Table 3.
FiO 2 adjustment following ABG analysis and its effects on oxygenation measured in the next ABG
|
PaO
2
(%) |
Adjustment of FiO
2
(%) |
Successive PaO
2
|
||
|---|---|---|---|---|
|
[n
= 61,073] | ||||
| [n = 107,888] | [n = 62,222] |
Higher |
Unchanged |
Lower |
| (Delta PaO 2 ) | (Delta PaO 2 ) | |||
| <7 kPa (1.2) |
Higher (34.7) |
96.6% (+5.3) |
0.4% |
3.0% (−0.5) |
| Unchanged (46.9) |
87.4% (+5.6) |
3.2% |
9.4% (−0.6) |
|
| Lower (18.4) |
95.1% (+7.9) |
2.4% |
2.5% (−0.9) |
|
| 7 to 10 kPa (25.3) |
Higher (27.9) |
76.3% (+3.1) |
2.7% |
21.0% (−0.9) |
| Unchanged (56.0) |
66.3% (+2.0) |
4.3% |
29.4% (−0.8) |
|
| Lower (16.1) |
61.3% (+2.6) |
3.6% |
35.1% (−1.0) |
|
| >10 kPa (73.4) |
Higher (10.8) |
48.6% (+4.6) |
2.1% |
49.3% (−3.1) |
| Unchanged (62.0) |
44.7% (+2.1) |
3.1% |
52.2% (−2.3) |
|
| Lower (27.2) |
23.5% (+2.4) |
1.7% |
74.8% (−4.6) |
|
| Total (100) | - | 46.3% (+2.6) | 2.7% | 51.0% (−2.9) |
Data presented as percentages of total and irrespective of adjustment of other ventilator settings (e.g., PEEP, I/E ratio). PaO2 = any recorded PaO2 stratified by self-reported ranges; successive PaO2 = PaO2 from successively registered ABG sample; Delta = mean difference between two successive ABG samples; Higher = increased FiO2 (column 2) or PaO2 (column 3), higher than previous level; unchanged = FiO2 or PaO2 equal to previous level; lower = decreased FiO2 or PaO2, lower than previous level. A total of 62,222 PaO2 measurements from 3,791 patients (57.7% of all 107,888 ABG samples) in the database is followed by an adjustment of ventilator settings, and 98.2% of PO2 measurements is followed by a successive PO2 measurement (n = 61,073) in the same patient when adjustment of FiO2 is also measured.