Optimal Time to Apply Combined Pulse Oximetry and Physical Examination Aiming in Detecting Severe and Critical Congenital Heart Diseases in Term Neonates

Background: Up to date, many studies around the world have proven the use of pulse oximetry(pox) as a screening test with high specificity, moderate sensitivity and a low overall false-positive rate, for detecting critical and severe Congenital Heart Diseases (c/s-CHD). Additional to that important neonatal nosology as acute/chronic lung disease, early onset of sepsis or PPHN can be early detected. Few studies have comment on the exact timing and the amount of measurements needed to obtain the optimal results.

Aim: Prospective screening study by pox + physical assessment, aiming to detect the optimal timing amount of measurements for optimal results

Population-Method: From June 2016 to August 2018, 2570 term neonates were screened in two major maternity units in Baku-Azerbaijan. Pox levels using a motion-tolerant pulse oximeter where blindly reported on the end of 1st and 3ed day of life by a team of trained nurses, using a simultaneous pre and post ductus arteriosus (pre/post DA) measurement. A second team manded by neonatologists then assessed these neonates on the same dates. Firstly, blinded to existing pox measurements and then combining them together with Physical Assessment(pox+PA). Cut-offs of pathological pox were below 90% in any measured site or persisting pre/post DA difference > 3%, following 2 assessments within 30 minutes apart. At day five from birth, all of them received Echo-2D screening from two examiners both double-blinded to the results of pox, pox + physician assessment and findings of previous Echo-2D.

Findings: From 2570 screened by Echo-2D, 47 CHD’s were found. 17/47: c-CHD & 5 s-CHD. 25/47 were simple/ moderate complex non-cyanotic CHD.

Pox team; detected 14/22 (63.63%) c-CHD at 24h post-birth. This raised 18/22(81.81%) at 72h post-birth. Also detected 65 cases (2.2%) of additional neonatal non- cardiac pathology.

Combined team: PA only 12/22(55.5%) & 14/ (63.63%). Pox+PA: 17/22(77.28%) & 20/22(90.91%) of c/s-CHD at 24 & 72h post-birth respectable. Additional, 75 cases (3%) neonatal non- cardiac pathology were detected.

Conclusion: Study showed that when the test when applied 72h post birth had the highest positive predicted value screening c/s-CHD test. An additional measurement in the end of first 24h, can determine