How different helmet fixing options could affect patients' pain experience during helmet-continuous positive airway pressure.

Background: Prolonged application time of helmet continuous positive airway pressure (CPAP) leads to better outcomes, but its timing can be influenced by the patient's tolerance. Aims and objectives: To investigate patients' pain and tolerance experience related to different options of helmet fixing system: 'armpits strap' versus 'counterweights system'. Design: This was a non-randomized crossover study performed in a 10-bed intensive care unit and referral extra corporeal membrane oxigenation (ECMO) centre of an Italian university hospital. Results: Twenty patients were enrolled. For helmet-CPAP cycles performed with the armpit straps option, the mean pain numerical rate on a 0-10 scale was: 0.5 +/- 1.4 at T-0 (baseline), 1.5 +/- 2.0 at T-1 (after 1 h) and 2.6 +/- 2.5 at T-2 (end of cycle) (p=0.023). The same analysis was performed for the counterweights fixing option. The mean score was 0.3 +/- 0.6 at T-0, 0.3 +/- 0.2 at T1 and 0.5 +/- 0.7 at T-2 (p=0.069). The mean duration for CPAP cycles performed with armpits strap and counterweights system was 3.0 +/- 1.0 and 3.9 +/- 2.3 h, respectively (p<0.001). The mean section of the Basilic vein that was investigated before wearing the helmet was equal to 0.23 +/- 0.20 cm2. After 1 h of therapy with the counterweight option and armpit straps, the mean increase of the vein's section was 0.27 +/- 0.21(p=0.099) and 0.30 +/- 0.25, respectively (p=0.080). Conclusions: The fixing system options in use to anchor the helmet during CPAP could worsen the pain experience level and cause device-related pressure ulcers. When compared with the armpit straps option, the counterweights system appears to be a suitable approach to minimize the risks of pressure sores and pain during the treatment. Relevance to practice: The helmet CPAP is a reliable therapy to manage acute respiratory failure. Major improvements regarding pulmonary alveolar recruitment and oxygen levels are strictly related to a prolonged time of helmet CPAP cycles. Using a counterweight fixing system, where the armpits straps are not necessary, could be helpful in reducing patients' pain experience.