Correspondence
Blood-Pressure Measurement
N Engl J Med 2009; 360:2034-2035May 7, 2009
- Article
To the Editor:
In their Video in Clinical Medicine and accompanying article, Williams et al. (Jan. 29 issue)1 omit an important step in blood-pressure measurement — the determination of orthostatic (postural) blood pressure. Although guidelines on this procedure are not consistent, it is generally recommended that orthostatic blood pressure be measured while the patient is in the standing position every minute during the first 3 minutes after he or she has been lying supine for 5 minutes.2 If the patient cannot stand for this period of time, the lowest systolic blood pressure should be recorded.
Orthostatic hypotension is a physical sign defined as a reduction of at least 20 mm Hg in systolic blood pressure or of at least 10 mm Hg in diastolic blood pressure within 3 minutes after standing.3 Guidelines for the management of hypertension recommend that orthostatic blood pressure be assessed in patients with diabetes, the elderly, patients receiving antihypertensive treatment, and patients with other conditions in which orthostatic hypotension may be common or suspected.4,5 The diagnosis of orthostatic hypotension is extremely important, since this condition is responsible for recurrent symptoms such as syncope, dizziness, and light-headedness, as well as serious injuries and deterioration in the quality of life.2
5 ReferencesDimitrios Terentes-Printzios, M.D.
Charalambos Vlachopoulos, M.D.
Christodoulos Stefanadis, M.D.
University of Athens Medical School, 11527 Athens, Greece1
Williams JS, Brown SM, Conlin PR. Videos in clinical medicine: blood-pressure measurement. N Engl J Med 2009;360(5):e6 (Web only). (Available at http://www.nejm.org.)
2
Brignole M ,Alboni P ,Benditt DG , et al. Guidelines on management (diagnosis and treatment) of syncope -- update 2004. Europace 2004;6:467-537
CrossRef | Web of Science | Medline3
The Consensus Committee of the American Autonomic Society and the American Academy of Neurology
Web of Science | Medline4
Mancia G ,De Backer G ,Dominiczak A , et al. 2007 Guidelines for the management of arterial hypertension: The Task Force for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). Eur Heart J 2007;28:1462-1536
Web of Science | Medline5
Chobanian AV ,Bakris GL ,Black HR , et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003;42:1206-1252
CrossRef | Web of Science | Medline
To the Editor:
In both the article and video on blood-pressure measurement, Williams et al. never mention the measurement of blood pressure in both arms. Blood pressure should initially be recorded in both arms because in a substantial number of patients, particularly the elderly, there are large differences (>10 mm Hg) in blood-pressure readings between the two arms. The arm with the higher value should be used for subsequent measurements.1
Several studies have compared blood-pressure measurements in the two arms. Almost all have reported differences. In one of the largest studies, involving 400 subjects and using simultaneous measurements with oscillometric devices, there were clinically important differences of more than 10 mm Hg in systolic blood pressure between the arms in 20% of subjects and differences of more than 10 mm Hg in diastolic blood pressure between the arms in 11% of subjects.2 Such data underscore the importance of measuring blood pressure in both arms initially, not only to prevent the misdiagnosis of hypertension but also to detect coarctation of the aorta, arterial obstruction in the arm,3 congenital heart disease, and unilateral neurologic and musculoskeletal abnormalities.4
4 ReferencesSonia K. Dudeja, M.D.
Rajesh K. Dudeja, M.D.
Daisy Hill Hospital Southern Health and Social Care Trust, Newry BT35 8NJ, United Kingdom
sonia.dudeja@dhh. n-i. nhs. uk 1
Blood pressure measurement. British Hypertension Society fact file 01/2006. (Accessed April 17, 2009, at http://www.bhsoc.org/bhf_factfiles/bhf_factfile_jan_2006.doc.)
2
Lane D ,Beevers M ,Barnes N , et al. Inter-arm differences in blood pressure: when are they clinically significant? J Hypertens 2002;20:1089-1095
CrossRef | Web of Science | Medline3
Pickering TG ,Hall JE ,Appel LJ , et al. Blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Hypertension 2005;45:142-161
Web of Science | Medline4
Perloff D ,Grim C ,Flack J , et al. Human blood pressure determination by sphygmomanometry. Circulation 1993;88:2460-2470
Web of Science | Medline
Author/Editor Response
The purpose of our Video in Clinical Medicine was to provide instruction in the proper technique for measuring blood pressure, which is critically important for the accurate staging and treatment of hypertension. Once these basic techniques are mastered, they can be generalized to a variety of clinical settings. Time and space limitations prevented us from addressing some points that may be relevant to blood-pressure evaluation, including those cited by Terentes-Printzios et al. and Dudeja and Dudeja. Nonetheless, these special circumstances still require adherence to the techniques demonstrated in the video.
We agree with Terentes-Printzios et al. that measuring blood pressure in patients who are in the standing position may identify persons with an orthostatic fall in blood pressure. Such a measurement would be particularly appropriate in patients with clinical conditions or risk factors that predispose them to orthostatic hypotension. Dudeja and Dudeja note that measuring blood pressure in both arms at an initial visit helps to uncover large differences in blood pressure between the arms. This finding may justify the preferential use of one arm (the one with the higher reading) for future blood-pressure measurements. We agree that this step may be appropriate. However, it is unclear whether blood-pressure differences between the arms are reproducible over time or whether they indicate intrinsic intraindividual variations in blood pressure.
Jonathan S. Williams, M.D., M.M.Sc.
Stacey Brown, M.S.
Brigham and Women's Hospital, Boston, MA 02115Paul R. Conlin, M.D.
Veterans Affairs Boston Healthcare System, West Roxbury, MA 02132
