Evaluating the Accuracy of Blood Pressure Measurement

혈압측정의 정확성 평가

Background : Blood pressure is an important indicator in diagnosis and assessing treatment of a patient. Clinical staffs use blood pressure on the assumption that measured value is accurate and reliable. However, whether measured blood pressure is accurate has been rarely investigated in Korea. Objectives : The aims of this study are to evaluate clinical staffs' knowledge and technique as well as accuracy of sphygmomanometer. Also the program to improve the measurement is developed. Methods : Seventy-three registered nurses were asked nine multiple choice questions including Korotkoff sound, cuff size, and deflation rate. Simultaneously characteristics of nurses were examined, age, working place, duration of employment and academic degree. A testing videotape(Standardizing Measurement Video-Tutored Course) was used for evaluating the accuracy of measurement. Testees were to read and record the 12 cases of blood pressure measurement, watching a falling mercury column and hearing Korotkoff sounds. After 10 minutes' education, they were again tested with the same cases. Additionally, 83 mercury sphygmomanometers were checked to find defects such as inaccurate calibration and zero setting, leaky bladder, etc. Results: For the knowledge testing correct response rate was 41.1%. They were the lowest in selecting the proper cuff size and Korotkoff sound. In examining accuracy of blood pressure with videotape, nurses had 67.7% correct response rate. The correct response rate was significantly improved by a session of education. About 23% of sphygmomanometers was without discernable defects. Conclusion : The knowledge and skill of clinical staffs along with the accuracy of equipment have to be improved. A properly designed education program would contribute to the accuracy improvement of blood pressure measurement. Also, more concerns should be given to the precision and maintenance of equipment.