Evaluating a Combined Volumetric and Gravimetric Method for Estimating Blood Loss in Small Breed Canine Dental Extractions

Abstract

Background Periodontal disease is one of the most common diseases in dogs and the most important reason for dental extractions. Especially small dogs are particularly sensitive to the physiological consequences of blood loss because of their total low blood volume. Until now, there are no validated methods published to quantify intraoperative blood loss during dental extraction in dogs. The original aim of this research was to measure the blood loss in small dogs (<15kg) with periodontal disease during dental extractions, using a combined gravimetric and volumetric method. However, during the initial phase of the data collection, methodological concerns were raised and the focus of the research shifted towards evaluating the relative accuracy of this method in the clinical setting. Methods A total of 19 dental extraction procedures were performed on 18 dogs (<15kg), on three clinical locations in the Netherlands. Before and afterwards, the volume of irrigation fluid in the dental unit reservoirs was measured, as well as the weight of used gauzes and other absorbing materials. The difference between the administered and recovered fluid was calculated as a measure of blood loss. In addition, multiple patient- and procedure related variables were registered; age, bodyweight, surgery time, blood pressure, number of extracted teeth and a subjective bleeding score. Results The difference in measured volumes varied between -148.8 ml and 50.1 ml, with a mean of -64.3 ± 51.9 ml. In 88.9% of the procedures, a negative value was observed. This indicated a systematic underestimation of the blood loss. Important causes were aerosol formation of the irrigation fluid and retention in the coat of the patient and the underlays. There were no significant correlations found between the calculated values and patient- or procedure related variables. Conclusions The combined volumetric and gravimetric method proved, in a clinical setting, to not be relatively accurate for quantification of blood loss in small dogs during dental extractions. This study emphasizes the methodological challenges of such measurements and highlight the need to develop alternative or refined methods such as improved collection techniques or additional measurement strategies, in order to obtain valid and reproducible estimates in the future.