ICU Clinicians Underestimate Breathing Discomfort in Ventilated Subjects

BACKGROUND: Breathing discomfort (dyspnea) during mechanical ventilation in the ICU may contribute to patient distress and complicate care. Assessment of nonverbal cues may allow care-givers to estimate patient breathing discomfort. This study assesses the accuracy of those caregiver estimates. METHODS: Thirty subjects were identified from ventilated, hemodynamically stable patients in the special care unit of Maine Medical Center. Those with impaired neurological function or too unstable to waken were excluded. Subjects provided a subjective score of breathing discomfort (0-10 using a modified Borg scale) during daily wake-up from sedation (sedation agitation score of 3 or 4). Clinicians (physicians, respiratory therapists, and nurses) then provided a blinded estimate of subject breathing discomfort (0-10) through observation of the subject and inspection of ventilator parameters alone. Subject scores and caregiver estimates were compared. RESULTS: All subjects reported breathing discomfort with median score (interquartile range) of 4 (3-4). Caregiver estimates of breathing discomfort were significantly lower than subject scores (2 [0-3]), and the discrepancy was seen in all professions (physicians 1 point lower [0-2], P =.02; respiratory therapists 1 point lower [0-2], P =.01; nurses 2 points lower [1-3], P <.001). There was a positive correlation between subject breathing discomfort and degree of underestimation (ie, the degree of underestimation increased as the subject scores rose). The 3 most commonly used cues were subjects' facial expression, use of accessory muscles, and nasal flaring. CONCLUSIONS: Significant breathing discomfort is prevalent in mechanically ventilated ICU patients and is underestimated by caregivers, regardless of profession. The increasing disparity in caregiver estimate as breathing discomfort rises may expose patients to levels of dyspnea that promote anxiety and fear. This study demonstrates the need for further development and standardization of methods to assess dyspnea in nonverbal patients.