The Role of High Flow Nasal Therapy in Chronic Respiratory Failure.

High-flow nasal therapy (HFNT) has an increasing role in the management of acute hypoxic respiratory failure. Due to its tolerable interface and ease of use, its role in chronic hypercapnic respiratory failure (CHRF) is emerging. This article examines the literature to date surrounding the short and long-term mechanisms of HFNT in sleep and wakefulness of CHRF patients. It is likely HFNT will have an increasing role in those patients intolerant of non-invasive ventilation.

Asymmetrical high-flow nasal cannula performs similarly to standard interface in patients with acute hypoxemic post-extubation respiratory failure: a pilot study.

BACKGROUND: Standard high-flow nasal cannula (HFNC) is a respiratory support device widely used to manage post-extubation hypoxemic acute respiratory failure (hARF) due to greater comfort, oxygenation, alveolar recruitment, humidification, and reduction of dead space, as compared to conventional oxygen therapy. On the contrary, the effects of the new asymmetrical HFNC interface (Optiflow® Duet system (Fisher & Paykel, Healthcare, Auckland, New Zealand) is still under discussion. Our aim is investigating whether the use of asymmetrical HFNC interface presents any relevant difference, compared with the standard configuration, on lung aeration (as assessed by end-expiratory lung impedance (EELI) measured by electrical impedance tomography (EIT)), diaphragm ultrasound thickening fraction (TFdi) and excursion (DE), ventilatory efficiency (estimated by corrected minute ventilation (MV)), gas exchange, dyspnea, and comfort. METHODS: Pilot physiological crossover randomized controlled study enrolling 20 adults admitted to the Intensive Care unit, invasively ventilated for at least 24 h, and developing post-extubation hARF, i.e., PaO2/set FiO2 < 300 mmHg during Venturi mask (VM) within 120 min after extubation. Each HFNC configuration was applied in a randomized 60 min sequence at a flow rate of 60 L/min. RESULTS: Global EELI, TFdi, DE, ventilatory efficiency, gas exchange and dyspnea were not significantly different, while comfort was greater during asymmetrical HFNC support, as compared to standard interface (10 [7-10] and 8 [7-9], p-value 0.044). CONCLUSIONS: In post-extubation hARF, the use of the asymmetrical HFNC, as compared to standard HFNC interface, slightly improved patient comfort without affecting lung aeration, diaphragm activity, ventilatory efficiency, dyspnea and gas exchange. CLINICAL TRIAL NUMBER: ClinicalTrial.gov. REGISTRATION NUMBER: NCT05838326 (01/05/2023). NEW & NOTEWORTHY: The asymmetrical high-flow nasal cannula oxygen therapy (Optiflow® Duet system (Fisher & Paykel, Healthcare, Auckland, New Zealand) provides greater comfort as compared to standard interface; while their performance in term of lung aeration, diaphragm activity, ventilatory efficiency, dyspnea, and gas exchange is similar.

In-Line Aerosol Therapy via Nasal Cannula during Adult and Paediatric Normal, Obstructive, and Restrictive Breathing.

High-flow nasal oxygen therapy is being increasingly adopted in intensive and home care settings. The concurrent delivery of aerosolised therapeutics allows for the targeted treatment of respiratory illnesses. This study examined in-line aerosol therapy via a nasal cannula to simulated adult and paediatric models with healthy, obstructive and restrictive lung types. The Aerogen Solo vibrating mesh nebuliser was used in combination with the InspiredTM O2FLO high-flow therapy system. Representative adult and paediatric head models were connected to a breathing simulator, which replicated several different states of lung health. The aerosol delivery was quantified at the tracheal level using UV-spectrophotometry. Testing was performed at a range of supplemental gas flow rates applicable to both models. Positive end-expiratory pressure was measured pre-, during and post-nebulisation. The increases in supplemental gas flow rates resulted in a decrease in aerosol delivery, irrespective of lung health. Large tidal volumes and extended inspiratory phases were associated with the greatest aerosol delivery. Gas flow to inspiratory flow ratios of 0.29-0.5 were found to be optimum for aerosol delivery. To enhance aerosol delivery to patients receiving high-flow nasal oxygen therapy, respiratory therapists should keep supplemental gas-flow rates below the inspiratory flow of the patient.

Terapia nasal de alto flujo en insuficiencia respiratoria grave por SARS-CoV-2 / High-flow nasal therapy in severe respiratory failure due to SARS-CoV-2

Resumen El uso de terapia nasal de alto flujo (TNAFO) en pacientes con insuficiencia respiratoria aguda grave (IRAG) por neumonía COVID-19 (NCOVID-19) es debatido. Ante la falta de camas en Unidades de Cuidados Intensivos en el Sistema de Salud Pública de la Provincia del Neuquén, se implementó su uso en salas generales. Con el objetivo de describir la experiencia de uso de la TNAFO en pacientes con IRAG por NCOVID-19, se llevó a cabo este estudio retrospectivo multicéntrico. El resultado primario fue la frecuencia de destete exitoso de TNAFO y la mortalidad intrahospitalaria (MIH). Se analizaron 299 pacientes, de éstos, 120 (40.1%) fueron retirados con éxito de la TNAFO. Esta fracasó en 59.8% (179), 44.1% (132) requirió ventilación mecánica invasiva (VMI) y 15.7% (47) no eran candidatos a la intubación. Un índice ROX ≥ 5 a las 6 h después del inicio, se asoció con el éxito de la TNAFO (OR 0.26 [IC 95% 0.15-0.46] p<0.0001). La MIH general fue del 48.5% (145/299), 70.4% (93/132) en aquellos con VMI, 4.2% (5/120) falleció post destete exitoso de la TNAFO y 100% (47/47) en el grupo no candidatos a la intubación. Los pacientes con TNAFO tuvieron una disminución estadísticamente significativa en la MIH y en días de internación. El uso de TNAFO en salas generales logró una reducción en la utilización de VMI, con una reducción de la mortalidad y días de estada en los internados por NCOVID-19 con IRAG.

Abstract The use of high-flow nasal therapy (HFNT) in patients with severe acute respiratory failure (SARF) due to COVID-19 pneu monia (NCOVID-19) is debated. Given the lack of beds in Intensive Care Units in the Public Health System of the Province of Neuquén, their use was implemented in general wards. This restrospective multicenter study was carried out to describe the experience of using HNFT in patients with SARF due to NCOVID-19. The primary outcome was the frequency of successful weaning from HFNT and in-hospital mortality (IHM). Two hundred ninety-nine patients were analyzed; 120 (40.1%) were successfully withdrawn from HFNT. This failed in 59.8% (179), 44.1% (132) required invasive mechanical ventilation (IMV), and 15.7% (47) was not candidates for intubation. A ROX index ≥ 5 at 6 h after initiation was associated with the success of HFNT (OR 0.26 [IC 95% 0.15-0.46] p<0.0001). The general IHM was 48.5% (145/299), 70.4% (93/132) in patients with IMV, 4.2% (5/120) died after successful weaning from HFNT and 100% (47/47) in the group not candidates for intubation. Patients with TNAFO had a statistically significant decrease in MIH and days of hospitalization. TNAFO in general wards achieved a decrease in the use of IMV, with a reduction in mortality and days of stay in hospitalized for NCOVID-19 with SARF.