Hemodynamic Alterations in Dogs Undergoing Pressure-controlled Ventilation with Positive End-expiratory Pressure
Video surgeries with abdominal or thoracic insufflation require special methods of ventilation, such as positive end-expiratory pressure. This study was conceived to evaluate hemodynamics in dogs undergoing pressure-controlled ventilation with PEEP. Six dogs were enrolled in the study. Anesthesia was induced with a bolus of propofol and maintained with propofol and sufentanil given continually. Respiratory rate was defined as 10 mpm, and ETCO2 was maintained in the 35-40 mmHg range. All dogs were ventilated with three different PEEP (0, 5 and 10 cmH2O) in a random sequence. Heart rate, systolic, mean and diastolic arterial pressures, central venous pressure, cardiac output, stroke index, mean pulmonary arterial pressure, mean pulmonary capillary wedge pressure, systemic vascular resistance index, pulmonary vascular resistance index, and coronary perfusion pressure were either measured or calculated twice at 20-minute intervals for each PEEP value. An analysis of variance and a post-hoc test of Tukey-Kramer were used to assess data statistically. Changing the PEEP did not influence the heart rate, systolic, mean and diastolic arterial pressures, central venous pressure, mean pulmonary capillary wedge pressure, and systemic vascular resistance index. However, mean pulmonary arterial pressure and pulmonary vascular resistance index did change in accordance with the PEEP. Results allowed concluding that pressure-controlled ventilation with varying levels of PEEP is not detrimental to the cardiovascular function under the conditions of this study.