THE 'NORMOBARIC OXYGEN PARADOX': INFLUENCE OF NEW MODELS ON THE EVOLUTION OF ERYTHROPOIETIN, RETICULOCYTE COUNT AND HEMOGLOBIN CONCENTRATION IN PATIENTS UNDERGOING BREAST RECONSTRUCTION SURGERY.
(Abstract release date: 05/19/16)
EHA Library. Calabrese R. 06/09/16; 134750; PB1850
Dr. Rossella Calabrese
Contributions
Contributions
Abstract
Abstract: PB1850
Type: Publication Only
Background
The 'Normobaric Oxygen Paradox' (NOP) is a physiologic mechanism that induces an increase of endogenous erythropoietin (EPO) production by creating a state of relative hypoxia in subjects previously exposed to a period of normobaric hyperoxia, followed by a rapid return to normoxia. To date, the oxygen exposure duration and the inspired oxygen fraction required to observe a significant increase in hemoglobin or EPO production are not clearly defined.
Aims
This study sought to observe the effect of two models of relative hypoxia compared to a control group on EPO, reticulocytes and hemoglobin stimulation through the NOP theory in patients undergoing breast reconstruction surgery.
Methods
After local ethic committee approval and obtaining written informed consent, thirty patients undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction were prospectively randomized into 3 groups. Nine patients were excluded from analysis for lack of results and/or patient withdrawal. The first group (G1; n=7) was exposed to 5 L O2/m for 60 minutes per day through a nasal cannula from day one to day nine postoperatively. The second group (G2; n=6) was similarly exposed to O2, but on alternate days, while the third group (G3; n= 8) served as control. All groups recived FiO2= 50% during surgery. Serum EPO was measured on day 0 and postoperatively on days 2, 3, 4 and 9. Serum hemoglobin level and reticulocyte count were measured on day 0 and postoperatively on days 7 and 9. Taking the initial value as 100%, percentage changes in EPO and reticulocytes were calculated, thereby allowing an appreciation of the magnitude on change rather than the absolute values. We used a two-way analysis of variance (ANOVA) for repeated measures to test the variation between groups and over time.
Results
We noticed a pic % EPO elevation at days 3 and 4 with no significant difference between the groups (fig 1). At day 9, % EPO in G1, G2 and G3 was 649,1±295,6; 478,5±305,1 and 406,1±124,6 mIU/mL respectively (p>0,05) (fig 2). However, the % EPO at day 9 in G1 tended to be more elevated compared to G2 and G3. At day 9, reticulocyte count was more elevated in G1 compared to G2 and G3 (fig 3). Hemoglobin level in G1, G2 and G3 was 10,04±0,77; 10,73±1,14 and 10,64±0,96 g/dL respectively (fig 4).
Conclusion
Relative hypoxia seems to be a stimulus for EPO production in all our groups. However, further studies are needed in non-surgical patients with larger sample size and longer follow-up to determine its real impact on hemoglobin.
Session topic: E-poster
Type: Publication Only
Background
The 'Normobaric Oxygen Paradox' (NOP) is a physiologic mechanism that induces an increase of endogenous erythropoietin (EPO) production by creating a state of relative hypoxia in subjects previously exposed to a period of normobaric hyperoxia, followed by a rapid return to normoxia. To date, the oxygen exposure duration and the inspired oxygen fraction required to observe a significant increase in hemoglobin or EPO production are not clearly defined.
Aims
This study sought to observe the effect of two models of relative hypoxia compared to a control group on EPO, reticulocytes and hemoglobin stimulation through the NOP theory in patients undergoing breast reconstruction surgery.
Methods
After local ethic committee approval and obtaining written informed consent, thirty patients undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction were prospectively randomized into 3 groups. Nine patients were excluded from analysis for lack of results and/or patient withdrawal. The first group (G1; n=7) was exposed to 5 L O2/m for 60 minutes per day through a nasal cannula from day one to day nine postoperatively. The second group (G2; n=6) was similarly exposed to O2, but on alternate days, while the third group (G3; n= 8) served as control. All groups recived FiO2= 50% during surgery. Serum EPO was measured on day 0 and postoperatively on days 2, 3, 4 and 9. Serum hemoglobin level and reticulocyte count were measured on day 0 and postoperatively on days 7 and 9. Taking the initial value as 100%, percentage changes in EPO and reticulocytes were calculated, thereby allowing an appreciation of the magnitude on change rather than the absolute values. We used a two-way analysis of variance (ANOVA) for repeated measures to test the variation between groups and over time.
Results
We noticed a pic % EPO elevation at days 3 and 4 with no significant difference between the groups (fig 1). At day 9, % EPO in G1, G2 and G3 was 649,1±295,6; 478,5±305,1 and 406,1±124,6 mIU/mL respectively (p>0,05) (fig 2). However, the % EPO at day 9 in G1 tended to be more elevated compared to G2 and G3. At day 9, reticulocyte count was more elevated in G1 compared to G2 and G3 (fig 3). Hemoglobin level in G1, G2 and G3 was 10,04±0,77; 10,73±1,14 and 10,64±0,96 g/dL respectively (fig 4).
Conclusion
Relative hypoxia seems to be a stimulus for EPO production in all our groups. However, further studies are needed in non-surgical patients with larger sample size and longer follow-up to determine its real impact on hemoglobin.
Session topic: E-poster
Abstract: PB1850
Type: Publication Only
Background
The 'Normobaric Oxygen Paradox' (NOP) is a physiologic mechanism that induces an increase of endogenous erythropoietin (EPO) production by creating a state of relative hypoxia in subjects previously exposed to a period of normobaric hyperoxia, followed by a rapid return to normoxia. To date, the oxygen exposure duration and the inspired oxygen fraction required to observe a significant increase in hemoglobin or EPO production are not clearly defined.
Aims
This study sought to observe the effect of two models of relative hypoxia compared to a control group on EPO, reticulocytes and hemoglobin stimulation through the NOP theory in patients undergoing breast reconstruction surgery.
Methods
After local ethic committee approval and obtaining written informed consent, thirty patients undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction were prospectively randomized into 3 groups. Nine patients were excluded from analysis for lack of results and/or patient withdrawal. The first group (G1; n=7) was exposed to 5 L O2/m for 60 minutes per day through a nasal cannula from day one to day nine postoperatively. The second group (G2; n=6) was similarly exposed to O2, but on alternate days, while the third group (G3; n= 8) served as control. All groups recived FiO2= 50% during surgery. Serum EPO was measured on day 0 and postoperatively on days 2, 3, 4 and 9. Serum hemoglobin level and reticulocyte count were measured on day 0 and postoperatively on days 7 and 9. Taking the initial value as 100%, percentage changes in EPO and reticulocytes were calculated, thereby allowing an appreciation of the magnitude on change rather than the absolute values. We used a two-way analysis of variance (ANOVA) for repeated measures to test the variation between groups and over time.
Results
We noticed a pic % EPO elevation at days 3 and 4 with no significant difference between the groups (fig 1). At day 9, % EPO in G1, G2 and G3 was 649,1±295,6; 478,5±305,1 and 406,1±124,6 mIU/mL respectively (p>0,05) (fig 2). However, the % EPO at day 9 in G1 tended to be more elevated compared to G2 and G3. At day 9, reticulocyte count was more elevated in G1 compared to G2 and G3 (fig 3). Hemoglobin level in G1, G2 and G3 was 10,04±0,77; 10,73±1,14 and 10,64±0,96 g/dL respectively (fig 4).
Conclusion
Relative hypoxia seems to be a stimulus for EPO production in all our groups. However, further studies are needed in non-surgical patients with larger sample size and longer follow-up to determine its real impact on hemoglobin.
Session topic: E-poster
Type: Publication Only
Background
The 'Normobaric Oxygen Paradox' (NOP) is a physiologic mechanism that induces an increase of endogenous erythropoietin (EPO) production by creating a state of relative hypoxia in subjects previously exposed to a period of normobaric hyperoxia, followed by a rapid return to normoxia. To date, the oxygen exposure duration and the inspired oxygen fraction required to observe a significant increase in hemoglobin or EPO production are not clearly defined.
Aims
This study sought to observe the effect of two models of relative hypoxia compared to a control group on EPO, reticulocytes and hemoglobin stimulation through the NOP theory in patients undergoing breast reconstruction surgery.
Methods
After local ethic committee approval and obtaining written informed consent, thirty patients undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction were prospectively randomized into 3 groups. Nine patients were excluded from analysis for lack of results and/or patient withdrawal. The first group (G1; n=7) was exposed to 5 L O2/m for 60 minutes per day through a nasal cannula from day one to day nine postoperatively. The second group (G2; n=6) was similarly exposed to O2, but on alternate days, while the third group (G3; n= 8) served as control. All groups recived FiO2= 50% during surgery. Serum EPO was measured on day 0 and postoperatively on days 2, 3, 4 and 9. Serum hemoglobin level and reticulocyte count were measured on day 0 and postoperatively on days 7 and 9. Taking the initial value as 100%, percentage changes in EPO and reticulocytes were calculated, thereby allowing an appreciation of the magnitude on change rather than the absolute values. We used a two-way analysis of variance (ANOVA) for repeated measures to test the variation between groups and over time.
Results
We noticed a pic % EPO elevation at days 3 and 4 with no significant difference between the groups (fig 1). At day 9, % EPO in G1, G2 and G3 was 649,1±295,6; 478,5±305,1 and 406,1±124,6 mIU/mL respectively (p>0,05) (fig 2). However, the % EPO at day 9 in G1 tended to be more elevated compared to G2 and G3. At day 9, reticulocyte count was more elevated in G1 compared to G2 and G3 (fig 3). Hemoglobin level in G1, G2 and G3 was 10,04±0,77; 10,73±1,14 and 10,64±0,96 g/dL respectively (fig 4).
Conclusion
Relative hypoxia seems to be a stimulus for EPO production in all our groups. However, further studies are needed in non-surgical patients with larger sample size and longer follow-up to determine its real impact on hemoglobin.
Session topic: E-poster
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