[Effects of tracheal gas insufflation on blood gases and respiratory mechanics in acute hypercapnia rabbits].

OBJECTIVE

To evaluate the effects of tracheal gas insufflation (TGI) on elimination of CO2 and improvement of ventilation efficiency.

METHODS

Using self-designed TGI device, physiological parameters such as PaCO2, Ppeak, Ppause, end expiratory carbondioxide pressure (PetCO2), lung statistic compliance(Cst), respiratory resistance(Re) and expiratory lung volume(VE) in the two animal groups of conventional mechanical ventilation (CMV) and hypercapnia (HC) by applying two different TGI flow(0.2 L/min and 0.4 L/min) were observed.

RESULTS

TGI can significantly decrease the PaCO2 level, enhance CO2 elimination and maintain PaCO2 in the normal range while decreasing VT by 30%, the eliminating effect of CO2 is flow dependent. TGI can elevate airway pressure in both animal groups, but the level of Ppeak, Ppause in HC group are significantly lower than those of CMV group. PetCO2 levels are significantly decreased after TGI while Re and VE increased significantly after TGI. TGI shows no obvious influence on Cst, mean arterial pressure and heart rate.

CONCLUSIONS

Our results reveals that TGI is a simple and practical adjunct method to mechanical ventilation, it can effectively decrease PaCO2, and maintain low airway pressure.