Table 1.
Characteristics of patients with and without hyperoxemia
| Case | Unadjusted | After IPWa | ||||
|---|---|---|---|---|---|---|
| Hyperoxemia | Non-hyperoxemia | P value | Hyperoxemia | Non-hyperoxemia | P value | |
| 58 | 186 | |||||
| Age, years, median (IQR) | 49 (35–67) | 60 (46–75) | 0.022 | 50 (31–65) | 53 (37–69) | 0.175 |
| Sex, male, n (%) | 34 (58.6%) | 126 (67.7%) | 0.202 | 83 (64.8%) | 85 (65.9%) | 0.860 |
| Injury mechanism, blunt, n (%) | 56 (98.2%) | 180 (97.3%) | 1.000 | 123 (97.6%) | 125 (97.7%) | 1.000 |
| Comorbidities (Charlson index), median (IQR) | 0 (0–0) | 0 (0–0) | 0.281 | 0 (0–0) | 0 (0–0) | 0.007 |
| Vital signs on arrival, median (IQR) | ||||||
| GCS | 6 (3–13) | 14 (11–15) | < 0.001 | 8 (5–14) | 10 (6–14) | 0.557 |
| RR | 21 (18–28) | 21 (18–26) | 0.687 | 20 (16–26) | 20 (15–28) | 0.696 |
| HR | 96 (77–120) | 90 (73–102) | 0.083 | 96 (80–120) | 90 (73–110) | 0.153 |
| BP systolic, mmHg | 124 (90–147) | 129 (103–154) | 0.353 | 133 (103-151) | 123 (83–158) | 0.220 |
| Injury severity, median (IQR) | ||||||
| AIS—head | 4 (0–5) | 2 (0–4) | < 0.001 | 4 (0–5) | 4 (0–5) | 0.663 |
| AIS—chest | 3 (0–4) | 3 (0–4) | 0.039 | 3 (0–4) | 3 (0–4) | 0.136 |
| ISS | 29 (25–38) | 26 (19–34) | 0.001 | 29 (25–38) | 29 (25–38) | 0.352 |
| SOFA score | 10 (8–11) | 8 (6–10) | 0.001 | 9 (7–11) | 8 (7–11) | 0.703 |
| Cardiac arrest after arrival, n (%) | 1 (1.7%) | 2 (1.1%) | 0.559 | 2 (1.6%) | 4 (3.1%) | 0.684 |
| Treatment | ||||||
| Tube thoracotomy, n (%) | 13 (22.4%) | 44 (23.7%) | 0.845 | 32 (25.0%) | 40 (31.0%) | 0.284 |
| Intubation at ED, n (%) | 47 (81.0%) | 58 (31.2%) | < 0.001 | 90 (70.3%) | 96 (74.4%) | 0.462 |
| Transfusionb, U, median (IQR) | ||||||
| RBC | 0 (0–4) | 0 (0–2) | 0.017 | 0 (0–4) | 0 (0–6) | 0.230 |
| FFP | 0 (0–6) | 0 (0–4) | 0.024 | 0 (0–4) | 0 (0–6) | 0.218 |
| Platelet | 0 (0–0) | 0 (0–0) | 0.276 | 0 (0–0) | 0 (0–0) | 0.178 |
| Hemostatic procedure, n (%) | ||||||
| Craniotomy | 19 (32.8%) | 19 (10.5%) | < 0.001 | 37 (28.9%) | 29 (23.2%) | 0.301 |
| Thoracotomy | 2 (3.4%) | 2 (1.1%) | 0.248 | 4 (3.1%) | 1 (0.8%) | 0.181 |
| Laparotomy | 6 (10.3%) | 13 (7.2%) | 0.438 | 11 (8.7%) | 10 (8.0%) | 0.849 |
| Angiography | 21 (36.2%) | 37 (20.4%) | 0.015 | 34 (26.6%) | 32 (25.4%) | 0.832 |
IPW inverse probability weighting, GCS Glasgow Coma Scale, RR respiratory rate, HR heart rate, BP blood pressure, AIS Abbreviated Injury Scale, ISS Injury Severity Score, SOFA sequential organ failure assessment, ED emergency department, RBC red blood cell, FFP flesh frozen plasma
aIPW was performed using propensity scores, and data were presented after excluding patients with propensity score of < 0.1 or > 0.9 bAmount of transfusion was calculated until 3 h after hospital arrival