Central venous catheterization
The complication rate of central venous catheterization (Table 3.2) is much higher than for peripheral i.v.s, thus the first question should be whether central venous cannulation is truly necessary (Table 3.3). When placed emergently, for instance in a trauma patient, these catheters should be replaced within 48 hours to reduce the risk of infection.
The next question deals with access site. The three most common insertion sites are as follows:
· Femoral Probably technically the easiest (remember, from lateral to medial,NAVEL – nerve, artery, vein, empty space, lympathics) and quickest, with the lowest rate of serious complications (though highest rate of minor complica-tions), but these catheters are more difficult to keep clean and therefore more likely to be a source of infection.
· Subclavian (SC) Once placed, this catheter location is probably the most com-fortable for the patient. Unfortunately, it carries a significant risk of pneumo-thorax (up to 3%), and the procedure can be very difficult when landmarks are obscured, as in obesity.
· Internal jugular (IJ) Anesthesiologists favor this location because of accessibility(we’re already at the head of the patient) and the low risk of pneumothorax. Incidentally, we prefer the right IJ over the left due to the “straightness” of the route to the heart and because we need not worry about the left-sided thoracic duct.
In addition to selecting a catheter size appropriate to the patient and indication, there are other features to consider (Table 3.4).
Because the majority of catheters in anesthesia are placed in the IJ location in an anesthetized patient, we will describe this technique. In an awake patient, we would add sedation, continual reassurance, and local anesthesia.