Comparison of cardiac index measurements in intensive care patients using continuous wave vs. pulsed wave echo-Doppler compared to pulse contour cardiac output

Intensive Care Medicine Experimental

Table 4 Subgroup analysis for rhythm and cardiac index including mean differences between measurements, the standard deviation of the differences and the 95% Bland–Altman limits of agreement

Measurements	No.	Mean difference (L/min/m²)	Standard deviation difference (L/min/m²)	95% Bland–Altman limits (L/min/m²)
Sinus rhythm
CW-VTI CI and PiCCO CI^a	50	− 0.17	0.63	(− 1.40, 1.07)
PW-VTI CI and PiCCO CI^a	50	− 0.53	0.51	(− 1.54, 0.47)
High CI (> 4 L/min)
CW-VTI CI and PiCCO CI^a	7	− 0.57	0.69	(− 1.93, 0.78)
PW-VTI CI and PiCCO CI^a	7	− 0.95	0.63	(− 2.19, 0.29)
Low CI (< 2.5 L/min)
CW-VTI CI and PiCCO CI^a	22	− 0.04	0.52	(− 1.06, 0.98)
PW-VTI CI and PiCCO CI^a	22	− 0.39	0.36	(− 1.10, 0.44)

N Number of patients; CI Cardiac Index; CW-VTI Continuous-wave Velocity Time integral; CW-VTI Pulsed-wave Velocity Time integral; PiCCO Pulse Contour Cardiac Output
^aDifferences calculated as values for CW-VTI minus value for PiCCO
^bDifferences calculated as values for CW-VTI minus value for PW-VTI