Fetal vs Adult Hemoglobin which is more efficient

Fetal vs Adult Hemoglobin: which is more efficient as an oxygen transporter? Robert R. Demers, BS, RRT, RCP, FAARC, FCCP Joshua Cosa, MA, RRT-NPS, RRT-ACCS, RCP Jason Jenkins, BSRC, RRT-NPS, RCP

FETAL VS ADULT HEMOGLOBIN What do we know? The differing affinities of oxygen What did we set out to define? Show the dissimilarities between fetal and adult Hb quantitatively What extent are practicing RCPs aware of the differences?

FETAL VS ADULT HEMOGLOBIN

FIGURING OUT THE DISSIMILARITIES Mathematical Model Kelman’s Equation used to calculate % O 2 saturation Applied to spreadsheet software to calculate O 2% values

DISSIMILARITY RESULTS AND SPECULATION Fetal Hemoglobin unloads far less (46. 1%) of it’s oxygen content than adult hemoglobin (64%) Adult hemoglobin is 139% as efficient as fetal Hb On a practical level, fetal Hb picks up O 2 easier but doesn’t like to let it go Some clinicians speculate that Hb F may serve a role in limiting O 2 delivery in utero

RCP AWARENESS What are we taught in respiratory school? We are often taught of the higher affinity of fetal hemoglobin Are practicing RCPs aware of that Hb F can inhibit release of oxygen to the tissues?

RCP AWARENESS We distributed a 1 page questionnaire to 27 NICU trained RCPs This question was asked: With regard to the respective efficiency of fetal and adult hemoglobin as a transporter of oxygen from the lung to the cell, select the single response which is correct by placing an “X” in the box alongside that response:

RCP AWARENESS The RCPs picked 1 of the following responses: Fetal hemoglobin is considerably more efficient as a transporter of oxygen Adult hemoglobin is considerably more efficient as a transporter of oxygen Fetal and adult hemoglobin are essentially equal in their efficiency as transporters of oxygen

AWARENESS RESULTS AND CONCLUSION 14 out of 27 respondents (52%) were unaware of the superiority of adult hemoglobin as an oxygen transporter We suspect that respiratory therapy instructors often focus on the enhanced affinity of Hb F at the placenta, while ignoring the disadvantage that the same affinity represents once blood is mobilized to fetal tissues.