Objective To prove the existence of renopulmonary interaction during mechanical ventilation and to identify the affecting factors.

Design Experimental, closed, randomized, comparative.

Material and Methods The study included a total of 15 healthy domestic piglets. Group A – spontaneously breathing piglets. Group B – piglets ventilated for 12 hours, VT 6 ml/kg. Group C – piglets ventilated for 12 hours, VT 10 ml/kg. Clinical monitoring and laboratory tests were recorded 1 hour after beginning of this experiment and after 12 hours (groups B and C). Mechanical ventilation was assessed by lung mechanics and ventilatory indexes, cardiovascular system by measurement of systemic pressure and echocardiography. The renal function was assessed by one-hour diuresis, laboratory tests, glomerular filtration, free water clearance and fractional excretion of sodium. The obtained data were statistically analyzed. Values of p<0.05 were considered statistically significant.

Results After 1 hour of mechanical ventilation the following parameters were decreased in both groups: global function of right ventricle (p<0.05), glomerular filtration (p<0.020), free water clearance (p<0.018) and fractional excretion of sodium (p<0.005). The decrease of the above parameters after 12 hours of mechanical ventilation was even more significant in group C (p<0.03). Left ventricle performance, systemic arterial pressure and one-hour diuresis were not influenced in the course of this study.

Conclusion Mechanical ventilation induces renopulmonary interaction. Tidal volume of 10 ml/kg and time influence systemic as well as regional hemodynamics and contribute to the decrease of glomerular filtration, sodium and fluid retention.