Catheter Issues





Introduction


Central venous catheters can be placed for a number of indications, including hemodialysis, chemotherapy, parenteral nutrition, and antibiotics. The intended duration of the catheters can be categorized as acute or chronic. While there is no defined time frame to differentiate acute from chronic, catheters for acute use are generally intended to remain in-dwelling in the patient for 4 to 6 weeks, whereas chronic catheters can remain in place for 12 months or more. The most common acute catheters include nontunneled hemodialysis and peripherally inserted central catheters (PICC). The acute catheters are characterized by a lack of a subcutaneous cuff near the skin exit site. The most common chronic catheters include tunneled hemodialysis, Hickman, Broviac, Groshong, (CR Bard, Tempe, AZ) and port-a-cath. The chronic catheters all have a subcutaneous cuff near the skin exit site, with the exception of the port-a-cath, which is entirely subcutaneous.


Regardless of the catheter type, the initial insertion of the catheter occurs in the same manner, with the exception of the PICC. The PICC is inserted in the upper arm either through the basilic vein or through a brachial vein. The remainder of the catheters are inserted preferentially in the internal jugular or the subclavian vein, followed by the femoral vein.


The preferred access site for any central venous catheter is the right internal jugular vein. The vein takes a straight path down to the superior vena cava, providing the path of least resistance for the wire, dilators, and catheter and minimizing the risk of kinking of the catheter. The internal jugular vein is preferable to the subclavian vein because it can be visualized easily with ultrasound (US). Additionally, while there is still a risk of central venous stenosis/occlusion with internal jugular catheters, the risk is less than with subclavian vein catheters.


A recent Cochrane review demonstrated that use of US in central venous catheter insertion reduced the rate of total overall complications by 71%. The number of participants with an inadvertent arterial puncture was reduced by 72%. A sterile-covered US probe should first be used to scan the course of the internal jugular vein in the neck and confirm its patency. Placing the patient in the Trendelenburg position will cause the vein to dilate, as well as reduce the risk of air embolism. The internal jugular vein is classically described as running lateral to the carotid artery and adjacent to it. However, variations in the anatomy are common and the relative position of the vein to the artery may vary through its course. The vein can be anterior, lateral posterior, or directly posterior to the artery. The course of the jugular vein in the neck should be imaged. A segment of the vein that is adjacent to the carotid artery ( Fig. 41.1 ), and not superficial or deep to the artery ( Fig. 41.2 ), is the preferred area for puncture.




Fig. 41.1


Duplex image demonstrating internal jugular vein ( IJV ) adjacent to common carotid artery ( CCA ).



Fig. 41.2


Duplex image demonstrating internal jugular vein ( IJV ) on top of common carotid artery ( CCA ).


Direct visualization of the needle entering the internal jugular vein, using US is the most effective way to avoid puncture of the carotid artery. Despite this care, the carotid artery can still be punctured through the internal jugular vein in the process of exchanging the US probe for the wire and threading the wire into the needle. During this process, the needle tip can be inadvertently advanced into the carotid artery through the jugular vein. The risk of this can be minimized by holding the needle firmly between the thumb and forefinger and stabilizing the heel of the hand and the remaining fingers against the patient. In addition, having the guidewire plastic loop secured to the drape by an Edna clamp allows rapid exchange between the US probe and wire, minimizing needle movement. After the wire has been inserted through the needle into the vein, the placement of the wire in the vein should be confirmed using US, either in the transverse or longitudinal orientation, to visualize the path of the wire. In addition, fluoroscopy can be utilized to confirm the position of the wire and that it is not crossing the midline, which would indicate possible arterial puncture. The wire should be to the right of the mediastinum, indicating access into the superior vena cava (SCV) and into the inferior vena cava (IVC).


A micropuncture 21-gauge needle and 0.018″ guidewire is recommended to make the initial puncture of the internal jugular vein. In the event that the carotid artery is inadvertently punctured with the micropuncture needle, the needle can be removed leaving a very small arteriotomy that will seal by holding pressure for 5 minutes in a patient with normal coagulation parameters. In patients who are hypotensive or poorly oxygenated, it may be unclear whether an arterial puncture was accessed, as a result of lack of return of bright red, pressurized blood. If there is concern for an arterial puncture, the 5-French coaxial sheath from the micropuncture set can be placed and the pressure can be transduced through the sheath to see whether the waveform is arterial or venous. A blood gas analysis of a sample from the sheath can also be sent to determine whether the values are consistent with an arterial or venous blood gas. Another option is to connect the sheath to a length of extension tubing and hold the tubing straight up; in patients with relatively normal hemodynamics, venous blood will not rise against gravity, whereas arterial blood will continue to rise through the tubing, eventually overflowing.


The major risk of leaving a catheter in the carotid artery is thrombus formation on the catheter and embolization of the thrombus into the brain. There are few data regarding the natural history of inadvertent catheterization of the carotid artery. In a survey of 45 vascular surgeons, most agree that if the injury is recognized in <4 hours, the catheter can be removed and pressure applied. In this instance, 30 minutes of pressure is recommended, followed by close monitoring for development of a hematoma. In the same survey, most agreed that if the injury is recognized later, because of track formation and increased risk of thrombus on the catheter, the catheter should be removed in the operating room, with open repair of the artery. Other small series have been described using percutaneous closure devices. These should be used with caution because the evidence to support their use is very limited and their use for this indication is off-label. Catheter size should also be considered when planning removal from an inadvertent arterial puncture, with larger catheters given more consideration for open surgical removal and repair.


Catheters intended for chronic use should be inserted in a procedure room under fluoroscopic guidance, for a number of reasons. The ideal position for the tip of any of these catheters is at the junction of the SVC and the right atrium. Hickman, broviac, and port-a-cath catheters are cut to the appropriate length to achieve this position. Fluoroscopic guidance is used to determine the length. Groshong and dialysis catheters are fixed lengths, and fluoroscopic guidance is used to determine the exit site for the catheter that will achieve the desired tip position.


Fluoroscopic imaging should be used to visualize wire, dilator, sheath, and catheter passage. Having the wire course through the SVC into the IVC allows extra stability of the wire without the risk of arrhythmia caused by the wire encountering the right heart chambers ( Fig. 41.3 ). Whenever any device is passed over the wire, visualization with fluoroscopy should be utilized. This is particularly true when using the left internal jugular vein. The tortuous path of the left internal jugular to the heart makes it possible for dilators and sheaths, especially the large diameter stiff devices used in placement of hemodialysis catheters, to kink the wire and to perforate the side wall of the central vein (innominate or SVC) into the pleural cavity or the mediastinum. This is most easily avoided by visualizing the manipulation of any device over the wire in its entirety and using no more than a minimal amount of pressure when advancing the device. A stiffer wire than the one included in the catheter insertion kit can facilitate passage of devices when the course is tortuous. When placing a catheter from the left jugular, the procedure should begin with US-guided access of the left internal jugular vein, as described previously, and placement of the J-wire. If the J-wire does not pass easily through the left innominate vein into the SVC and IVC, an angled catheter can be used to guide the J-wire or a Glidewire into the correct position. The wire can then be exchanged for a stiff wire, which allows adequate stiffness to support the dilators and the peel-away sheaths. The dilator only needs to be inserted to a depth to dilate the soft tissue tract. The insertion of the peel-away sheath should be visualized in its entirety with fluoroscopy to ensure the wire is not being kinked. If any increased amount of resistance is encountered, the device should be removed and a smaller diameter device should be attempted. If this is still met with increased resistance, a contrast venogram should be performed to determine whether there is a stenosis, occlusion, or other anatomic obstruction of the vein.


Apr 3, 2021 | Posted by in VASCULAR SURGERY | Comments Off on Catheter Issues
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