Table 1 Patient characteristics of the study population stratified by PaO2 in first arterial blood gas analysis after arrival in hospital (n = 147)
ALL (n = 147) | Hypoxemia (n = 1) | Normoxemia (n = 26) | Mild Hyperoxemia (n = 30) | Severe Hyperoxemia (n = 90) | p | |
|---|---|---|---|---|---|---|
Demographics | ||||||
Age (years, [IQR]) | 49 [30–65] | 29 [NA] | 44 [29–53] | 53 [29–68] | 49 [30–66] | .59 |
Male, gender [n,%] | 116 [78.9] | 0[0] | 23 [88.4] | 25 [83.3] | 68 [75.5] | .21 |
Mechanism | ||||||
RTC [n,%] | 66 [44.9] | 1 [100] | 12 [46.2] | 16 [53.3] | 37 [41.1] | .45 |
Falls [n,%] | 54 [36.7] | 0 [0] | 9 [34.6] | 9 [30.0] | 36 [40.0] | |
Assault [n,%] | 10 [6.8] | 0 [0] | 3 [11.5] | 3 [10] | 4 [4.4] | |
Intentional self-harm [n,%] | 9 [6.1] | 0 [0] | 1 [3.8] | 2 [6.7] | 6 [6.6] | |
Accidental injury (other) [n,%] | 3 [2.0] | 0 [0] | 1 [3.8] | 0 [0] | 2 [2.2] | |
Fire exposure [n,%] | 3 [2.0] | 0 [0] | 0 [0] | 0 [0] | 3 [3.3] | |
Other | 2 [1.4] | 0 [NA] | 0 [NA] | 0 [NA] | 2 [2.2] | |
Body regions injured | ||||||
Head [n,%] | 118 [80.3] | 1 [100] | 23 [88.5] | 22 [73.3] | 72 [80] | .52 |
Chest [n,%] | 38 [25.9] | 0 [0] | 10 [38.5] | 11 [36.7] | 17 [18.9] | .09 |
Vital signs on arrival HEMS | ||||||
GCS [IQR] | 8 [4–11] | 4 [NA] | 5 [3–9] | 9 [5–12] | 8 [5–11] | .02 |
SpO2 (%, lQR] | 98 [88–100] | 98 [NA] | 92 [88–99] | 98 [98–99] | 98 [88–100] | .63 |
SBP (mean, 95%CI) | 132 [126–138] | 86 [NA] | 129 [115–142] | 134 [117–150] | 133 [126–140] | .005 |
HR (mean, 95%CI) | 96 [91–101] | 122 [NA] | 104 [92–117] | 97 [84–110] | 93 [86–99] | .68 |
Pre-hospital interventions | ||||||
PHEA | ||||||
Pre-oxygenation [n,%] | 147 | 1 [100] | 26 [100] | 30 [100] | 90 [100] | NA |
ApOx [n,%] | 2 | 0 [NA] | 1 [3.8] | 1 [3.3] | 0 [0] | .35 |
Peri-Post-PHEA | 56 | 0 [NA] | 15 [57.7] | 14 [46.7] | 27 [30.0] | .04 |
Desaturation [n,%] | ||||||
Post intubation FiO2 | ||||||
1.0 [n,%] | 144 [97.3] | 1 [0.7] | 26 [34.6] | 28 [30] | 89 [28.9] | .52 |
0.5 [n,%] | 3 [1.7] | 0 [0] | 0 [0] | 2 [6.7] | 1 [1.1] | |
Thoracostomies [n,%]* | 35 [23.8] | 0 [NA] | 8 [30.8] | 11 [36.7] | 16 [17.8] | .14 |
Transfusion and/or Code Red [n,%] | 26 [17.7] | 0 [NA] | 6 [23.1] | 8 [26.7] | 12 [13.3] | .31 |
In-hospital oxygen treatment | ||||||
Pulse oximetry SpO2 HEMS upon arrival in hospital (n = 142) | 100 [98–100] | 76 [NA] | 98 [95–100] | 100 [98–100] | 100 [99–100] | .01 |
FiO2 | ||||||
Maintained at 1.0 [n,%] | 26 [17.7] | 0 [0] | 6 [23.1] | 2 [6.7] | 18 [20] | .82 |
Downtitrated (0.8–0.2) | 120 [81.6] | 1 [100] | 20 [66.9] | 28 [93.3] | 71 [78.9] | |
Unknown | 1 | 0 | 0 | 0 | 1 [1.1] | |
ABGA results | ||||||
PaO2 [median, IQR] | 36.7 [18.5–52.2] | 7.9 [NA] | 13.8 [11.1–14.9] | 19.5 [18.4–23.6] | 46.3 [39.0–60.8] | < .001 |
PaCO2 [median, IQR] | 6.1 [5.6–7.0] | 9.0 [NA] | 6.8 [5.9–7.5] | 6.3 [5.8–7.1] | 5.9 [5.3–6.5] | .016 |
pH [median, IQR] | 7.3 [7.2–7.4] | 7.14 [NA] | 7.3 [7.2–7.4] | 7.3 [7.2–7.3] | 7.3 [7.3–7.4] | .002 |