Original Articles

Correlation of a Novel Noninvasive Tissue Oxygen Saturation Monitor to Serum Central Venous Oxygen Saturation in Pediatric Patients with Postoperative Congenital Cyanotic Heart Disease

^* Department of Internal Medicine and Pediatrics, UCLA Medical Center, Mattel Children’s Hospital UCLA, Los Angeles, California
^† Department of Medicine Statistics Core, David Geffen School of Medicine at UCLA, Los Angeles, California
^‡ UCLA Clinical and Translational Science Institute, Los Angeles, California
^§ Department of Pediatrics, Division of Critical Care, Mattel Children’s Hospital UCLA and David Geffen School of Medicine at UCLA, Los Angeles, California

Address correspondence to: Robert B. Kelly, MD, Mattel Children’s Hospital UCLA, 10833 Le Conte Avenue, 12-494 MDCC, Los Angeles, CA 90095. E-mail: rkelly@mednet.ucla.edu

Received: 14 June 2012
Accepted: 16 January 2013

Abstract

Using a novel noninvasive, visible-light optical diffusion oximeter (T-Stat VLS Tissue Oximeter; Spectros Corporation, Portola Valley, CA) to measure the tissue oxygen saturation (S_tO₂) of the buccal mucosa, the correlation between S_tO₂ and central venous oxygen saturation (S_cvO₂) was examined in children with congenital cyanotic heart disease undergoing a cardiac surgical procedure. Paired S_tO₂ and serum S_cvO₂ measurements were obtained postoperatively and statistically analyzed for agreement and association. Thirteen children (nine male) participated in the study (age range, 4 days to 18 months). Surgeries included Glenn shunt procedures, Norwood procedures, unifocalization procedures with Blalock-Taussig shunt placement, a Kawashima/Glenn shunt procedure, a Blalock-Taussig shunt placement, and a modified Norwood procedure. A total of 45 paired S_tO₂-S_cvO₂ measurements was obtained. Linear regression demonstrated a Pearson’s correlation of .58 (95% confidence interval [CI], .35–.75; p < .0001). The regression slope coefficient estimate was .95 (95% CI, .54–1.36) with an interclass correlation coefficient of .48 (95% CI, .22–.68). Below a clinically relevant average S_cvO₂ value, a receiver operator characteristic analysis yielded an area under the curve of .78. Statistical methods to control for repeatedly measuring the same subjects produced similar results. This study shows a moderate relationship and agreement between S_tO₂ and S_cvO₂ measurements in pediatric patients with a history of congenital cyanotic heart disease undergoing a cardiac surgical procedure. This real-time monitoring device can act as a valuable adjunct to standard noninvasive monitoring in which serum S_cvO₂ sampling currently assists in the diagnosis of low cardiac output after pediatric cardiac surgery.