title: Comparison of Portapres with standard sphygmomanometry in pregnancy.
abstract: BACKGROUND
  Continuous beat-to-beat noninvasive blood pressure (BP) measurement is possible with Portapres. It constructs finger arterial waveforms beat-to-beat. Dedicated software is used to analyze the arterial waveforms. A new technique has been developed to reconstruct brachial intra-arterial pressure that uses return to flow (RTF). This method has been validated against invasive intra-arterial measurements in nonpregnant individuals.
  
  
  OBJECTIVE
  To validate Portapres in normal and preeclamptic pregnant women against standard aneroid sphygmomanometry according to Riva-Rocci-Korotkoff (RRK).
  
  
  METHODS
  In 30 normotensive (10 in each trimester) and 20 preeclamptic women, two trained observers blinded from each other's results took BP measurements with a standard sphygmomanometer. These measurements were compared with sequential same-arm averaged measurements obtained during 30 sec by Portapres, following protocols from the Association for the Advancement of Medical Instrumentation (AAMI, mean accepted difference < or = 5 mmHg, SD < or = 8) and British Hypertension Society (BHS, gradings A down to D).
  
  
  RESULTS
  A total of 150 measurement pairs were analyzed. Cumulative percentages of absolute pressure differences for all women (BHS) and mean pressure differences (SD) for different trimesters and preeclampsia (AAMI) between sphygmomanometry and Portapres were calculated. Overall, mean difference (SD) for systolic BP was 5 (SD 8) and for diastolic BP was -3 (SD 8), although analysis of variance revealed a significant effect for preeclampsia on diastolic differences between the two methods of BP measurement ( p<0.001).
  
  
  CONCLUSIONS
  Portapres with RTF, developed to equal intra-arterial brachial pressure, compares reasonably well to RRK and overall meets the criteria set by the AAMI. According to the BHS, Portapres receives a B-grading for diastolic BP and a C-grading for systolic BP. As Portapres measures BP and calculates cardiac output continuously and noninvasively, it would appear worthwhile to further evaluate this device in pathological pregnancies.
authors.affiliation: Department of Obstetrics, Academic Medical Center, P.O. Box 22660, 1100 DD Amsterdam, The Netherlands.
authors.forename: Wouter J K
authors.initials: WJ
authors.lastname: Hehenkamp
authors.forename: Saskia
authors.initials: S
authors.lastname: Rang
authors.forename: Jeroen
authors.initials: J
authors.lastname: van Goudoever
authors.forename: Willem J W
authors.initials: WJ
authors.lastname: Bos
authors.forename: Hans
authors.initials: H
authors.lastname: Wolf
authors.forename: Joris A M
authors.initials: JA
authors.lastname: van der Post
mesh_terms: D000293:Adolescent; D000328:Adult; D001795:Blood Pressure Determination / Q000295:instrumentation / Q000592:standards; D015924:Blood Pressure Monitors / Q000592:standards*; D005260:Female; D006801:Humans; D011225:Pre-Eclampsia / Q000503:physiopathology; D011247:Pregnancy