Use of automated home blood pressure monitoring in pregnancy

Abstract

Lo et al1Lo C Taylor RS Gamble G McCowan I North RA. Use of automated home blood pressure monitoring in pregnancy: is it safe?.Am J Obstet Gynecol. 2002; 187: 1321-1328Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar compared the relationship between blood pressure that was measured with the automated blood pressure measurement device Omron HEM-705CP (Omron Healthcare Inc) and mercury sphygmomanometry in normotensive and preeclamptic pregnant women. Wide individual variation in blood pressure levels were recorded with the Omron HEM-705CP device compared with the mercury sphygmomanometer gold standard. Severe hypertension was occasionally missed with the Omron HEM-705CP device. Trained patients are able to provide reliable self-measured blood pressure with user-friendly automatic devices. When an automatic device is used, preference should be given to devices that have been authorized by a regular validation procedure. Most validation procedures assess the accuracy of the test device compared with the true indirect blood pressure measured by mercury sphygmomanometry.2O'Brien E Petrie J Litter W de Swiet M Tadfield PL Altman DG et al.The British Hypertension Society protocol for the evaluation of blood pressure measuring devices.J Hypertens. 1993; 11: S43-S62Google Scholar Preferably the automatic device and the mercury sphygmomanometer are connected to one arm cuff by means of a T connector. Stethoscopes with dual sets of earpieces permit duplicate mercury sphygmomanometer measurements. Automatic and the duplicate mercury sphygmomanometer measurements are taken simultaneously in a blinded manner. Consistency of the “true” indirect blood pressure needs to be established on paired mercury sphygmomanometer readings, and validity of the test device is studied by comparison of automatic with mercury sphygmomanometer readings according to accepted standards.2O'Brien E Petrie J Litter W de Swiet M Tadfield PL Altman DG et al.The British Hypertension Society protocol for the evaluation of blood pressure measuring devices.J Hypertens. 1993; 11: S43-S62Google Scholar Validation of automatic blood pressure measurement devices is cumbersome, time consuming, and expensive because a large number of subjects are tested across a wide range of blood pressures, requiring employment of many well-trained observers. Also, automatic devices need to be periodically recalibrated. For research purposes, in addition to recalibration, the validity of each device should be periodically reassessed.3Naschitz JE Gaitini L Loewenstein L Keren D Zuckerman E Tamir A et al.In-field validation of automatic blood pressure measuring devices.J Hum Hypertens. 2000; 14: 37-42Crossref PubMed Scopus (19) Google Scholar In simplifying the validation process of the Omron HEM-705CP for monitoring blood pressure in normotensive and preeclamptic pregnant women, the work by Lo et al has potential shortcomings: consistency of the “true” indirect blood pressure and adequacy of self-measured blood pressure with automatic devices were not established, and blood pressure measurements with the automatic device mercury sphygmomanometry were not simultaneous. Nevertheless, the conclusion of the present and previous studies converge in recognition that the accuracy of the Omron HEM-705CP is inadequate and this instrument should not be used to monitor blood pressure in preeclampsia.