title: Accurate, noninvasive continuous monitoring of cardiac output by whole-body electrical bioimpedance.
abstract: OBJECTIVE
  Cardiac output (CO) is measured but sparingly due to limitations in its measurement technique (ie, right-heart catheterization). Yet, in recent years it has been suggested that CO may be of value in the diagnosis, risk stratification, and treatment titration of cardiac patients, especially those with congestive heart failure (CHF). We examine the use of a new noninvasive, continuous whole-body bioimpedance system (NICaS; NI Medical; Hod-Hasharon, Israel) for measuring CO. The aim of the present study was to test the validity of this noninvasive cardiac output system/monitor (NICO) in a cohort of cardiac patients.
  
  
  METHODS
  Prospective, double-blind comparison of the NICO and thermodilution CO determinations.
  
  
  METHODS
  We enrolled 122 patients in three different groups: during cardiac catheterization (n = 40); before, during, and after coronary bypass surgery (n = 51); and while being treated for acute congestive heart failure (CHF) exacerbation (n = 31). MEASUREMENTS AND INTERVENTION: In all patients, CO measurements were obtained by two independent blinded operators. CO was measured by both techniques three times, and an average was determined for each time point. CO was measured at one time point in patients undergoing coronary catheterization; before, during, and after bypass surgery in patients undergoing coronary bypass surgery; and before and during vasodilator treatment in patients treated for acute heart failure.
  
  
  RESULTS
  Overall, 418 paired CO measurements were obtained. The overall correlation between the NICO cardiac index (CI) and the thermodilution CI was r = 0.886, with a small bias (0.0009 +/- 0.684 L) [mean +/- 2 SD], and this finding was consistent within each group of patients. Thermodilution readings were 15% higher than NICO when CI was < 1.5 L/min/m(2), and 5% lower than NICO when CI was > 3 L/min/m(2). The NICO has also accurately detected CI changes during coronary bypass operation and vasodilator administration for acute CHF.
  
  
  CONCLUSIONS
  The results of the present study indicate that whole-body bioimpedance CO measurements obtained by the NICO are accurate in rapid, noninvasive measurement and the follow-up of CO in a wide range of cardiac clinical situations.
authors.affiliation: Cardiology Department, Assaf-Harofeh Medical Center, Zerifin, Israel. cotterg@hotmail.com
authors.forename: Gad
authors.initials: G
authors.lastname: Cotter
authors.forename: Yaron
authors.initials: Y
authors.lastname: Moshkovitz
authors.forename: Edo
authors.initials: E
authors.lastname: Kaluski
authors.forename: Amram J
authors.initials: AJ
authors.lastname: Cohen
authors.forename: Hilton
authors.initials: H
authors.lastname: Miller
authors.forename: Daniel
authors.initials: D
authors.lastname: Goor
authors.forename: Zvi
authors.initials: Z
authors.lastname: Vered
mesh_terms: D006328:Cardiac Catheterization; D002302:Cardiac Output; D002307:Cardiography, Impedance / Q000379:methods*; D004311:Double-Blind Method; D006333:Heart Failure / Q000188:drug therapy / Q000503:physiopathology; D006801:Humans; D008991:Monitoring, Physiologic / Q000379:methods; D011446:Prospective Studies; D013815:Thermodilution; D014665:Vasodilator Agents / Q000627:therapeutic use
chemical_list: D014665:Vasodilator Agents