Dyspnea as a marker of prognosis in immunocompromised patients with acute respiratory failure.

BACKGROUND

Acute hypoxemic respiratory failure (AHRF) is the leading cause of intensive care unit (ICU) admission in immunocompromised patients, in whom both intubation and mortality rates are higher than in the general ICU population. This study explores dyspnea on admission as it relates to clinical outcomes.

METHODS

Secondary analysis of the Efraim study, a prospective multinational cohort study of immunocompromised patients with AHRF admitted to the ICU. Dyspnea was quantified by a numeric rating scale (dyspnea-NRS) from zero to 10. Factors associated with dyspnea-NRS were assessed with linear regression. Hierarchical model was used to assess factors independently associated with invasive mechanical ventilation (intubation) and hospital mortality.

RESULTS

547 patients were included. On ICU admission, median dyspnea-NRS was 5 (interquartile range 4-7). Variables independently associated with dyspnea-NRS were underlying immune defect unrelated to hematological malignancy, chronic heart failure, high SOFA score and respiratory rate. Intubation rate was 41 %. Variables independently associated with intubation were dyspnea-NRS ≥5 (odds ratio [OR] 2.61, p < 0.001), high SOFA (OR per point 1.10, p = 0.006) and fungal infection (OR 2.02, p = 0.020)., while respiratory rate and PaO2/FiO2 were not. Hospital mortality was 37 %. Variables independently associated with hospital mortality were age (OR per year 1.02, P = 0.009), SOFA score (OR per point, 1.13, P < 0.001) and dyspnea-NRS (OR per point 1.19, P < 0.001).

CONCLUSIONS

In immunocompromised patients admitted to the ICU for AHRF, dyspnea at admission is moderate to severe and is associated with clinical outcomes. Dyspnea-NRS ≥5 is associated with an increase in intubation rate and hospital mortality.