Background: Standard measures of dyspnea rely on the patient's self-report. Declining consciousness and/or cognitive function and nearness to death may interfere with dyspnea reporting making the patient vulnerable to undertreatment or overtreatment.
Methods: An observational design was used with 89 consecutive patients referred for inpatient palliative care consultation. Patients were included if they were at risk for dyspnea because of one or more of the following: lung cancer, chronic obstructive pulmonary disease (COPD), heart failure, or pneumonia. Patients were asked "Are you short of breath?" and asked to quantify any distress by pointing to a visual analogue scale (VAS). Other measures included: consciousness, cognitive state, terminal illness severity, and patient demographics.
Results: More than half of the patients (54%) were unable to provide a yes or no response. Only 20 of 41 (49%) able to respond with yes or no were able to quantify any distress with the VAS. Ability to self-report was positively associated with consciousness (p < 0.01), cognitive state (p < 0.01), and terminal illness severity (p < 0.01). A significant inverse relationship was found between consciousness and terminal illness severity (p < 0.01). Declines in consciousness and cognitive state were strongly correlated with nearness to death (p < 0.01).
Conclusions: Declining consciousness and/or cognitive state are expected when patients are near death. The ability to give even the simplest self-report (yes or no) about dyspnea is lost in the near-death phase of terminal illness, yet the ability to experience distress may persist and may be overlooked and undertreated or overtreated. Other methods for symptom assessment are needed in this context.