the comparison between the impacts of henna and nail polish on pulse oximetry among healthy women

background & aim : pulse oximetry is a frequently used and standard non-invasive method for monitoring oxygen (o2)-saturation in blood. many factors including dark skin and pigmentation may effect on rate of saturation of the blood oxygen absorbed by pulse oximetry. the effect of nail polish and/or henna color on blood oxygen has not been yet identified and the present study has been carried out by aiming at the review on impact of henna and nail polish on results of pulse oximetry. methods & materials : in the current investigation, clinical trial was studied on 60 resident young women at ages 20-40 by means of purposeful sampling method. initially, 20 g of iranian original henna was solved in 30 ml water and put on forefinger of non-dominant hand of the subjects. the other fingers of the same hand were stained by red, black, and white nail polish, respectively. the middle finger of the same hand was considered as the control variable. then, blood o2-saturation was measured by two calibrated pulse oximetry devices simultaneously. results : the results indicated that henna (p = 0.020), red nail polish (p ≤ 0.001), and white nail polish (p = 0.020) have increased significantly the rate of o2-saturation absorbed by pulse oximetry. the impact of black nail polish (p = 0.100) on o2-saturation was not significant, but it has changed the mean rate of o2-saturation. test result of anova with iterative values of f = 10.385 and p ≤ 0.001 showed the significant statistical difference among mean values of o2-saturation (henna, red, black, white, and control nail polish). conclusion : henna and nail polish may effect on percent of o2-saturation that showed by pulse oximetry and this may lead to error in monitoring of the patient. as a result, it is recommended to use other areas of the hand to put pulse oximetry sensor if henna is utilized and nail polish to be removed before installing the given sensor.