Table 2 Anatomical and physiological study variables collected at 0.5h, according to RIFLE classification
Variable | NO AKI (n: 27) | RIFLE 1-Risk (n: 18) | RIFLE 2-Injury (n: 18) | RIFLE 3-Failure (n: 15) | p-value |
|---|---|---|---|---|---|
Respiratory variables | |||||
Tidal volume (mL) | 401 (± 215) | 422 (± 189) | 441 (± 201) | 397 (± 197) | 0.903 |
Respiratory rate (bpm) | 29 (± 11) | 26 (± 11) | 26 (± 9) | 21 (± 9) | 0.084 |
Mean airway pressure (cmH2O) | 14.2 (± 6.2) | 16.2 (± 6.9) | 20.7 (± 9.7) | 26.2 (± 10.1) | < 0.001 |
PEEP measured (cmH2O) | 8.4 (± 5.5) | 10.1 (± 6.5) | 13.1 (± 7.5) | 19.9 (± 8.3) | < 0.001 |
Driving pressure (cmH2O) | 5.5 (± 2.2) | 6.5 (± 2.25) | 7.7 (± 3.8) | 5.4 (± 2.0) | 0.027 |
Mean pleural pressure (cmH2O) | 6.7 (± 2.7) | 6.3 (± 3.6) | 7.2 (± 1.9) | 7.3 (± 3.4) | 0.742 |
Stress-Transpulmonary pressure (mmHg) | 7.8 (± 4.2) | 10.6 (± 5.2) | 13.6 (± 7.9) | 13.8 (± 6.7) | 0.004 |
Strain, fraction | 1.13 (± 0.54) | 1.21 (± 0.49) | 1.20 (± 0.47) | 1.02 (± 0.37) | 0.687 |
Airway resistance (cmH2O*min/L) | 0.17 (± 0.07) | 0.19 (± 0.07) | 0.20 (± 0.07) | 0.23 (± 0.08) | 0.060 |
Elastance, respiratory system (cmH2O/mL) | 39.7 (± 11.9) | 43.0 (± 12.6) | 54.0 (± 28.3) | 60.6 (± 25.1) | 0.005 |
Elastance, lung (cmH2O/mL) | 20.9 (± 10.2) | 26.1 (± 8.9) | 35.6 (± 27.2) | 45.3 (± 21.5) | < 0.001 |
Elastance, chest-wall (cmH2O/mL) | 18.8 (± 5.7) | 17.0 (± 7.5) | 18.5 (± 4.4) | 15.3 (± 10.5) | 0.435 |
Specific elastance | 7.2 (± 3.5) | 8.9 (± 3.8) | 12.3 (± 8.8) | 15.1 (± 7.9) | 0.001 |
Mechanical power, respiratory system (J/min) | 20.3 (± 9.4) | 22.8 (± 11.4) | 30.5 (± 10.7) | 25.0 (± 7.8) | 0.011 |
Mechanical power, lung (J/min) | 13.1 (± 6.7) | 16.3 (± 7.8) | 22.1 (± 8.5) | 22.4 (± 17.7) | 0.010 |
Hemodynamic | |||||
Heart rate (bpm) | 107 (± 24) | 122 (± 21) | 135 (± 27) | 142 (± 30) | < 0.001 |
Mean arterial pressure (mmHg) | 78 (± 10) | 81 (± 14) | 80 (± 14) | 71 (± 7) | 0.082 |
Central venous pressure (mmHg) | 10 (± 4) | 10 (± 5) | 11 (± 5) | 11 (± 3) | 0.613 |
Mean perfusion pressure (mmHg) | 69 (± 10) | 70 (± 13) | 69 (± 15) | 60 (± 8) | 0.066 |
Mean pulmonary artery pressure (mmHg) | 23 (± 5) | 24 (± 9) | 27 (± 8) | 31 (± 7) | 0.016 |
Cardiac output (L/min) | 4.24 (± 1.17) | 4.14 (± 0.83) | 4.03 (± 1.44) | 4.25 (± 1.24) | 0.943 |
Central venous oxygen saturation (%) | 83 (± 7) | 88 (± 6) | 83 (± 8) | 79 (± 10) | 0.028 |
Lactates (mg/dL) | 1.00 (± 0.54) | 1.11 (± 0.51) | 1.17 (± 0.91) | 1.40 (± 1.12) | 0.440 |
Infused catecholamines (mcg/Kg) | 0.013 (± 0.029) | 0.023 (± 0.045) | 0.072 (± 0.114) | 0.075 (± 0.056) | 0.005 |
Blood gas analysis | |||||
PaO2 (mmHg) | 232 (± 26) | 248 (± 18) | 246 (± 20) | 238 (± 22) | 0.336 |
PaCO2 (mmHg) | 27 (± 9) | 26 (± 9) | 26 (± 12) | 32 (± 14) | 0.093 |
pH | 7.65 (± 0.14) | 7.70 (± 0.10) | 7.69 (± 0.13) | 7.60 (± 0.16) | 0.143 |