Body surface area calculation for dogs and cats using LiDCO and PICCO monitors

Cardiac output, stroke volume, and measurement of other hemodynamic parameters can be useful in the management of critical patients. Given the broad size disparity of veterinary patients, the raw values can vary widely. Their indexed values, however, allow for quick assessment of hemodynamic status and a more standardized target setting by the veterinary care team. Monitors such as lithium dilution cardiac output (LiDCO) and pulse contour cardiac output (PICCO) can display and record the data using indexed values as long as the correct body surface area (BSA) is used. In people, the BSA is calculated using the DuBois formula by entering the patient's weight and height; however, it does not apply to animals because the equivalent relationship is not represented by this formula. Given that the hemodynamic monitors are manufactured for use in human patients, the calculations need to the adapted for veterinary use. As such, the Dubois formula has been rearranged to calculate an assumed height to be entered in the monitor software along with the patient's weight. Once the information is entered, a correct BSA will be calculated by the monitor, and indexed data will be readily available for analysis.

Tables with the calculated heights for dogs and cats were generated. The weights and calculated heights were computed into the LiDCO and PICCO monitors for verification, and the correct BSAs were displayed as a result.

The information supplied here allows clinicians and researchers to quickly input patient data into the hemodynamic monitor and obtain indexed data. Indexed data facilitates advanced hemodynamic monitoring by standardizing targets (goal-directed therapy) and allowing for quicker comparison between patients. The table could be used with any monitor that utilizes the DuBois formula for BSA calculation, but the resulting BSA should be validated before proceeding with hemodynamic monitoring.