The comparison between intermittent Pao2 samples and a continuous transcutaneous PO2 recording can be compared to viewing a sports event by means of a single black and white photograph taken during the game versus a televised version complete with instant replays. Transcutaneous monitoring has made it possible to visualize the immediate effect of therapeutic maneuvers on PO2 as well as the physiologic response to a variety of routine procedures. In certain clinical situations with circulatory compromise, this measurement of tissue oxygenation may be a more pertinent clinical parameter than Pao2. The ability to monitor transcutaneous O2 tension continuously should enable researchers to further unravel the relationship of Po2 to various neonatal disorders such as retinopathy of prematurity, bronchopulmonary dysplasia, and intraventricular hemorrhage.
Other physiologic parameters may also be measured transcutaneously. A transcutaneous Pco2 monitor is now in use clinically, and a transcutaneous pH electrode, still in the developmental process, should be available in the near future. Like the transcutaneous Po2 monitor, these devices generate a continuous flow of clinical data enabling nurses and physicians to make rapid informed decisions based on the patient's current physiologic status.