Transpulmonary thermodilution in neonates undergoing arterial switch surgery

Abstract

Measurement of the global end-diastolic volume index (GEDI) by transpulmonary thermodilution (TPTD) has become a useful technique for measuring preload in adults. This study aimed to investigate the hemodynamic changes in neonates during the postoperative period after arterial switch surgery. Over a 13-month period, the postoperative data of 12 neonates with transposition of the great arteries were retrospectively investigated. Arterial and central venous blood pressures were monitored, Cardiac index (CI), stroke volume index (SVI), systemic vascular resistance index (SVRI), GEDI, and extravascular lung water index (ELWI) were measured by thermodilution. The CI was significantly correlated with the SVRI only in the closed chest condition (r = -0.92; P < 0.001). The CI and SVI values were significantly lower and the ELWI and SVRI values significantly higher in both the open and closed chest conditions than the postextubation values. The relationship between change in GEDI and change in CI was stronger in the open chest condition (r = 0.93; P < 0.006) than in the closed chest condition (r = 0.75; P = 0.055). However, the latter just missed statistical significance. According to the findings, TPTD seems to be a useful tool for assessing cardiac function after neonatal arterial switch surgery. Establishment of normal values will be essential for proper guidance of therapy for this population using volumetric parameters.