Prone Positioning During High Flow Oxygen Therapy in Acute Hypoxemic Respiratory Failure

Plain-language summary

Background High-flow nasal cannula (NHF) are a promising tool for administering oxygen to critically ill patients with high respiratory demand. Prone positioning (PP) is a simple and cost-effective strategy that since 1980s has been used in mechanically ventilated patients with acute respiratory failure to treat oxygenation impairment. A large randomized study detected a relevant survival benefit by prone positioning in patients with moderate to severe acute respiratory distress syndrome (ARDS) undergoing invasive mechanical ventilation and managed with the ARDS network PEEP-FiO2 table strategy. Theoretically, PP may benefit spontaneous breathing patients too, but data concerning its application in such context are limited to small case series and a retrospective study. The investigators designed a pilot feasibility study to assess the safety and efficacy of prone positioning in acute hypoxemic respiratory failure patients noninvasively treated with NHF. Methods Patients: 15 adult hypoxemic (PaO2/FiO2\<200 mmHg with respiratory rate greater than 25 breaths per minute) non-hypercapnic patients with acute respiratory failure. PaO2/FiO2 will be assessed while the patients is receiving 50 L/min of 50% oxygen via a standard face mask for a 15-minute monitoring period at study entry. Protocol Eligible patients will undergo NHF for 1 hour in the supine semi-recumbent position (baseline, BL). Afterwards, each enrolled patient will be placed in the prone position for 2 hours. After a 2-hour PP period, the patient will be rotated and will undergo 1 hour of NHF in the semi recumbent supine position (Supine step). Measurements Patient's demographics will be collected at study entry. At the end of the monitoring period, and then on a hourly basis the following data will be collected: * Respiratory rate, SpO2, pH, PaCO2, PaO2, SaO2, PaO2/FiO2; * Heart Rate, arterial blood pressure; * Dyspnea, as defined by the VAS dyspnoea scale; * Discomfort, as defined by a visual analogic scale (VAS) adapted to rate the procedural pain of ICU patients; * End expiratory lung impedance (EELI), tidal volume distribution, global and regional lung dynamic strain (Change in lung impedence due to tidal volume/ELLI). * Work of breathing, assessed by pressure-time product (PTP) of the esophageal pressure and inspiratory swings in this signal. * Occurrence of pendelluft phenomenon The number of adverse events will be also recorded for each study step.

Who can participate

What they're measuring

Trial details