Distribution and reference values of peripheral perfusion index in neonates from population-wide screening

• Published in: BMJ paediatrics open Vol. 8; no. 1; p. e002607
• Main Authors: Sasikumar, Navaneetha, Madhavankutty Nair, Sreehari, Gutjahr, Georg, Bendapudi, Perraju, Moosa, Abdulrazak, Prasenan, Krishna, Rajan, Vishnu Raj, Sudhakar, Abish, Kumar, Raman Krishna
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd 21.06.2024; BMJ Publishing Group LTD; BMJ Publishing Group
• Subjects: Age; Birth weight; Cardiology; Cardiovascular disease; Children & youth; Congenital diseases; Datasets; Developing Countries; Female; Gender; Girls; Heart; Humans; Infant, Newborn; Low and Middle Income Countries; Machine learning; Male; Medical screening; Neonatal Screening - methods; Neonatology; Newborn babies; Oximetry - methods; Pediatrics; Perfusion Index; Public sector; Pulse oximetry; Reference Values; Regression analysis; Screening; Sepsis; Neonatology; Low and Middle Income Countries; Developing Countries; Cardiology
• ISSN: 2399-9772; 2399-9772
• DOI: 10.1136/bmjpo-2024-002607

BackgroundPeripheral perfusion index (PPI) is useful in a variety of neonatal settings. Currently, available reference values are from small numbers and highly variable.MethodsWe sought to generate reference values of PPI by analysing previously collected data from newborns who underwent mandated universal pulse oximetry and PPI screening from 2018 to 2021 using uniform protocol and equipment. Q-Q plots and boxplots were used to visualise distributions. Kernel density estimation for heaped and rounded data was used to estimate percentiles of the distributions.ResultsData from 388 205 newborns who underwent universal pulse oximetry screening in the first week of life were used for this analysis. Pre and postductal values showed a non-normal distribution and skewed to the left, the former had a thicker tail with more extreme values. Minor, but statistically significant differences were seen in the PPI values from day 1 to 7. Median preductal PPI (2.77, IQR:1.83–3.93) was significantly higher than postductal (2.38 IQR: 1.41–3.55) (p<0.01). PPI values increased with weight and boys had higher PPI. Kernel estimates of the percentiles in the overall sample and subgroups for gender and weight have been provided for preductal and post-ductal values.ConclusionThis study, based on the largest available dataset, provides reference values for PPI in newborns. A significant influence of gender and birth weight on PPI values in newborns has been identified. Future research on understanding the influence of age, sex, birth weight, gestational age, ambient temperature and genetic factors on PPI is recommended.