Skip to main content

Table 2 Ventilator data and physiological parameters after mechanical ventilation according to the ARDS Network protocol low positive end-expiratory pressure (PEEP) table (ARDSNet) and after 4 h of mechanical ventilation according to the electrical impedance tomography based protocol (EIT Protocol)

From: Individualization of PEEP and tidal volume in ARDS patients with electrical impedance tomography: a pilot feasibility study

Parameter (unit) ARDSNet EIT Protocol p
Stress (mbar) 14.1 ± 3.9 17.2 ± 4.4 0.0007
Strainrelease (ratio) 0.80 [0.70–1.10] 1.13 [0.96–1.59] 0.015
Elung,spec (mbar) 15.9 ± 5.8 14.2 ± 4.8 0.26
Strainrecr. (ratio) 0.56 ± 0.14 0.55 ± 0.19 0.77
PaO2/FiO2 (mmHg) 151 ± 31 209 ± 53 0.0001
PaCO2 (mmHg) 58 ± 11 61 ± 9 0.28
pH 7.31 ± 0.07 7.29 ± 0.05 0.17
VT (ml/kg PBW) 5.8 ± 0.47 5.7 ± 0.92 0.96
Paw.plat (mbar) 20.3 [18.5–22.4] 27.9 [25.4–29.1] 0.0001
PEEP (mbar) 10 [8–10] 16.5 [14–18] 0.0001
Crs (ml/mbar) 38.2 ± 8.8 37.9 ± 11.4 0.83
VPEEP (ml) 348 [311–457] 603 [400–809] 0.0004
Clung (ml/mbar) 60.07 ± 23.48 63.53 ± 26.38 0.33
ΔPaw (mbar) 10.4 ± 2.2 10.4 ± 2.0 0.96
ΔPTP (mbar) 7.0 ± 2.3 6.6 ± 2.1 0.19
SDRVD (%) 8.3 ± 2.8 6.6 ± 1.9 0.022
Ptp,plat (mbar) 4.9 [1.4–6.9] 17.9 [15.6–19.0]  < 0.0001
Ptp,exp (mbar) -3.5 [-5.9–1.1] 3.25 [-0.7–4.7] 0.0002
Tidal power (J/min) 4.96 ± 1.87 4.24 ± 1.24 0.047
EELV (ml) 1637 [1450–2228] 2348 [2034–3201]  < 0.0001
FRCrelease (ml) 1176 ± 439 1317 ± 443 0.17
FRCrecr. (ml) 1267 [1141–1803] 1704 [1496–2512] 0.0001
Cardiac Index* (l/min/m2) 3.4 [2.4–4.5]* 3.4 [2.5–5.0]* 0.19*
NE (µg/kg/min) 0.12 [0.01–0.26] 0.12 [0.01–0.26] 0.55
  1. Normally distributed variables are presented as mean ± standard deviation, whereas non-normally distributed variables are presented as median [interquartile range]
  2. PaO2 arterial partial pressure of oxygen, FiO2 inspired fraction of oxygen, Crs respiratory system compliance, Clung lung compliance, ΔPaw airway driving pressure, ΔPTP transpulmonary driving pressure, NE norepinephrine dosage, Paw.plat airway plateau pressure, PEEP positive end-expiratory pressure (measured at airway opening), VPEEP PEEP volume (calculated by multiplying PEEP with Crs), Ptp,plat transpulmonary plateau pressure (calculated as difference between Paw.plat and plateau esophageal pressure), Ptp,exp end-expiratory transpulmonary pressure (calculated as difference between PEEP and end-expiratory esophageal pressure), SDRVD standard deviation of regional ventilation delay, EELV end-expiratory lung volume, FRCrecr. recruitment-adjusted functional residual capacity, calculated as EELV–Crs * PEEP, FRCrelease release-derived functional residual capacity, calculated as EELV–released volume during an exhalation to ambient pressure, PBW predicted body weight, Strainrelease release-derived strain, calculated as volume change above FRCrel, normalized to FRCrel, Strainrecr. recruitment-adjusted strain, calculated as volume change above FRCrecr., normalized to FRCrecr, VT tidal volume
  3. *Cardiac output measurements were available in 14 patients