Table 1 Characterization of the study population

N

243

Age (SD)

72.8 (± 17.8)

Female sex

113 (47)

Clinical indication for blood gas assessment

 Respiratory failure

204 (84)

  - Desaturation

  - Suspected/manifest pneumonia

  - Unknown

  - Cardiac failure, ROSC

  - Suspected/manifest PE

  - Exacerbation of known COPD

  - Active COVID-19 infection

68

44

40

19

12

11

10

 Other

39 (16)

  - Altered mental status

  - Sepsis

  - Metabolic disorder

  - Smoke inhalation, airway trauma

  - Anaphylaxis

  - Intoxication

  - Anemia, major bleeding

  - Hypothermia

13

6

5

4

4

4

2

1

Patient characteristics at the time of sampling

 Heart rate > 90/min

114 (47)

 Mean arterial pressure < 65 mmHg

14 (6)

 Saturation < 90%

39 (16)

 Ongoing supplemental oxygen

71 (29)

 Respiratory rate > 20/min

134 (55)

 Temperature > 38 or < 36 °C

78 (32)