Validation of non-invasive haemodynamic methods in patients with liver disease: the Finometer and the Task Force Monitor

Patients with advanced cirrhosis often present a hyperdynamic circulation characterized by a decrease in systolic and diastolic blood pressure (SBP and DBP), and an increase in heart rate (HR) and cardiac output (CO). Accurate assessment of the altered circulation can be performed invasively; however, due to the disadvantages of this approach, non-invasive methods are warranted. The purpose of this study was to compare continuous non-invasive measurements of haemodynamic variables by the Finometer and the Task Force Monitor with simultaneous invasive measurements. In 25 patients with cirrhosis, SBP, DBP and HR were measured non-invasively and by femoral artery catheterization. CO was measured non-invasively and by indicator dilution technique. The non-invasive pressure monitoring was considered acceptable with a bias (accuracy) and a SD (precision) not exceeding 5 and 8mmHg, respectively, as recommended by the Association for the Advancement of Medical Instrumentation. The accuracy and precision of the Finometer and the Task Force Monitor were as follows: SBP: -36 +/- 179 and -89 +/- 175mmHg, respectively; DBP: 42 +/- 96 and 19 +/- 86mmHg, respectively; HR: 20 +/- 69 and 22 +/- 62bpm, respectively; and CO: 01 +/- 16 and -10 +/- 20Lmin(-1), respectively. The study demonstrates that the overall performances of the Finometer and the Task Force Monitor in estimating absolute values of SBP, DBP, HR and CO in patients with cirrhosis are not equivalent to the gold standard, but may have an acceptable performance with repeated measurements.