The invention relates to 
medical instruments, in particular to a tracheal 
catheter capable of directly monitoring the end-tidal 
carbon dioxide partial pressure of an infant. The tracheal 
catheter comprises a 
catheter body, a 
cuff, a connector, an opening and a thin tube, wherein the 
cuff is connected to one end of the catheter body, the connector is arranged at the other end of the catheter body, the opening is arranged in a position, between the 
cuff and the connector and close to the cuff, of the catheter body and connected with the thin tube, and the 
tail end of the thin tube is connected with an end-tidal 
carbon dioxide monitor. The tracheal catheter has the advantages that the tracheal catheter is improved to solve the technical problem that due to the fact that the infant is low in 
body weight, if an existing 
tail-end sampling device is used, the 
dilution effect of 
fresh air flow in the tracheal catheter on 
carbon dioxide is evident, and the measured end-tidal carbon dioxide is evidently lower than an actual value, the sampling part opening 1 is close to the top end of the tracheal catheter, the inner 
diameter of the thin tube 2 is small, the 
fresh air quantity in the thin tube 2 is low, influence of the 
fresh air flow on the collected 
breathing gas at the top end of the tracheal catheter is small, the end-tidal carbon dioxide level can be reflected accurately, and the tracheal catheter is evident in use effect.