Table 3.
Brain oxygen and lung function in obese and non-obese patients
| Physiological variable (SD) | Obese n (SD) | Non-obese n (SD) | P value |
|---|---|---|---|
| Mean PaO2/FiO2 ratio | 290.8 (25.5) | 338.0 (16.4) | 0.11 |
| FiO2 | |||
| Daily minimum FiO2 | 55.0 (3.3) | 48.3 (1.7) | 0.06 |
| Daily mean FiO2 | 62.2 (3.8) | 59.0 (2.2) | 0.44 |
| Daily maximum FiO2 | 76.9 (3.1) | 73.6 (2.6) | 0.41 |
| PaO2 | |||
| Daily PaO2 | 178.2 (16.1) | 192.3 (11.6) | 0.47 |
| Daily minimum PaO2 | 96.0 (17.9) | 107.1 (10.8) | 0.58 |
| Daily maximum PaO2 | 338.6 (27.3) | 327.3 (18.2) | 0.72 |
| PbtO2 | |||
| Initial PbtO2 mmHg | 17.1 (2.6) | 33.6 (3.2) | <0.01 |
| Daily minimum PbtO2 mmHg (average min) | 15.1 (1.5) | 19.9 (2.1) | 0.09 |
| Daily mean PbtO2 mmHg (average mean) | 25.8 (1.8) | 31.8 (1.9) | 0.03 |
| Daily maximum PbtO2 mmHg (average max) | 44.6 (5.1) | 51.9 (2.8) | 0.18 |
| Percentage of time PbtO2 < 20 mmHg | 26.3 (29.1) | 13.9 (17.4) | 0.03 |
| Minutes hypoxic or compromised (PbtO2 < 20 mmHg) | 1780 (2386) | 779 (808) | 0.02 |
Values in bold are statistically significant
Data are expressed as mean ± standard deviation (SD)
max maximum, min minimum, P bt O 2 partial pressure of brain tissue oxygen, PaO 2 partial pressure of arterial oxygen, FiO 2 fraction of inspired oxygen