Variable | Unit of measure | Prp=2 cmH2O | Prp=4 cmH2O | ||
---|---|---|---|---|---|
NCPAP | HFNC | NCPAP | HFNC | ||
Pressures | |||||
Prp at EE | cmH2O | 2.1 (1.9;2.4) | 1.9 (1.7;2.2) | 3.8 (3.3;4.2) | 3.8 (3.6;4.1) |
ΔPrp | cmH2O | 1.3 (1.1;2.4) | 1.7 (1.2;2.4) | 1.2 (1.1;2.0) | 2.0 (1.5;3.1) |
ΔPL | cmH2O | 4.1 (3.2;5.9) | 4.2 (3.4;5.4) | 3.3 (2.7;5.3) | 4.3 (3.3;6.5) |
Breathing pattern | |||||
Ti | s | 0.41 (0.32;0.47) | 0.42 (0.37;0.53) | 0.43 (0.35;0.61) | 0.56 (0.45;0.64) |
Te | s | 0.40 (0.31;0.50) | 0.53 (0.40;0.66) | 0.47 (0.34;0.75) | 0.58 (0.47;0.76) |
RR | breaths/min | 76 (63;98) | 63 (53;80) | 69 (46;89) | 53 (44;66) |
VT | mL | 5.77 (4.76;6.75) | 5.29 (3.46;7.95) | 6.89 (4.33;8.41) | 7.54 (3.97;10.17) |
MV | L/min | 439 (263;514) | 336 (221;391) | 366 (274;480) | 402 (221;531) |
%AB | % | 89 (84;97) | 95 (85;100) | 91 (74;102) | 89 (83;106) |
IAI | % | 34.7 (29.3;39.7) | 37.2 (32.0;51.5) | 31.0 (23.7;55.0) | 33.8 (21.5;61.9) |
LBI | 1.07 (1.05;1.10) | 1.10 (1.06;1.18) | 1.07 (1.05;1.15) | 1.09 (1.04;1.18) | |
PTP | cmH2O*s | 0.82 (0.66;0.99) | 0.94 (0.68;1.12) | 0.71 (0.54;1.13) | 1.13 (0.86;1.53) |
Mechanical properties | |||||
R | cmH2O*s/L | 47.3 (31.7;61.5) | 48.3 (35.6;76.9) | 43.6 (27.1;67.8) | 44.8 (28.4;66.9) |
Cdyn | mL/cmH2O | 2.96 (1.84;4.32) | 2.76 (1.16;3.56) | 2.80 (1.76;5.03) | 2.75 (1.59;4.55) |
Gas exchange | |||||
SpO2 | % | 93 (90;98) | 91 (90;97) | 96 (91;98) | 95 (92;97) |
PtcO2 | mm Hg | 56.0 (51.0;69.0) | 56.0 (47.5;69.5) | 62.0 (54.5;73.0) | 61.0 (57.0;72.0) |
PtcCO2 | mm Hg | 40.0 (34.0;42.0) | 41.0 (36.5;43.5) | 41.0 (31.5;44.0) | 40.0 (36.5;42.0) |
WOB | |||||
WOBi/VT | cmH2O | 2.32 (1.89;3.67) | 2.52 (1.96;3.11) | 2.15 (1.47;3.50) | 2.79 (1.87;4.33) |
eWOB/VT | cmH2O | 1.00 (0.52;2.12) | 0.92 (0.45;1.19) | 0.94 (0.72;1.67) | 0.89 (0.62;1.90) |
rWOBi/VT | cmH2O | 1.19 (1.09;1.89) | 1.53 (1.31;1.95) | 1.31 (1.08;1.97) | 1.74 (1.13;2.43) |
rWOBiup/VT | cmH2O | 0.52 (0.24;0.71) | 0.60 (0.33;0.86) | 0.35 (0.21;0.56) | 0.54 (0.48;0.99) * |
Data are expressed as median (IQR).
*p<0.05.
%AB, percentage contribution of the abdomen to VT; Cdyn, dynamic compliance; EE, end expiration; eWOB, elastic work of breathing; HHHFNC, heated, humidified, high-flow, nasal cannula; IAI, Inspiratory Asynchrony Index; LBI, Labour Breathing Index; MV, minute ventilation; NCPAP, nasal continuous positive airways pressure; PL, transpulmonary pressure; Prp, retropharyngeal pressure; PtcO2 and PtcCO2, transcutaneous partial pressure of oxygen and carbon dioxide; PTP, pressure time product; R, lung resistance; RR, respiratory rate; rWOBi, inspiratory resistive work of breathing; rWOBiup, inspiratory resistive work of breathing associated with the upper respiratory system; SpO2,oxygen saturation; Te, expiratory time; Ti, inspiratory time; VT, tidal volume; WOBi, inspiratory work of breathing.