Comparison of patients with short weaning (<3 days from polysomnography (PSG) to planned extubation) versus prolonged weaning (≥3 days after PSG)
| Short weaning | Prolonged weaning | p-value | |
| Subjects | 27 | 18 | |
| Patient characteristics | |||
| Age years | 61 (55–69) | 66 (62–76) | 0.09 |
| Male | 18 (67) | 14 (78) | 0.51 |
| BMI kg·m−2 | 31 (26–37) | 28 (25–34) | 0.42 |
| SAPS II at admission | 45 (38–56) | 46 (36–61) | 0.95 |
| Underlying cardiac disease | 9 (33) | 6 (33) | 0.99 |
| Underlying chronic lung disease | 10 (37) | 8 (44) | 0.76 |
| Duration of mechanical ventilation prior to PSG days | 8 (4–13) | 13 (5–20) | 0.19 |
| Days with sedation n | 5 (3–13) | 8 (4–14) | 0.33 |
| Days with midazolam n | 4 (2–9) | 8 (2–12) | 0.44 |
| Cumulative dose of midazolam mg | 552 (213–1644) | 1152 (276–2880) | 0.34 |
| Respiratory and clinical parameters at time of PSG | |||
| MIP cmH2O | 39 (33–56) | 43 (34–64) | 0.58 |
| P0.1 cmH2O | 3.6 (3.3–3.8) | 3.6 (3.5–3.7) | 0.32 |
| pH | 7.43 (7.41–7.48) | 7.42 (7.36–7.47) | 0.39 |
| PCO2 mmHg | 45 (38–51) | 44 (40–47) | 0.83 |
| PaO2/FIO2 mmHg | 233 (193–279) | 235 (175–252) | 0.33 |
| SOFA score | 3 (2–3) | 4 (3–6) | 0.02# |
| Creatinine µmol·L−1 | 59 (46–86) | 106 (61–284) | 0.02# |
| RASS score | 0 (−0.5–0) | 0 (0–0) | 0.17 |
| ICDSC score | 2 (0–4) | 3 (0.3–4) | 0.72 |
| Delirium | 10 (37) | 6 (33) | >0.99 |
| MRC score | 55 (39–60) | 31 (24–55) | 0.02# |
| ICU-acquired weakness (MRC score <48) | 9 (33) | 12/17 (71) | 0.03# |
| Severe weakness (MRC score <30) | 3 (11) | 8/17 (47) | 0.01# |
| Sleep characteristics | |||
| Sleep duration h | 5 (2–7) | 4 (2–7) | 0.59 |
| Duration of sleep stage 1 min | 16 (1–50) | 0 (0–0) | <0.01# |
| Duration of sleep stage 2 min | 130 (1–45) | 0 (0–0) | <0.01# |
| Duration of sleep stage 3 min | 36 (0–118) | 0 (0–0) | <0.01# |
| Duration of REM sleep stage min | 16 (0–52) | 0 (0–5) | <0.01# |
| Atypical sleep | 6 (22) | 14 (78) | <0.01# |
| No deep sleep | 8 (30) | 14 (78) | <0.01# |
| No REM sleep | 8 (30) | 12 (67) | 0.03# |
| No EEG reactivity at eyes opening | 3/26 (12) | 9/17 (53) | <0.01# |
| Altered EEG reactivity at eyes opening | 8/26 (31) | 14/17 (82) | <0.01# |
Data are presented as n, median (interquartile range), n (%) or n/N (%), unless otherwise stated. BMI: body mass index; SAPS: Simplified Acute Physiological Score; MIP: maximal inspiratory pressure; P0.1: negative airway pressure generated against occlusion during the first 0.1 s of spontaneous inspiration; PCO2: carbon dioxide tension; PaO2: arterial oxygen tension; FIO2: inspiratory oxygen fraction; SOFA: Sequential Organ Failure Assessment; RASS: Richmond Agitation–Sedation Scale; ICDSC: Intensive Care Delirium Screening Checklist; MRC: Medical Research Council; ICU: intensive care unit; REM: rapid eye movement; EEG: electroencephalogram. #: p<0.05.