Skip to main content

Table 4 Physiological variables and diaphragm shear modulus according to the outcome of the spontaneous breathing trial

From: Ultrasound shear wave elastography for assessing diaphragm function in mechanically ventilated patients: a breath-by-breath analysis

  SBT success (n = 12) SBT failure (n = 13)
Start of SBT End of SBT p value Start of SBT End of SBT p value
Clinical variables
Systolic AP, mmHg 140 (129–157) 126 (121–159) 0.109 136 (124–150) 158 (128–161) 0.045
Heat rate, min−1 93 (84–99) 97 (81–103) 0.541 110 (90–118) 111 (95–121) 0.391
Breathing pattern
VT, mL/kg 4.1 (3.2–5.6) 4.1 (3.4–5.4) 0.894 3.2 (2.9–3.3) 3.5 (2.9–4.9) 0.423
Respiratory rate, cycles/min 24 (18–34) 25 (19–26) 0.332 24 (20–29) 32 (27–34) 0.288
Diaphragm function
ΔPdi, cmH2O 5.9 (4.1–17.4) 9.5 (5.2–12.0) 0.777 20.7 (12.5–29.1) 15.3 (8.8–27.5) 0.570
PTPdi, cmH2O.s/breath 3.2 (1.9–10.3) 5.7 (3.2–11.9) 0.903 11.6 (9.3–15.0) 7.9 (5.0–10.7) 0.495
PTPdi, cmH2O.s/min 70 (47–364) 138 (73–209) 0.853 239 (187–446) 263 (134–316) 0.602
ΔSMdi, kPa 9.8 (7.8–13.4) 7.4 (4.8–9.7) 0.323 13.5 (8.8–15.9) 7.6 (5.6–14.6) 0.879
  1. Results are shown as median (Q1-Q3). SBT, spontaneous breathing trial; AP, arterial pressure; VT, tidal volume; ΔPdi, inspiratory changes in transdiaphragmatic pressure; PTPdi, transdiaphragmatic pressure time product; ΔSMdi, inspiratory changes in diaphragm shear modulus