British Journal of Anaesthesia

Active noise cancelling headphones with white noise to aid sleep in non-ventilated, non-delirious critical care patients: a randomised crossover trial

      Patients sleep poorly in ICU owing to multiple factors, including excessive noise. Many sources of disturbance, such as alarms and communication between staff, cannot be modified. Earplugs have been trialled and may offer some benefit; however, newer technologies such as active noise cancelling headphones with white noise masking (ANCH) have never been trialled in critical care patients. In this study, we aimed to assess the impact of ANCH on the sleep of critical care patients, whilst assessing tolerability of equipment, and reliability of actigraphy bands.
      All critical care patients on the general ICU and HDU were screened daily for eligibility. Patients were excluded if they were receiving invasive or noninvasive ventilation, were delirious, were an infection risk, were expected to be discharged before study completion, did not have capacity to give consent, or refused consent. Patients were enrolled for two nights, spending one night wearing the headphones (intervention night), and one night receiving standard care (control night). Patients were randomised into group A or B, which determined the order of intervention night vs control night, to control for confounders. Primary outcome was the change in perceived sleep quality, measured by the Richards–Campbell Sleep Questionnaire, which is validated for use in ICU patients. Other data was collected using an actigraphy band (Xiaomi MiBand 2) worn by each participant, and a researcher composed a questionnaire capturing patient experience.
      Fourteen critical care patients in the Royal Infirmary of Edinburgh completed this randomised crossover trial within the first 5 weeks of recruitment. The mean difference in RCSQ score between intervention and control night was 5.7 (95% confidence interval [CI], –14.9–26.3). Although the mean difference suggested improved sleep, this finding was not statistically significant, with CIs overlapping 0, and P-value of 0.55. Data from the actigraphy bands was unreliable and often failed to collect any data.
      Overall, 76% of participants reported that caregiving activities disturbed their sleep, whereas as only 21% of participants reported that noise disturbed sleep.
      Active noise cancelling headphones with white noise masking did not improve all patients' sleep in critical care. Adequate noise attenuation may not be enough to improve sleep if other factors, such as pain and caregiving activities, are more disruptive. However some patients may benefit from this simple intervention.