The low-flow mask oxygen is a more effective, comfortable, and easy-to-follow treatment for psychogenic hyperventilation syndrome: a double-blind, randomized controlled trial

Objectives To compare the effect of low-flow mask oxygenation (LFMO) with breathing training (BT) for psychogenic hyperventilation syndrome (PHVS), providing more options and evidence for clinical treatment. Methods A randomized double-blinded controlled experiment was registered in the Chinese Clinical Trial Registry on 01/06/2023 with a defined number (ChiCTR2300072044) and approved by the Ethics Committee of (REDACT) (GYZXLL2023070) and then conducted there from 10 May 2024 to 23 November 2024. Participants with PHVS were blindly randomized into the LFMO group and the BT group, then the LFMO group inhaled 3L/minute oxygen with the oxygen mask and breathed freely, while the BT group performed the breath training led by researchers face-on-face. The recovery length from PHVS, the Nijmegen Questionnaire score at fifteen minutes since the intervention, the Nijmegen Questionnaire score at the end of the intervention, and the comfort/tolerance score (participant rating via NRS) were collected as the primary outcome. The secondary outcome was measured by the mean breath rate during the recovery (Calculated by dividing the total number of breaths during the intervention by time) and laboratory results, including the PH, lactate, K+, Ca2+, PO ₂ , and PCo _2. Results Forty-five participants (all Asian) completed the study and were included in the analysis (21 for the LFMO group and 24 for the BT group), mainly female (75%, n=33). All demographic characteristics between the two groups are within the reasonable range and have no significant difference. However, significant differences were measured among the outcomes, including the oxygen index (480.22±29.64, 311.01±15.45, p<0.001), Mean breath rate during recovery (19.17±1.74,28.24±2.53, p<0.001), and the LFMO group showed significant advantages in both the length of recovery (22.94±2.81, p<0.001) and comfort/tolerance (5.86±1.24, p<0.001). Conclusion Compared to breath training therapy, the low-flow mask oxygenation is a more effective, comfortable, and easy-to-follow treatment for PHVS.