Introduction

Acute kidney injury (AKI) is a common sequela to human trauma occurring in up to 25% of trauma patients with 10% of these requiring renal replacement therapy. Trauma is occasionally cited as a cause of AKI in cats, with one study reporting up to 10% cases of AKI were due to trauma. However, the prevalence of azotemia and AKI in veterinary trauma is unknown. The primary aim of this retrospective study was to describe the prevalence of azotemia in canine and feline trauma patients. The secondary aim was to determine AKI prevalence and whether there was any association between azotemia and AKI with trauma severity and outcome.

Methods

A search of the institutional VetCot trauma registry was performed at a university teaching hospital (April 2017–February 2021). Patients were included if they had a blood creatinine value within 6 hours of presentation. Azotemia was defined as creatinine >140 mmol/L and sub-grouped into post-renal causes, intrinsic and fluid-responsive AKI according to the International Renal Interest Society. Trauma type, animal trauma triage score (ATT score) and survival to discharge were compared between azotemic (AG) and non-azotemic groups (NAG) using Fisher’s exact or Mann Whitney U tests. P<0.05 was considered statistically significant.

Results

Thirty-nine of 397 (9.8%) patients were azotemic at presentation (9/223, 4% dogs, 30/174, 17.2%, cats). Eleven/39 (28.2%) patients had a post-renal cause of their azotemia, 27/39 (71.0%) had AKI and 1/39 (2.56%) had a mixed cause of azotemia. Of those patients with AKI where follow-up blood work was available 9/17 (52.9%) were classified as having fluid responsive AKI. Median ATT score on presentation was higher in AG than NAG (AG 3 [range 0–12] NAG 2 [range 0–10][p=0.005]). Twenty-nine of 39 (74.3%) AG patients survived to discharge and 312/352 (88.6%) NAG patients survived to discharge. When post-renal causes of azotemia were excluded, azotemic patients were less likely to survive than non-azotemic patients (p=0.03).

Conclusion

Azotemia is common in the canine and feline trauma population and appears associated with trauma severity. The presence of AKI in canine and feline trauma patients is associated with non-survival.

E-mail: estacey1@rvc.ac.uk