Residence at a high altitude exposes a person to relative hypoxia compared to what a person residing at sea level experiences. This results in a slightly higher hemoglobin level in the blood for a person residing at altitude as compared to that of a person residing at sea level. The following analysis was based on patient data collected in the Andes and coastal regions of Ecuador.
hemoglobin at altitude in g/L =
= (6.83 * (EXP(0.000445 * (altitude in meters)))) + 113.3
hematocrit at altitude in percent =
= (0.449 * (EXP(0.000859 * (altitude in meters)))) + 35.6
At sea level, the ratio of hemoglobin (in g/L) divided by hematocrit (in percent) is 3.34 (which is the ratio if enter 0 for altitude in the above equations).
Correction of a hemoglobin value can be performed using the following table:
(1) for a value at an altitude, the comparable value at sea level can be estimated by subtracting the correction factor
(2) for a value at sea level, the comparable value at altitude can be estimated by adding the correction fraction.
|
Altitude in meters |
Correction to Hemoglobin in g/L |
|
0 |
0 |
|
100 |
0 |
|
200 |
1 |
|
300 |
1 |
|
400 |
1 |
|
500 |
2 |
|
600 |
2 |
|
700 |
3 |
|
800 |
3 |
|
900 |
3 |
|
1000 |
4 |
|
1100 |
4 |
|
1200 |
5 |
|
1300 |
5 |
|
1400 |
6 |
|
1500 |
7 |
|
1600 |
7 |
|
1700 |
8 |
|
1800 |
8 |
|
1900 |
9 |
|
2000 |
10 |
|
2100 |
11 |
|
2200 |
11 |
|
2300 |
12 |
|
2400 |
13 |
|
2500 |
14 |
|
2600 |
15 |
|
2700 |
16 |
|
2800 |
17 |
|
2900 |
18 |
|
3000 |
19 |
|
3100 |
20 |
|
3200 |
22 |
|
3300 |
23 |
|
3400 |
24 |
|
3500 |
26 |
from Table 2, page 629
If this data is analyzed in JMP, the correction can be estimated as:
correction in g/L =
= (0.0000016 * ((altitude in meters) ^2)) + (0.0016113 * (altitude in meters)) + 0.4359886
Specialty: Hematology Oncology, Clinical Laboratory
