Abstract des Autors

Objective:This study examines the validity of a new closed circuit method to measure CO-haemoglobin (COHb) and tHb-mass. Materials and methods:20 male students of the University of Leipzig participated in the study after written informed consent. The procedure was approved by the local ethics committee. On 2 succeeding days measurements of total COHb were performed. The subjects took one deep breath of 100% CO and then kept connected to a closed breathing circuit for another 15 min. The CO-dilution space was calculated from the CO-difference in capillary blood before and after the rebreathing period. Day1: before blood letting, Day 2 24h after the test of Day 1. Blood letting: After blood volume measurement on Day 1, the students attended a regular blood donation in the university bloodbank (480 ml). Results:Mean haemoglobin volumes Day 1: 900,8 ± 188 g; Day 2: 821,4 ± 184 g; mean difference 79,5 ± 29 g (p<0.0001). Hb-mass calculated from the Hb-loss due to blood letting is 69 ± 5 g. The difference of 10 g between theoretical and measured hemoglobin loss is not significant. Conclusion: The results indicate a high test – retest correlation of the new CO-rebreathing method when the HbCO distribution space was calculated. Therefore this method is apparently suitable for high precision measurements of intraindividual changes of even small amounts of haemoglobin-changes. Verf.-Referat