Bench Evaluation of Four Portable Oxygen Concentrators Under Different Conditions Representing Altitudes of 2438, 4200, and 8000 m

International audienceBunel, Vincent, Amr Shoukri, Frederic Choin, Serge Roblin, Cindy Smith, Thomas Similowski, Capucine Morélot-Panzini, and Jésus Gonzalez. Bench evaluation of four portable oxygen concentrators under different conditions representing altitudes of 2438, 4200, and 8000 m. High Alt Med Biol. 17:370–374, 2016.—Air travel is responsible for a reduction of the partial pressure of oxygen (O2) as a result of the decreased barometric pressure. This hypobaric hypoxia can be dangerous for passengers with respiratory diseases, requiring initiation or intensification of oxygen therapy during the flight. In-flight oxygen therapy can be provided by portable oxygen concentrators, which are less expensive and more practical than oxygen cylinders, but no study has evaluated their capacity to concentrate oxygen under simulated flight conditions. We tested four portable oxygen concentrators during a bench test study. The O2 concentrations (FO2) produced were measured under three different conditions: in room air at sea level, under hypoxia due to a reduction of the partial pressure of O2 (normobaric hypoxia, which can be performed routinely), and under hypoxia due to a reduction of atmospheric pressure (hypobaric hypoxia, using a chamber manufactured by Airbus Defence and Space). The FO2 obtained under conditions of hypobaric hypoxia (chamber) was lower than that measured in room air (0.92 [0.89–0.92] vs. 0.93 [0.92–0.94], p = 0.029), but only one portable oxygen concentrator was unable to maintain an FO2 ≥ 0.90 (0.89 [0.89–0.89]). In contrast, under conditions of normobaric hypoxia (tent) simulating an altitude of 2438 m, none of the apparatuses tested was able to achieve an FO2 greater than 0.76. (0.75 [0.75–0.76] vs. 0.93 [0.92–0.94], p = 0.029). Almost all portable oxygen concentrators were able to generate a sufficient quantity of O2 at simulated altitudes of 2438 m and can therefore be used in the aircraft cabin. Unfortunately, verification of the reliability and efficacy of these devices in a patient would require a nonroutinely available technology, and no preflight test can currently be performed by using simple techniques such as hypobaric hypoxia

Morphologic, immunphenotypic and clinical discriminators between T-cell/histiocyterich large B-cell lymphoma and lymphocyte-predominant Hodgkin lymphoma

BACKGROUND: Features of T-cell/histiocyte rich large B-cell lymphoma (THRLBCL) overlap with those of lymphocyte predominant Hodgkin lymphoma (LPHL). The two lymphomas may represent a spectrum of the same disease, and differentiation between the two can sometimes be difficult. We looked at histomorphologic, immunophenotypic and clinical information that may help differentiate the two entities. METHODS: Cases of THRLBCL and LPHL were blindly reviewed and studied for histological pattern (nodular vs. diffuse), nuclear features and pattern of expression of CD20, CD30, CD57, epithelial membrane antigen (EMA) and Epstein-Barr virus (EBV). A score encompassing diffuse histology, high nuclear grade, CD20 single-cell pattern, CD30+, CD57-, EMA-, and EBV+was estimated for the diagnosis of TCHRLBCL. RESULTS: There were 58 cases, including 30 cases of TCHRLBL and 28 cases of LPHL. The median age was 36 years for TCHRLBCL and 21 years for LPHL (P=0.0001). Three types of nuclei were identified (lymphocytic/histocytic, Reed-Sternberg and centroblast-like). The latter two high-grade nuclei were suggestive of TCHRLBCL. TCHRLBCL and LPHL, respectively, showed diffuse histology, 90% vs. 4% (P=0.001), single CD20+ cells, 93% vs. 3.5% (P=0.00004), CD30+ cells, 30% vs. 0% (P=0.01), CD57+ cells, 41% vs. 93% (P=0.008), EMA+cells, 27% vs. 60% (P=0.113), EBV+cells, 24% vs. 0% (P=0.117), high nuclear grade, 70% vs. 0% (P=0.001), total score 2-7 (mean 4.68) vs. 0-2 (mean 0.72) (P=0.001), high stage, 86% vs. 7% (P=0.0001). CONCLUSION: Our findings indicate that a combination of multiple parameters can help differentiate between the two diseases. Two cases originally diagnosed as LPHL were re-assigned the diagnosis of THRLBCL

Initiation of non-invasive ventilation in amyotrophic lateral sclerosis and clinical practice guidelines: Single-centre, retrospective, descriptive study in a national reference centre

<p>In amyotrophic lateral sclerosis (ALS), respiratory muscle weakness leads to respiratory failure. Non-invasive ventilation (NIV) maintains adequate ventilation in ALS patients. NIV alleviates symptoms and improves survival. In 2006, French guidelines established criteria for NIV initiation based on limited evidence. Their impact on clinical practice remains unknown. Our objective was to describe NIV initiation practices of the main French ALS tertiary referral centre with respect to guidelines. In this retrospective descriptive study, 624 patients followed in a single national reference centre began NIV between 2005 and 2013. We analysed criteria used to initiate NIV, including symptoms, PaCO₂, forced vital capacity, maximal inspiratory pressures and time spent with SpO₂ <90% at night. At NIV initiation, 90% of patients were symptomatic. Median PaCO₂ was 48 mmHg. The main criterion to initiate NIV was ‘symptoms’ followed by ‘hypercapnia’ in 42% and 34% of cases, respectively. NIV was initiated on functional parameters in only 5% of cases. Guidelines were followed in 81% of cases. In conclusion, despite compliance with French guidelines, the majority of patients are treated at the stage of symptomatic daytime hypoventilation, which suggests that NIV is initiated late in the course of ALS. Whether this practice could be improved by changing guidelines or increasing respiratory-dedicated resources remains to be determined.</p