Limitations of Cerebral Oxygenation Monitoring by Near-Infrared Spectroscopy in Children With Cyanotic Congenital Heart Disease and Profound Polycythemia

In this case series, a group of 10 patients with significantly high preoperative hematocrit secondary to congenital cardiovascular disease for whom regional cerebral oxygen saturation was unmeasureable via nearinfrared spectroscopy were identified. Institutional review board approval was obtained for the review of records and data collection for patients with failure of intraoperative NIRS detection. In a period of 1 year (2010), 10 of 1,820 (0.55%) patients were identified intraoperatively and in the cardiac catheterization laboratory with failed NIRS monitoring and profound polycythemia (ie, hematocrit values significantly above the laboratory reference range). After the induction of anesthesia, appropriate-sized bilateral INVOS 5100 sensors (Somanetics Corp, Troy, MI) were placed on the patient’s forehead. If the rSO2 was unobtainable (failure to display a value on the monitor screen), the probes were removed and placed on the attending anesthesiologist to confirm that the probes and equipment were functional. The probes were replaced onto the patient’s forehead, and again an rSO2 value failed to display. Data collection included demographics, hematocrit, hemodynamic variables, and ventilatory variables, and the presence or absence of rSO2 detection was recorded with every arterial blood gas analysis.