Spirometria Side Stream (SSS) in cani sottoposti a ventilazione artificiale

Spontaneous ventilation is the first choice during general anaesthesia in dogs. Several procedures, such as thoracic surgery and muscle relaxation, or respiratory diseases of the patient, might require mechanical ventilation (IPPV). The outcome of mechanical ventilation is critically dependent on the value of the respiratory system compliance (CDYN). This study focuses on CDYN variation during general anaesthesia in 17 dogs undergoing IPPV. The ventilation parameters set at the beginning of anaesthesia were left unchanged throughout the procedure to avoid influencing CDYN values. Respiratory parameters (VT, VRM, P-peak, P-Plateau, PEEP and CDYN) and P/V and F/V loops, were continuously recorded using Side Stream Spirometry (SSS), by a “Capnomac Ultima” (Datex Ohmeda®) monitor. The CDYN/Kg values were correlated to recumbence and duration of anaesthesia. Our results show a correlation between CDYN and body weight and a decreasing trend of the CDYN values in the course of anaesthesia, respectively of -7,1% (T1-T2) and of -12.4% (T1-T4). No correlation was found between CDYN variation and recumbence or anaesthesia duration. This study aims at improving the veterinary anaesthetists’ familiarity with CDYN values during mechanical ventilation in dogs.