Table 4 Characteristics of the patients by increased work of breathing, as well as the response of the variables to the dead-space addition test
From: A pilot study of a new test to predict extubation failure
Positive: With increased work of breathing | Negative: Without increased work of breathing | ||||
|---|---|---|---|---|---|
n = 12 | n = 140 | ||||
Mean | (SD) | Mean | (SD) | P value | |
Age (years) | 71.5 | (13.4) | 59.2 | (17.0) | 0.027 |
Extubation failure (%) | 75.0% | 9.3% | < 0.001 | ||
Women (%) | 50.0% | 21.1% | 0.144 | ||
COPD (%) | 33.3% | 35.0% | 1.000 | ||
SAPS II | 39 | (14) | 35 | (13) | 0.403 |
Days on mechanical ventilation: days (median and interquartile range) | 6 | (3 to 11) | 9 | (5 to 17.5) | 0.193 |
Mean blood pressure (mmHg) | 97 | (14) | 93 | (13) | 0.241 |
Heart rate (beats/minute) | 92 | (12) | 88 | (17) | 0.476 |
Respiratory rate | 23 | (6) | 24 | (9) | 0.855 |
PaO2 (mmHg) | 88 | (33) | 99 | (42) | 0.440 |
pCO2 (mmHg) | 51 | (13) | 41 | (10) | 0.363 |
End-tidal carbon dioxide (mmHg) | 37 | (8) | 34 | (8) | 0.396 |
PCO2 – end-tidal carbon dioxide gradient (mmHg) | 14 | (12) | 7 | (9) | 0.665 |
Increase in mean blood pressure (mmHg) | 20 | (12) | 0 | (9) | < 0.001 |
Increase in heart rate (beats/minute) | 24 | (29) | 2 | (10) | 0.027 |
Increase in respiratory rate | 13 | (11) | 1 | (6) | 0.040 |
Decrease in PaO2 (mmHg) | -14 | (26) | 4 | (35) | 0.178 |
Increase in pCO2 (mmHg) | 6 | (12) | 1 | (8) | 0.156 |
Increase in end-tidal carbon dioxide (mmHg) | 4 | (7) | 1 | (6) | 0.086 |
Increase in pCO2 – end-tidal carbon dioxide gradient (mmHg) | 2 | (15) | 0 | (8) | 0.782 |