Introduction

Acute kidney injury (AKI) is a cause of morbidity and mortality amongst veterinary and human critical patients. Mechanical ventilation (MV) is associated with an increased risk of AKI amongst human ICU populations, however, the prevalence of MV associated AKI and its effect on outcome has not been described in a veterinary ICU population. The objective of this study was to assess the prevalence of AKI in dogs undergoing MV in ICU and identify factors associated with its occurrence and survival to discharge.

Methods

Retrospective cohort study in clients owned dogs in a veterinary teaching hospital. Medical records for dogs ventilated for >24 hours within the ICU were evaluated for signalment, primary diagnosis, reason for initiating MV, ventilator settings, clinicopathological findings on admission, IRIS AKI grade based on serial blood creatinine and urinary output monitoring, multiorgan dysfunction syndrome (MODS) score, management during MV, and outcome. Acute kidney injury was defined according to the IRIS guidelines recommendations for AKI grading. Logistic regression was used to identify independent predictors for development of AKI and survival. In the univariable analysis, variables with a value of P≤0.10 were examined by multivariable analysis with significance defined as P≤0.05.

Results

Between December 2016 and September 2021, 142 dogs underwent MV in the ICU, of which 49 required MV>24 hours. Of these 59% (29/49) demonstrated evidence of AKI with 62% (18/29), 10% (3/29), 24% (7/29), and 4% (1/29) developing grades I, II, III and IV respectively. No risk factors were identified for MV-associated AKI. Forty-two percent (21/49) of patients survived to discharge with multivariable logistic regression identifying an increase in age (OR: 0.66, CI [95%] 0.49–0.91, P=0.01) and MODS score (OR: 0.22, CI [95%] 0.06–0.88, P=0.03) inversely correlated with survival.

Conclusions

AKI frequently occurs in ICU patients requiring prolonged MV, however in this population AKI was not a predictor of patient outcome.

E-mail: richard.trinder@live.com.au