Clinical assessment of blood pressure

This study was performed to determine the blood pressure measuring techniques and accuracy of sphygmomanometers used by physicians in ambulatory care clinics on the Avalon Peninsula of Newfoundland. Of the 114 participating physicians, no physician completely followed all the recommended BP measuring techniques of the American Heart Association. Almost all physicians supported the patient's arm at heart level to measure BP. Fewer physicians used the following recommended techniques; palpation to initially assess systolic BP (38%), measurement of BP in both arms (23%), an appropriate rate of cuff deflation (18%), measurement of BP in recommended patient positions (10%), the appropriate length of rest (4%) or use of a cuff of appropriate size (3%). Approximately 8% of mercury sphygmomanometers were out of calibration by at least 4 mmHg but none were out by more than 6 mmHg. Forty percent of aneroid sphygmomanometers were out of calibration by at least 4 mmHg and of these 30% were out by 10 mmHg or more. Mercury and aneroid sphygmomanometers were used by 60% of physicians. Aneroid sphygmomanometers were used exclusively by 34% of physicians, while 5% of physicians relied solely on mercury devices. Standardized techniques for BP measurement are not used and inaccurate sphygmomanometers are common; these factors may lead to misclassification of blood pressure and inappropriate treatment of patients.