[The effect of traditional and high frequency controlled lung ventilation on pulmonary and systemic hemodynamics and...

The absence of direct studies of pulmonary circulation in the majority of papers, as well as the effect of various techniques of controlled lung ventilation on pulmonary microcirculation and the right heart made us start the present investigation. Ultrasound sensors have been implanted on the pulmonary artery cone and aortic arch in 30 healthy cats during thoracotomy under pentobarbital anesthesia (30-40 mg/kg). Blood flow through the pulmonary artery and aorta, as well as their interrelation have been studied using MX-01. BP and PAP were registered using an invasive technique. Computer assessment of other hemodynamic parameters used cardiac output values into the pulmonary artery and into the aorta for the calculation of pulmonary circulation parameters and systemic circulation parameters, respectively. Pulmonary microcirculation has been studied by an original technique of intravital biomicroscopy of the lungs, with the image recorded on the video camera. To determine the index of capillary perfusion a semiautomatic device for image analysis ("Leitz" and "Olivetti") was used. It has been established that in high-frequency jet ventilation there is a redistribution of circulating blood towards systemic circulation. Right ventricular work decreases by 53.6% (p < 0.05) due to a drop in vascular resistance in pulmonary circulation (p < 0.05) and pulmonary artery pressure (p < 0.05), while left ventricular work decreases by 14.8% (p < 0.05). Thus, there is a predominant load reduction in the right heart compartments. In conventional controlled lung ventilation microcirculatory bed of the lungs is subjected to characteristic deformation, i. e. distension enhancing vascular resistance and thus leading to additional load on the right heart compartments.(ABSTRACT TRUNCATED AT 250 WORDS)