Published on 07/02/2015 by admin
Filed under Anesthesiology
Last modified 22/04/2025
This article have been viewed 1179 times
Michael J. Murray, MD, PhD
Central venous cannulas are frequently placed to measure central venous pressure; to administer fluid, blood products, parenteral nutrition, and vasoactive drugs; and to provide access for insertion of pulmonary artery catheters and transvenous cardiac pacing electrodes. Anesthesia providers most often cannulate the internal jugular vein (IJV), subclavian vein, or femoral vein, although the latter is not commonly used because cannulating the femoral vein increases the risk of infection. This chapter discusses placement of a cannula in the IJV.
Because the IJV is readily accessible, cannulating the IJV is easier than cannulating other sites (and is therefore associated with a lower rate of complications), resulting in the IJV being most anesthesia providers’ preferred site for obtaining central venous access. Although either side may be used, the favored approach is from the right because the angle of entry into the right IJV is close to 180 degrees (resulting in a slightly higher success rate and, therefore, a slightly lower complication rate), whereas, on the left, the angle is closer to 90 degrees. In addition, the performance of this technique on the right is easier for right-handed operators.
An important landmark in cannulating the IJV is the triangle formed by the sternal and clavicular heads of the sternocleidomastoid muscle and the clavicle. With the patient’s head turned 20 to 30 degrees to the side opposite the site of insertion, the apex of the triangle is identified by palpating the juncture of the two heads of the muscle. (Turning the head further than 30 degrees tends to compress the IJV and pulls it posteriorly and medially so that it lies behind the internal carotid artery.) The IJV lies just medial to the lateral head of the sternocleidomastoid muscle at a depth of 1 to 3 cm.
The traditional approach to cannulating the IJV was to place the patient in the Trendelenburg position, sterilize the skin with a povidone-iodine topical antiseptic, and drape the patient after drawing a line along the medial aspect of the lateral sternocleidomastoid and a line along the lateral aspect of the medial sternocleidomastoid. Where the two lines intersected was the point typically chosen to infiltrate a small amount of local anesthetic and the site for insertion of a “finder” needle that was attached to a 3-mL to 5-mL syringe. While applying negative pressure, the syringe with needle attached was advanced at a 45-degree angle to the skin toward the ipsilateral breast. If deoxygenated blood was not aspirated after penetrating to a depth of 3 to 5 cm, the needle was withdrawn and moved 1 to 2 mm medially or laterally and another attempt was made. More cephalad or caudal insertion sites were typically avoided because the carotid artery lies anterior to the IJV high in the neck and the cupola of the lung lies low in the neck. With this technique, many clinicians palpated the carotid artery before performing a venipuncture to verify the position of the artery in relationship to the IJV.
The Seldinger approach was developed 6 decades ago, with a modified version used most often today to obtain central venous access. With the traditional Seldinger technique, an 18G thin-wall needle is inserted into the IJV, a guidewire is passed, the needle is removed, a dilator is threaded over the guidewire, the dilator is removed, a cannula (or introducer) is inserted over the guidewire, the guidewire is removed, the cannula or introducer is sutured in place, and a dressing is applied. The modified version is identical except that, rather than using a bare thin-wall needle to initially access the IJV, a thinner needle with an overlying catheter is inserted, and once venous blood is aspirated, the catheter is advanced into the IJV and the needle is withdrawn. The advantage of using the modified Seldinger technique is that many consider it easier to use manometry or waveform analysis to confirm entry into the vein with a catheter than with an 18G thin-wall needle in place. Once venous pressure is confirmed, the remainder of the procedure is as described here—a guidewire is inserted through the catheter, the catheter removed, a dilator advanced over the guidewire, and so on.
Placement and maintenance of central venous cannulas is associated with a number of complications, most specifically, bloodstream infections, carotid artery puncture and cannulation, and pneumothorax.
Several clinical practice guidelines have recently been developed to decrease the morbidity (and mortality) associated with the placement of central venous cannulas. To decrease the incidence of central line–associated bloodstream infections, the Centers for Disease Control and Prevention published Guidelines for the Prevention of Intravascular Catheter-Related Infections in 2011. These guidelines recommend that inserters of central lines use surgical handwashing, maximal sterile barriers during insertion (hat and mask, sterile gloves and gown, and sterile drape—large enough to entirely cover the patient), and 2% chlorhexidine with isopropyl alcohol to sterilize the skin and that inserters allow the antiseptic to dry before inserting the catheter.
In 2012, the American Society of Anesthesiologists Task Force on Central Venous Access likewise released a report with several recommendations to decrease complications and to improve the success rate of central venous cannulation. Although the literature was ambivalent about the best site for accessing central venous circulation, the task force did indeed recommend the IJV as the optimum site for cannulation and agreed that, when clinically appropriate and feasible, central venous access should be attempted while the patient was in the Trendelenburg position. The task force made no recommendation regarding the Seldinger technique (using a wire through a thin-wall needle) versus a modified Seldinger technique (using a catheter over the needle and wire through the catheter). Instead, the task force recommended that the choice of technique be based on the clinical situation and the skill of the anesthesia provider.
The most significant change in these guidelines was the recommendation that static ultrasonography be used for identifying the IJV prior to skin puncture and that real-time ultrasonography be used for needle, wire, and catheter placement into the IJV. Documentation of intravenous placement of the needle prior to insertion of the large-bore catheter could also be by (1) manometry, (2) pressure waveform analysis, (3) venous blood gas, (4) fluoroscopy, (5) continuous electrocardiography, (6) transesophageal echocardiography, or (7) chest radiography.
Many anesthesiologists and anesthesia departments have incorporated the recommendations from the Centers for Disease Control and Prevention and the American Society of Anesthesiologists into protocols for the placement of central venous cannulas. There is little debate about the use of the Centers for Disease Control and Prevention guidelines in decreasing the risk of infection, but there is some concern about the use of ultrasonography for identifying the IJV and placing central venous cannulas during emergency situations in which an ultrasound machine may not be immediately available, or when time is so critical that the experienced clinician considers that the time required for the use of ultrasonography is not justified. Evidence from the United Kingdom indicates that, since the use of ultrasound for central venous access became widespread in 2004, the chance of success in emergency situations has decreased when using the traditional anatomic approach. This has been found to be especially true for individuals who have trained after 2004, individuals who simply do not have the experience that their predecessors had with the anatomic approach.
This conundrum is ironic because, over the last several years, the health care system has been emulating the airline industry, emphasizing training on simulators, crew resource management, and situational awareness to improve patient outcomes. Perhaps clinicians can learn from a report released by the Federal Aviation Administration in 2010 following an analysis of more than 700 incidents. The report concluded that too great a reliance on technology and not enough emphasis on fundamental skills was a hazard in the emergency incidents that were reviewed. In a similar light, clinicians could justifiably conclude that they must use their judgment to identify patients in whom they can safely use the anatomic approach for cannulation of the IJV so that they can maintain the skills and experience necessary to perform competently in emergency situations.
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