Pulse oximetry: a tool for diagnosis and hemodynamic assessment in pediatrics

Abstract

Since more than 30 years, pulse oximetry is used in pediatrics to monitor respiratory function and adjust oxygen therapy. Advances in signal processing of plethysmographic curves may confer additional interest for hemodynamic evaluation. The perfusion index (PI) deriving from pulse oxymetry and quantifying the pulsatile component of the signal has been proposed as continuous and noninvasive indicator of distal vessel function. The clinical practice with this index has mainly been developed in neonates. In the context of congenital heart disease screening, a value of < 0.70 may indicate critical left heart obstruction. In premature neonates, observations also suggest that PI may be relevant to diagnose low systemic outpout or persistent ductus arteriosus. Indices derived from respiratory variations of pulse oximeter plethysmograph amplitude have been mainly tested in children before or during surgery, to assess volemia and predict fluid responsiveness in the operating room. However, the currently debated data based on these indices may still not allow their use to guide reliable fluid administration. Further studies are required, particularly in children hospitalized in the intensive care unit, to demonstrate that pulse oximetry is an accurate hemodynamic tool, as clearly established in adults.