Effect of henna application on pulse oximetry reading among sick children admitted in an emergency unit: A single-center prospective observational study from Nigeria

Abstract

Background: As red henna interferes with the working principles of pulse oximetry, it affects peripheral oxygen saturation readings. This study was conducted to determine the effect of henna on the pulse oximetry of sick children admitted to the emergency department (ED). Subjects and Methods: This was a prospective observational study on 100 sick children admitted to ED. The red henna was applied on the right index finger and right toe, while the left index finger and left toe served as control. SpO2 readings for the upper limbs and lower limbs were recorded simultaneously and compared. Results: The median (interquartile range) age was 4.0 (2.0–8.6) years. There was no significant difference between SpO2 (95.9±4.2 vs. 95.4±4.4) for the upper limb finger (t = 1.147, P = 0.254) and Spo2 (95.3% ±4.9% vs. 95.7% ±3.9%) for lower limb finger (t = 0.954, P = 0.342) with henna and their corresponding pair without henna. However, the SpO2 of children with hypoxia (92.12% ±5.6% vs. 86.88% ±9.6%) for upper limb finger (92.00% ±5.7% vs. 88.41% ±5.5%) and for the toe was significantly higher on digits with henna compared with their pairs without henna (t = 3.167, P = 0.006 upper limb pair; t = 6.351, P = 0.013 for lower limb pair). Conclusions: Red henna application does not significantly affect the reading of pulse oximetry among children without hypoxia but significantly overestimates the oximetry reading in hypoxic children.