Abstract 1919: The Postoperative Systemic Inflammatory Response and Organ Injury are not Influenced by Bypass Temperature During Paediatric Open Heart Surgery: A Randomised Trial
Objectives: Systemic cooling during cardiopulmonary bypass (CPB) is widely used as a potential method of attenuating the CPB-related systemic inflammatory response syndrome (SIRS) and organ injury. However, this strategy is poorly investigated in children undergoing surgery for congenital heart disease (CHD). We compared the effects of moderate (24°C) and mild (34°C) hypothermia during CPB on biochemical and clinical markers of SIRS and organ injury, and on early outcome after surgery for CHD.
Methods: 66 children undergoing corrective surgery for CHD (median age 5 months, mean weight 6.2±2.3kg) were randomised to either 24°C or 34°C CPB temperature. Perfusion strategies were otherwise identical. Clinical data and blood samples were collected before CPB, 5 minutes after cross-clamp release, and 4, 24 and 48 hours after CPB. Blood was analysed for markers of inflammation (cytokines), innate immunity (Toll-like receptors 2 and 4), and organ dysfunction (creatinine, micro-albuminuria, S100B). Patients were followed up until hospital discharge. Data were analysed using ANOVA.
Results: The incidence of postoperative SIRS, according to standard definitions, was 52% in the 24°C group, and 56% in the 34°C group (p=0.9). CPB temperature did not influence the duration of mechanical ventilation (33±35 for 24°C versus 26±27 hours for 24°C, p=0.4), ICU stay (47±37 versus 45±33 hours, p=0.8), or total perioperative blood loss (31±16 versus 32±31 ml/kg). Blood markers of inflammation, innate immunity, and organ dysfunction were not influenced by CPB temperature at any time point (see table⇓; results are expressed as mean±SD).
Conclusion: Postoperative SIRS and organ dysfunction are not influenced by CPB temperature. The routine application of hypothermic CPB may not have a protective role in children undergoing surgery for CHD.