Retrospective evaluation of red blood cell distribution width as a prognostic factor in critically ill dogs (December 2016 to April 2017): 127 cas

Objective To evaluate the association between RBC distribution width (RDW) and in-hospital mortality, length of hospitalization, and leukocyte count in critically ill dogs. Design Retrospective study. Setting University teaching hospital. Animals One hundred and twenty-seven dogs admitted to the ICU from December 2016 to April 2017. Patients were included if they had a CBC performed within the first 24 h of admission. Interventions None. Measurements and Main Results The overall in-hospital mortality rate was 29% (37/127), and median length of hospital stay was 3 days (interquartile range [IQR], 5). The median RDW value was 13.8% (IQR, 1.6%; reference interval, 11.9%-14.5 %). The canine Acute Patient Physiologic and Laboratory Evaluation (APPLE) fast score was calculated in 81 of 127 (64%) patients; the median score was 24/50 (IQR, 9). There was no significant correlation between RDW and APPLE fast score (P = 0.163). Subgroup analysis was performed according to the following diagnostic categories: abdominal (36%; 46/127), hematological (13%; 16/127), respiratory (13%; 16/127), neurological (12%; 15/127), cardiovascular (11%; 14/127), integument (3%; 4/127), trauma (3%; 4/127), musculoskeletal (2%; 3/127), and others (7%; 9/127). Increased RDW was not associated with in-hospital mortality overall (P = 0.381) or in any individual subgroup analysis. No association was found between length of hospitalization and RDW values in either survivors (P = 0.548) or nonsurvivors (P = 0.083). The correlation between RDW and leukocyte count was nonsignificant (P = 0.12). Conclusions In this study, admission RDW was not associated with in-hospital mortality or length of hospitalization in critically ill dogs. The correlation between RDW and leukocyte count was nonsignificant.