Inferior and Superior Vena Cava Saturation Monitoring After Neonatal Cardiac Surgery

Abstract

Objectives: Superior vena cava oxygen saturation (SVC O 2 ) monitoring is well described for early detection of hemodynamic deterioration after neonatal cardiac surgery but inferior vena cava vein oxygen saturation (IVC O 2 ) monitoring data are limited.

Design: Retrospective cohort study of 118 neonates with congenital heart disease (52 single ventricle) from February 2008 to January 2014.

Setting: Pediatric cardiac ICU.

Patients: Neonates (< 30 d) with concurrent admission IVC O 2 and SVC O 2 measurements after cardiac surgery with cardiopulmonary bypass.

Interventions: None.

Measurements and main results: The primary aim was to correlate admission IVC O 2 and SVC O 2 . Secondary aims included: correlate flank or cerebral near-infrared spectroscopy with IVC O 2 and SVC O 2 , respectively, and exploratory analysis to evaluate associations between oximetry data and a composite adverse outcome defined as any of the following: increasing serum lactate or vasoactive support at 2 hours post-admission, cardiac arrest, or mortality. Admission IVC O 2 and SVC O 2 correlated ( r = 0.54; p < 0.001). However, IVC O 2 measurements were significantly lower than paired SVC O 2 (mean difference, -6%; 95% CI, -8% to -4%; p < 0.001) with wide variability in sample agreement. Logistic regression showed that each 12% decrease in IVC O 2 was associated with a 12-fold greater odds of the composite adverse outcome (odds ratio [OR], 12; 95% CI, 3.9-34; p < 0.001). We failed to find an association between SVC O 2 and increased odds of the composite adverse outcome (OR, 1.8; 95% CI, 0.99-3.3; p = 0.053). In an exploratory analysis, the area under the receiver operating curve for IVC O 2 and SVC O 2 , and the composite adverse outcome, was 0.85 (95% CI, 0.77-0.92) and 0.63 (95% CI, 0.52-0.73), respectively. Admission IVC O 2 had strong correlation with concurrent flank near-infrared spectroscopy value ( r = 0.74; p < 0.001). SVC O 2 had a weak association with cerebral near-infrared spectroscopy ( r = 0.22; p = 0.02).

Conclusions: In postoperative neonates, admission IVC O 2 and SVC O 2 correlate. Lower admission IVC O 2 may identify a cohort of postsurgical neonates at risk for low cardiac output and associated morbidity.