METHOD : Data were prospectively collected in 2 cohorts of patients: major operations requiring hemodynamic monitoring (operating room [OR]) and critically ill patients (intensive care unit [ICU]). Noninvasive hemoglobin measurements (SpHb) were recorded and were then compared with laboratory hemoglobin measurementsCONLUSION: Noninvasive hemoglobin monitoring is a new technology that correlated with laboratory values and supports the continued study of noninvasive hemoglobin monitoring.