Wundows複合機能システム

Wundows複合機能システム

Sunday, December 22, 2013

非観血 心拍出料計

Impedance cardiography revisited G Cotter1, A Schachner2, L Sasson2, H Dekel2 and Y Moshkovitz3 1 Divisions of Clinical Pharmacology and Cardiology, Duke University Medical Center, Durham, NC, USA 2 Angela & Sami Sharnoon Cardiothoracic Surgery Department, Wolfson Medical Center, Israel 3 Department of Cardiac Surgery, Assuta Hospital, Petah Tikva, Israel E-mail: gad.cotter@duke.edu Received 7 February 2006, accepted for publication 9 June 2006 Published 5 July 2006 Online at stacks.iop.org/PM/27/817 Abstract Previously reported comparisons between cardiac output (CO) results in patients with cardiac conditions measured by thoracic impedance cardiography (TIC) versus thermodilution (TD) reveal upper and lower limits of agreement with two standard deviations (2SD) of approximately ±2.2 l min−1, a 44% disparity between the two technologies. We show here that if the electrodes are placed on one wrist and on a contralateral ankle instead of on the chest, a configuration designated as regional impedance cardiography (RIC), the 2SD limit of agreement between RIC and TD is ±1.0 l min−1, approximately 20% disparity between the two methods. To compare the performances of the TIC and RIC algorithms, the raw data of peripheral impedance changes yielded by RIC in 43 cardiac patients were used here for software processing and calculating the CO with the TIC algorithm. The 2SD between the TIC and TD was ±1.7 l min−1, and after annexing the correcting factors of the RIC formula to the TIC formula, the disparity between TIC and TD further declined to ±1.25 l min−1. Conclusions: (1) in cardiac conditions, the RIC technology is twice as accurate as TIC; (2) the advantage of RIC is the use of peripheral rather than thoracic impedance signals, supported by correcting factors. Keywords: cardiac output measurements

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