title: Noninvasive Doppler ultrasonography for assessing cardiac function: can it replace the Swan-Ganz catheter?
abstract: BACKGROUND
  Cardiac function, including cardiac index (CI), traditionally has been measured by a pulmonary artery catheter (PAC). A noninvasive alternative for measuring cardiac function would offer obvious advantages.
  
  
  METHODS
  A prospective study of trauma and nontrauma patients was performed in a surgical intensive care unit over a 3-month period. CI was determined using both a standard PAC and a continuous-wave Doppler ultrasound (UTS). The study had 2 phases: phase I was nonblinded and phase II was blinded; the correlation between UTS- and PAC-derived CI was assessed.
  
  
  RESULTS
  A total of 120 paired measurements of CI were observed in 31 patients. The UTS-derived CI measurements showed agreement with PAC measurements in both phase I and phase II of the study with a bias of .06 L/min/m(2) +/- .4 L/min/m(2). Paired measurements correlated well in both phase I (r = .97, R2 = .95, P < .0001) and phase II (r = .93, R2 = .86, P < .0001) of the study.
  
  
  CONCLUSIONS
  Doppler UTS correlates well with PAC measurements of CI. This noninvasive modality is an accurate and safe alternative to PAC.
authors.affiliation: Department of Surgery, Cedars-Sinai Medical Center, 8700 Beverly Blvd., 8215 NT, Los Angeles, CA 90048, USA.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Jain
authors.forename: Alexander
authors.initials: A
authors.lastname: Allins
authors.forename: Ali
authors.initials: A
authors.lastname: Salim
authors.forename: Amir
authors.initials: A
authors.lastname: Vafa
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Wilson
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Margulies
mesh_terms: D000293:Adolescent; D000328:Adult; D002407:Catheterization, Swan-Ganz / Q000379:methods*; D002648:Child; D016638:Critical Illness / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D011446:Prospective Studies; D012372:ROC Curve; D018608:Ultrasonography, Doppler / Q000379:methods*; D016276:Ventricular Function / Q000502:physiology*; D055815:Young Adult