Anemia is traditionally diagnosed and managed using circulating hemoglobin concentration (\[Hb\]). However, \[Hb\] is influenced by plasma volume and may not accurately reflect the total amount of hemoglobin available for oxygen transport. Total hemoglobin mass (Hbmass), measured using the optimized carbon monoxide rebreathing method, provides a direct assessment of the body's oxygen-carrying capacity but has never been extensively investigated in patients presenting to the emergency department with non-life-threatening anemia. The hypothesis of the PHENOEMEMIA study is that routine blood hemoglobin concentration is only moderately correlated with Hbmass and therefore does not fully reflect the physiological severity of anemia. PHENOEMEMIA is a prospective single-center interventional physiological study including adults presenting to the emergency department with non-life-threatening anemia. Each participant undergoes routine clinical assessment, standardized symptom questionnaires, additional blood sampling for biological and hemorheological analyses, focused transthoracic echocardiography, near-infrared spectroscopy assessment of tissue oxygenation, and Hbmass measurement using the optimized carbon monoxide rebreathing technique. The primary objective is to evaluate the correlation between blood hemoglobin concentration and Hbmass normalized to body weight. Secondary objectives include describing the relationships between Hbmass, biological markers of anemia, clinical symptoms, cardiac adaptation, blood rheology, tissue oxygenation, and physiological phenotypes of anemia.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
59
Measurement of total hemoglobin mass using the optimized carbon monoxide rebreathing technique with capillary carboxyhemoglobin assessment.
Standardized focused transthoracic echocardiography including assessment of stroke volume, cardiac output and left ventricular filling parameters
Non-invasive assessment of tissue oxygen saturation and microvascular reactivity using near-infrared spectroscopy.
Laboratory assessment of blood viscosity, red blood cell deformability and aggregation from additional blood samples.
Assessment of fatigue, dyspnea, quality of life and anemia-related symptoms using standardized questionnaires.
Emergency department, Edouard Herriot Hospital, Hospices Civils de Lyon
Lyon, France
Correlation coefficient between blood hemoglobin concentration and body weight-normalized total hemoglobin mass
Correlation between routine blood hemoglobin concentration (g/dL) and total hemoglobin mass normalized to body weight (g/kg) measured using the optimized carbon monoxide rebreathing technique. Pearson's or Spearman's correlation coefficient will be calculated according to data distribution.
Time frame: Baseline (single study visit during emergency department stay)
Association between total hemoglobin mass and biological markers of anemia
Correlation between total hemoglobin mass and routine biological markers including mean corpuscular volume, mean corpuscular hemoglobin concentration, reticulocyte count, ferritin, transferrin saturation, soluble transferrin receptor, C-reactive protein, vitamin B12 and folate concentrations.
Time frame: Baseline
Association between total hemoglobin mass and clinical manifestations of anemia
Association between total hemoglobin mass and fatigue (MFI-20), dyspnea (mMRC), quality of life (EQ-5D-5L), and anemia-related symptoms including palpitations, chest pain and headache.
Time frame: Baseline
Association between total hemoglobin mass, blood volume and cardiovascular adaptation
Correlation between total hemoglobin mass, blood volume parameters and focused transthoracic echocardiographic measurements including stroke volume, cardiac output, velocity-time integral, mitral inflow velocities and Mitral Annular Plane Systolic Excursion (MAPSE).
Time frame: Baseline
Association between blood rheology and tissue oxygenation
Association between blood viscosity, red blood cell deformability, red blood cell aggregation and tissue oxygenation assessed by near-infrared spectroscopy.
Time frame: Baseline
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