diagnosed with IPA. Among them, 60% had a probable diagnosis and 40% possible. Clinical presentation was similar for IPA and other pulmonary infections. Compared to those with other pulmonary infections, IPA was more commonly diagnosed in patients with long-standing disease (p = .00012) and among patients receiving 3 or more lines of myeloma therapies (p = .04). Thirty-day mortality rates following diagnostic bronchoscopy did not differ between IPA and non-IPA patients. (p = .85). CONCLUSIONS: Multiple myeloma patients had an increased risk for IPA, most notably in patients with 3 or more lines of anti-myeloma treatment and more advanced disease. This clearly emphasises the vigilance needed for IPA in these patients.

Clinical Spectrum, Diagnosis and Outcome of Rare Fungal Infections in Patients with Hematological Malignancies: Experience of 15-Year Period from a Single Tertiary Medical Center.

BACKGROUND: Patients with hematological malignancies and allogeneic hematopoietic stem-cell transplant recipients carry a high risk of rare (non-Aspergillus molds and non-Candida yeasts) invasive fungal infections (IFI). METHODS: We retrospectively evaluated and described the patient profile, clinical manifestations, isolated species, treatment and outcome of patients with hematological malignancies diagnosed with these rare IFIs during 15 years in a large single hemato-oncology center. RESULTS: Eighty-seven patients with hematological malignancies treated in our center had at least one positive culture or molecular identification of a rare fungus. Ninety-three isolates were considered the etiological agents of the infection. The most common underlying hematological malignancy was acute myeloid leukemia, 36 patients (41.4%). Eighty patients (91%) received chemotherapy less than 30 days prior to IFI diagnosis. The most frequent site of infection was the respiratory tract: 34 patients (39%) had pulmonary and 19 patients (22%) had a sinusal or nasopharyngeal infections. Disseminated infection, defined as positive blood cultures or parallel infection in multiple organ systems, was documented in 20 patients (23%). The most common fungal species were Fusarium (35%) and Zygomycetes (25%). Coinfection with more than one fungus was noted in 20 patients (23%). Forty-seven of 87 patients (54%) in this study died within 90 days of IFI diagnosis. CONCLUSIONS: Rare IFIs in patients with hematological malignancy become increasingly frequent. Early identification with traditional and molecular methods is important in management of these patients.

Safety of Bronchoalveolar Lavage in Hematological Patients with Thrombocytopenia. A Retrospective Cohort Study.

Background: Hospitalized hematological patients often require bronchoalveolar lavage (BAL). Scarce evidence exists regarding the potential risks in patients with very severe thrombocytopenia (VST). Methods: This retrospective-cohort study included adult hematological in-patients with VST, defined as platelets<20x103/µL, undergoing BAL during 2012-2021. Mechanically ventilated patients or those with known active bleeding were excluded. Primary outcomes included major bleeding halting the BAL or deemed significant by the treating physician, need for any respiratory support other than low flow O2, or death within 24 hours. Any other bleedings were recorded as secondary outcomes. Results: Of the 507 patients included in the final analysis, the 281 patients with VST had lower hemoglobin (Md=0.3, p=0.003), longer prothrombin-time (Md=0.7s, p=0.025), higher chances of preprocedural platelet transfusion (RR 3.68, 95%CI [2.86,4.73]), and only one primary-outcome event (death of septic shock 21h postprocedurally) - compared with 3 (1.3%) events (two bleedings halting procedure and one need for non-invasive-ventilation) in patients with platelets ≥20x103/µL (p=0.219). The risk of minor spontaneously resolved bleeding was higher (RR=3.217, 95% CI [0.919,11.262]) in patients with VST (4.3% vs 1.3%, p=0.051). No association was found between the complications recorded and preprocedural platelets, age, aPTT, P.T., hematological status, or platelet transfusion. Conclusions: This data suggests BAL to be safe even when platelet counts are <20x103/µL.

Combining reservoir mask oxygenation with high-flow nasal cannula in the treatment of hypoxemic respiratory failure among patients with COVID-19 pneumonia: a retrospective cohort study.

BACKGROUND: Concerns regarding positive-pressure-ventilation for the treatment of coronavirus disease 2019 (COVID-19) hypoxemia led the search for alternative oxygenation techniques. This study aimed to assess one such method, dual oxygenation, i.e., the addition of a reservoir mask (RM) on top of a high-flow nasal cannula (HFNC). METHODS: In this retrospective cohort study, the records of all patients hospitalized with COVID-19 during 2020-2022 were reviewed. Patients over the age of 18 years with hypoxemia necessitating HFNC were included. Exclusion criteria were positive-pressure-ventilation for any indication other than hypoxemic respiratory failure, transfer to another facility while still on HFNC and "do-not-intubate/resuscitate" orders. The primary outcome was mortality within 30 days from the first application of HFNC. Secondary outcomes were intubation and admission to the intensive care unit. RESULTS: Of 659 patients included in the final analysis, 316 were treated with dual oxygenation and 343 with HFNC alone. Propensity for treatment was estimated based on background diagnoses, laboratories and vital signs upon admission, gender and glucocorticoid dose. Inverse probability of treatment weighted regression including age, body mass index, Sequential Organ Failure Assessment (SOFA) score and respiratory rate oxygenation index showed treatment with dual oxygenation to be associated with lower 30-day mortality (adjusted hazard ratio, 0.615; 95% confidence interval, 0.469-0.809). Differences in the secondary outcomes did not reach statistical significance. CONCLUSIONS: Our study suggests that the addition of RM on top of HFNC may be associated with decreased mortality in patients with severe COVID-19 hypoxemia.

Pulmonary epithelial markers in phenotypes of chronic lung allograft dysfunction.

BACKGROUND: Airway epithelial injury is thought to be a key event in the pathogenesis of chronic lung allograft dysfunction (CLAD). We investigated whether markers of epithelial activity and injury in bronchoalveolar lavage fluid (BAL) correlate with CLAD diagnosis and major CLAD phenotypes: bronchiolitis obliterans syndrome (BOS) vs restrictive allograft syndrome (RAS)-related phenotypes (including RAS, mixed phenotype, and all other patients with RAS-like opacities). METHODS: CLAD status and phenotypes were retrospectively determined in a cohort of all consecutive adult, first, bilateral lung transplants performed 2010-2015, with available BAL samples. All patients with RAS-related phenotypes were included and 1:1 matched with BOS patients based on the time from transplant to CLAD-onset. Subjects who were CLAD-free for a minimum of 3 years post-transplant were 1:1 matched to CLAD patients and included as controls. Proteins that maintain the barrier function of the airway epithelial mucosa (club cell secretory protein, surfactant protein-D and epithelial mucins: MUC1, MUC5AC, MUC5B, MUC16), as well as epithelial cell death markers (M30&M65 representing epithelial cell apoptosis and overall death, respectively), were measured in BAL obtained within 6-months post CLAD onset using a double-sandwich ELISA or a multiplex bead assay. Protein levels were compared using Mann-Whitney-U-test. Association between protein levels and graft survival was assessed using Cox proportional hazards models, adjusted for CMV serology mismatch status and CLAD phenotype. RESULTS: Fifty-four CLAD (27 BOS, 11 RAS, 7 mixed, 9 others with RAS-like opacities) patients and 23 CLAD-free controls were included. Median BAL levels were significantly higher in patients with CLAD compared to CLAD-free controls for M30 (124.5 vs 88.7 U/L), MUC1 (6.8 vs 3.2 pg/mL), and MUC16 (121.0 vs 30.1 pg/mL). When comparing CLAD phenotypes, M30 was significantly higher in patients with RAS-related phenotypes than BOS (160.9 vs 114.6 U/L). In multivariable models, higher M30 and MUC5B levels were associated with decreased allograft survival after CLAD onset independent of phenotype (p < 0.05 for all). CONCLUSIONS: Airway epithelial mucins and cell death markers are enhanced in the BAL of patients with CLAD and can assist in differentiating between CLAD phenotypes and post-CLAD outcomes. Abnormal airway mucin expression and epithelial cell death may be involved in the pathogenesis of CLAD, and therefore their detection may aid in future selection of targeted therapies.

Functional Capacity in Patients Who Recovered from Mild COVID-19 with Exertional Dyspnea.

BACKGROUND: Post mild COVID-19 dyspnea is poorly understood. We assessed physiologic limitations in these patients. METHODS: Patients with post mild COVID-19 dyspnea (group A) were compared (pulmonary function tests, 6-min walk test (6MWT), echocardiography and cardiopulmonary exercise test (CPET)) to post moderate/severe COVID-19 (group B) and to CPET and spirometry of patients with unexplained dyspnea (group C). RESULTS: The study included 36 patients (13 in A, 9 in B and 14 in C). Diffusion capacity was lower in group B compared to group A (64 ± 8 vs. 85 ± 9% predicted, p = 0.014). 6MWT was normal and similar in both patient groups. Oxygen uptake was higher in group A compared to groups B and C (108 ± 14 vs. 92 ± 13 and 91 ± 23% predicted, p = 0.013, 0.03, respectively). O2 pulse was normal in all three groups but significantly higher in the mild group compared to the control group. Breathing reserve was low/borderline in 2/13 patients in the mild group, 2/9 in the moderate/severe group and 3/14 in the control group (NS). CONCLUSIONS: Patients with post mild COVID-19 dyspnea had normal CPET, similar to patients with unexplained dyspnea. Other mechanisms should be investigated and the added value of CPET to patients with post mild COVID-19 dyspnea is questionable.

Phenotyping CLAD after single lung transplant: Limits and prognostic assessment of the 2019 ISHLT classification system.

BACKGROUND: Phenotyping chronic lung allograft dysfunction (CLAD) in single lung transplant (SLTX) is challenging, due to the native lung contribution to pulmonary function test (PFT). We aimed to assess the applicability and prognostic performance of International Society for Heart and Lung Transplantation (ISHLT) classification in SLTX. METHODS: In this retrospective study of adult, first, SLTX performed 2009-2017, patients with persistent drop in FEV1≥20% were assessed by 2 independent adjudicators to determine CLAD status and phenotype. Interobserver agreement (IOA) was calculated (Cohen's Kappa) for CLAD, phenotype and presence of RAS (resttrictive allograft syndrome)-like opacities (RLO). Association of CLAD phenotypes with time to death or retransplant (ReTx), adjusted for age at SLTX, sex, CMV mismatch and native lung condition, were assessed using Cox proportional hazards models. RESULTS: Of 172 SLTX recipients, 92 experienced a persistent drop in FEV1>20%. Following adjudication, 67 were diagnosed with CLAD. We noted a moderate IOA for CLAD diagnosis (Kappa 0.69) and poor IOA for phenotype adjudication (Kappa 0.52). The final phenotype adjudication was 31 bronchiolitis obliterans syndrome (BOS) (46.3%), 13 RAS (19.4%), 2 mixed (3%), 2 Undefined (3%), and 19 remained Unclassified (28.3%). Using these adjudicated phenotypes, RAS was significantly associated with a higher risk of death/ReTx compared to other groups (HR 2.98, 95%CI [1.39-6.4]). The adjudication of RLO had the best IOA (Kappa 0.73). The presence of RLO was a strong predictor of death or ReTx (HR 2.37, 95%CI [1.2-4.5]), regardless of the final phenotype. CONCLUSIONS: PFT interpretation is challenging in SLTX. A classification essentially relying on imaging, which harbored good IOA, obtained better prognostic performance than a classification using published physiological cut-offs.

Risk assessment of chronic lung allograft dysfunction phenotypes: Validation and proposed refinement of the 2019 International Society for Heart and Lung Transplantation classification system.

BACKGROUND: Chronic lung allograft dysfunction (CLAD) is a heterogeneous condition. Characterization of CLAD phenotypes is essential to enhance the understanding of pathogenesis and guide new therapies. The study objective was to validate the new International Society for Heart and Lung Transplantation (ISHLT) CLAD classification system and further explore patients who do not fall into the defined CLAD sub-categories. METHODS: We performed a single-center, retrospective cohort study of adult, first, bilateral lung transplants performed from 2010 to 2015. Patients with CLAD were classified on the basis of the 2019 ISHLT consensus document. CLAD phenotypes and other potential predictors of survival after CLAD onset were assessed using Kaplan-Meier and Cox proportional hazards models. RESULTS: Among the 174 subjects with CLAD, 104 (59.8%) had bronchiolitis obliterans syndrome (BOS), 16 (9.2%) restrictive allograft syndrome (RAS), 9 (5.2%) mixed, and 19 (10.9%) undefined phenotype. A total of 26 patients (14.9%) did not match any of these 4 categories and remained unclassified. Allograft survival post-CLAD onset was longer for patients with BOS (median, 500 days) than patients with RAS (median, 372 days) or mixed (median, 328 days). The 45 patients (26.8%) with undefined/unclassified phenotype were combined and recategorized on the basis of the presence or absence of characteristic RAS-like opacities on chest imaging; those with RAS-like opacities had significantly worse allograft survival than patients with BOS (hazard ratio, 2.14; 95% confidence interval, 1.17-3.93; p = 0.014) and similar survival to RAS or mixed phenotype. CONCLUSIONS: The new ISHLT CLAD phenotype classification is informative with regards to post-CLAD outcomes. Chest imaging demonstrating persistent parenchymal or pleural fibrosis may be used for risk-stratification of patients who do not match the major CLAD phenotypes.

Diabetes and Lung Disease: A Neglected Relationship.

BACKGROUND: Diabetes mellitus is a systemic disorder associated with inflammation and oxidative stress which may target many organs such as the kidney, retina, and the vascular system. The pathophysiology, mechanisms, and consequences of diabetes on these organs have been studied widely. However, no work has been done on the concept of the lung as a target organ for diabetes and its implications for lung diseases. AIM: In this review, we aimed to investigate the effects of diabetes and hypoglycemic agent on lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, pulmonary hypertension, and lung cancer. We also reviewed the potential mechanisms by which these effects may affect lung disease patients. RESULTS: Our results suggest that diabetes can affect the severity and clinical course of several lung diseases. CONCLUSIONS: Although the diabetes-lung association is epidemiologically and clinically well-established, especially in asthma, the underlying mechanism and pathophysiology are not been fully understood. Several mechanisms have been suggested, mainly associated with the pro-inflammatory and proliferative properties of diabetes, but also in relation to micro- and macrovascular effects of diabetes on the pulmonary vasculature. Also, hypoglycemic drugs may influence lung diseases in different ways. For example, metformin was considered a potential therapeutic agent in lung diseases, while insulin was shown to exacerbate lung diseases; this suggests that their effects extend beyond their hypoglycemic properties.

Diagnostic role of polymerase chain reaction in bronchoalveolar lavage fluid for invasive pulmonary aspergillosis in immunocompromised patients - A retrospective cohort study.

BACKGROUND: This study aimed to evaluate the diagnostic role of PCR detection of Aspergillus DNA in the broncho-alveolar lavage (BAL) fluid in a large cohort of patients suspected to have invasive pulmonary aspergillosis (IPA). METHODS: Consecutive immunocompromised patients who underwent bronchoscopy with BAL sampling and PCR detection of Aspergillus DNA for the diagnosis of pulmonary infiltrates were included in the study. Galactomannan (GM) antigen testing in BAL and serum and BAL fungal culture were also performed. Patients were classified as having IPA (proven/probable/possible) or no-IPA according to the EORTC/MSG diagnostic criteria. RESULTS: During 12 years (2005-2016), 1248 bronchoscopies were performed for 1072 patients. 77% had hematological malignancy, of them 40% had AML and 35.6% underwent HSCT. IPA was diagnosed in 531 patients (42.5%), 7-proven, 280-probable and 244-possible. PCR was positive in 266 cases, of them 213 had IPA, indicating a true positive rate of 80% (213/266) and a false positive rate of 20% (53/266). These results establish the diagnostic performance of PCR to have sensitivity of 40%, specificity of 93%, PPV- 80% and NPV-68%. Of 244 patients with possible IPA, 80 had positive PCR. Including PCR in the diagnostic criteria would move 80 cases from the possible group to the probable one. A combination of positive PCR and/or BAL-GM increases sensitivity to 74%, while positivity of both tests elevates PPV to 99.4%. CONCLUSIONS: Inclusion PCR for the detection of Aspergillus-DNA in BAL in the mycological criteria of the EORTC/MSG definitions increases the rate and the certainty of IPA diagnosis.

Age-Adjusted Cutoff D-Dimer Level to Rule Out Acute Pulmonary Embolism: A Validation Cohort Study.

BACKGROUND: The diagnosis of pulmonary embolism in the Emergency Room setting is challenging. Multiple patients have to undergo radiologic assessment with its inherent shortcomings. The D-dimer test with accepted cutoff level of 500 µg/L is associated with a high proportion of false-positive results. The present study aimed to validate the advantages of using an age-adjusted D-dimer cutoff level, compared with 500-µg/L value in the diagnosis of acute pulmonary embolism. METHODS: This study evaluated patients admitted to the Rambam Emergency Room between 2011 and 2014 with a suspected diagnosis of pulmonary embolism. Patient data, D-dimer plasma levels, and imaging results were collected. The study cohort was subdivided according to the D-dimer levels below and above 500 µg/L. The group with levels above 500 µg/L was further assessed using the newly suggested age-adjusted D-dimer cutoff level, defined as age multiplied by 10. RESULTS: Files of 1241 patients were reviewed; 654 patients with low or intermediate risk for pulmonary embolism had a D-dimer level above 500 µg/L. Two hundred eight (208) patients had a D-dimer level above 500 µg/L but below the age-adjusted cutoff value; one of them was diagnosed with pulmonary embolism (0.48% [95% confidence interval 0%-2.6%]). Four hundred forty-six (446) patients had a D-dimer level above the age-adjusted cutoff value, and 28 of them were diagnosed with pulmonary embolism (6.28% [95% confidence interval 4.2%-8.9%]), representing a negative predictive value of 99.5% for the age-adjusted cutoff level. CONCLUSIONS: An age-adjusted D-dimer cutoff level may be safely used to exclude pulmonary embolism in patients with a low or intermediate probability for acute pulmonary embolism, alleviating the need to perform unnecessary imaging evaluations.