COMPARISON OF THORACIC ELECTRICAL BIOIMPEDANCE AND THERMODILUTION FOR THE MEASUREMENT OF CARDIAC INDEX IN PATIENTS WITH SEVERE SEPSIS

Cardiac index was measured using thoracic bioimpedance (Clbi)and thermodilution (Cltd) in 19 patients with proven sepsis,undergoing artificial ventilation of the lungs. There was apoor correlation between the techniques (r = 0.36, 242 datasets, regression line Clbi = 0.16 Cltd + 2.56 litre min^–1m^–2). The overall bias (Cltd-Clbi) was 1.69 litre min^–1m^–2 with limits of agreement (precision) of +4.17 to –0.79litremin^–1 m^–2. In individual patients the bias was from0.46 to 4.56 litre min¹ m^–2 with the limits of agreementfrom ±0.29 to ±2.55 litre min^–1 m^–2around the bias values. The two techniques cannot be used interchangeablyin this group of patients. (Br. J. Anaesth. 1993; 70: 58–62) ^*Present address, for correspondence: Nuffield Department ofAnaesthetics, Radcliffe Infirmary, Woodstock Road, Oxford OX26HE