Duplicate measures of hemoglobin mass within an hour: feasibility, reliability, and comparison of three devices in supine position

Andreas Breenfeldt Andersen, Thomas Christian Bonne, Nikolai Baastrup Nordsborg, Henrik Holm-Sørensen, Jacob Bejder*

*Corresponding author for this work


Duplicate measure of hemoglobin mass by carbon monoxide (CO)-rebreathing is a logistical challenge as recommendations prompt several hours between measures to minimize CO-accumulation. This study investigated the feasibility and reliability of performing duplicate CO-rebreathing procedures immediately following one another. Additionally, it was evaluated whether the obtained hemoglobin mass from three different CO-rebreathing devices is comparable. Fifty-five healthy participants (22 males, 23 females) performed 222 duplicate CO-rebreathing procedures in total. Additionally, in a randomized cross-over design 10 participants completed three experimental trials, each including three CO-rebreathing procedures, with the first and second separated by 24 h and the second and third separated by 5-10 min. Each trial was separated by >48 h and conducted using either a glass-spirometer, a semi-automated electromechanical device, or a standard three-way plastic valve designed for pulmonary measurements. Hemoglobin mass was 3 ± 22 g lower (p < 0.05) at the second measure when performed immediately after the first with a typical error of 1.1%. Carboxyhemoglobin levels reached 10.9 ± 1.3%. In the randomized trial, hemoglobin mass was similar between the glass-spirometer and three-way valve, but ∼6% (∼50 g) higher for the semi-automated device. Notably, differences in hemoglobin mass were up to ∼13% (∼100 g) when device-specific recommendations for correction of CO loss to myoglobin and exhalation was followed. In conclusion, it is feasible and reliable to perform two immediate CO-rebreathing procedures. Hemoglobin mass is comparable between the glass-spirometer and the three-way plastic valve, but higher for the semi-automated device. The differences are amplified if the device-specific recommendations of CO-loss corrections are followed.

Original languageEnglish
JournalScandinavian Journal of Clinical and Laboratory Investigation
Issue number1
Pages (from-to)1-10
Number of pages10
Publication statusPublished - Feb 2024


  • Carbon Monoxide
  • Carboxyhemoglobin/analysis
  • Feasibility Studies
  • Female
  • Hemoglobins/analysis
  • Humans
  • Male
  • Reproducibility of Results
  • Supine Position
  • Red cell mass
  • study
  • reliability and validity
  • blood volume
  • erythrocyte volume
  • carboxyhemoglobin
  • hematology
  • methodological


Dive into the research topics of 'Duplicate measures of hemoglobin mass within an hour: feasibility, reliability, and comparison of three devices in supine position'. Together they form a unique fingerprint.

Cite this