Carfilzomib-associated thrombotic microangiopathy: clinical features and outcomes.

BACKGROUND AND HYPOTHESIS: Carfilzomib, a new proteasome inhibitor indicated for patients with relapsed/refractory myeloma, has been associated with cases of thrombotic microangiopathy (CFZ-TMA). The role of variants in the complement alternative pathway and therapeutic potential of complement blockade with eculizumab remain to be determined. METHODS: We report 37 cases of CFZ-TMA recorded in the French reference center for TMA with their clinical characteristics, genetic analysis and outcome according to treatments. RESULTS: A trigger was identified in more than half of cases, including 8 influenza and 5 SARS-CoV-2 cases. All patients presented with acute kidney injury (AKI) (KDIGO stage 3 in 31 (84%) patients) while neurological (n=13, 36%) and cardiac damage (n=7, 19%) were less frequent. ADAMTS13 and complement activity were normal (n= 28 and 18 patients tested) and no pathogenic variant in the alternative complement pathway was found in 7 patients tested.TMA resolved in most (n=34, 94%) patients but 12 (44%) still displayed stage 3 AKI at discharge. Nineteen (51%) patients were treated with therapeutic plasma exchange, 14 (38%) patients received corticosteroids and 18 (50%) were treated with eculizumab. However none of these treatments demonstrated a significant impact on outcomes. CONCLUSION: This study is the largest case series of CFZ-TMA since its approval in 2012. Patients present with severe AKI and experience frequent sequelae. Complement variants and blockade therapy do not seem to play a role in the pathophysiology and prognosis of the disease.

Evaluation of T Cell Response to SARS-CoV-2 in Kidney Transplant Recipients Receiving Monoclonal Antibody Prophylaxis and the Utility of a Bivalent mRNA Vaccine Booster Dose.

Monoclonal antibodies have been administered to kidney transplant recipients (KTRs) with a poor or non-responder status to SARS-CoV-2 vaccination. The cellular response to SARS-CoV-2 has been poorly studied in this context. We assessed the T cell response to SARS-CoV-2 in 97 patients on the day of the injection of tixagevimab/cilgavimab using an IFNγ enzyme-linked immunospot assay (ELISPOT). Among the 97 patients, 34 (35%) developed COVID-19 before the injection. Twenty-nine (85.3%) had an ELISPOT compatible with a SARS-CoV-2 infection. There was no difference between KTRs under belatacept or tacrolimus treatment. Sixty-three patients (64.9%) had no known COVID-19 prior to the ELISPOT, but nine (14.3%) had a positive ELISPOT. In 21 KTRs with a positive ELISPOT who received a booster dose of a bivalent mRNA vaccine, median antibody titers and spike-reactive T cells increased significantly in patients under tacrolimus but not belatacept. Our study emphasizes the potential usefulness of the exploration of immune cellular response to SARS-CoV-2 by ELISPOT. In KTRs with a positive ELISPOT and under CNI therapy, a booster dose of mRNA vaccine seems effective in inducing an immune response to SARS-CoV-2.

Assessment of epidemiology and outcomes of adult patients with kidney-limited thrombotic microangiopathies.

Thrombotic microangiopathies (TMA) are usually associated with hematological features (RH-TMA). The epidemiology of TMA limited to kidneys (RL-TMA) is unclear Therefore, patients with TMA and native kidney biopsies were identified during 2009-2022 in 20 French hospitals and results evaluated. RL-TMA was present in 341/757 (45%) patients and associated with lower creatinine levels (median 184 vs 346 µmol/L) than RH-TMA. RL-TMA resulted from virtually all identified causes, more frequently from anti-VEGF treatment and hematological malignancies but less frequently from shigatoxin-associated hemolytic uremic syndrome (HUS), systemic sclerosis, gemcitabine and bacterial infection, and even less frequently when three or more causes/triggers were combined (RL-TMA: 5%; RH-TMA: 12%). RL-TMA was associated with significantly lower major cardiovascular events (10% vs 20%), kidney replacement therapy (23% vs 43%) and death (12% vs 20%) than RH-TMA during follow-up (median 28 months). Atypical HUS (aHUS) was found in 326 patients (RL-TMA: 43%, RH-TMA: 44%). Among the 69 patients with proven complement-mediated aHUS, eculizumab (anti-C5 therapy) was used in 43 (62%) (RL-TMA: 35%; RH-TMA: 71%). Among the 257 other patients with aHUS, including 51% with RL-TMA, eculizumab was used in 29 but with unclear effects of this treatment. Thus, RL-TMA represents a very high proportion of patients with TMA and results from virtually all known causes of TMA and includes 25% of patients with complement-mediated aHUS. Adverse outcomes of RL-TMA are lower compared to RH-TMA but remain significant. Anti-C5 therapy was rarely used in RL-TMA, even in proven complement-mediated aHUS, and its effects remain to be assessed.

Anti SARS-CoV-2 Monoclonal Antibodies in Pre-Exposure or Post-Exposure in No- or Weak Responder to Vaccine Kidney Transplant Recipients: Is One Strategy Better than Another?

Background: Kidney transplant recipients (KTRs) are likely to develop severe COVID-19 and are less well-protected by vaccines than immunocompetent subjects. Thus, the use of neutralizing anti-SARS-CoV-2 monoclonal antibodies (mAbs) to confer a passive immunity appears attractive in KTRs. Methods: This retrospective monocentric cohort study was conducted between 1 January 2022 and 30 September 2022. All KTRs with a weak antibody response one month after three doses of mRNA vaccine (anti spike IgG < 264 (BAU/mL)) have received tixagevimab-cilgavimab in pre-exposure (group 1), post-exposure (group 2) or no specific treatment (group 3). We compared COVID-19 symptomatic hospitalizations, including intensive care unit hospitalizations, oxygen therapy, and death, between the three groups. Results: A total of 418 KTRs had SARS-CoV-2 infection in 2022. During the study period, we included 112 KTRs in group 1, 40 KTRs in group 2, and 27 KTRs in group 3. The occurrence of intensive care unit hospitalization, oxygen therapy, and COVID-19 death was significantly increased in group 3 compared to group 1 or 2. In group 3, 5 KTRs (18.5%) were admitted to the intensive care unit, 7 KTRs (25.9%) needed oxygen therapy, and 3 KTRs (11.1%) died. Patients who received tixagevimab-cilgavimab pre- or post-exposure had similar outcomes. Conclusions: This retrospective real-life study supports the relative effectiveness of tixagevimab-cilgavimab on COVID-19 infection caused by Omicron, used as a pre- or post-exposure therapy. The continued evolution of Omicron variants has made tixagevimab-cilgavimab ineffective and reinforces the need for new therapeutic monoclonal antibodies for COVID-19 active on new variants.

Renal replacement therapy initiation strategies in comatose patients with severe acute kidney injury: a secondary analysis of a multicenter randomized controlled trial.

PURPOSE: The effect of renal replacement therapy (RRT) in comatose patients with acute kidney injury (AKI) remains unclear. We compared two RRT initiation strategies on the probability of awakening in comatose patients with severe AKI. METHODS: We conducted a post hoc analysis of a trial comparing two delayed RRT initiation strategies in patients with severe AKI. Patients were monitored until they had oliguria for more than 72 h and/or blood urea nitrogen higher than 112 mg/dL and then randomized to a delayed strategy (RRT initiated after randomization) or a more-delayed one (RRT initiated if complication occurred or when blood urea nitrogen exceeded 140 mg/dL). We included only comatose patients (Richmond Agitation-Sedation scale [RASS] < - 3), irrespective of sedation, at randomization. A multi-state model was built, defining five mutually exclusive states: death, coma (RASS < - 3), incomplete awakening (RASS [- 3; - 2]), awakening (RASS [- 1; + 1] two consecutive days), and agitation (RASS > + 1). Primary outcome was the transition from coma to awakening during 28 days after randomization. RESULTS: A total of 168 comatose patients (90 delayed and 78 more-delayed) underwent randomization. The transition intensity from coma to awakening was lower in the more-delayed group (hazard ratio [HR] = 0.36 [0.17-0.78]; p = 0.010). Time spent awake was 10.11 days [8.11-12.15] and 7.63 days [5.57-9.64] in the delayed and the more-delayed groups, respectively. Two sensitivity analyses were performed based on sedation status and sedation practices across centers, yielding comparable results. CONCLUSION: In comatose patients with severe AKI, a more-delayed RRT initiation strategy resulted in a lower chance of transitioning from coma to awakening.

ROX index performance to predict high-flow nasal oxygen outcome in Covid-19 related hypoxemic acute respiratory failure.

BACKGROUND: Given the pathophysiology of hypoxemia in patients with Covid-19 acute respiratory failure (ARF), it seemed necessary to evaluate whether ROX index (ratio SpO2/FiO2 to respiratory rate) could accurately predict intubation or death in these patients initially treated by high-flow nasal oxygenation (HFNO). We aimed, therefore, to assess the accuracy of ROX index to discriminate between HFNO failure (sensitivity) and HFNO success (specificity). METHODS: We designed a multicentre retrospective cohort study including consecutive patients with Covid-19 ARF. In addition to its accuracy, we assessed the usefulness of ROX index to predict HFNO failure (intubation or death) via logistic regression. RESULTS: Among 218 ARF patients screened, 99 were first treated with HFNO, including 49 HFNO failures (46 intubations, 3 deaths before intubation). At HFNO initiation (H0), ROX index sensitivity was 63% (95%CI 48-77%) and specificity 76% (95%CI 62-87%) using Youden's index. With 4.88 as ROX index cut-off at H12, sensitivity was 29% (95%CI 14-48%) and specificity 90% (95%CI 78-97%). Youden's index yielded 8.73 as ROX index cut-off at H12, with 87% sensitivity (95%CI 70-96%) and 45% specificity (95%CI 31-60%). ROX index at H0 was associated with HFNO failure (p = 0.0005) in univariate analysis. Multivariate analysis showed that SAPS II (p = 0.0003) and radiographic extension of pulmonary injuries (p = 0.0263), rather than ROX index, were predictive of HFNO failure. CONCLUSIONS: ROX index cut-off values seem population-specific and the ROX index appears to have a technically acceptable but clinically low capability to discriminate between HFNO failures and successes in Covid-19 ARF patients. In addition, SAPS II and pulmonary injuries at ICU admission appear more useful than ROX index to predict the risk of intubation.

Magnesium sulphate in patients with thrombotic thrombocytopenic purpura (MAGMAT): a randomised, double-blind, superiority trial.

PURPOSE: Studies have suggested benefits from magnesium sulphate in thrombotic thrombocytopenic purpura (TTP). We aimed to measure the effects of magnesium sulphate supplementation on TTP recovery. METHODS: In this multicenter, randomised, double-blind, controlled, superiority study, we enrolled adults with a clinical diagnosis of TTP. Patients were randomly allocated to receive magnesium sulphate (6 g intravenously followed by a continuous infusion of 6 g/24 h for 3 days) or placebo, in addition to the standard treatment. The primary outcome was the median time to platelet normalisation (defined as a platelet count ≥ 150 G/L). Efficacy and safety were assessed by intention-to-treat. RESULTS: Overall, we enrolled 74 participants, including one who withdrew his/her consent. Seventy-three patients were further analyzed, 35 (48%) allocated to magnesium sulphate and 38 (52%) to placebo. The median time to platelet normalisation was 4 days (95% confidence interval [CI], 3-4) in the magnesium sulphate group and 4 days (95% CI 3-5) in the placebo group. The cause-specific hazard ratio of response was 0.93 (95% CI 0.58-1.48, p = 0.75). The number of patients with ≥ 1 serious adverse reactions was similar in the two groups. By day 90, four patients in the magnesium sulphate group and two patients in the placebo group had died (p = 0.42). The most frequent adverse event was low blood pressure occurring in 34% in the magnesium sulphate group and 29% in the placebo group (p = 0.80). CONCLUSION: Among patients with TTP, the addition of magnesium sulphate to the standard of care did not result in a significant improvement in time to platelet normalisation.

Thrombotic microangiopathy associated with anticancer and immune system targeting drugs: New insights from real-world data using the WHO pharmacovigilance database.

BACKGROUND: The worldwide development of immune system targeting/anticancer drugs has revolutionized immuno-oncology, but their implication in thrombotic microangiopathy syndromes (TMA) is increasingly suspected. Using real-world data, the aim of this study was to identify drugs associated with TMA reporting and to describe the evolution of TMA reporting over time with a focus on these drugs. METHODS: A global disproportionality study was performed using the individual case safety reports (ICSRs) extracted from the World Health Organization (WHO) pharmacovigilance database (VigiBase) from its inception (1968) to April 30, 2022. RESULTS: Of the 31,251,040 ICSRs, 6946 cases of suspected drug-induced TMA were included from 55 countries. The outcome was fatal in 18.2% of cases. A total of 72 immune system targeting/anticancer drugs were associated with significant overreporting, including 17 drugs with a potential new safety concern for TMA. Although the rate of TMA reporting per million of ICSRs has remained fairly stable, an absolute increase in reported cases of suspected drug-induced TMA has been observed over the last decade. The pattern of drugs reported in TMA has evolved with a substantial increase in the proportion of cases involving immune system-targeting drugs/anticancer drugs from 47.3% (205/433) in the period 1992-2001 to 80.7% (3819/4730) in the period 2012-2021. CONCLUSION: Several recently marketed immune system targeting/anticancer drugs have been identified as potential new drugs associated with TMA, which will require confirmatory studies. The number of drugs associated with TMA reporting markedly increased within the past 10 years, primarily due to innovative anticancer drugs.

Predictors of acute ischemic cerebral lesions in immune-mediated thrombotic thrombocytopenic purpura and hemolytic uremic syndrome.

BACKGROUND: The immune form of thrombotic thrombocytopenic purpura (iTTP) and the hemolytic and uremic syndrome (HUS) are two major forms of thrombotic microangiopathy (TMA). Their treatment has been recently greatly improved. In this new era, both the prevalence and predictors of cerebral lesions occurring during the acute phase of these severe conditions remain poorly known. AIM: The prevalence and predictors of cerebral lesions appearing during the acute phase of iTTP and Shiga toxin-producing Escherichia coli-HUS or atypical HUS were evaluated in a prospective multicenter study. METHODS: Univariate analysis was performed to report the main differences between patients with iTTP and those with HUS or between patients with acute cerebral lesions and the others. Multivariable logistic regression analysis was used to identify the potential predictors of these lesions. RESULTS: Among 73 TMA cases (mean age 46.9 ± 16 years (range 21-87 years) with iTTP (n = 57) or HUS (n = 16), one-third presented with acute ischemic cerebral lesions on magnetic resonance imagery (MRI); two individuals also had hemorrhagic lesions. One in ten patients had acute ischemic lesions without any neurological symptom. The neurological manifestations did not differ between iTTP and HUS. In multivariable analysis, three factors predicted the occurrence of acute ischemic lesions on cerebral MRI: (1) the presence of old infarcts on cerebral MRI, (2) the level of blood pulse pressure, (3) the diagnosis of iTTP. CONCLUSION: At the acute phase of iTTP or HUS, both symptomatic and covert ischemic lesions are detected in one third of cases on MRI. Diagnosis of iTTP and the presence of old infarcts on MRI are associated with the occurrence of such acute lesions as well as increased blood pulse pressure, that may represent a potential target to further improve the therapeutic management of these conditions.

Epidemiology, clinical presentation, and outcomes of 620 patients with eosinophilia in the intensive care unit.

PURPOSE: Although eosinophil-induced manifestations can be life-threatening, studies focusing on the epidemiology and clinical manifestations of eosinophilia in the intensive care unit (ICU) are lacking. METHODS: A retrospective, national, multicenter (14 centers) cohort study over 6 years of adult patients who presented with eosinophilia ≥ 1 × 109/L on two blood samples performed from the day before admission to the last day of an ICU stay. RESULTS: 620 patients (0.9% of all ICU hospitalizations) were included: 40% with early eosinophilia (within the first 24 h of ICU admission, ICU-Eo1 group) and 56% with delayed (> 24 h after ICU admission, ICU-Eo2 group) eosinophilia. In ICU-Eo1, eosinophilia was mostly due to respiratory (14.9%) and hematological (25.8%) conditions, frequently symptomatic (58.1%, mainly respiratory and cardiovascular manifestations) requiring systemic corticosteroids in 32.2% of cases. In ICU-Eo2, eosinophil-related organ involvement was rare (25%), and eosinophilia was mostly drug-induced (46.8%). Survival rates at day 60 (D60) after ICU admission were 21.4% and 17.2% (p = 0.219) in ICU-Eo1 and ICU-Eo2 patients, respectively. For ICU-Eo1 patients, in multivariate analysis, risk factors for death at D60 were current immunosuppressant therapy at ICU admission, eosinophilia of onco-hematological origin and the use of vasopressors at ICU admission, whereas older age and the use of vasopressors or mechanical ventilation at the onset of eosinophilia were associated with a poorer prognosis for ICU-Eo2 patients. CONCLUSION: Eosinophilia ≥ 1 × 109/L is not uncommon in the ICU. According to the timing of eosinophilia, two subsets of patients requiring different etiological workups and management can be distinguished.

Retrospective study of 59 cases of cancer-associated thrombotic microangiopathy: presentation and treatment characteristics.

BACKGROUND: Cancer-associated thrombotic microangiopathy (TMA) is a rare disease, with a poor prognosis. The classical treatment is urgent chemotherapy. Few data are available on the efficacy of plasma exchange (PE) and eculizumab in these patients. METHODS: Cases of cancer-related TMA treated between January 2008 and December 2019 in 12 French treatment centres were retrospectively analysed, excluding cases associated with chemotherapy and stem cell transplantation. Patients were divided into four groups depending on the treatment received: none, PE therapy alone, chemotherapy, with or without PE therapy, or eculizumab, with or without chemotherapy and PE therapy. RESULTS: The data of 59 patients with cancer-associated TMA were analysed. Twenty of these cases were related to a cancer recurrence. The cancer was metastatic in 90% of cases (53/59). Bone marrow invasion was observed in 20/41 biopsies. Some laboratory results, including disseminated intravascular coagulation high ferritin and C-reactive protein, were suggestive of cancer. None of the 16 patients whose alternative complement pathway was assessed had abnormal levels of protein expression or activity. The median survival time was 27 days. Chemotherapy was significantly associated with improved survival, with a 30-day survival rate of 85% (17/20) among patients who received PE and chemotherapy, versus 20% (3/15) among patients who received PE alone. Patients treated with eculizumab in addition to chemotherapy and PE therapy did not have longer overall survival or higher haematological remission rates than those treated with chemotherapy and PE therapy alone. Renal remission rates were non-significantly higher, and times to remission non-significantly shorter, in the eculizumab group. CONCLUSIONS: Nephrologists and oncologists should make themselves aware of cancer diagnoses in patients with TMA and bone marrow biopsies should be performed systematically in these cases. All 59 patients had poor survival outcomes, but patients treated with urgent initiation of chemotherapy survived significantly longer than those who were not.

Trends in major intensive care medicine journals: A machine learning approach.

PURPOSE: Intensive care medicine (ICM) has the particularity of being a multidisciplinary specialty and its literature reflects this multidisciplinarity. However, the proportion of each field in this literature and its trend dynamics are not known. The objective of this study was to analyze the ICM literature, extract latent topics and search for the presence of research trends. MATERIAL AND METHODS: Abstracts of original articles from the top ICM journals, from their inception until December 31st, 2019, were included. This corpus was fed into a structural topic modeling algorithm to extract latent semantic topics. The temporal distribution was then analyzed and the presence of trends was searched by Mann-Kendall trends tests. RESULTS: Finally, 49,276 articles from 10 journals were included. After topic modeling analysis and experts' feedback, 124 research topics were selected and labeled. Topics were categorized into 19 categories, the most represented being respiratory, fundamental and neurological research. Increasing trends were observed for research on mechanical ventilation and decreasing trends for cardiopulmonary resuscitation. CONCLUSIONS: This study reviewed all articles from major ICM journals in a comprehensive way. It provides a better understanding of ICM research landscape by analyzing the temporal evolution of latent research topics in the ICM literature.

Prevalence, characteristics and outcome of cardiac manifestations in critically-ill antiphospholipid syndrome patients.

AIMS: Antiphospholipid syndrome (APS) is a rare autoimmune disease defined by thrombotic events occurring in patients with persistent antiphospholipid antibodies. Cardiac manifestations in critically-ill APS patients are poorly investigated. We conducted a study to assess the prevalence, the characteristics and the prognosis of cardiac manifestations in thrombotic APS patients admitted to intensive care unit (ICU). METHODS AND RESULTS: A French, national, multicentre, retrospective study, conducted, from January 2000 to September 2018, including all APS patients admitted to 24 participating centres' ICUs with any new thrombotic (arterial, venous or microvascular) manifestation. Cardiac manifestations were defined as any new cardiac abnormalities relying on clinical examination, cardiac biomarkers, echocardiography, cardiac magnetic resonance (CMR) and coronarography. One hundred and thirty-six patients (female 72%) were included. Mean age at ICU admission was 46 ± 15years. Cardiac manifestations were present in 71 patients (53%). In patients with cardiac involvement, median left ventricular ejection fraction (LVEF) was 40% [28-55], troponin was elevated in 93% patients, coronary angiogram (n = 19, 27%) disclosing a coronary obstruction in 21%. CMR (n = 21) was abnormal in all cases, with late gadolinium enhancement in 62% of cases. Cardiac manifestations were associated with a non-significant increase of mortality (32% vs. 19%, p = 0.08). After 1-year follow-up, median LVEF was 57% [44-60] in patients with cardiac involvement. CONCLUSION: Cardiac involvement is frequent in critically-ill thrombotic APS patients and may be associated to more severe outcome. Increased awareness on this rare cause of myocardial infarction with or without obstructive coronary artery is urgently needed.

Immune-mediated thrombotic thrombocytopenic purpura prognosis is affected by blood pressure.

Background: The prevalence, prognostic role, and diagnostic value of blood pressure in immune-mediated thrombotic thrombocytopenic purpura (iTTP) and other thrombotic microangiopathies (TMAs) remain unclear. Methods: Using a national cohort of iTTP (n = 368), Shigatoxin-induced hemolytic uremic syndrome (n = 86), atypical hemolytic uremic syndrome (n = 84), and hypertension-related thrombotic microangiopathy (n = 25), we sought to compare the cohort's blood pressure profile to assess its impact on prognosis and diagnostic performances. Results: Patients with iTTP had lower blood pressure than patients with other TMAs, systolic (130 [interquartile range (IQR) 118-143] vs 161 [IQR 142-180] mmHg) and diastolic (76 [IQR 69-83] vs 92 [IQR 79-105] mmHg, both p < 0.001). The best threshold for iTTP diagnosis corresponded to a systolic blood pressure <150 mmHg. iTTP patients presenting with hypertension had a significantly poorer survival (hazard ratio 1.80, 95% confidence interval 1.07-3.04), and this effect remained significant after multivariable adjustment (hazard ratio = 1.14, 95% confidence interval 1.00-1.30). Addition of a blood pressure criterion modestly improved the French clinical score to predict a severe A disintegrin and metalloprotease with thrombospondin type 1 deficiency in patients with an intermediate score (i.e., either platelet count <30 × 109/L or serum creatinine <200 µM). Conclusions: Elevated blood pressure at admission affects the prognosis of iTTP patients and may help discriminate them from other TMA patients. Particular attention should be paid to blood pressure and its management in these patients.

Kidney Histopathology Can Predict Kidney Function in ANCA-Associated Vasculitides with Acute Kidney Injury Treated with Plasma Exchanges.

BACKGROUND: Data from the PEXIVAS trial challenged the role of plasma exchange (PLEX) in ANCA-associated vasculitides (AAV). We aimed to describe kidney biopsy from patients with AAV treated with PLEX, evaluate whether histopathologic findings could predict kidney function, and identify which patients would most benefit from PLEX. METHODS: We performed a multicenter, retrospective study on 188 patients with AAV and AKI treated with PLEX and 237 not treated with PLEX. The primary outcome was mortality or KRT at 12 months (M12). RESULTS: No significant benefit of PLEX for the primary outcome was found. To identify patients benefitting from PLEX, we developed a model predicting the average treatment effect of PLEX for an individual depending on covariables. Using the prediction model, 223 patients had a better predicted outcome with PLEX than without PLEX, and 177 of them had >5% increased predicted probability with PLEX compared with without PLEX of being alive and free from KRT at M12, which defined the PLEX-recommended group. Risk difference for death or KRT at M12 was significantly lower with PLEX in the PLEX-recommended group (-15.9%; 95% CI, -29.4 to -2.5) compared with the PLEX not recommended group (-4.8%; 95% CI, 14.9 to 5.3). Microscopic polyangiitis, MPO-ANCA, higher serum creatinine, crescentic and sclerotic classes, and higher Brix score were more frequent in the PLEX-recommended group. An easy to use score identified patients who would benefit from PLEX. The average treatment effect of PLEX for those with recommended treatment corresponded to an absolute risk reduction for death or KRT at M12 of 24.6%. CONCLUSIONS: PLEX was not associated with a better primary outcome in the whole study population, but we identified a subset of patients who could benefit from PLEX. However, these findings must be validated before utilized in clinical decision making.

High-flow oxygen therapy versus noninvasive ventilation: a randomised physiological crossover study of alveolar recruitment in acute respiratory failure.

High-flow nasal cannula (HFNC) oxygen therapy has recently shown clinical benefits in hypoxaemic acute respiratory failure (ARF) patients, while the value of noninvasive ventilation (NIV) remains debated. The primary end-point was to compare alveolar recruitment using global end-expiratory electrical lung impedance (EELI) between HFNC and NIV. Secondary end-points compared regional EELI, lung volumes (global and regional tidal volume variation (V T)), respiratory parameters, haemodynamic tolerance, dyspnoea and patient comfort between HFNC and NIV, relative to face mask (FM). A prospective randomised crossover physiological study was conducted in patients with hypoxaemic ARF due to pneumonia. They received alternately HFNC, NIV and FM. 16 patients were included. Global EELI was 4083 with NIV and 2921 with HFNC (p=0.4). Compared to FM, NIV and HFNC significantly increased global EELI by 1810.5 (95% CI 857-2646) and 826 (95% CI 399.5-2361), respectively. Global and regional V T increased significantly with NIV compared to HFNC or FM, but not between HFNC and FM. NIV yielded a significantly higher pulse oxygen saturation/inspired oxygen fraction ratio compared to HFNC (p=0.03). No significant difference was observed between HFNC, NIV and FM for dyspnoea. Patient comfort score with FM was not significantly different than with HFNC (p=0.1), but was lower with NIV (p=0.001). This study suggests a potential benefit of HFNC and NIV on alveolar recruitment in patients with hypoxaemic ARF. In contrast with HFNC, NIV increased lung volumes, which may contribute to overdistension and its potentially deleterious effect in these patients.