Gaining vascular access may be difficult in sick children. Fluids can be infused within the medullary space of the tibial or femoral diaphysis.


Site selection:

(1) proximal tibia, 2 finger breadths below the tibial tuberosity

(2) distal femur, 1 finger breadth above the patella (with the knee extended)

(3) other sites: distal tibia at medial malleolus, distal fibular at lateral malleolus, anterior iliac crest, posterior iliac crest, sternum


The bone selected should not be fractured, since the infusate will then leak into the soft tissues.



(1) Restrain the site if necessary.

(2) Carefully clean the skin as for a blood culture and use aseptic technique for insertion and site care.

(3) If the child is awake or rousable inject local anesthetic.

(4) Use a 16 or 18 gauge needle with trocar (to prevent obstruction by soft tissue) and preferrably a hubplate (aids and limits insertion, simplifies maintenance).

(3) Insert the needle in the midline with a 60 to 80° angle to the skin surface (10 to 30° from vertical), pointing away from the epiphyseal plate (distal in tibia, proximal in femur).


Verification of proper placement:

(1) There is a drop off in resistance after penetrating the cortical bone.

(2) Bone marrow can be aspirated (this may be absent if the marrow mostly fat).

(3) Fluids are infused without significant edema.

(4) The needle stays upright on its own.


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