Several surgical and diagnostic procedures can be performed on thoracic surgery in the equine. To carry out these procedures controlled mechanical ventilation (CMV) is necessary, as well as full understanding of the possible side effects of this type of ventilation. Six healthy equine were used under anesthesia wiith CMV to do right hemithorax approach. The goals were to evaluate efficiency of CMV in the improvement of ventilation and oxigenation as well as in the prevention of pulmonar atelectasis during intrathoracic manipulation. For such evaluation of physiologic parameters measurement, ventigraphy and blood gas analysis were performed. A decrese in PaCO2 and rise of pH values were observed, in despite of pneumothorax presence. Also the interpleural pressure showed elevated values during CMV. The use of CMV, during thoracotomy, allows padronization of respiratory rates with improvement of ventilation and for this, further normalization of alterations in PaCO2 and pH. As well as it allows visually adequate lung expansion. CMV promotes interpleural pressure elevation while the thoracic cavity remains closed.
controlled ventilation; ventigraphy; thoracotomy; equine
