title: Assessment of global tissue perfusion and oxygenation in neonates and infants after open-heart surgery.
abstract: OBJECTIVE
  Monitoring and preserving adequate perfusion and oxygen balance is a primary objective of critical care. This prospective observational study aimed to assess the relationship between global haemodynamic parameters and variables reflecting tissue oxygenation during the early period following corrective cardiac surgery in neonates and infants. The postoperative time course of oxygen delivery and consumption was evaluated. As surrogate markers of oxygen balance, the central venous oxygen saturation (ScvO2) and venoarterial PCO2 difference (PvaCO2) were thoroughly investigated.
  
  
  METHODS
  Thirteen children <1 year of age who underwent open-heart surgery were prospectively enrolled. In addition to conventional postoperative monitoring, transpulmonary thermodilution (TPTD) was used to monitor cardiac output and calculate oxygen delivery and consumption. In parallel with each TPTD measurement, arterial and central venous blood gas values were recorded. Global haemodynamic parameters and oxygenation measurements were compared with weighted linear regression statistics and Pearson's correlation coefficient.
  
  
  RESULTS
  Data from 145 TPTD measurements and 304 blood gas samples were recorded. The early postoperative period was characterized by a supply-dependent oxygen consumption, as demonstrated by the direct correlation between the change in oxygen delivery and consumption (r = 0.62, P < 0.001). Regarding haemodynamic parameters, none of the heart rate, mean arterial pressure or cardiac index correlated with the measured ScvO2. However, the ScvO2 and PvaCO2 were found to correlate significantly (r = -0.49, P < 0.001), and both strongly related to oxygen extraction.
  
  
  CONCLUSIONS
  Both the ScvO2 and PvaCO2 are reliable and comparable parameters in following tissue oxygen balance during the early postoperative course after open-heart surgery in neonates and infants. As part of multiparameter monitoring, our data highlight the importance of regular ScvO2 measurements and PvaCO2 calculations in paediatric intensive care.
authors.affiliation: Department of Anesthesiology and Intensive Therapy, Gottsegen György Hungarian Institute of Cardiology, Budapest, Hungary.
authors.forename: Mihály
authors.initials: M
authors.lastname: Gergely
authors.forename: László
authors.initials: L
authors.lastname: Ablonczy
authors.forename: Edgár A
authors.initials: EA
authors.lastname: Székely
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Sápi
authors.forename: János
authors.initials: J
authors.lastname: Gál
authors.forename: András
authors.initials: A
authors.lastname: Szatmári
authors.forename: Andrea
authors.initials: A
authors.lastname: Székely
mesh_terms: D062186:Arterial Pressure; D015415:Biomarkers / Q000097:blood; D001784:Blood Gas Analysis; D002302:Cardiac Output; D006348:Cardiac Surgical Procedures; D003422:Critical Care; D005260:Female; D006339:Heart Rate; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D013815:Thermodilution; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D010100:Oxygen
keywords: Critical care; Haemodynamics; Oxygen consumption; Thermodilution