Estimativa do volume urinário por meio da ultrassonografia em cães e modelos experimentais

Abstract

The urinary volume and residual urine volume are pieces of information that can provide relevant clinical data for dogs and cats, especially those that are hospitalized. Various methods can be used to assess this volume, such as urethral catheterization or even cystocentesis. However, these methods carry the risk of injury to the urinary tract. As an alternative, volume estimation by ultrasound has been proposed. Therefore, the aim of the present study was to evaluate urinary volume estimation formulas described in the human and veterinary literature in dogs and experimental models. Nine male dog cadavers and twelve experimental models were used to evaluate small, medium, and large volumes of residual urine using three different formulas. Data were collected by three different examiners, including two imaging specialists and one non-imaging specialist. Each examiner recorded three longitudinal and transverse images and obtained measurements of width, length, and height at each proposed volume. The measurements were then averaged, and the urinary volume was estimated using the three proposed formulas. All three formulas showed higher accuracy in estimating smaller volumes, with a gradual decrease in accuracy as the urinary volume increased. The error of all formulas was less than 10%, even when compared to estimates in experimental models and dogs. One formula achieved the highest accuracy in this study, especially in estimating residual and small volumes, while the other two were more accurate in estimating medium and large volumes. There was variation in estimation between imaging and non-imaging examiners, but the variation was small. Therefore, it is believed that non-imaging professionals can also use this method to estimate urinary volume, with prior familiarity with ultrasound potentially increasing accuracy. In conclusion, urinary volume estimation by ultrasound is an accurate and non invasive method that can be characterized as an alternative and viable approach to the evaluation of the urinary tract.