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Table 3 Patient ventilator interaction indices at different levels of PEEPe for 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*
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)  
  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 extrinsic positive end-expiratory pressure (PEEPe)0%; 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, PEEPe extrinsic PEEP, TTRIG diaphragm electrical activity (EAdi)-to-trigger time difference, TCYC-OFF cycling-off timing difference