A Novel Scale to Assess Humidification during Noninvasive Ventilation: A Prospective Observational Study.

Objective: To develop a novel scale to assess humidification during noninvasive ventilation (NIV). Methods: This study was performed in an ICU of a teaching hospital. Three ICU practitioners with more than 10 years of clinical experience developed an oral humidification scale with a range of 1-4 points. Each studied the current literature on humidification and examined 50 images of mouths of NIV patients with different levels of humidification. Then, through discussion, a consensus scale was developed. Next, 10 practitioners and 33 NIV patients were recruited to validate the scale. Finally, the patients rated the dryness of their mouths using the 1-4 visual scale just after the practitioners' assessment. Talking and discussion were forbidden during the assessment, and the scorers were blinded to each other. Results: We performed 36 assessments in 33 NIV patients. Three patients were assessed twice each more than 2 days apart. The interitem correlation coefficients between the 10 practitioners ranged from 0.748 to 0.917. Fleiss's kappa statistic was 0.516, indicating moderate agreement among practitioners. Of the 33 patients, 5 (15%) were unable to make an assessment using the 1-4 visual scale. Among the remainder, 55.7% provided scores that matched those given by the practitioners; 13.7% of scores were 1 point higher than that rated by the practitioners, and 20.7% were 1 point lower. Only 10% were beyond a 1-point difference. The kappa coefficient was 0.483 between patients and practitioners. Conclusions: The oral humidification scale showed moderate agreement between practitioners. It was also highly accurate in reflecting the level of humidification assessed by patients.