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Table 1 Patient characteristics of the study population stratified by PaO2 in first arterial blood gas analysis after arrival in hospital (n = 147)

From: Incidence of hyperoxia in trauma patients receiving pre-hospital emergency anaesthesia: results of a 5-year retrospective analysis

  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
  1. RTC, road traffic collision; SpO2, Oxygen saturation; GCS, Glasgow coma score; SBP, systolic blood pressure; HR, heart rate; PHEA, pre-hospital emergency anesthetic; FiO2, fraction of inspired oxygen; ABGA, Arterial Blood Gas Analysis; PaO2, Partial pressure of oxygen, PaCO2, Partial pressure of CO2. *unilateral or bilateral