Southmed began producing ventilation hoods in response to the 2020 COVID-19 pandemic. Helmet-type interfaces have been used for the delivery of non-invasive ventilation (NIV) and the administration of positive end expiratory pressure (PEEP) for a number of years. There are a number of articles showing an improved outcome in cases such as acute respiratory distress syndrome (ARDS). (1). Non-invasive ventilation offers significant advantages reducing the need for sedation. It also allows for prone positioning with reduced nursing intensity. Furthermore, there is the possibility of using the ventilation hoods without the need to be connected to a ventilator, a significant benefit in a COVID pandemic in which ventilator units may be in full use.
Helmet ventilation may offer advantages over face mask positive pressure ventilation including increased patient comfort, reduced leakage and failure of the mask to achieve a satisfactory seal. (2)
More recent experience has shown PEEP administered via a ventilation hood to be advantageous for some patients with COVID-19 infection. There is a suggestion of a reduction in the requirement for invasive ventilation. There is also evidence to suggest positive pressure via a helmet is preferred by the patient compared to a conventional face mask. The problems of regular leakage of aerosols around the mask particularly with patient movement is greatly reduced with the use of a ventilation hood.
While ventilation hoods are not recommended solely as viral 'containment' devices, the ventilation hood produced by Southmed has connections for viral filters on all outflow channels (including on its free-breathing valve). This potentially reduces the risk of cross infection between medical staff and the patient.
In 2020 Professor Antonio Pesenti (head of Intensive care medicine at the University of Milan, Italy) presented evidence recommending the use of hood ventilation in certain cases with COVID-19 infection. His findings suggest 20-35% of patients improve with the use of non-invasive ventilation via the hood interface avoiding the need for intubation. "CPAP is advised using a helmet in preference to a face mask interface. CPAP value are set between 10 and 12 cm H20 according to patient's needs, tolerance and any side- effects".
(1) Patel BK, et al. Effect of noninvasive ventilation delivered by hood vs face mask on the rate of endotracheal intubation in patients with acute respiratory distress syndrome. JAMA, 2016, June 14, 315(22). 2435-2441.
(2) Davide Chiumello Paolo Pelosi Eleonora Carlesso Paolo Severgnini Michele Aspesi Chiara Gamberoni Massimo Antonelli Giorgio Conti Maurizio Chiaranda Luciano Gattinoni. "Noninvasive positive pressure ventilation delivered by helmet vs. standard face mask". Intensive Care Med (2003) 29&colon1671-1679.
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