an 11-month-old male was brought to the emergency room after trapping his head between two fence posts. He was having severe breathing problems and was cold and sweaty. Pulse rate was low. general anesthesia was administered by the anesthesiologist prior to emergency surgical repair of the crushed larynx and trachea, After the patient had been transferred to the surgical floor, the anesthesiologist inserted a percutaneous arterial line (cathetera0 to monitor the patient..