The freedom from the risk of pneumothorax makes this approach of particular value in patients known to have impaired pulmonary function and for those who have had to undergo surgery with a period of intermittent positive-pressure ventilation. It is also of particular value in the very elderly for the same reason.
Care should be taken in selecting the site of insertion because some veins of the antecubital fossa may be obliterated by previous peripheral intravenous cannulations. The best tributary is the median basilic vein on the left, followed by the right median basilic, and finally the median cephalic veins at the elbow. The passage of long central venous catheters through these tributaries leading in to the cephalic vein is not generally preferred because of the difficulty sometimes experienced in negotiating the segment of vein situated in the deltopectoral groove as it penetrates the layers of fascia before entering the subclavian vein. Successful placement is achieved most often by using the simpler and more direct median basilic route.
The venous anatomy should be delineated by a tourniquet. This should be placed high up the arm so that it does not encroach on to the draped area and zone of skin preparation. If the patient is shocked and the veins are collapsed, a cut-down procedure should be considered first rather than destroying a valuable route of venous access by multiple unsuccessful percutaneous puncture attempts. Very recently an ingenious technique has been described ( Williams eia[ 1997). With a tourniquet in place around the upper arm, any small vein present in the arm or hand is identified and the smallest cannula available (e.g. 'blue 22 gauge') inserted. This is then connected to a bag of warm crystalloid solution which is infused under pressure without releasing the upper arm tourniquet. After a few minutes, the venous tree of the arm is filled with crystalloid and it is then easy to identify a suitable large-caliber vein and insert the appropriate central venous catheter or large-bore peripheral catheter under local anesthesia.
The central catheter should be advanced along the vein, slowly and without force. If obstruction of the catheter's progress should be encountered, it may be withdrawn a fraction and a further attempt made. Often, gentle rotation of the catheter around its long access will help to negotiate the valve or tributary. The position of the catheter tip should be checked to ensure that it lies in the superior vena cava or its junction with the innominate vein.
Was this article helpful?