Study of the Accuracy of Sphygmomanometers in a Teaching Hospital at Peshawar

Background: Defects or inaccuracy of sphygmomanometers may be the source of error in the diagnosis of hypertension. In this study we examined the physical condition and accuracy of sphygmomanometers used in various units of a teaching hospital. Material & Methods: This study was conducted at Khyber Teaching Hospital, Peshawar, including both wards and out patient departments from July, 2008 to January, 2009. We tested the accuracy and physical condition of 100 consecutively available sphygmomanometers. A test manometer was defined as being intolerant if it deviated from the new, standard manometer by greater than ±3 mmHg at 2 or more of the test pressure levels. Results: Out of 100 sphygmomanometers, 62 were collected from 15 different wards and 38 from the Out Patient Departments. Forty-six (46%) of these showed deviation from the new mercury manometer by greater than ± 3 mmHg at two or more of the test points. Regarding physical defects there were defective pump bulbs in (60%), defective rubber tubing (38%), and mercury level not pointing to the zero in (37%). Thirtyfour (55%) of the 62 ward sphygmomanometers and 12 (32%) of the 38 OPD sphygmomanometers were intolerant. In total, 46 (46%) of the 100 test sphygmomanometers were intolerant. There were faults in the inflation-deflation system of 46 (46%) sphygmomanometers. There was leakage in system of 34 (34%) sphygmomanometers. Conclusion: The functional and physical conditions of sphygmomanometers used in our set up are insufficient and defective. Sphygmomanometers in use should be regularly assessed.