Cardiopulmonary effects of lying position in anesthetized and mechanically ventilated dogs.

Cardiopulmonary effects of right-lateral and supine (on back) lying position were investigated in 8 anesthetized and mechanically ventilated dogs. Complete hemodynamic and respiratory monitoring were obtained. Heart rate was significantly higher, blood pressure, systemic vascular resistance and left and right ventricular stroke work were significantly lower in supine in comparison to right-lateral position. Arterial and mixed-venous oxygen tensions and mixed-venous oxygen saturation were significantly higher in right-lateral position. Compliance was significantly higher and peak ventilation pressure significantly lower in supine position. Arterio-to-mixed-venous-oxygen content difference, oxygen consumption and utilization were significantly higher and respiratory quotient was significantly lower in supine position in comparison to right-lateral position. All other obtained parameters were not be influenced by posture.