Table 6.

Logistic regression - backward selection

Parameter	P -value	Odds ratio	95% CI
Polydistrectual arteriopathy	0.0023	2.82	1.45 to 5.50
Chronic obstructive pulmonary disease	0.0198	2.61	1.16 to 5.87
Arterial hypertension	0.0214	2.09	1.12 to 3.93
Arterial catheter 20- versus 18-gauge	<0.0001	0.35	0.21 to 0.58
Sedation	0.0131	0.5	0.29 to 0.86