Transcutaneous oxygen measurement to evaluate drug effects.

The evaluation of pharmacologic effects in perinatal medicine is dependent on our clinical methods for measurement and monitoring of the mother, the fetus, and the newborn infant. The development of a noninvasive continuous method of measuring PO2, the transcutaneous PO2 electrode, has greatly enhanced the ability to assess effects of drugs on the cardiorespiratory system. During labor, diazepam and meperidine have been documented to cause respiratory depression and significant decreases in PO2. The advantageous effect of epidural anesthesia on the oxygen-cardiorespirogram of mothers in labor has also been demonstrated. Both fetal and maternal tcPO2 have been successfully assessed during the administration of peridural catheter anesthesia (carticaine) and during suppression of labor with fenoterol. In the newborn infant, monitoring of tcPO2 has been helpful in assessing the residual effects of drugs administered during labor and delivery, in prescribing the appropriate and safe dose of oxygen, and in defining the effects of theophylline on the oxygen-cardiorespirogram. We have also demonstrated the effect of furosemide on PO2 in the treatment of pulmonary edema accompanying bronchopulmonary dysplasia and of indomethacin for the management of patent ductus arteriosus. Use of tcPO2 measurements for clinical pharmacologic evaluation is a promising addition to our research techniques.