Table 1.
Clinical characteristics of the development and validation cohort stratified by the presence or absence of early postoperative tracheal re-intubation. Values are number (proportion), mean (SD) or median (IQR [range]).
| Development cohort (n =
90,893) |
Validation cohort (n =
67,046) |
|||
|---|---|---|---|---|
| No tracheal re-intubation (n = 90,194) | Tracheal re-intubation (n = 699) | No tracheal re-intubation (n = 66,459) | Tracheal re-intubation (n = 587) | |
| Sex; male | 40,523 (45%) | 372 (53%) | 28,050 (42%) | 298 (51%) |
| Age; years | 56 (17) | 63 (16) | 56 (17) | 63 (15) |
| Body mass index; kg.m−2 | 28.6 (7.1) | 28.5 (7.8) | 28.8 (7.3) | 28.9 (7.9) |
| ASA physical status | 2 (2–3 [1–5]) | 3 (2–3 [1–5]) | 2 (2–3 [1–5]) | 3 (2–3 [1–5]) |
| Chronic pulmonary disease | 16,943 (19%) | 228 (33%) | 12,353 (19%) | 188 (32%) |
| Heart failure | 7395 (8%) | 240 (34%) | 4219 (6%) | 101 (17%) |
| Emergency surgery | 4,711 (5%) | 104 (15%) | 4,965 (8%) | 88 (15%) |
| High-risk surgical servicesa | 40,348 (45%) | 413 (59%) | 30,267 (46%) | 301 (51%) |
| Duration of procedure; min | 177 (122–253 [9–1153]) | 232 (146–343 [31–885]) | 156 (112–222 [0–1147]) | 183 (124–267 [15–874] |
| Duration of intra-operative MAP< 55 mmHg; min | 0 (0–2 [0–614]) | 2 (0–6 [0–258]) | 1 (0–3 [0–243]) | 1 (0–4 [0–59]) |
| Procedural severity score for morbidity | 41 (18) | 54 (17) | 39 (16) | 49 (17) |
| Packed red blood cells; 0 units | 86,299 (96%) | 572 (82%) | 64,250 (97%) | 496 (85%) |
| Packed red blood cells; 1–2 units | 3189 (4%) | 93 (13%) | 1981 (3%) | 76 (13%) |
| Packed red blood cells; ≥ 3 units | 706 (1%) | 34 (5%) | 228 (0%) | 15 (3%) |
| Fluids; lb | 1.5 (1.0–2.5 [0.0–30.8]) | 2.0 (1.0–3.5 [0.0–20.2]) | 3.5 (2.5–5.0 [0.0–34.0]) | 4.0 (2.5–6.5 [0.0–24.9]) |
| Oral morphine equivalent of total long-acting intra-operative opioid dose; mg | 15 (2–27 [0–545] | 7 (0–24 [0–408]) | 14 (0–24 [0–558]) | 14 (0–24 [0–102]) |
| 95% effective dose of total NMBA; mg | 2.7 (1.7–4.1 [0.0–46.7]) | 3.3 (2.1–5.1 [0.0–19.0]) | 2.2 (1.2–3.2 [0.0–40.7]) | 2.6 (1.5–4.0 [0.0–17.8]) |
| Neostigmine dose;mg | 2 (0–4 [0–23]) | 3 (0–4 [0–10] | 3 (0–4 [0–20]) | 3 (0–4[0–8]) |
| Dose equivalent of inhalational anaesthetic; MAC | 0.6 (0.4–0.8 [0.0–2.5]) | 0.5 (0.3–0.8 [0.0–1.6]) | 0.9 (0.7–1.1 [0.0–3.0]) | 0.9 (0.7–1.1 [0.0–2.4]) |
| Noradrenaline equivalent of vasopressor dose; mg | 0.1 (0.0–0.3 [0.0–97.5] | 0.3 (0.1–0.8 [0.0–91.0] | 0.0 (0.0–0.1 [0.0–72.5]) | 0.1 (0.0–0.5 [0.0–45.7]) |
| SpO2 5 min post-tracheal intubation; % | 100 (99–100 [45–100]) | 100 (99–100 [80–100]) | 99 (99–100 [60–100]) | 100 (98–100 [82–100] |
| FIO2; % | 52 (38–58 [21–100]) | 57 (46–77 [21–100] | 54 (48–60 [21–100]) | 58 (52–78 [21–100]) |
| Lung-protective ventilationc | 55,417 (61%) | 354 (51%) | 19,163 (29%) | 148 (25%) |
ASA, American Society of Anesthesiologists; MAP, mean arterial pressure; NMBA, neuromuscular blocking agent; MAC, minimum alveolar concentration; FIO2, fraction of inspired oxygen; SpO2, peripheral capillary oxygen saturation.
a
Includes vascular surgery, transplant surgery, neurosurgery, thoracic surgery, general surgery and burns.
b
Crystalloid:colloid ratio 1:1.5.
c
Lung-protective ventilation was defined as driving pressure ≤ 15 mmHg(median plateau pressure–median positive end-expiratory pressure).