Table 3:

Characteristics of identified vascular injections

n%
Distance from needle tip to vessel
    <1 cm only1130%
    >1 cm only25%
    Both <1 cm and >1 cm2362%
    Immediate washout (vessel not seen)13%
Combined epidural injection
    Vascular only2568%
    Epidural + vascular1232%
Washout pattern
     None00%
     Delayed3286%
     Immediate514%
Vessel type
     Definite venous (n = 5)411%
     Probable venous (n = 4)2773%
     Indeterminate (n = 3)411%
     Probable arterial (n = 2)25%
     Definite arterial (n = 1)00%