Pulse oximetry at the roadside: a study of pulse oximetry in immediate care.

The measurement of tissue oxygen saturation with a pulse oximeter is of proved value in the hospital setting. The development of a portable oximeter has allowed this investigation to be performed during the prehospital phase of a patient's care. Pulse oximetry was performed at the roadside in 25 patients with abnormal trauma scores and found to be of benefit in detecting and monitoring hypoxia in patients with airway obstruction, depressed respiration due to head injury, and, in particular, with closed chest injuries. There were no practical difficulties associated with the use of the instrument either at the roadside or in a moving ambulance. The portable pulse oximeter is a valuable aid in the prehospital monitoring of patients with trauma.