key: cord-0851990-z8ys4e2f
authors: Retucci, Mariangela; Aliberti, Stefano; Ceruti, Clara; Santambrogio, Martina; Tammaro, Serena; Cuccarini, Filippo; Carai, Claudia; Grasselli, Giacomo; Oneta, Anna Maria; Saderi, Laura; Sotgiu, Giovanni; Privitera, Emilia; Blasi, Francesco
title: Prone and lateral positioning in spontaneously breathing patients with COVID-19 pneumonia undergoing non-invasive helmet CPAP treatment
date: 2020-07-15
journal: Chest
DOI: 10.1016/j.chest.2020.07.006
sha: bcc81a7dd98e90b07775caedd12dcea3ba70e7b0
doc_id: 851990
cord_uid: z8ys4e2f

nan

Patients with COVID-19 pneumonia can develop hypoxemic acute respiratory failure (hARF) which might require the application of a positive end-expiratory pressure (PEEP) (1) . Non-invasive continuous positive airway pressure (CPAP) improves oxygenation and reduces the need for endotracheal intubation in comparison with standard oxygen therapy in patients with severe hARF due to pneumonia (2, 3) . During CPAP treatment, patients with hARF might also benefit of additional interventions, such as prone positioning (4) . Pronation of awake, spontaneously breathing, non-intubated patients with hARF is feasible, safe, and associated with a significant benefit on oxygenation (5, 6) . Lateral position may be also associated with beneficial effects on gas exchange, especially in unilateral widespread infiltrates (7) . Finally, a recent experience demonstrated that awake, early self-proning improves oxygen saturation in COVID-19 patients (8) .

The objective of this study was to evaluate the efficacy of both prone and lateral positioning in patients undergoing helmet CPAP because of hARF caused by COVID-19 pneumonia.

A pilot, observational, prospective study was conducted at the COVID-19 respiratory highdependency unit (HDU) of the Policlinico Hospital in Milan, Italy, between March and April 2020.

The respiratory HDU is characterized by a nurse:patient ratio per shift of 1:4, multivariable monitors, non-invasive ventilators (NIV) and life support, on-site intubation and invasive ventilation, attending physicians available 24/7, bronchoscopy and arterial blood gas analysis inside the unit (9) . Consecutively recruited adults (≥18 years) with hARF caused by laboratoryconfirmed COVID-19 pneumonia undergoing helmet CPAP treatment were included in this study.

All patients undergoing helmet CPAP had a Glasgow Coma Scale (GCS) of 15, were spontaneously breathing, and non-intubated. The IRB of the Policlinico hospital approved the study (#345_2020).

Patients with at least one of the following criteria were excluded: need for immediate intubation; GCS<15, systolic blood pressure (SBP) < 90 mmHg, and SpO 2 <90% at FiO 2 >0.8. Patients underwent either prone or lateral positioning according to standard operating procedures and the last chest X-ray or chest CT scan. A trial of prone/lateral position as an intervention in COVID-19 patients undergoing helmet CPAP if their PaO 2 :FiO 2 ratio evaluated during helmet CPAP treatment was persistently below 250 after at least 48 hours since helmet CPAP was started. Lateral position was performed when lung impairment was mainly monolateral, placing the lung with no or less involvement down, whereas prone position was adopted when lung impairment was bilateral, see Table 1 and Figure 1 .c for all patients who completed the trial. In terms of primary endpoint, 6 (15.4%) trials were successful with a decrease of A-aO 2 of 20% during the trial or more in comparison to baseline. 3 (7.7%) trials showed a A-aO 2 decrease of at least 30% in comparison with baseline values. 17 (46.1%) trials showed a decrease of less than 20% of A-aO 2 . A total of 15 (38.5%) trials failed: 1 (2.6%) patient experienced a decrease of SBP (below 90 mmHg), 2 developed discomfort (5.1%), 3 (7.7%) an increase in RR, and 9 (23.1%) an increase of A-aO 2 . Among trials conducted in prone positioning, 33.3% succeeded, 41.7% showed a decreased A-aO 2 (less than 20%), whereas 25% failed. Among trials conducted in lateral positioning, 8% succeeded, 52% showed a decrease of A-aO 2 (less than 20%), while 40% failed. Improved gas exchange which was achieved during the trial reverted returning to the semi-seated position (Table 1) . 7/26 (26.9%) patients underwent intubation and were mechanically ventilated, and 2 (7.7%) died.

The main study findings are: 1) only a small proportion of prone/lateral positioning tests This study has several limitations. First, it was designed as a "purely physiologic" study, without assessment of the potential impact of prone/lateral positioning on clinical outcomes or confounders, such as setting (e.g., FiO 2 and PEEP) and length of CPAP treatment before the trial. 

No sponsors have been involved in the present study 

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Scientific Group on Respiratory Intensive Care of the Italian Association of Hospital Pneumologists. Increased number and expertise of italian respiratory high-dependency care units: the second national survey

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Prone positioning in severe acute respiratory distress syndrome