Review of physiologic mechanisms in response to anemia
| Table 2: Grading of studies evaluating biological processes | ||||||
| Topic of study | No, (%) | Level of evidence | ||||
| LI | LII | LIII | LIV | |||
| O2 delivery and consumption | 27 | (16.8) | ||||
| Human | 24 | (15.0) | 12 | 2 | 9 | 1 |
| Laboratory | 3 | (1.9) | 2 | 0 | 1 | 0 |
| Adaptation to anemia or transfusions | 49 | (30.6) | ||||
| Cardiac adaptation | ||||||
| Human | 8 | (5.0) | 0 | 0 | 6 | 2 |
| Laboratory | 23 | (14.4) | 0 | 17 | 6 | 0 |
| Microcirculation and viscosity | ||||||
| Human | 1 | (0.6) | 0 | 1 | 0 | 0 |
| Laboratory | 5 | (3.1) | 3 | 2 | 0 | 0 |
| Oxyhemoglobin dissociation curve and 2,3-DPG concentration studies | 12 | (7.5) | 3 | 5 | 2 | 2 |
| Hemodilution | 84 | (52.5) | ||||
| Cardiovascular effect* | ||||||
| Human | 4 | (2.5) | 0 | 2 | 2 | |
| Laboratory | 17 | (10.6) | 10 | 1 | 6 | 0 |
| Coronary flow studies | ||||||
| Human | 7 | (4.4) | 3 | 1 | 2 | 0 |
| Laboratory | 47 | (29.4) | 16 | 2 | 28 | 1 |
| Cerebral flow studies | ||||||
| Human | 3 | (1.9) | 1 | 1 | 1 | 1 |
| Laboratory | 4 | (2.5) | 4 | 0 | 0 | 0 |
| Other organ flow | 2 | (1.3) | 0.00 | 2 | 0.00 | 0 |
| Total human studies | 58 | (36.3) | 19 | 11 | 22 | 6 |
| Total laboratory studies | 102 | (63.8) | 35 | 25 | 41 | 1 |
| Total % |
160 | 54 33.8 |
36 22.5 |
63 39.4 |
7 4.4 |
|
| Note: 2,3DPG = 2,3diphosphoglycerate.
*We differentiated between studies focusing on mechanisms of cardiac adaptation and those looking at the cardiovascular effects of hemodilution. | ||||||