Introduction

Transesophageal echocardiography (TEE) is a minimally invasive diagnostic tool that can be used to monitor hemodynamic variables during non-cardiac procedures.

Objectives

The aim of this study was to compare hemodynamic variables in dogs anesthetized using three different techniques.

Methods

This prospective and randomized study was conducted using 20 healthy dogs monitored with ECG, noninvasive blood pressure, and pulse oximetry. Hemodynamic variables were measured/calculated using Doppler-TEE. All dogs were randomly assigned to Groups PS (propofol 8 mg/kg - sevoflurane 2.5%); MK (midazolam 0.2 mg/kg - ketamine 10 mg/kg); or MS (midazolam 0.5 mg/kg - sevoflurane 2.5%). All patients received the same IV fluid rate (5 ml/kg/h). ANOVA (posthoc DMS test) was used to analyze normally distributed data, and the Kruskal-Wallis test was used to analyze non-normally distributed data.

Results

Median HR was higher (p<0.001) in dogs in Group MK (124±22 bpm) when compared to dogs in Groups PS (98±18 bpm) and MS (100±17 bpm). Systolic arterial pressure (SAP) was higher in dogs in Group MK (129±7 mm Hg) than in dogs in groups PS (99±7 mm Hg) and MS (103±12 mm Hg; p>0.05). Trivial mitral regurgitation was more frequent in dogs in the MK group (p<0.05). The AoVmax was higher in the dogs in group MK (108±12 m/s; p=0.007) than in the other groups. There was no difference between the groups PS (86±5) and MS (93±16 m/s; p>0.05). The ventricular filling pressure and the E/A velocity ratio were not different between groups (p>0.05). Cardiac output and stroke volume were not statistically different between groups (p=0.19 and 0.6, respectively).

Conclusion

MK produced higher HR, AoVmax, and SAP, but other hemodynamic variables were similar among groups. Depending on the situation, these values can help to recognize intraoperative hemodynamic instability.