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Vascular access enables the administration of analgesia and antibiotics, vasoactive
medications during cardiac arrest, crystalloid solutions in severe
dehydration and hypovolemia, blood transfusion for hemorrhagic shock
from trauma or GI bleeding, and therapy-guiding central venous pressure
measurements in sepsis and heart failure.1 Multiple
factors determine the route and site for venous access.
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Infusion rate is of critical importance in the resuscitation
of severe hypovolemia or hemorrhage.1,2 Infusion
rates through a medical catheter behave according to Poiseuille’s
law:
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The rate of flow is directly proportional to the
catheter radius and the pressure gradient, and inversely proportional
to the dynamic fluid viscosity and catheter length. Flow rates are
increased by increasing the catheter radius, increasing the pressure
gradient (use of gravity, manual push-pull devices, pressure bag
application, or commercial rapid infusing devices), decreasing viscosity
(coadministration of crystalloid with viscous blood products), and/or
decreasing catheter length (peripheral angiocatheter vs. triple
lumen catheter). Flow rates are maximized by using the largest
internal diameter catheter possible.
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Peripheral Venous
Anatomy of the Upper Extremity
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The most commonly accessed veins for peripheral catheterization
of the upper extremity are the dorsal hand veins and the veins of
the antecubital fossa. The venous anatomy of the upper extremity
can be seen in Figure 33-1.
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Peripheral Venous
Anatomy of the Lower Extremity
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Peripheral catheterization of the superficial veins of the lower
extremity is more difficult and often requires venous cutdown of
the great and small saphenous veins.
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The great saphenous vein receives contributions from the medial
aspect of the foot and originates at its medial dorsal aspect. The
saphenous vein traverses the lower leg anterior and superior to
the medial malleolus. It courses posterior to the medial condyle
of the femur and along the medial thigh where it terminates into
the femoral vein approximately 3 cm below the inguinal ligament.
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The small saphenous vein originates posterior to
the lateral malleolus as a continuation of the lateral dorsal foot
veins. It traverses to the middle of the posterior lower leg, ascends
directly cephalad, terminating in the popliteal vein.
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The femoral vein is the primary deep vein of the lower extremity.
It is located medial to the femoral artery. The vessels course together
through the proximal thigh.
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The
cephalic vein originates at the radial aspect of the dorsal hand
vein network, coursing the lateral aspect of the forearm, then medially
over the anterior forearm approaching the antecubital fossa. The
cephalic vein communicates with the basilic vein via the median
cubital vein located in the antecubital fossa. It ascends the upper
arm in the groove along the lateral border of the biceps muscle,
passing between the deltoid ...