Table 2. Variables of double cycling, inspiratory effort, ventilation, and sedation status within the first 3 days of mechanical ventilation.
| Increased (n = 9) | Decreased (n = 9) | Unchanged (n = 1) | P value | |
|---|---|---|---|---|
| Double cycling index, % | ||||
| Day 1 | 1.1 (0.2–3.8) | 0.2 (0.0–1.2) | 0.1 | 0.225 |
| Day 2 | 1.5 (0.4–2.0) | 0.4 (0.2–0.4) | 0.2 | 0.207 |
| Day 3 | 5.7 (2.2–8.3) | 0.4 (0.0–2.3) | 0.3 | 0.100 |
| ΔPes, cmH2O | ||||
| Day 1 | −7.4 (−12.1–−2.9) | −2.9 (−5.1–−0.7) | −1.0 | 0.068 |
| Day 2 | −6.5 (−11.1–−3.1) | −2.6 (−4.9–−1.6) | −0.8 | 0.022 |
| Day 3 | −12.2 (-16.3–−7.5) | −2.9 (−8.3–−1.2) | −2.5 | 0.026 |
| Thickening fraction, % | ||||
| Day 1 | 14.6 (3.2–42.6) | 17.5 (11.5–21.5) | 17.1 | 0.394 |
| Day 2 | 11.6 (5.9–31.3) | 14.6 (6.1–21.1) | 31.1 | 0.357 |
| Day 3 | 18.8 (11.0–38.0) | 13.2 (8.3–17.4) | 26.1 | 0.086 |
| Ventilatory variables over the first 3 days | ||||
| Driving pressure, cmH2O | 12 (10–14) | 12 (10–14) | 12 | 1.000 |
| PEEP, cmH2O | 10 (8–11) | 10 (7–11) | 8 | 0.793 |
| Flow trigger, L/min | 3.0 (2.5–3.0) | 3.0 (3.0–3.0) | 3.0 | 0.169 |
| Inspiratory time, sec | 0.9 (0.8–1.1) | 1.0 (0.9–1.0) | 1.2 | 0.948 |
| Respiratory rate, per min | 18 (12–22) | 16 (15–20) | 15 | 0.800 |
| VT of normally triggered breath, mL/kg IBW | 9.2 (8.1–11.3) | 9.2 (6.9–10.4) | 7.8 | 0.577 |
| VT of double cycled breath, mL/kg IBW | 14.3 (8.8–16.4) | 11.1 (8.9–14.7) | 10.1 | 0.638 |
| RASS | ||||
| Day 1 | −3.0 (−3.5–−1.8) | −2.5 (−3.5–−1.7) | −5 | 0.595 |
| Day 2 | −2.5 (−3.8–−1.0) | −2.5 (−3.5–−1.0) | −4 | 0.821 |
| Day 3 | −2.0 (−2.5–−0.5)* | −2.0 (−3.8–−1.0) | −2 | 0.150 |
| Fentanyl use, μg/kg | ||||
| Day 1 | 12.5 (8.9–14.2) | 9.8 (5.4–12.2) | 12.0 | 0.770 |
| Day 2 | 8.5 (6.1–10.8) | 4.3 (3.5–8.9)* | 0.8 | 0.867 |
| Day 3 | 8.5 (4.4–11.3) | 4.3 (0.7–6.9)* | 0.0 | 0.310 |
Data are expressed as median with interquartile range unless otherwise noted. P values indicate comparisons between increased (n = 9) versus decreased (n = 9) diaphragm thickness.
*p < 0.05 versus Day 1. ΔPes, inspiratory esophageal pressure swing; PEEP, positive end-expiratory pressure; VT, tidal volume; IBW, ideal body weight; RASS, Richmond Agitation-Sedation Scale.