Accuracy Validation of Pulse Oximeters used at Hospitals : A Cross-Sectional Study performed in Stockholm

Sammanfattning: This thesis had the purpose to look into the accuracy of the pulse oximeter, the experienced as well as the actual. A pulse oximeter utilizes optics to non-invasively estimate the oxygen saturation (SO2) in the blood with an indirect value (SpO2). The accuracy of the pulse oximeter and its two belonging sensors (ear and finger) was compared against the method that is considered to give the most reliable value of this parameter, i.e. arterial blood gas test (SaO2). The experienced accuracy was evaluated with the help of a questionnaire. The target group was healthcare professionals at four main hospitals in Stockholm, and further three departments were chosen at each hospital; lung, cardiology, and emergency department. Additional data was collected with help of measurements performed on patients, where readings from pulse oximeters were compared against arterial blood gas tests. Data was collected from two measurement sites on the body, the ear and the finger. Differences between SpO2 and SaO2 as well as differences between ear and finger for the same pulse oximeter were investigated. The result from the two methods indicated that the healthcare professionals were aware of existing deviations between SpO2 and SaO2, and some also had strategies to deal with them. The trend of the collected data was analyzed to draw a conclusion of the most accurate pulse oximeter according to the tests. There was not enough data collected to make any statistical conclusion, but according to the data none of the pulse oximeters fulfilled the set requirement. Differences existed when SpO2 was compared against SaO2, and also when SpO2 from the ear and finger for the same pulse oximeter were compared against each other. According to the data, one pulse oximeter was concluded to be more accurate than the others. Suggestions for future work can be to collect a bigger amount of data to be able to draw a statistical conclusion, and eventually focus on interviews to look deeper into the healthcare professionals’ strategies and workflow.