High-Flow Nasal Cannula and Standard Oxygen in Acute Hypoxemic Respiratory Failure Due to COVID-19.

BACKGROUND: The evidence regarding benefits of high-flow nasal cannula (HFNC) in patients with COVID-19 is controversial. The aim of this study was to evaluate the impact of HFNC in comparison with standard oxygen therapy on the frequency of endotracheal intubation at 28 d in subjects with acute hypoxemic respiratory failure (AHRF) secondary to SARS-CoV-2 infection. METHODS: A retrospective, age- and sex-matched-paired, cohort study was conducted in subjects with moderate-to-severe AHRF. Intervention group was treated with HFNC, and control group was treated with standard oxygen therapy. Baseline characteristics and clinical evolution were analyzed. Mantel-Haenszel test was used for categorical variables. Paired samples Wilcoxon test was used for quantitative variables. Multivariate analysis was performed using conditional multiple logistic regression. RESULTS: Eighty-four subjects were included. The median time from admission to progression of oxygen therapy to FIO2 ≥ 0.5 or HFNC was 1 (interquartile range [IQR] 0-3) d. PaO2 /FIO2 at the time of oxygen therapy progression showed a median of 150.5 (IQR 100.0-170.0) for the entire sample and was lower in HFNC group compared with control group (median 135 [IQR 96-162] vs median 158 [IQR 132-174], respectively, P = .02). Endotracheal intubation at 28 d was observed in 54.8% HFNC and 73.8% standard oxygen (unadjusted odds ratio 0.38 [95% CI 0.13-1.07], P = .069). In the multivariate analysis, presence of dyspnea at hospital admission, Sequential Organ Failure Assessment score, and PaO2 /FIO2 at time of progression of oxygen therapy to FIO2 ≥ 0.5 was identified as confounding factors for the association between the intervention group and the outcome. Use of HFNC was not an independent predictor of endotracheal intubation frequency after adjusting confounders (odds ratio 0.26 [95% CI 0.04-1.51], P = .13). CONCLUSIONS: In this study, HFNC therapy in subjects with AHRF secondary to COVID-19 was not an independent predictor of endotracheal intubation, compared with standard oxygen therapy, after adjusting for confounders.

Automatic detection of reverse-triggering related asynchronies during mechanical ventilation in ARDS patients using flow and pressure signals.

Asynchrony due to reverse-triggering (RT) may appear in ARDS patients. The objective of this study is to validate an algorithm developed to detect these alterations in patient-ventilator interaction. We developed an algorithm that uses flow and airway pressure signals to classify breaths as normal, RT with or without breath stacking (BS) and patient initiated double-triggering (DT). The diagnostic performance of the algorithm was validated using two datasets of breaths, that are classified as stated above. The first dataset classification was based on visual inspection of esophageal pressure (Pes) signal from 699 breaths recorded from 11 ARDS patients. The other classification was obtained by vote of a group of 7 experts (2 physicians and 5 respiratory therapists, who were trained in ICU), who evaluated 1881 breaths gathered from recordings from 99 subjects. Experts used airway pressure and flow signals for breaths classification. The RT with or without BS represented 19% and 37% of breaths in Pes dataset while their frequency in the expert's dataset were 3% and 12%, respectively. The DT was very infrequent in both datasets. Algorithm classification accuracy was 0.92 (95% CI 0.89-0.94, P < 0.001) and 0.96 (95% CI 0.95-0.97, P < 0.001), in comparison with Pes and experts' opinion. Kappa statistics were 0.86 and 0.84, respectively. The algorithm precision, sensitivity and specificity for individual asynchronies were excellent. The algorithm yields an excellent accuracy for detecting clinically relevant asynchronies related to RT.

Effects of High-Flow Nasal Cannula on End-Expiratory Lung Impedance in Semi-Seated Healthy Subjects.

BACKGROUND: High-flow nasal cannula (HFNC) enables delivery of humidified gas at high flow while controlling the FIO2 . Although its use is growing in patients with acute respiratory failure, little is known about the impact of HFNC on lung volume. Therefore, we aimed to assess lung volume changes in healthy subjects at different flows and positions. METHODS: This was a prospective physiological study performed in 16 healthy subjects. The changes in lung volumes were assessed by measuring end-expiratory lung impedance by using electrical impedance tomography. All the subjects successively breathed during 5 min in these following conditions: while in a supine position without HFNC (T0) and 3 measurements in a semi-seated position at 45° without HFNC (T1), and with HFNC at a flow of 30 L/min (T2), and 50 L/min (T3). RESULTS: Compared with the supine position, the values of end-expiratory lung impedance significantly increased with the subjects in a semi-seated position. End-expiratory lung impedance significantly increased after HFNC initiation in subjects in a semi-seated position and further increased by increasing flow at 50 L/min. When taking the end-expiratory lung impedance measurement in subjects in a semi-seated position (T1) as reference, the differences among the medians of global end-expiratory lung impedance were statistically significant (P < .001), which amounted to 1.05 units in T1; 1.12 units in T2; and 1.44 units in T3 (P < .05 for all comparisons, Wilcoxon test). The breathing frequency did not differ between the supine and semi-seated position (T0 and T1) but significantly decreased after initiation of HFNC and further decreased at high flow. T0 and T1 were not different (P = .13); whereas there was a statistically significant difference among T1, T2, and T3 (P < .05, post hoc test with Bonferroni correction). CONCLUSIONS: In healthy subjects, the semi-seated position and the use of HFNC increased end-expiratory lung impedance globally. These changes were accompanied by a significant decrease in the breathing frequency.

Adaptación cultural y validación del Dizziness Handicap Inventory: versión Argentina / Cross-cultural adaptation and validation of the Dizziness Handicap Inventory: Argentine version

Introducción y objetivos: El Dizziness Handicap Inventory es una herramienta útil para cuantificarla autopercepción de la discapacidad en pacientes con vértigo, mareo o inestabilidad y su impacto en actividades de la vida diaria. El Dizziness Handicap Inventory identifica problemas de orden funcional, físico y emocional relacionados con trastornos del equilibrio. Nuestro objetivo es realizar la adaptación cultural y validación del Dizziness Handicap Inventory al castellano argentino a partir de la versión española. Métodos: Se incluyeron personas sanas y pacientes con vértigo, mareo o inestabilidad, de 18 a 85 años, argentinos nativos capaces de comprender castellano. Sobre la versión española se realizaron modificaciones lingüísticas y culturales para obtenerla versión argentina. Esta versión se administró a un grupo de 108 pacientes, 2 veces, en un lapso de 24 a 72 h. Se evaluó consistencia interna, confiabilidad test-retest y validez de constructo a través de: Escala Visual Análoga, Romberg, Romberg en tándem y marcha en tándem. Resultados: Se encontró una alta consistencia interna (Alfa=0,87), y muy alta confiabilidad testretest del Dizziness Handicap Inventory total (coeficiente de correlación intraclase: 0,98) y sus subescalas. Se encontraron correlaciones significativas entre Romberg y el Romberg en tándemcon el Dizziness Handicap Inventory total y la subescala funcional. La subescala emocional mostró una correlación significativa cuando se comparó con Romberg y Romberg en tándem ojos abiertos (p < 0,05).Conclusiones: La versión argentina del Dizziness Handicap Inventory mostró ser una herramienta confiable y válida para cuantificar la autopercepción de la discapacidad debida a vértigo, mareo o inestabilidad(AU)

Introduction and objectives: The Dizziness Handicap Inventory is a useful tool for quantifying self-perceived handicap in patients with vertigo, dizziness or unsteadiness and its impact on daily living activities. The Dizziness Handicap Inventory identifies functional, physical and emotional disorders related to balance disturbance. Our objective was to cross-culturally adapt the Peninsular Spanish version of the Dizziness Handicap Inventory for use in Argentina and validate the adapted Argentinian version. Methods: We included both healthy subjects and patients with vertigo, dizziness or unsteadiness, aged 18 to 85 years, native Spanish-speaking Argentinians. We introduced linguistic and cultural modifications to the Peninsular Spanish version to obtain the Argentinian one. This version was given twice to 108 patients, 24 to 72 h apart. Internal consistency, test-retest reliability and construct validity were assessed using a visual analogue scale, the Romberg test, the tandem Romberg test and the tandem gait test. Results: We found high internal consistency (Alfa=0.87) and very high test-retest reliability for the total Dizziness Handicap Inventory score (intraclass correlation coefficient: 0.98) and its subscales. The total Dizziness Handicap Inventory and the functional subscale were found to correlate significantly with the Romberg and tandem Romberg tests. The emotional subscales howed a significant correlation with the Romberg test and the eyes-open tandem Romberg test(P<.05)Conclusions: The Argentinian version of the Dizziness Handicap Inventory proved to be a reliable and valid tool to quantify self-perceived handicap resulting from vertigo, dizziness or unsteadiness(AU)

[Cross-cultural adaptation and validation of the Dizziness Handicap Inventory: Argentine version]. / Adaptación cultural y validación del Dizziness Handicap Inventory: versión Argentina.

INTRODUCTION AND OBJECTIVES: The Dizziness Handicap Inventory is a useful tool for quantifying self-perceived handicap in patients with vertigo, dizziness or unsteadiness and its impact on daily living activities. The Dizziness Handicap Inventory identifies functional, physical and emotional disorders related to balance disturbance. Our objective was to cross-culturally adapt the Peninsular Spanish version of the Dizziness Handicap Inventory for use in Argentina and validate the adapted Argentinian version. METHODS: We included both healthy subjects and patients with vertigo, dizziness or unsteadiness, aged 18 to 85 years, native Spanish-speaking Argentinians. We introduced linguistic and cultural modifications to the Peninsular Spanish version to obtain the Argentinian one. This version was given twice to 108 patients, 24 to 72 h apart. Internal consistency, test-retest reliability and construct validity were assessed using a visual analogue scale, the Romberg test, the tandem Romberg test and the tandem gait test. RESULTS: We found high internal consistency (α=0.87) and very high test-retest reliability for the total Dizziness Handicap Inventory score (intraclass correlation coefficient: 0.98) and its subscales. The total Dizziness Handicap Inventory and the functional subscale were found to correlate significantly with the Romberg and tandem Romberg tests. The emotional subscale showed a significant correlation with the Romberg test and the eyes-open tandem Romberg test (P<.05) CONCLUSIONS: The Argentinian version of the Dizziness Handicap Inventory proved to be a reliable and valid tool to quantify self-perceived handicap resulting from vertigo, dizziness or unsteadiness.