Ear plugs, eye masks, and risk of bias

Dear Dr. Buchman,

We read with interest the randomized clinical trial assessing the impact of earplugs and eye masks on sleep quality in the surgical ICU by Obanor and colleagues[1]. We applaud the authors’ efforts to assess a nonpharmacologic option to help normalize Circadian cycling in a patient population at high risk for disturbed sleep. While the investigators observed a significant improvement in the Richards-Campbell sleep questionnaire score[2], it is notable that there was not an improvement in satisfaction overall for patients who completed a modified Family Satisfaction in the ICU survey[3], and we still do not know if this intervention reliably helps us decrease the most concerning potential sequela of disturbed sleep – ICU delirium.

Because the earplug and mask intervention does not allow patient, nurse, or intensivist blinding, there is significant potential for bias. The authors note that the Richards-Campbell sleep questionnaire is validated against polysomnography, but this is not the case in the setting of an unblinded intervention. The authors note an overall sleep score of 64.5 for the intervention group “indicating better-than-normal sleep” and indicate that a score of 50 is normal. The control group overall score of 47.3 is likely not statistically different from “normal”, despite patients being in the ICU with hourly flap checks. This seems to highlight the limitations of the tool in this setting. Furthermore, in the modified Family Satisfaction survey a “Poor” rating for each nursing communication, level of light during sleep, and ICU atmosphere occurred only in the intervention group and may have been directly related to the mask and earplug intervention. Thus, while the findings are encouraging, the results do not yet warrant wide-spread adoption of this intervention.

We commend the authors on their work. Future interventional trials evaluating earplugs and eye masks in the ICU should target patients at higher risk for delirium and should use additional objective outcomes (i.e., actigraphy, electroencephalogram-based measures) to optimize the translatability of the findings. Given the simplicity of the earplug and eye mask intervention, it is a strong candidate for a pragmatic trial to evaluate effects on sleep quality, ICU delirium, and patient satisfaction.