Urinary neutrophil gelatinase-associated lipocalin concentration changes after acute haemorrhage and colloid-mediated reperfusion in anaesthetized dogs

ObjectiveTo determine changes in urine neutrophil gelatinase-associated lipocalin concentration (uNGAL) in anaesthetized Greyhound dogs that developed acute tubular damage following haemorrhage and resuscitation with colloid-based fluids. Study designProspective experimental study. AnimalsSeven healthy adult entire male Greyhound dogs. MethodsDuring isoflurane anaesthesia, approximately 50mLkg(-1) of blood was removed to maintain mean arterial pressure (MAP) 40mmHg for 1hour followed by gelatin-based colloid administration to maintain MAP 60mmHg for 3hours. Data, including oxygen extraction ratio and uNGAL, were collected before (T0) and immediately following (T1) haemorrhage, and hourly during reperfusion (T2-T4). After T4, dogs were euthanized and renal tissue was collected for histology. Statistical analysis was performed using repeated-measures one-way anova. Data are presented as means (95% confidence interval). ResultsHistology identified renal tubular epithelial damage in all dogs. Urine NGAL concentration increased from 12.1 (0-30.6)ngmL(-1) at T0 to 122.0 (64.1-180.0)ngmL(-1) by T3. Compared with T0, uNGAL was significantly higher at T3 (p=0.016) and was increased 24-fold. Conclusions and clinical relevanceDespite wide individual variation in baseline uNGAL, increases in uNGAL were observed in all dogs, suggesting that this biomarker has the potential to detect renal tubular injury following haemorrhage-induced hypotension and colloid-mediated reperfusion.