In case of urgent need for venous access (in the emergency room, in the operating room, in emergency wards, etc.) it is necessary to distinguish between children with easy peripheral access (i.e., well palpable/visible superficial veins in the upper limbs) vs. children with 'difficult' veins.

Though the child 'without veins' obviously does not exist, in many situations (in approximately 24% of pediatric patients who arrive in the emergency room) the superficial veins of the upper limbs may be hardly visible and/or palpable. This category of pediatric patients has recently been classified with the English acronym 'DIVA' (Difficult IntraVenous Access), normally referring to the difficulty of accessing the superficial veins of the upper limbs (i.e. located less than 6-7 mm deep).

Of course, in case of difficulty in accessing the superficial veins of the upper limbs, it is also possible to place a short cannula in superficial veins of the neck (external jugular vein in the cervical tract) or of the lower limbs: though, these accesses must be removed within 24 hours, due to the high risk of dislocation (external jugular vein) or venous thrombosis (veins of the lower limbs).