Intraoperative Assessment of Fluid Responsiveness in Normotensive Dogs under Isoflurane Anaesthesia

Despoina Skouropoulou; Luca Lacitignola; Caterina Di Bella; Marzia Stabile; Claudia Acquafredda; Nicola Brienza; Salvatore Grasso; Antonio Crovace; Fabrizio Iarussi; Francesco Staffieri

doi:10.3390/vetsci8020026

Intraoperative Assessment of Fluid Responsiveness in Normotensive Dogs under Isoflurane Anaesthesia

Vet Sci. 2021 Feb 11;8(2):26. doi: 10.3390/vetsci8020026.

Authors

Affiliations

¹ Section of Veterinary Clinics and Animal Production, Department of Emergency and Organ Transplantation, Aldo Moro University, 70010 Bari, Italy.
² Ph.D. Course in Organs and Tissues Transplantation and Cellular Therapies, Department of Emergency and Organ Transplantations, Aldo Moro University, 70124 Bari, Italy.
³ Section of Anesthesia and Intensive Care, Department of Emergency and Organ Transplantation, Aldo Moro University, 70124 Bari, Italy.

Abstract

The aim of this study was to evaluate the incidence of fluid responsiveness (FR) to a fluid challenge (FC) in normotensive dogs under anaesthesia. The accuracy of pulse pressure variation (PPV), systolic pressure variation (SPV), stroke volume variation (SVV), and plethysmographic variability index (PVI) for predicting FR was also evaluated. Dogs were anaesthetised with methadone, propofol, and inhaled isoflurane in oxygen, under volume-controlled mechanical ventilation. FC was performed by the administration of 5 mL/kg of Ringer's lactate within 5 min. Cardiac index (CI; L/min/m²), PPV, (%), SVV (%), SPV (%), and PVI (%) were registered before and after FC. Data were analysed with ANOVA and ROC tests (p < 0.05). Fluid responsiveness was defined as 15% increase in CI. Eighty dogs completed the study. Fifty (62.5%) were responders and 30 (37.5%) were nonresponders. The PPV, PVI, SPV, and SVV cut-off values (AUC, p) for discriminating responders from nonresponders were PPV >13.8% (0.979, <0.001), PVI >14% (0.956, <0.001), SPV >4.1% (0.793, <0.001), and SVV >14.7% (0.729, <0.001), respectively. Up to 62.5% of normotensive dogs under inhalant anaesthesia may be fluid responders. PPV and PVI have better diagnostic accuracy to predict FR, compared to SPV and SVV.

Keywords: dogs; fluid responsiveness; plethysmographic variability index; pulse pressure variation; stroke volume variation; systolic pressure variation.