Introduction
Methods
Patients
Measurements
PSP and PSN
Pneumatically controlled PS
Neurally controlled PS
Study protocol
Determination of static PEEPi
Spontaneous breathing and return to PS at different levels of PEEPe
Patient | Gender | Diagnosis | APACHE II | Days on MV | FiO2
| CRS
| RRS
| PEEPiSTAT
| FEV1 |
---|---|---|---|---|---|---|---|---|---|
% | ml/cm H2O | cm H2O/l/s | cm H2O | % predicted | |||||
1 | M | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 32 | 5 | 40 | 33 | 19 | 6 | 56 |
2 | M | AECOPD, pneumonia, type 2 respiratory failure | 33 | 6 | 40 | 43 | 15 | 8 | 48 |
3 | M | AECOPD, pneumonia, type 2 respiratory failure, septic shock | 22 | 4 | 40 | 40 | 16 | 6 | 62 |
4 | M | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 34 | 4 | 40 | 42 | 18 | 5 | 41 |
5 | M | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 35 | 3 | 40 | 30 | 16 | 5 | 58 |
6 | M | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 33 | 2 | 40 | 26 | 16 | 6 | 55 |
7 | M | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 31 | 5 | 40 | 27 | 21 | 5 | 38 |
8 | F | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 32 | 5 | 40 | 31 | 27 | 5 | 47 |
9 | M | AECOPD, pneumonia, type 2 respiratory failure, septic shock | 42 | 8 | 40 | 42 | 23 | 5 | 46 |
10 | M | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 30 | 1 | 40 | 40 | 26 | 5 | 50 |
11 | F | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 31 | 2 | 40 | 23 | 24 | 6 | 37 |
12 | F | AECOPD, pneumonia, type 2 respiratory failure, pulmonary encephalopathy | 34 | 1 | 50 | 20 | 17 | 8 | 44 |
Mean | 32.4 | 3.8 | 40.8 | 33.1 | 19.8 | 5.8 | 48.5 | ||
SD | 4.5 | 2.1 | 2.9 | 8.1 | 4.2 | 1.1 | 8.0 |
Data analysis
Parameters during volume control ventilation (and no spontaneous breathing)
Respiratory parameters during spontaneous breathing on PSP or PSN
Analysis of patient-ventilator interaction
Statistics
Results
Parameter | Mode | PEEPe0%
| PEEPe40%
| PEEPe80%
| PEEPe120%
|
P* |
---|---|---|---|---|---|---|
P̅aw (cm H2O) | PSP
| 10.9 (10.3, 11.3) | 12.9 (12.3, 13.3)a
| 15.0 (14.8, 16.3)ab
| 17.4 (16.8, 18.3)abc
| <0.001 |
PSN
| 11.4 (10.8, 11.6)x
| 13.1 (12.1, 13.3)a
| 15.2 (14.4, 16.4)ab
| 17.5 (16.9, 18.6)abc
| ||
PEEPe (cm H2O) | PSP
| 0.6 (0.4, 1.0)z
| 2.3 (2.2, 2.5)az
| 4.7 (4.2, 5.4)ab
| 7.1 (6.5, 7.5)abc
| <0.001 |
PSN
| 1.0 (0.5, 1.2)x
| 2.5 (2.3, 3.0)a
| 4.7 (4.4, 5.4)ab
| 7.0 (6.6, 7.5)abc
| ||
VT (ml/kg) | PSP
| 5.4 (4.2, 6.7)z
| 5.8 (4.9, 6.8)z
| 5.9 (5.0, 6.6)abz
| 5.5 (5.2, 7.0)ab
| <0.001 |
PSN
| 4.6 (4.3, 5.8)x
| 5.0 (4.4, 5.9)a
| 4.9 (4.6, 6.7)ab
| 5.0 (4.6, 7.1)abc
| ||
BfN (breaths/min) | PSP
| 20.2 (17.7, 29.3)z
| 20.5 (17.6, 28.9)z
| 21.5 (17.2, 26.9)z
| 20.9 (17.9, 30.3) | 0.003 |
PSN
| 26.4 (17.3, 30.7)x
| 24.4 (17.2, 33.2) | 22.1 (18.1, 31.5)ab
| 20.5 (16.0, 29.6)ab
| ||
VE (l/min) | PSP
| 6.05 (5.25, 8.13)z
| 6.54 (5.47, 8.91)a
| 7.05 (5.67, 9.02)a
| 7.07 (5.70, 11.62)a
| <0.001 |
PSN
| 6.43 (5.31, 9.54)x
| 6.92 (5.53, 9.98)a
| 7.14 (5.50, 9.20)a
| 7.79 (5.74, 9.66)a
| ||
VT/TiP (ml/s) | PSP
| 424 (390, 446)z
| 429 (389, 472) | 436 (386, 458) | 438 (396, 466) | 0.013 |
PSN
| 414 (302, 491)x
| 443 (334, 508)a
| 452 (338, 526)a
| 479 (361, 513)a
| ||
TiN (s) | PSP
| 0.90 (0.72, 1.03) | 0.90 (0.74, 0.94) | 0.84 (0.73, 0.98) | 0.87 (0.69, 0.93) | NS |
PSN
| 0.84 (0.71, 0.96) | 0.77 (0.71, 0.86) | 0.81 (0.74, 0.86) | 0.84 (0.73, 0.95) | ||
TeN (s) | PSP
| 2.12 (1.43, 2.60)z
| 2.22 (1.45, 2.93) | 2.17 (1.58, 3.14)z
| 2.13 (1.53, 2.58) | 0.050 |
PSN
| 1.76 (1.16, 2.66)x
| 2.09 (1.20, 2.77)a
| 2.02 (1.24, 2.59)a
| 2.14 (1.33, 2.92)a
| ||
TiN/TtN (%) | PSP
| 29.6 (27.5, 36.5) | 28.7 (24.5, 39.0) | 27.1 (23.4, 36.3) | 26.1 (23.0, 36.7) | NS |
PSN
| 31.4 (25.6, 37.8) | 29.4 (23.9, 38.5) | 29.7 (24.6, 38.3) | 30.6 (22.5, 36.8) | ||
pH | PSP
| 7.36 (7.33, 7.41) | 7.38 (7.36, 7.41)a
| 7.39 (7.34, 7.44)a
| 7.39 (7.33, 7.42)a
| 0.009 |
PSN
| 7.37 (7.33, 7.40)x
| 7.39 (7.34, 7.42)a
| 7.38 (7.32, 7.45)a
| 7.38 (7.35, 7.42)a
| ||
PaCO2 (mm Hg) | PSP
| 37.9 (32.0, 48.6) | 35.9 (31.2, 46.1) | 36.3 (32.1, 46.8) | 33.5 (32.9, 43.3) | NS |
PSN
| 40.4 (29.8, 47.5) | 34.2 (31.2, 42.1) | 35.4 (32.8, 41.8) | 36.5 (30.7, 41.9) | ||
PaO2 (mm Hg) | PSP
| 84.0 (79.9, 113.9) | 94.8 (84.9, 116.7) | 98.7 (90.0, 124.3) | 103.9 (84.0, 117.2) | NS |
PSN
| 89.7 (83.5, 122.9) | 106.6 (81.2, 124.1) | 99.4 (91.0, 123.9) | 109.0 (95.0, 125.8) | ||
MAP (mm Hg) | PSP
| 89.0 (76.0, 92.7) | 88.0 (77.0, 92.7) | 86.7 (77.7, 91.7) | 89.3 (79.0, 91.3) | NS |
PSN
| 88.3 (75.7, 91.3) | 88.0 (75.3, 90.4) | 88.7 (78.3, 91.0) | 86.7 (80.3, 92.0) |
Patient-ventilator interaction
Parameter | Mode | PEEPe0%
| PEEPe40%
| PEEPe80%
| PEEPe120%
|
P* |
---|---|---|---|---|---|---|
TTRIG (ms) | PSP
| 276 (169, 370)z
| 198 (156, 357)az
| 183 (143, 312)abz
| 154 (33, 236)abcz
| <0.001 |
PSN
| 69 (56, 82)x
| 54 (32, 70) | 59 (17, 82) | 76 (54, 90) | ||
TCYC-OFF (ms) | PSP
| 76 (21, 36)z
| 126 (44, 401)az
| 130 (47, 432)abz
| 106 (14, 314)abcz
| <0.001 |
PSN
| 12 (8, 14)x
| 8 (2, 14) | 5 (−2, 12) | 2 (−7, 10) | ||
NeuroSync index (%) | PSP
| 29.1 (13.9, 46.8)z
| 25.3 (15.5, 40.9)az
| 20.6 (13.5, 37.1)abz
| 17.7 (10.5, 38.9)abcz
| <0.001 |
PSN
| 5.6 (4.2, 7.8)x
| 6.0 (4.9, 8.3) | 6.2 (5.1, 8.5) | 6.7 (3.8, 10.3) | ||
EAdi without assist (%) | PSP
| 0.8 (0, 10.1) | 1.1 (0, 18.7) | 0 (0, 10.8) | 0 (0, 11.4) | <0.001 |
PSN
| 0 (0, 0) | 0 (0, 0) | 0 (0, 0) | 0 (0, 0) | ||
Synchrony (inside box) (%) | PSP
| 4.7 (0, 16.3)z
| 7.8 (0, 20)az
| 11.5 (0, 37.4)abz
| 7 (0.2, 46.3)abcz
| <0.001 |
PSN
| 89.4 (76.2, 97.9)x
| 91.3 (76, 95.7) | 88 (78, 93) | 80 (63.4, 97.4) | ||
Dyssynchrony (outside box) (%) | PSP
| 83.5 (76.3, 92)z
| 79.3 (63, 86.7)az
| 76.9 (62, 87.5)abz
| 70.9 (52.3, 89.3)abcz
| <0.001 |
PSN
| 9 (2.1, 23.1)x
| 7.3 (1.8, 21.1) | 10.8 (6.5, 17.4) | 18.6 (2.1, 32.7) |
Neural (EAdi variables) and mechanical (Pes variables) effort
Parameter | Mode | PEEPe0%
| PEEPe40%
| PEEPe80%
| PEEPe120%
|
P* |
---|---|---|---|---|---|---|
Δ P̅esTRIG (cm H2O) | PSP
| −0.9 (−2.2, −0.6)z
| −0.9 (−2.0, −0.5)z
| −0.6 (−1.2, −0.4)abz
| −0.4 (−0.9, −0.2)abcz
| <0.001 |
PSN
| −0.2 (−0.3, −0.0)x
| −0.1 (−0.3, −0.0) | −0.1 (−0.3, −0.0) | −0.1 (−0.3, −0.0) | ||
Δ P̅esTOT (cm H2O) | PSP
| −2.2 (−3.2, −0.8)z
| −1.7 (−3.3, −0.7)z
| −1.0 (−1.9, −0.1)abz
| −0.4 (−2.2, 0.2)acz
| <0.001 |
PSN
| −0.7 (−1.6, −0.3) | −0.6 (−1.0, −0.2)a
| −0.4 (−0.8, 0.4)ab
| −0.3 (−0.8, 0.4)abc
| ||
PTPesTRIG (cm H2O*s/min) | PSP
| −5.0 (−23.8, −2.7)z
| −3.3 (−19.4, −1.5)z
| −2.4 (−10.5,−1.1)abz
| −1.3 (−4.2, −0.3)abcz
| <0.001 |
PSN
| −0.2 (−0.6, −0.1)x
| −0.2 (−0.4, −0.0) | −0.0 (−0.3, 0.1) | −0.1 (−0.4, 0.0) | ||
PTPesTOT (cm H2O*s/min) | PSP
| −44.5 (−81.3, −13.9)z
| −29.7 (−58.3, −11.5)z
| −17 (−34.2, −2.6)abz
| −7.3 (−49.8, 3.0)abcz
| <0.001 |
PSN
| −15.8 (−27.7,−5.9) | −11.5 (−16.7, −4.9)a
| −7.5 (−15.4, 5.5)ab
| −5.1 (−14.1, 4.2)abc
| ||
ÊAdiTRIG (μV) | PSP
| 3.1 (1.9, 4.8)z
| 2.6 (2.0, 4.1)z
| 2.1 (1.8, 4.1)abz
| 1.8 (1.7, 3.4)abcz
| <0.001 |
PSN
| 1.3 (1.1, 1.7)x
| 1.1 (1.0, 1.3)a
| 1.1 (1.0, 1.3)ab
| 1.0 (0.9, 1.2)ab
| ||
ÊAdiTOT (μV) | PSP
| 7.9 (5.7, 11.6) | 7.0 (6.2, 11.8) | 6.3 (5.0, 9.5) | 6.7 (4.7, 9.9) | <0.001 |
PSN
| 7.1 (4.8, 11.8) | 6.4 (5.5, 11.8) | 6.3 (4.6, 9.5) | 6.2 (4.4, 9.1) | ||
Δ P̅es/Δ P̅L (%) | PSP
| 24.5 (35.4, 11.0)z
| 18.2 (29.8, 8.3)z
| 12.5 (22.7, 1.3)abz
| 6.6 (21.1, −2.70)abcz
| <0.001 |
PSN
| 7.0(12.1, 2.9)x
| 5.4 (6.9, 2.2) | 2.8 (7.6, −4.5)ab
| 2.2 (7.6, −5.1)abc
| ||
NME (cm H2O/μV) | PSP
| −0.27 (−0.34, −0.16)z
| −0.22 (−0.32, −0.11)az
| −0.13 (−0.28, −0.03)abz
| −0.09 (−0.15, 0.02)abcz
| <0.001 |
PSN
| −0.11 (−0.22, −0.04) | −0.07 (−0.15, −0.03)a
| −0.06 (−0.10, 0.04)ab
| −0.05 (0.08, 0.06)abc
|
Neuromechanical efficiency (NME)
Discussion
Patient-ventilator interaction
Conclusion
Key messages
-
Neurally controlled pressure support ventilation is feasible in patients with COPD demonstrating intrinsic PEEP
-
Neurally controlled pressure support, compared to conventional, pneumatically controlled pressure support, improves patient-ventilator interaction and reduces inspiratory effort, even in the absence of external PEEP
-
Neurally controlled pressure support overcomes the need for extrinsic PEEP, in order to overcome intrinsic PEEP in COPD patients