Skip to main content

Table 2 Ventilation parameters during the total analyzed period and the high driving pressure periods (ΔP ≥ 15 cmH2O)

From: Driving pressure during proportional assist ventilation: an observational study

Ventilation parameters

All patients total analyzed period

18 periods of high ΔP versus the rest of the analyzed period (low-ΔP) from eight patients

Low-ΔP period

High-ΔP period

FiO2(%)

40 (30–50)*

40 (35–50)

40 (35–50)

PEEP (cmH2O)

8 (6–8)

8 (8–10)

8 (7–8)

PaO2/FiO2

239 (182–280)*

246 (174–269)#

213 (149–237)

PAV+ % assist

40 (25–50)

40 (25–50)

45 (30–50)

Respiratory Rate (breaths per min)

23 (20–27)

24 (22–28)

25 (22–29)

VT mL/kg IBW

7.3 (6.5–8.3)

7.3 (7–7.9)#

7.6 (7.3–8.1)

VE (L/min)

10.2 (8.7–11.2)

10.2 (9.1–11.4)

10.1 (8.6–11.9)

RTOT(cmH2O/L/s)

9.5 (8.3–12)*

10.8 (8.7–13)#

12.5 (8.8–15.7)

RPAV(cmH2O/L/s)

6.2 (4.6–8.6)

7.9 (3.5–9.2)

7.7 (5.8–10.5)

PEEPi (cmH2O)

0.3 (0.1–0.7)

0.3 (0–0.5)

0.2 (0.1–0.8)

Crs (mL/cmH2O)

56 (42–71)**

38 (32–45)##

27 (24–30)

Ti (sec)

0.89 (0.80- 1.04)*

0.85 (0.77–0.97)

0.81 (0.70–0.85)

WOB (J/L)

0.9 (0.8–1.1)**

1.1 (0.9–1.3)##

1.5 (1.2–1.7)

ΔP (cmH2O)

7.8 (6.3–9.9)**

12 (10.2–12.3)##

15.6 (15.1–16.1)

  1. FiO2 fraction of inspired oxygen  %, PEEP: positive end-expiratory pressure, PaO2 arterial oxygen tension in mmHg, PAV+: proportional assist ventilation, VT tidal volume, VE minute ventilation, RTOT total calculated resistance (patient airways + artificial airway), RPAV patient resistance calculated by PAV+ software (difference between RTOT and estimated resistance of the artificial airway, after input of intratracheal tube size), PEEPi intrinsic PEEP, CPAV respiratory system compliance calculated by PAV+, Ti inspiratory time, WOB work of breathing, ΔP driving pressure
  2. Values are presented as median and interquartile range. * p < 0.05, ** p < 0.0001 for high-ΔP-time vs. complete analysis of all patients (Mann–Whitney U test), and #p < 0.05, ##p < 0.0001 for high-ΔP-time versus low-ΔP-time (rest of the recording) of the same patient (Friedman’s two-way analysis of variance by ranks)