Response.

To the Editor:

We thank Dr Fiorentino and coworkers for their interest in our recently published experience on prone and lateral positioning in spontaneously breathing patients with COVID-19 pneumonia undergoing noninvasive helmet CPAP treatment. Noninvasive ventilation (NIV) and noninvasive CPAP have been extensively used during the COVID-19 pandemic, as documented by several observational studies published over the past few months, although no randomized controlled studies have been designed to investigate their safety and efficacy in this specific population. , Different clinical challenges of prone and lateral positioning in spontaneously breathing patients with COVID-19 pneumonia undergoing NIV/CPAP treatment should be acknowledged, including an adequate patients’ selection and the correct use of the interface. First, Dr Fiorentino and coworkers accurately underlined the crucial role of both radiology and lung ultrasounds in identifying potential responders. However, we should also acknowledge potential difficulties in performing chest CT scans in patients with severe COVID-19 as well as the low specificity of lung ultrasounds in deeply characterizing the interstitial pattern of a COVID-19 pneumonia. Second, the identification of a positive physiological response to the application of positive end-expiratory pressure during helmet CPAP treatment along with optimal levels of positive end-expiratory pressure is of paramount importance. Recent data documented a successful lung recruitability test in fewer than 30% of COVID-19 patients undergoing CPAP, and these tests also should be considered in clinical practice in patients undergoing prone and lateral positioning to document safety and efficacy of this intervention. Third, the management of the interface, either facemask or helmet, during NIV/CPAP should be optimized during prone and lateral positioning, as anticipated by Dr Fiorentino and coworkers. A 180-degree rotation of the helmet during CPAP/NIV treatment is crucial to have the safety (anti-asphyxia) valve free from any possible obstruction. The use of armpit braces could be avoided to improve patients’ tolerance during prone or lateral positioning, and rolled sheets or pillows could be used to prevent skin lesions caused by ischemia, shearing forces, or mechanical stress because of the pressure of the helmet collar on the patient’s neck. Patients also should be trained to safety move their arms or legs and identify a comfortable position during prone/lateral positioning. Finally, prone/lateral positioning in spontaneously breathing patients with COVID-19 pneumonia undergoing CPAP/NIV treatment should always be planned in a safe environment with very-well-trained staff.