Table 3.

Multivariate model of hypercapnia versus normocapnia in relation to neurological outcome

	OR	95% CI	P value
Hypercapnia (normocapnia reference)	0.70	0.44–1.11	0.13
TTM group (33 °C reference)	1.00	0.71–1.42	0.99
Age (per year)	1.07	1.05–1.08	< 0.001
Sex (male reference)	1.34	0.84–2.15	0.22
Chronic heart failure (yes/no)	2.09	0.98–4.46	0.06
Asthma/COPD (yes/no)	1.32	0.72–2.43	0.37
Bystander witnessed arrest (yes/no)	0.61	0.35–1.07	0.09
Bystander CPR (yes/no)	0.87	0.57–1.33	0.53
Time to ROSC (per min)	1.03	1.02–1.04	< 0.001
GCS-Motor score (1 vs 2–5)	2.5	1.72–3.57	< 0.001
Shock on admission (yes/no)	1.56	0.88–2.75	0.13
First rhythm shockable (yes/no)	0.19	0.11–0.33	< 0.001
pH (per 1.0 unit increase)	0.28	0.07–1.17	0.08

Hypercapnia = PaCO₂ > 6.0 kPa, normocapnia = PaCO₂ 4.5–6.0 kPa, hypocapnia = PaCO₂ < 4.5 kPa

OR < 1 indicates better outcome

OR odds ratio, CI confidence interval, TTM Target Temperature Management, COPD chronic obstructive pulmonary disease, CPR cardiopulmonary resuscitation, ROSC return of spontaneous circulation, GCS Glasgow Coma Scale