Table 1 Characteristics of patients according to extubation success or failure, as well as the parameters measured at the start of the dead-space test and the increase occurring during the test
From: A pilot study of a new test to predict extubation failure
Extubation failure | Successful extubation | ||||
|---|---|---|---|---|---|
n = 22 | n = 130 | ||||
Mean | (SD) | Mean | (SD) | P value | |
GENERAL DATA | |||||
Age (years) | 66 | (14) | 59 | (17) | 0.070 |
Women (%) | 10 (47%) | 35 (27%) | 0.103 | ||
COPD (%) | 6 (27%) | 47 (36%) | 0.477 | ||
SAPS II | 38 | 11 | 35 | 14 | 0.508 |
Days under mechanical ventilation: days (median and interquartile range) | 11 | (9.5 to 34) | 6 | (3 to 11) | 0.010 |
BEFORE THE TEST | |||||
Mean blood pressure | 95 | (12) | 93 | (13) | 0.406 |
Heart rate (beats/minute) | 91 | (14) | 88 | (17) | 0.548 |
Respiratory rate | 24 | (6) | 24 | (9) | 0.873 |
PaO2 (FiO2 0.4; mmHg) | 94 | (35) | 99 | (43) | 0.611 |
pCO2 (mmHg) | 44 | (12) | 42 | (10) | 0.307 |
End-tidal carbon dioxide (mmHg) | 36 | (9) | 34 | (8) | 0.227 |
(PCO2 – end-tidal carbon dioxide) gradient | 7 | (9) | 7 | (9) | 0.925 |
DURING THE TEST | |||||
Increase in mean blood pressure (mmHg) | 6 | (17) | 0 | (9) | 0.131 |
Increase in heart rate (beats per minute) | 11 | (24) | 3 | (11) | 0.146 |
Increase in respiratory rate | 7 | (9) | 1 | (7) | 0.001 |
Decrease in PO2 (mmHg) | 0 | (41) | 3 | (34) | 0.650 |
Increase in PCO2 (mmHg) | 7 | (19) | 1 | (5) | 0.178 |
Increase in end-tidal carbon dioxide (mmHg) | 1 | (6) | 1 | (6) | 0.982 |
Increase in PCO2-end-tidal carbon dioxide gradient (mmHg) | 3 | (10) | -0.2 | (8) | 0.150 |
Increased work of breathing (intercostal retraction) | 9 (41%) | 3 (2%) | < 0.001 | ||