The Role of Intraoperative Regional Oxygen Saturation Using Near Infrared Spectroscopy in the Prediction of Low Output Syndrome After Pediatric Heart Surgery

Abstract

We report on the applicability of intraoperative regional oxygen saturation (rSO2) desaturation score by near-infrared spectroscopy in the early detection of postoperative low output state (LOS) in infants with congenital heart disease who underwent cardiac surgery. Between July and October 2011 the intra- and immediate postoperative courses of 22 patients undergoing elective cardiac surgery for congenital heart disease were analyzed. The intraoperative cerebral and somatic rSO2 were measured and a rSO2 desaturation score calculated (by multiplying the rSO2 below 50% of the threshold by seconds). The aim of the study was to evaluate the applicability of intraoperative rSO2 de-saturation score in the early detection of postoperative LOS. Thirteen of 22 patients (62%) had an intraoperative cerebral rSO2 desaturation score >3000% per second. Patients with a rSO2 de-saturation score >3000% per second had a significantly lower intraoperative central venous saturation (SvO2, p = 0.002), cardiac index (CI, p = 0.004), oxygen availability indexed (DO2I, p = 0.0004), and a significantly higher extraction of oxygen (ERO2, p = 0.0005) when compared to patients with a rSO2 desaturation score <3000% per second. Nine patients had postoperative LOS; all of them had an intraoperative rSO2 de-saturation score >3000% per second (9/13 patients, 69%; p = 0.001) requiring prompt treatment with major inotropic support, surface hypothermia, and extracorporeal membrane oxygenation (ECMO) support (n = 4). Twenty-one patients survived. One patient died from ventricular failure and inability to wean from ECMO support. The intraoperative use of NIRS provided an early warning sign of hemodynamic or metabolic compromise, enabling early and rapid intervention to prevent or reduce the severity of potentially life-threatening complications.