Novel use of new parameters in nirs cerebral oximetry in cabg surgery to display changes in brain perfusion

Abstract

technique. This study aimed to evaluate the PF after major cardiac surgery. Methods: This was an ancillary study of the SUCCES study (clinical trial number: 02782520), a prospective randomized study whose purpose was to compare the hemodynamic effect of a fluid challenge with hypertonic saline or lactated Ringer's Ò. Inclusion criteria were patients requiring a Swan-Ganz catheter (SGc) for cardiac surgery and requiring fluid challenge during the postoperative period. Cardiac index (CI) was monitored simultaneously in patients by the PF or by an SGc continuous thermodi-lution. Statistical analysis was performed using linear regression and Bland-Altman analysis. Intermethod agreement during volume expansion was assessed using the Kappa statistic. Results: The data of 22 patients were reviewed. We analyzed 12,734 pairs of measurements. CI values were slightly but significantly different between the SGc system (2.52 § 0.52, 95% confidence interval of the mean: 2.51-2.53 L/min/m 2) and the PF (2.58 § 0.72, 95% confidence interval of the mean: 2.57-2.59 L/ min/m 2), p < 0.001. The correlation coefficient was R = 0.86 (95% confidence interval = 0.84 to 0.88, p <0.001), the bias was À0.06 L/min, and limits of agreement were À1.18 to 1.05 L/min, with a percentage of error of 44%. Response to volume expansion was considered as positive for 12 (75%) cases in the SGc group and for 2 (12%) cases in the PF group (weighted Kappa À0.09; 95% confidence interval = À0.35 to 0.17). Discussion: The concordance between PF and SGc is moderate after cardiac surgery. The PF did not correctly track changes in CI during fluid expansion.