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Sunday, September 16, 2018

IDEAL POSITION OF TIP OF RIGHT IJV CATHETER

  • Different methods have been suggested in the literature
  • Catheter tips positioned approximately 3 cm below the right tracheobronchial angle will lie in close proximity to the atriocaval junction but will remain extracardiac in location
  • Pere P.W. studied correlation between the length of catheter inserted and patient's height and observed that catheters inserted through right IJV from midcervical point or lower puncture to Height/10cm ended in SVC, while those inserted more than Height/10 + 1cm, 47% ended in right atrium
  • Some studies argued that the catheter tip should lie above the pericardial reflection to prevent serious and potentially lethal complications like cardiac tamponade, malignant arrhythmias, placement in coronary sinus and tricuspid valve damage. The upper limit of the pericardial reflection cannot be seen on a plain chest X-ray, but it is generally accepted to be below the carina.
  • Most clinicians aim to place the catheter tip at the level of the carina with whichever formula they follow. This position carries the risk of migration, thrombosis, and malfunction.
  • A recent paper has demonstrated that a catheter with its tip positioned peripheral to the atriocaval junction was more likely to undergo internal repositioning and venous thrombosis.
  • The lower placement is preferred for left-sided IJV cannulations, because aiming the catheter tip placement above the pericardial reflection in this scenario is more likely to lead to oblique placement and abutment against the wall, which is a risk factor for perforation. It seems, therefore, that a free-floating catheter tip in a wider portion of the IJV is more important than placing the catheter above the pericardial reflection.
  • This becomes even more relevant in the light of the observations by Schuster and colleagues13that the pericardium can ascend alongside the medial wall of the SVC by up to 5 cm (mean 3 cm). Thus, catheter tip placement even 3 cm above the SVC–RA junction might not obviate the risk of tamponade in all patients.
  • Recently many studies have questioned the placement of the catheter tip in the middle SVC. They argue , emphasizing the importance of having a free-floating tip (not abutting the vessel wall) rather than its placement above the pericardial reflection. This can be achieved by placing the catheter tip in lower SVC and upper RA (target zone, within 2 cm above and 1 cm below the SVC–RA junction). In this position, the SVC is wider, meaning that the catheter tip is likely to float freely with minimal chance of abutment. Furthermore, a catheter placed in this position is amenable to confirmation by TOE.
  • Ahn and colleagues have suggested a radiological landmark-based technique for ‘parking’ the catheter within the target zone. They adjudged the depth of CVC insertion by summing [1] the distance between the sternoclavicular joint and the carina (measured offline from the chest radiograph using an internal measuring tool available on the picture archiving and communication system), [2] the distance between the point of insertion and the sternoclavicular joint, and [3] 1.5 cm. The eventual location of the CVC tip was confirmed by TOE. The authors concluded that the catheter tip was positioned more accurately and the determined depth of CVC insertion correlated better with the actual distance from the skin insertion point to the RA–SVC junction with the radiological landmark-based technique compared with Peres’ formula of central venous catheterization via the right IJV
  • N.B: Also note that from the right internal jugular and left subclavian approaches, the veins respectively take straight and gently curving trajectories to the superior vena cava. However, the right subclavian vein takes a near-right angle turn into the superior vena cava, and the left internal jugular approach incorporates two turns, one into the brachiocephalic vein and a second into the superior vena cava. These turns create potential for the venous side walls to be punctured by a dilator failing to negotiate a curve appropriately.

  • Ref: Quest to determine the ideal position of the central venous catheter tip D. K. Tempe1,* and S. Hasija, British Journal of Anaesthesia 118 (2): 148–50 (2017)



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