To the Editor:—
During subclavian vein catheterization, one of the most common misplacements of the catheter is into the ipsilateral internal jugular vein (IJV). Chest radiography is performed to identify the exact location of the catheter and procedure-related complications.1Misplaced catheters have increased risks of thrombophlebitis in addition to impairment of the central venous pressure (CVP) measurement.2Recently, Ambesh et al. 3,4showed that manual occlusion of the ipsilateral IJV in the supraclavicular fossa during and after insertion of subclavian vein catheter is successful in preventing and diagnosing the misplacement of the subclavian vein catheter into the IJV, respectively. Since Ambesh et al. developed this maneuver and reported excellent results, no other study has validated these results. Therefore, in a randomized and controlled study, we tested whether the Ambesh maneuver is successful in preventing and diagnosing the misplacement of a subclavian vein catheter into the IJV.
After approval by the Ethics Committee (King George’s Medical University, Lucknow, India), 300 adult patients of either sex scheduled to undergo central venous cannulation through the subclavian approach were randomly allocated into two groups of 150 each. Informed verbal consent was obtained from all patients before the procedure. In a patient lying supine with a 15°–20° Trendelenburg position and the head turned to the left, the junction of the medial one third and lateral two thirds of the clavicle in the right infraclavicular area was chosen as the puncture point. An 18-gauge introducer needle was inserted at this point and directed toward the sternoclavicular joint. After free flow of venous blood, the J-tip guide wire was threaded through the cannula into the subclavian vein. In the Ambesh maneuver group of patients, the ipsilateral IJV was occluded, as described by Ambesh et al. ,3during threading of the J guide wire, whereas in control group, no such maneuver was performed. The subclavian vein catheter was then railroaded over the guide wire. The catheter was then connected with a transducer, and the CVP value and waveform pattern were observed. Next, the Ambesh maneuver4was reapplied for approximately 10 s, and changes in CVP value and waveform pattern were noted. If there was an increase in CVP value by more than 3 cm H2O along with flattening of the waveform, it was presumed that the catheter tip was misplaced into the ipsilateral IJV. At the end of the procedure, chest radiography was performed, and position of the catheter was identified in all patients. The characteristics of the patients were analyzed using the Student t test and Fisher exact test. P values were two-tailed, and P > 0.05 was considered significant.
The age, sex, and body weight of the patients were comparable in two groups. Five patients in the control group and 7 patients in the Ambesh maneuver group could not be cannulated; therefore, 145 patients in the control group and 143 patients in the Ambesh maneuver group were analyzed. Chest x-ray films showed that in control group, there were 10 (6.9%) misplaced catheters, 9 (6.2%) in ipsilateral IJV and 1 (0.7%) in opposite subclavian vein, whereas in the Ambesh maneuver group, there were 2 (1.4%) (95% confidence interval, 1.4–6.9%; P < 0.05) misplaced catheters, both in the opposite subclavian vein and none in the IJV. The operator experienced difficulty in inserting the guide wire in 3 patients of control group and 9 patients of Ambesh maneuver group. The withdrawal and reinsertion of the guide wire and catheter were easy.
The correct placement of the central venous catheter is an essential prerequisite for accurate monitoring of CVP and long-term use of the catheter. Misplacement of the tip may enhance the risk of clot formation, thrombophlebitis, and catheter erosion in addition to impaired CVP measurement.2,5Recently, Domino et al. 6reported that the proportion of malpractice claims related to central catheters and vascular access injury has increased significantly. The incidence of malpositioning of CVP catheters through the infraclavicular technique of the subclavian vein varies between 4% and 8%.3–5Our study shows a 6.9% incidence of misplacement of subclavian vein catheter through the right infraclavicular approach, and most of the misplacements were in the ipsilateral IJV (6.2%). The operator encountered difficulty in insertion of the guide wire in only 3 patients without IJV occlusion and in 9 patients with IJV occlusion. It becomes obvious that the guide wire in some of these 9 patients of the IJV occlusion group was intending to go into the ipsilateral IJV, but the IJV was occluded manually. The occlusion of ipsilateral IJV in the supraclavicular area may have prevented the cephalad insertion of the guide wire and therefore the subclavian vein catheter into the IJV.
We conclude that the Ambesh maneuver is a simple, inexpensive, and handy bedside technique that helps in preventing and diagnosing the misplacement of a subclavian vein catheter into the IJV. We strongly believe that the Ambesh maneuver should be used in all patients undergoing subclavian vein catheterization.
*King George’s Medical University, Lucknow, India. dksingh_kgmu@rediffmail.com
