Anemia
Conditions
Keywords
Anemia, Hemoglobin Mass, Carbon Monoxide Rebreathing, Emergency Medicine, Blood Volume, Hemorheology, Tissue Oxygenation, Near Infrared Spectroscopy, Echocardiography, Physiological Phenotyping
Brief summary
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.
Interventions
DEVICETotal hemoglobin mass measurement
Measurement of total hemoglobin mass using the optimized carbon monoxide rebreathing technique with capillary carboxyhemoglobin assessment.
DIAGNOSTIC_TESTFocused transthoracic echocardiography
Standardized focused transthoracic echocardiography including assessment of stroke volume, cardiac output and left ventricular filling parameters
DIAGNOSTIC_TESTNear-infrared spectroscopy
Non-invasive assessment of tissue oxygen saturation and microvascular reactivity using near-infrared spectroscopy.
OTHERBlood rheology assessment
Laboratory assessment of blood viscosity, red blood cell deformability and aggregation from additional blood samples.
OTHERSymptom assessment
Assessment of fatigue, dyspnea, quality of life and anemia-related symptoms using standardized questionnaires.
Sponsors
Hospices Civils de Lyon
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Masking description
Not applicable. All participants undergo the same study procedures and no masking is performed.
Intervention model description
Prospective, single-center, single-arm physiological study in which all participants undergo standardized clinical assessment, biological sampling, hemoglobin mass measurement using the optimized carbon monoxide rebreathing technique, focused transthoracic echocardiography, near-infrared spectroscopy, blood rheology assessment and symptom questionnaires during a single study visit.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adult patients aged 18 years or older. * Presentation to the emergency department. * Blood hemoglobin concentration \<10 g/dL. * Non-life-threatening clinical condition at presentation. * Able to understand the study information and provide written informed consent. * Affiliated with a health insurance system.
Exclusion criteria
* Glasgow Coma Scale score \<15. * Shock Index \>0.9. * Acute clinically significant gastrointestinal, gynecological or other active bleeding within the previous 24 hours. * Oxygen saturation \<92% on room air. * Suspected acute myocardial ischemia. * Carbon monoxide poisoning. * Pregnancy or breastfeeding. * Adults lacking legal capacity to provide consent. * Individuals deprived of liberty by judicial or administrative decision. * Individuals under psychiatric care without consent. * Individuals under legal protection (guardianship or curatorship). * Individuals not affiliated with a health insurance system.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Correlation coefficient between blood hemoglobin concentration and body weight-normalized total hemoglobin mass | Baseline (single study visit during emergency department stay) | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Association between total hemoglobin mass and biological markers of anemia | Baseline | 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. |
| Association between total hemoglobin mass and clinical manifestations of anemia | Baseline | 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. |
| Association between total hemoglobin mass, blood volume and cardiovascular adaptation | Baseline | 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). |
| Association between blood rheology and tissue oxygenation | Baseline | Association between blood viscosity, red blood cell deformability, red blood cell aggregation and tissue oxygenation assessed by near-infrared spectroscopy. |
Countries
France
Contacts
CONTACTFabien COISY, MD
CONTACTVirginie-Eve LVOVSCHI, MD
Outcome results
None listed