Background
Methods
Experimental preparation
Measurement protocol
Electrical impedance tomography (EIT)
Calculation of the regional gas flow during four different parts of the respiratory cycle
Spirometry
Statistical evaluation
Results and discussion
Validation of gas flow
Physiological data
n = 7 | Unit | Mean | sd |
---|---|---|---|
HR | per minute | 80.3 | 10.9 |
MAP | mmHg | 79.3 | 9.7 |
MPAP | mmHg | 21.7 | 5.7 |
PaO2 / FiO2
| mmHg | 437.7 | 89.1 |
SVR | dyn * s/cm-5
| 1051.6 | 76.5 |
PVR | dyn * s/cm-5
| 240.7 | 53.5 |
Dyn. Compl. | l/mbar | 38.5 | 11.3 |
Healthy baseline | Lavage injury | |||||
---|---|---|---|---|---|---|
n = 6 | Unit | Mean | sd | Mean | sd | p |
HR | per minute | 86.2 | 14.1 | 122.1 | 30.1 | 0.048* |
MAP | mmHg | 76.1 | 11.0 | 71.1 | 15.6 | 0.613 |
MPAP | mmHg | 20.1 | 8.0 | 39.2 | 15.1 | 0.031* |
PaO2 / FiO2
| mmHg | 444.7 | 69.7 | 144.1 | 45.2 | 0.002** |
SVR | dyn * s/cm-5
| 999.1 | 111.1 | 1101.4 | 114.5 | 0.333 |
PVR | dyn * s/cm-5
| 201.1 | 71.2 | 426.2 | 99.1 | 0.023* |
dyn. compl. | l/mbar | 38.5 | 11.3 | 17.7 | 12.1 | 0.039* |
Distribution of tidal volume
Healthy baseline | Lavage injury | ||||||
---|---|---|---|---|---|---|---|
n = 6 | Unit | Mean | sd | Mean | sd | p | |
ROI 1 | ventral / nondependent | % | 15.1 | 11.1 | 17.1 | 16.6 | 0.647 |
ROI 2 | middle | % | 58.3 | 20.2 | 76.8 | 19.5 | 0.061 |
ROI 3 | dorsal / dependent | % | 35.7 | 13.2 | 11.1 | 9.9 | 0.032* |
Flow pattern (ROI analysis)
PIF | Phase 1 | Inspiration | Global ROI | Ventral ROI$/§
| Middle ROI | Dorsal ROI | |
---|---|---|---|---|---|---|---|
PEEP [mbar] | VT/weight [ml/kg] | Lung | n | Mean ± sd [ml/s] | Mean ± sd [ml/s] | Mean ± sd [ml/s] | Mean ± sd [ml/s] |
0 | 15 | healthy | 7 | 467.27 ± 56.69 | 109.87 ± 15.45 | 317.60 ± 34.38 | 298.54 ± 120.62 |
0 | 20 | healthy | 7 | 571.94 ± 100.47 | 126.10 ± 17.69 | 345.79 ± 54.36 | 327.13 ± 127.57 |
5 | 15 | healthy | 7 | 510.92 ± 102.16 | 116.04 ± 14.20 | 324.25 ± 73.59 | 334.11 ± 135.32 |
5 | 20 | healthy | 7 | 621.80 ± 85.20 | 129.70 ± 16.65 | 396.75 ± 50.78 | 348.89 ± 139.71 |
10 | 15 | healthy | 7 | 550.89 ± 82.35 | 105.82 ± 13.13 | 335.46 ± 48.16 | 339.63 ± 132.18 |
10 | 20 | healthy | 7 | 711.67 ± 104.68 | 123.85 ± 22.84 | 424.07 ± 84.16 | 402.98 ± 143.06 |
5 | 15 | healthy | 6 | 901.90 ± 92.06 | 118.94 ± 32.59 | 512.73 ± 81.67 | 283.00 ± 59.44 |
5 | 15 | LAV | 6 | 968.55 ± 64.49 | 158.94* ± 24.26 | 602.78* ± 91.51 | 335.89 ± 83.67 |
LIF
|
Phase 2
|
Inspiration
|
Global ROI
|
Ventral ROI
$
|
Middle ROI
|
Dorsal ROI
| |
PEEP [mbar]
|
V
T
/weight [ml/kg]
|
Lung
|
n
|
Mean ± sd [ml/s]
|
Mean ± sd [ml/s]
|
Mean ± sd [ml/s]
|
Mean ± sd [ml/s]
|
0 | 15 | healthy | 7 | 72.04 ± 16.52 | 10.26 ± 5.27 | 36.77 ± 28.00 | 19.03 ± 4.99 |
0 | 20 | healthy | 7 | 86.66 ± 36.51 | 10.80 ± 4.08 | 43.22 ± 24.84 | 17.66 ± 4.93 |
5 | 15 | healthy | 7 | 55.58 ± 23.32 | 5.65 ± 4.35 | 18.02 ± 3.12 | 16.05 ± 4.31 |
5 | 20 | healthy | 7 | 52.11 ± 10.05 | 9.50 ± 4.76 | 27.59 ± 15.06 | 10.45 ± 5.20 |
10 | 15 | healthy | 7 | 47.17 ± 16.57 | 7.83 ± 3.67 | 23.31 ± 8.22 | 11.93 ± 9.44 |
10 | 20 | healthy | 7 | 64.37 ± 45.81 | 8.69 ± 4.00 | 32.91 ± 5.27 | 18.07 ± 15.34 |
5 | 15 | healthy | 6 | 13.58 ± 2.70 | 4.03 ± 0.52 | 18.55 ± 8.65 | 12.72 ± 5.84 |
5 | 15 | LAV | 6 | 19.09* ± 5.14 | 2.82 ± 1.83 | 10.74* ± 5.29 | 13.02 ± 3.73 |
PEF
|
Phase 3
|
Expiration
|
Global ROI
|
Ventral ROI
$/§
|
Middle ROI
|
Dorsal ROI
| |
PEEP [mbar]
|
V
T
/ weight [ml/kg]
|
Lung
|
n
|
Meann ± msd [ml/s]
|
Mean ± sd [ml/s]
|
Mean ± sd [ml/s]
|
Mean ± sd [ml/s]
|
0 | 15 | healthy | 7 | -587.38 ± 86.73 | -130.15 ± 21.79 | -360.79 ± 60.67 | -344.81 ± 140.78 |
0 | 20 | healthy | 7 | -687.01 ± 138.84 | -141.14 ± 24.29 | -419.64 ± 68.85 | -360.89 ± 135.22 |
5 | 15 | healthy | 7 | -609.64 ± 164.78 | -122.24 ± 16.87 | -359.02 ± 71.82 | -351.49 ± 156.67 |
5 | 20 | healthy | 7 | -675.96 ± 142.03 | -119.51 ± 20.03 | -397.41 ± 67.45 | -413.33 ± 170.68 |
10 | 15 | healthy | 7 | -581.72 ± 119.23 | -107.19 ± 13.15 | -356.31 ± 53.46 | -353.22 ± 127.59 |
10 | 20 | healthy | 7 | -685.25 ± 114.72 | -108.40 ± 13.30 | -395.27 ± 41.11 | -383.60 ± 152.15 |
5 | 15 | healthy | 6 | -666.61 ± 62.94 | -94.05 ± 12.91 | -373.52 ± 74.09 | -257.96 ± 47.51 |
5 | 15 | LAV | 6 | -734.43* ± 44.74 | -130.40* ± 26.63 | -441.15 ± 102.11 | -349.22 ± 145.95 |
LEF
|
Phase 4
|
Expiration
|
Global ROI
|
Ventral ROI
$
|
Middle ROI
§
|
Dorsal ROI
| |
PEEP [mbar]
|
V
T
/ weight [ml/kg]
|
Lung
|
n
|
Mean ± sd [ml/s]
|
Mean ± sd [ml/s]
|
Mean ± sd [ml/s]
|
Mean ± sd [ml/s]
|
0 | 15 | healthy | 7 | -40.23 ± 25.65 | -5.74 ± 4.36 | -27.25 ± 14.37 | -7.11 ± 5.85 |
0 | 20 | healthy | 7 | -58.85 ± 30.50 | -8.73 ± 4.94 | -48.72 ± 19.19 | -16.04 ± 7.86 |
5 | 15 | healthy | 7 | -50.20 ± 17.22 | -5.41 ± 4.37 | -27.87 ± 8.07 | -3.74 ± 1.78 |
5 | 20 | healthy | 7 | -62.46 ± 37.63 | -5.46 ± 2.57 | -47.50 ± 13.66 | -16.79 ± 10.81 |
10 | 15 | healthy | 7 | -49.84 ± 37.89 | -3.77 ± 2.04 | -23.78 ± 22.54 | -9.10 ± 11.72 |
10 | 20 | healthy | 7 | -86.42 ± 27.98 | -6.67 ± 3.74 | -51.34 ± 15.72 | -15.81 ± 5.00 |
5 | 15 | healthy | 6 | -39.16 ± 23.89 | -5.71 ± 3.26 | -26.44 ± 10.16 | -8.36 ± 4.09 |
5 | 15 | LAV | 6 | -36.15 ± 27.84 | -6.29 ± 2.20 | -20.37 ± 16.26 | -2.63* ± 1.00 |
ROI/comparison | Estimator | 95% CI | P | ||
---|---|---|---|---|---|
PIF
| ventral < = > middle | -238,8 | -275,9 | -201,6 |
0,008
|
exp. #1 | ventral < = > dorsal | -223,3 | -260,4 | -186,2 |
0,008
|
middle < = > dorsal | 15,4 | -79,9 | 110,8 | 0,309 | |
PIF
| ventral: BL < = > LAV | 40,0 | 11,6 | 68,4 |
0,036
|
exp. #2 | middle: BL < = > LAV | 90,1 | 3,5 | 176,6 |
0,048
|
dorsal: BL < = > LAV | 52,9 | -18,7 | 124,4 | 0,068 | |
LIF
| ventral < = > middle | -21,5 | -30,7 | -12,3 |
0,021
|
exp. #1 | ventral < = > dorsal | -6,7 | -16,0 | 2,5 | 0,068 |
middle < = > dorsal | 14,8 | -4,0 | 25,5 | 0,073 | |
LIF
| ventral: BL < = > LAV | -1,2 | -2,4 | 0,0 | 0,097 |
exp. #2 | middle: BL < = > LAV | -7,8 | -14,8 | -0,8 |
0,045
|
dorsal: BL < = > LAV | 0,3 | -4,5 | 5,1 | 0,798 | |
PEF
| ventral < = > middle | 260,0 | 220,6 | 299,4 |
0,008
|
exp. #1 | ventral < = > dorsal | 246,5 | 207,1 | 285,9 |
0,008
|
middle < = > dorsal | -13,5 | -117,4 | 90,4 | 0,384 | |
PEF
| ventral: BL < = > LAV | -36,4 | -56,1 | -16,6 |
0,027
|
exp. #2 | middle: BL < = > LAV | -67,6 | -155,7 | 20,5 | 0,065 |
dorsal: BL < = > LAV | -91,3 | -188,0 | 5,5 | 0,053 | |
LEF
| ventral < = > middle | 31,8 | 22,1 | 41,4 |
0,015
|
exp. #1 | ventral < = > dorsal | 5,5 | -4,2 | 15,1 | 0,088 |
middle < = > dorsal | -26,3 | -37,7 | -14,9 |
0,022
| |
LEF
| ventral: BL < = > LAV | -0,6 | -3,3 | 2,2 | 0,235 |
exp. #2 | middle: BL < = > LAV | 6,1 | -7,1 | 19,3 | 0,109 |
dorsal: BL < = > LAV | 5,7 | 3,2 | 8,3 |
0,022
|