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Table 4 Neural and mechanical indices of respiratory effort at different levels of PEEPe during PSP and PSN

From: Neural versus pneumatic control of pressure support in patients with chronic obstructive pulmonary diseases at different levels of positive end expiratory pressure: a physiological study

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

 
  1. Values are presented as median (25–75 % interquartile range). *P values for one-way repeated measures analysis of variance on ranks for the eight conditions: •within the same mode: a P <0.05 compared to PEEPe0%; b P <0.05 compared to PEEPe40%; c P < 0.05 compared to PEEPe80%. Between modes: z P <0.05 compared to PSN at same PEEPe comparison of PSN zero PEEP to PSP optimal PEEP: x P <0.05 PEEPe0% at PSN vs. PEEPe80% at PSP. PSP pneumatically triggered and cycled-off pressure support, PSN neurally triggered and cycled-off pressure support ventilation, ΔP̅esTRIG pre-trigger mean deflection of esophageal pressure, ΔP̅esTOT total inspiratory mean deflection for esophageal pressure, PTPesTOT total inspiratory pressure time product per minute for esophageal pressure, PTPesTRIG pre-trigger pressure time product per minute for esophageal pressure, ÊAdiTOT peak inspiratory diaphragm electrical activity (EAdi) for total inspiration, ÊAdiTRIG peak pre-trigger EAdi, ΔP̅es/ΔP̅L esophageal pressure contribution to transpulmonary pressure during inspiration, NME neuromechanical efficiency calculated for esophageal pressure