Table 1 Baseline characteristics of all cases and adjusted to 30-day favourable neurological outcome defined as cerebral performance categories (CPC) 1 and 2. Data presented in n (%) or median [Q1; Q2]

MISSION & RESCUE CHARACTERISTICS

Weekend mission

296

80 (27.0)

20 (35.7)

60 (25.0)

0.104

Season

296

 Winter

62 (20.9)

12 (21.4)

50 (20.8)

 Spring

85 (28.7)

15 (26.8)

70 (29.2)

 Summer

94 (31.8)

21 (37.5)

73 (30.4)

 Fall

55 (18.6)

8 (14.3)

47 (19.6)

0.682

Helicopter hoist operation

296

15 (5.1)

1 (1.8)

14 (5.8)

0.214

Remote location

296

51 (17.2)

10 (17.9)

41 (17.1)

0.890

Response time, minutes

280

16.0 [13.0; 21.0]

15.0 [11.0; 18.0]

17.0 [13.0; 22.0]

< 0.001

On-scene time, minutes

238

33.5 [24.0; 51.0]

26.0 [18.0; 33.0]

37.0 [27.0; 57.0]

< 0.001

PATIENT CHARACTERISTICS

Age, years

296

5.0 [1.0; 12.0]

3.5 [1.0; 8.5]

6.0 [1.0; 13.0]

0.152

Age group

296

 < 1 year

56 (18.9)

11 (19.6)

45 (18.8)

 1–6 years

114 (38.5)

28 (50.0)

86 (35.8)

 7–16 years

126 (42.6)

17 (30.4)

109 (45.4)

0.091

Sex, male

182 (61.5)

33 (58.9)

149 (62.1)

0.662

COMORBIDITIES

 Known comorbidity

296

62 (20.9)

11 (19.6)

51 (21.2)

0.790

 Cardiovascular

296

19 (6.4)

4 (7.1)

15 (6.2)

0.806

 Respiratory

296

11 (3.7)

1 (1.8)

10 (4.2)

0.396

 Neurological

296

11 (3.7)

3 (5.4)

8 (3.3)

0.471

 Syndrome

296

7 (2.4)

1 (1.8)

6 (2.5)

0.751

 Premature birth

296

4 (1.4)

1 (1.8)

3 (1.2)

0.755

 Diabetes

296

1 (0.3)

0 (0.0)

1 (0.4)

0.628

 Other

296

9 (3.0)

1 (1.8)

8 (3.3)

0.544

CPR CHARACTERISTICS

Aetiology

296

 Traumatic cardiac arrest

97 (32.8)

3 (5.4)

94 (39.2)

 Non-traumatic cardiac arrest

199 (67.2)

53 (94.6)

146 (60.8)

< 0.001

Dispatcher-identified cardiac arrest

296

148 (50.0)

32 (57.1)

116 (48.3)

0.235

Dispatcher-assisted CPR

296

44 (14.9)

8 (14.3)

36 (15.0)

0.892

Witnessed cardiac arrest

296

109 (36.8)

27 (48.2)

82 (34.2)

0.050

Bystander CPR

296

197 (66.6)

52 (92.2)

145 (60.4)

< 0.001

Resuscitation delay > 2 min

296

157 (53.0)

12 (21.4)

145 (60.4)

< 0.001

ALS before HEMS arrival

296

206 (69.6)

36 (64.3)

170 (70.8)

0.337

Tracheal tube

296

193 (65.2)

22 (39.3)

171 (71.2)

< 0.001

Body temperature, Celsius°

76

33.5 [30.9; 35.0]

33.8 [32.2; 35.7]

33.0 [30.5; 34.6]

0.118

Resuscitation attempted

296

 Yes

245 (82.8)

32 (57.1)

213 (88.8)

 No

51 (17.2)

24 (42.9)

27 (11.2)

< 0.001

Chest compressions

296

241 (81.4)

29 (51.8)

212 (88.3)

< 0.001

First rhythm

296

 Asystole

155 (52.4)

4 (7.1)

151 (62.9)

 Pulseless Electrical Activity

45 (15.2)

5 (8.9)

40 (16.7)

 Pulseless Ventricular Tachycardia

1 (0.3)

0 (0.0)

1 (0.4)

 Pulseless Ventricular Fibrillation

23 (7.8)

8 (14.3)

15 (6.2)

 Asystole

155 (52.4)

4 (7.1)

151 (62.9)

 Normal Sinus Rhythm / no CPR

30 (10.1)

29 (51.8)

1 (0.4)

 Unknown

25 (8.4)

10 (17.9)

15 (6.2)

 No measures (obviously dead)

17 (5.7)

0 (0.0)

17 (7.1)

< 0.001

Defibrillation

296

37 (12.5)

10 (17.9)

27 (11.2)

0.178

Number of shocks

35

1.0 [1.0; 3.0]

1.0 [1.0; 1.0]

1.0 [1.0; 3.0]

0.243

Adrenaline

296

197 (66.6)

10 (17.9)

187 (77.9)

< 0.001

Ongoing CPR during transport

296

61 (20.6)

4 (7.1)

57 (23.8)

0.006

Duration of CPR, minutes

251

24.0 [8.0; 41.0]

0.0 [0.0; 10.0]

30.0 [15.0; 45.0]

< 0.001

Duration of bystander BLS, minutes

185

5.0 [0.0; 10.0]

2.0 [1.0; 5.0]

7.0 [0.0; 12.0]

0.066