The association between hemodynamic parameters on routine clinical monitoring and mortality after the Norwood operation: the utility of near infrared spectroscopy

Introduction: Routine hemodynamic parameters have largely been used to help guide clinical management after the Norwood operation. Changes in these parameters that indicate increased risk of cardiac arrest or death have not been well delineated and rather age population normal are frequently applied to this unique patient population. This study aimed to compare conventional hemodynamics parameters in children with parallel circulation in the 48 hours prior to discharge or death. Methods: This was a retrospective study including patients after the Norwood operation. By virtue, all these patients had parallel circulation. Blood pressure, respiratory rate, heart rate, arterial saturation by pulse oximetry, shock index, cerebral near infrared spectroscopy, and renal near infrared spectroscopy were collected in the 48 hours immediately preceding either discharge home or death. Results: Heart rate was significantly higher at multiple time points leading up to death in non-survivors, and significantly lower the hour before death. Systolic blood pressure was significantly lower in non-survivors 48 hours prior to discharge but not at any other timepoint. Respiratory rate was significantly lower in non-survivors. Arterial saturation by pulse oximetry was significantly lower in non-survivors. Shock index was significantly higher in non-survivors at multiple time points prior to death. Cerebral near infrared spectroscopy was significantly lower in non-survivors at multiple time points prior to death. Renal near infrared spectroscopy was significantly lower in non-survivors at multiple time points prior to death. Near infrared spectroscopy was most consistently altered in the hours immediately preceding death. Conclusion: Conventional hemodynamic monitoring patterns can help facilitate identification of those at risk for death. However, changes are subtle and present in only a few parameters. Near infrared spectroscopy changes more dramatically in non-survivors and may better identify individuals at risk of death.