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Table 3 Ventilatory parameters at high, intermediate and low inspiratory effort

From: Flow Index accurately identifies breaths with low or high inspiratory effort during pressure support ventilation

 

Low inspiratory effort

Intermediate inspiratory effort

High inspiratory effort

P

P0.1 (cmH2O)

0.7 (0.3–1.0)

1.2 (0.9–1.7)

1.6 (1.2–1.7)

< 0.001

Pmusc (cmH2O)

1.6 (0.7–2.3)

6.3 (5.7–7.6)

12.9 (12.5–15.2)

< 0.001

Flow Index

1.6 (1.2–2.4)

3.4 (2.7–4.2)

8.1 (6.9–10.8)

< 0.001

RR (breaths min−1)

24 (16–30)

26 (20–34)

24 (22–26)

0.431

RR/VT (breaths L−1 min−1)

48 (27–91)

56 (30–78)

33 (32–38)

0.421

\({\dot{\text{V}}}\)E (L min−1)

9.4 (7.3–13.5)

12.0 (9.9–15.4)

13.2 (11.7–15.4)

0.075

VT/IBW (mL kg−1)

8.1 (5.9–10.5)

7.9 (6.9–9.6)

10.0 (9.3–11.1)

0.124

PTP (cmH2O s min−1)

11.9 (3.6–22.7)

81.2 (73.9–108.1)

189.9 (159.9–205.3)

< 0.001

PTPtot (cmH2O s min−1)

41.2 (19.0–79.4)

178.4 (121.9–209.9)

279.9 (243.9–344.6)

< 0.001

PS (cmH2O)

13 (8–17)

4 (3–6)

3 (1–10)

< 0.001

  1. High inspiratory effort was defined as Pmusc greater than 10 cmH2O. Low inspiratory effort was defined as Pmusc lower than 5 cmH2O. P values were obtained with Kruskal Wallis test
  2. P0.1, airway occlusion pressure; Pmusc, pressure generated by respiratory muscles; RR, respiratory rate; VT, tidal volume; IBW, ideal body weight; \({\dot{\text{V}}}\) E, minute ventilation; PTP, pressure time product from the start of the inspiratory flow; PTPtot, pressure time product from the start of the inspiratory effort; PS, pressure support
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Critical Care

ISSN: 1364-8535