Calculation of Effective Fio2, Step 1
Flow, L/min | Factor With Weight of | ||||||||
---|---|---|---|---|---|---|---|---|---|
0.7 kg | 1.0 kg | 1.25 kg | 1.5 kg | 2 kg | 2.5 kg | 3 kg | 3.5 kg | 4 kg | |
0.01 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
0.03 (1/32) | 4 | 3 | 2 | 2 | 2 | 1 | 1 | 1 | 1 |
0.06 (1/16) | 9 | 6 | 5 | 4 | 3 | 2 | 2 | 2 | 2 |
0.125 (1/8) | 18 | 12 | 10 | 8 | 6 | 4 | 4 | 4 | 4 |
0.15 | 21 | 15 | 12 | 10 | 8 | 6 | 5 | 4 | 4 |
0.25 (1/4) | 36 | 25 | 20 | 17 | 13 | 10 | 8 | 7 | 6 |
0.5 (1/2) | 71 | 50 | 40 | 33 | 25 | 20 | 17 | 14 | 13 |
0.75 (3/4) | 100 | 75 | 60 | 50 | 38 | 30 | 25 | 21 | 19 |
1.0 (1.0) | 100 | 100 | 80 | 67 | 50 | 40 | 33 | 29 | 25 |
1.25 | 100 | 100 | 100 | 83 | 63 | 50 | 42 | 36 | 31 |
1.5 | 100 | 100 | 100 | 100 | 75 | 60 | 50 | 43 | 38 |
2.0 | 100 | 100 | 100 | 100 | 100 | 80 | 67 | 57 | 50 |
3.0 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 86 | 75 |
Adapted from equations 3 and 4 in ref 1. The rule of thumb (implicit in the table) is that, for most infants in the STOP-ROP study, if flow (in liters per minute) exceeds body weight (in kilograms), then the effective Fio2 equals the nasal cannula oxygen concentration.