Principi T, Pantanetti S, Catani F, Elisei D, Gabbanelli V, Pelaia P, Leoni P. Intensive Care Med. 2004 Jan;30(1):147-50
Comparison study of nCPAP through helmet vs face mask on 17 patients with moderate to severe acute respiratory failure. Arterial oxygen saturation, heart rate, respiratory rate and blood pressure were measured. Authors conclude early nCPAP with helmet imrpoves oxygentation in this scenario.
Link to abstract.