The concept of Patient Blood Management requires preoperative diagnostic of anemia. To avoid the harmful procedure of venous puncture for drawing a blood sample, noninvasive measurement of hemoglobin has been developed. However noninvasive measurement of hemoglobin has yet been not accurate enough to replace invasive hemoglobin measurement. This study investigates if a noninvasive measurement tool can serve as a screening tool to find out for which patients invasive measurement of hemoglobin is necessary.

The noninvasive hemoglobin measurement tool Pronto® can measure hemoglobin noninvasively by a sensor clip. The investigators analyzed previous studies with the Pronto device and calculated two cut-off values of the noninvasive hemoglobin device. If noninvasive hemoglobin values are higher than cut off value 1 the investigators postulate that with a sensitivity of 99% the participant has no anemia. To confirm this, participants who are supposed to undergo elective surgery and come to the preoperative anesthetic ambulance are measured by the Pronto-device. The noninvasive measurements are compared with the laboratory values of the patients and cut-off value 1 can be confirmed.

Inclusion Criteria:

• Adults and children >=3kg that are planned to undergo elective surgery
• Written informed consent

Exclusion Criteria:

• no written informed consent