The use of pulse transit time in pediatric sleep studies: A systematic review

As a surrogate measure of blood pressure, pulse transit time (PTT) is commonly used in studies investigating arterial function and respiratory sleep disturbance. A systematic search of the literature was conducted with the aim of reviewing the usefulness of the technique within pediatric sleep studies. All studies that used PTT as a diagnostic tool during sleep in infants, children or adolescents were considered. The search yielded 425 articles, of which 21 full-text articles met inclusion criteria, the majority reporting on obstructive sleep apnea (OSA). PTT was used alongside polysomnography (PSG) in all studies. Several studies supported the potential of PTT to detect central apneic events in both infants and children and obstructive events in children, with implications for use as a screening tool for OSA, albeit with some limitations. Only one study validated PTT against blood pressure (BP), and only against systolic arterial pressure (SAP), showing significant negative correlations between PTT and SAP. PTT tracked well against BP and heart rate (HR) over acute cardiovascular perturbations in several studies. PTT is simple to execute, cost-efficient to run, and more tolerable than alternatives to measuring continuous BP in children. However its potential as a core clinical tool remains to be determined.