Low central venous saturation predicts poor outcome in patients with brain injury after major trauma: a prospective observational study

Table 3 Results of the relative risk analysis (95% confidence interval) related to 28-day mortality.

	RR	95% CI	P	Sens	Spec	PPV	NPV
Age ≥ 40 *	2.7	1.1–7	0.032	0.77	0.46	0.25	0.91
Age ≥ 45	-	-	0.198	-	-	-	-
Age ≥ 50	-	-	0.113	-	-	-	-
AIS (Head/Neck) ≥ 3	-	-	0.272	-	-	-	-
AIS (Head/Neck) ≥ 4 *	4.1	1.3–13.1	0.007	0.86	0.46	0.26	0.94
ISS ≥ 30 *	3	1.2–7.7	0.017	0.77	0.53	0.27	0.91
ISS ≥ 35 *	3.8	1.7–8.7	0.001	0.68	0.71	0.35	0.91
ISS ≥ 40 *	2.4	1.149–5	0.03	0.46	0.79	0.32	0.87
SAPS II ≥ 40	-	-	0.188	-	-	-	-
SAPS II ≥ 45 *	2.9	1.2–6.9	0.017	0.73	0.58	0.28	0.91
SAPS II ≥ 50 *	2.3	1.1–4.8	0.046	0.55	0.7	0.29	0.87
Marshall score ≥ 2 *	14.7	3.6–60.1	< 0.001	0.91	0.71	0.41	0.97
Marshall score ≥ 3 *	5.8	2.8–12	< 0.001	0.59	0.89	0.54	0.91
Lactate ≥ 3 mmol/l *	6.8	1.7–27.8	< 0.001	0.90	0.51	0.30	0.96
Lactate ≥ 4 mmol/l *	4.8	1.9–12.3	< 0.001	0.75	0.70	0.37	0.92
Lactate ≥ 5 mmol/l *	4.2	2–9	< 0.001	0.55	0.85	0.46	0.89
ScvO₂ ≤ 65% *	2.3	1.1–4.8	0.034	0.46	0.78	0.31	0.87
ScvO₂ ≤ 70%	-	-	0.186	-	-	-	-

The cut-off values have been chosen based on statistically significant mean values of subgroups analysis (survived vs deceased patients, see Table 2).
Statistical analyses were performed using the two-tails Fisher's exact test (95% confidence interval). P-values were considered significant if less than 0.05 (*).
RR: Relative Risk; CI: Confidence Interval; Sens: Sensitivity; Spec: Specificity; PPV = Positive Predictive Value; NPV = Negative Predictive Value; SAPS: Simplified Acute Physiology Score; GCS: Glasgow Coma Scale; ISS: Injury Severity Score; AIS: Abbreviate Injury Scale; ScvO₂: central venous oxygen saturation.

ISSN: 1757-7241