Skip to main content

Table 3 Electrical impedance tomography and pressure-volume curve data

From: Variation of poorly ventilated lung units (silent spaces) measured by electrical impedance tomography to dynamically assess recruitment

Variable PEEP 5 incremental phase PEEP 10 incremental phase PEEP 15 PEEP 10 decremental phase PEEP 5 decremental phase Friedman test p value
Nondependent silent spaces, % 0.4 [0–3.3] 1.3 [0–3.9] 1.4 [0.4–4.3] 1.7 [0.5–3.0] 0.7 [0.1–2.2] 0.109
Dependent silent spaces, % 16.3 [11.7–17.9] 12.3 [9.2–15.2]a 8.7 [6.2–11.1]a,b 10.4 [8.0–12.7]a,c 13.6 [9.1–16.2]a,c,d < 0.001
Center of ventilation ventral-dorsal, % 41.9 [38.1–48.8] 46.3 [41.8–50.8]a 49.4 [46.9–54.8]a,b 47.7 [44.3–52.3]a,c 43.2 [40.9–50.9]a,c,d < 0.001
Regional compliance (ROI 4), ml/cmH2O 3.09 [1.21–4.95] 4.32 [2.92–6.03]a 5.90 [4.63–6.8]a,b 6.01 [4.53–6.53]a,b 4.27 [2.64–5.34]c,d < 0.001
Regional compliance (ROI 3), ml/cmH2O 10.52 [7.74–12.27] 12.32 [8.64–14.03]a 13.12 [10.41–14.96]a,b 13.10 [10.77–17.35]a,b 11.25 [9.11–14.5]a,d < 0.001
Regional compliance (ROI 2), ml/cmH2O 13.9 [12.24–18.97] 13.55 [12.82–17.06] 13.09 [11.07–15.93]b 14.95 [12.59–19.32]b,c 14.74 [11.38–20.21] 0.026
Regional compliance (ROI 1), ml/cmH2O 10.53 [7.51–13.27] 7.89 [5.93–9.73] 6.15 [4.63–8.15]a,b 7.68[6.95–10.96]c 10.98 [6.26–12.58]c < 0.001
Tidal distribution index 1.9 [1.4–2.9] 1.3 [0.8–1.7]a 1.0 [0.7–1.2]a,b 1.3 [1.1–1.7]a,c 1.8 [1.4–2.2]a,c < 0.001
Regional compliance dependent lung, ml/cmH2O 11.9 [10.4–16.7] 17.7 [12.3–19.2]a 19.1 [14.2–21.3]a,b 18.9 [15.7–22.8]a,b 16.0 [12.3–19.8]a,d < 0.001
Regional compliance nondependent lung, ml/cmH2O 25.3 [21.3–30.4] 22.7 [19.5–25.8] 20.0 [16.6–22.8]b 24.3 [18.7–28.5]c 26.4 [17.5–30.7] < 0.001
∆EELV, ml 170 [132–242] 495 [411–565]a 800 [638–943]a,b 435 [336–574]a,c 190 [133–262]b,c,d < 0.001
∆EELI, ml 170 [105–260] 559 [404–716]a 1190 [903–1378]a,b 777 [500–930] a,b,c 270 [191–410]a,b,c,d < 0.001
Recruitment
P-V curve, ml
Baseline 87.60 [32.20–119.00] 114.50 [71.50–171.00] −82.20 [−164.70 to 3.00] −101.20 [−158.50 to −28.00]  
Recruitment
P-V curve, ml/kg IBW
Baseline 1.32 [0.66–2.18] 2.09 [1.05–3.22] −1.61 [−3.26 to 0.04] −1.65 [−2.22 to −0.59]  
  1. Abbreviations: PEEP Positive end-expiratory pressure, RM Recruitment maneuver, ROI Region of interest, ∆EELV Change in end-expiratory lung volume, ∆EELI Change in end-expiratory lung impedance, P-V Pressure-volume, IBW Ideal body weight
  2. Data are expressed as median [IQR]
  3. Wilcoxon post-hoc analysis for couples: aStatistically significant difference from PEEP 5 incremental phase; bStatistically significant difference from PEEP 10 incremental phase; cStatistically significant difference from PEEP 15; dStatistically significant difference from PEEP 10 decremental phase