Relationship between tricuspid annular plane systolic excursion, fluid responsiveness and volume status in hospitalised dogs with circulatory abnormalities.

AIMS: To evaluate the echocardiographic variable tricuspid annular plane systolic excursion normalised to body weight (TAPSEnorm) as a predictor of fluid responsiveness in hospitalised dogs with haemodynamic and tissue perfusion alterations and to investigate the association of left ventricular internal diameter in diastole normalised to body weight (LVIDdN) and aortic velocity time integral (VTIAo) with TAPSEnorm. METHODS: A single-centre, prospective study was carried out in a cohort of spontaneously breathing dogs, hospitalised for any reason, with severe haemodynamic and tissue perfusion alterations. The echocardiographic variables TAPSEnorm, LVIDdN, and VTIAO were measured. A bolus of 30 mL/kg of lactated Ringer's solution was administered and then VTIAo was subsequently remeasured. Patients were classified as fluid responsive if VTIAo increased by ≥15% after fluid expansion, or non-responsive if VTIAo increased by <15% after fluid expansion. The area under the receiver operating characteristic (AUROC) curve was generated to evaluate the ability of TAPSE to predict fluid responsiveness. Simple regression models were used to assess the linear relationship between TAPSEnorm and LVIDdN or VTIAO. RESULTS: TAPSEnorm was lower in fluid responsive dogs (mean 0.57 (95% CI = 0.50-0.64) cm/kg) compared to non-responsive dogs (mean 0.76 (95% CI = 0.62-0.90) cm/kg). The AUROC for TAPSEnorm was 0.827 (95% CI = 0.65-1.00). The optimal cut-off point was 0.76 with sensitivity of 80 (95% CI = 28.4-99.5)% and specificity of 86.7 (95% CI = 69.3-99.2)%, positive predictive value of 50 (95% CI = 15.7-84.3)% and negative predictive value of 96.3 (95% CI = 81-99.9)%. A monotonic linear relationship was observed between TAPSEnorm and LVIDdN (p<0.001) and between TAPSEnorm and VTIAo (p=0.001). CONCLUSIONS AND CLINICAL RELEVANCE: TAPSEnorm could be useful in determining those dogs that are likely to respond to a fluid bolus from those that are likely to be non-responsive. Additionally, a positive linear association between the LVIDdN and the TAPSEnorm suggests that TAPSEnorm decreases at lower preload values. The present study results suggest that TAPSEnorm could be a valuable tool for evaluating blood volume status and fluid responsiveness in hospitalised dogs.Abbreviations: AUROC: Area under the receiver operating characteristic; CO: Cardiac output; ICC: Intraclass correlation coefficient; LVIDd: Left ventricular internal diameter in diastole; LVIDdN: Left ventricular internal diameter in diastole normalised to body weight; TAPSE: Tricuspid annular plane systolic excursion; TAPSEnorm: Tricuspid annular plane systolic excursion normalised to body weight; VTIAo: Aortic velocity time integral.