It seems intuitively obvious that a signed informed consent is mandatory before CVC insertion, but in clinical practice, it is not that straightforward. CVC insertions in the ICU are extremely common, occur at all hours of the day, and may be crucial for early and appropriate resuscitation and commencement of care. Many critically ill patients, especially in urban settings, have no available family members or legal net of kin. Obtaining informed consent for these patients may inappropriately delay completion of the procedure and impact quality of care. Because of these considerations, there is no uniform clinical or legal opinion regarding the necessity of individual informed consent prior to all CVC insertions or other ICU procedures [25]. Some institutions have dealt with this matter by developing a single general “consent form for critical care” that is signed one time for each individual ICU admission and covers all commonly performed bedside procedures. A recent review reported that 14% of all surveyed ICUs used such a consent form, and overall consent practice varied widely. In general, providers in medical ICUs sought consent for CVC insertion more often than providers in surgical ICUs [25]. Given the lack of agreement on this topic, it seems prudent to make a few recommendations: (1) Written informed consent should be obtained prior to all truly elective CVC insertion or other procedures (2). Whenever possible, competent patients or legal next of kin of incompetent/incapacitated patients should be thoroughly informed of the indications, risks, and benefits of emergency CVC insertion prior to the performance of the procedure. If informed consent is not possible prior to CVC insertion, then consent should be obtained as soon as possible after completion of the procedure. A signed consent form
is always preferable, but sometimes not feasible. Oral consent should be documented in the procedure note by the person obtaining assent. (3) Emergent CVC placement should not be delayed inappropriately by efforts to obtain consent—oral or written. Patients and family should be told as soon as possible after insertion why the CVC was required. (4) A general consent form that is signed one time as close as possible to ICU admission is a reasonable way to try and inform patients of the benefits/risks of procedures without incurring unnecessary delays or consumption of clinical time. This form can also serve as a useful reference for patients and families of all the various common procedures that are performed in the ICU. (5) Finally, it is good practice to document the practice that is used in the ICU “Policies and Procedures” book and the rationale for it.

Many patients requiring CVC have an unstable airway or are hemodynamically unstable. These considerations should impact preparation and choice of site. For example, many patients are claustrophobic and will not tolerate their face being covered; others who are dyspneic will not tolerate lying flat. In our experience, significant physiologic decompensation or even “code blues” may occur during CVC placement because the operator is focused on establishing access and/or interprets the silent patient as one who is having no problems. Every patient should be specifically assessed prior to CVC regarding their positioning, airway, and hemodynamic stability. On more than one occasion, we have placed a femoral catheter because a patient could not lie flat or needed emergency venous access for endotracheal intubation. Once the patient is stabilized, the appropriate site/catheter can then be inserted under less unstable/rigorous conditions.

Ultrasound enables immediate identification of anatomic variation, confirmation of vessel patency, and direct visualization of the needle entering the vessel. The difference between vein and artery can be determined by compressibility, shape, Doppler flow, and increasing size with the Valsalva or other maneuvers. Veins are usually ovoid in shape, completely compressible, and have thin walls; in contrast, arteries are circular, difficult to compress, and have thick walls.

When performing ultrasound, the same general technique is followed regardless of the site of puncture [6]. A quick, nonsterile survey should be made with the vascular probe to quickly identify the presence of a suitable vein for catheterization. After sterile preparation of the patient and site, the vascular probe should be used with a sterile probe cover kit. This kit contains a sterile sleeve, sterile jelly, and rubber bands. To apply the sterile sleeve, have an assistant place nonsterile jelly inside the sleeve and then place probe in the sleeve. Extend the sleeve over the cord and fasten the sleeve with rubber bands. One band should be fastened toward the head of the probe to ensure the jelly remains in place for optimal imaging. Sterile jelly is then applied to the tip of probe on the outside of sleeve.

The target vessels may be visualized using a transverse or longitudinal view. The transverse approach is technically easier than the longitudinal approach and is the best approach for beginners. The transverse view allows identification of the target vein in relation to the artery, which helps decrease risk of unintentional puncture of the artery. Once identified, the vein should be centered underneath the probe. An 18-gauge needle should slowly be advanced with the skin puncture site proximal to the probe, so that vessel puncture is directly visualized. With this approach, the needle traverses diagonally across the ultrasound plane and appears as single bright echogenic foci on ultrasound image. Needle position may be better ascertained by slightly moving the needle back and forth displacing the surrounding soft tissue and possible tenting of vessel wall. It is important to note the depth of the vessel on the ultrasound image to be mindful of how far to penetrate safely with the needle. The return of blood flow confirms intravascular placement of the needle tip, and CVC placement may proceed in the usual fashion. It is good practice to confirm guidewire placement within the vein as well. The longitudinal approach gives more information but is more difficult. When using the longitudinal approach, the plane of the ultrasound and of the needle must be perfectly aligned and is best for one operator to be holding both probe and needle. First, the vein artery must be visualized using the transverse view. The probe should then be turned 90 degrees to image just the vein in the long-axis view. Enter the skin just adjacent to the probe at a 45-degree angle. The needle and needle tip can be directly viewed as it is advanced through the vessel. Once in place, advance the guidewire under direct visualization.

Availability of a mobile catheter cart that contains all necessary supplies and that can be wheeled to the patient’s bedside is good practice and likely reduces overall catheter infection rate by decreasing breaks in sterile technique [26]. In our experience, the mobile cart is also an excellent way to standardize all catheter insertions, facilitate communication of procedural tasks (such as use of a time-out), and allow for staff to timely complete mandatory forms.

Catheter tip location is a very important consideration in CVC placement. The ideal location for the catheter tip is the distal innominate or proximal superior vena cava (SVC), 3 to 5 cm proximal to the caval–atrial junction. Positioning of the catheter tip within the right atrium or right ventricle should be avoided. Cardiac tamponade secondary to catheter tip perforation of the cardiac wall is uncommon, but two thirds of patients suffering this complication die [27]. Perforation likely results from vessel wall damage from infused solutions combined with catheter tip migration that occurs from the motion of the beating heart as well as patient arm and neck movements. Migration of catheter tips can be impressive: 5 to 10 cm with antecubital catheters and 1 to 5 cm with IJV or SCV catheters [28,29]. Other complications from intracardiac catheter tip position include provocation of arrhythmias from mechanical irritation and infusion of caustic medications or unwarmed blood [30].

Correct placement of the catheter tip is relatively simple, beginning with an appreciation of anatomy. The caval–atrial junction is approximately 16 to 18 cm from right-sided skin punctures and 19 to 21 cm from left-sided insertions and is relatively independent of patient gender and body habitus [31,32]. Insertion of a standard 20-cm triple-lumen catheter to its full length frequently places the tip within the heart, especially following right-sided insertions. A chest radiograph should be obtained following every initial CVC insertion to ascertain catheter tip location and to detect complications. The right tracheobronchial angle is the most reliable landmark on plain film chest X-ray for the upper margin of the SVC, and is always at least 2.9 cm above the caval–atrial junction. The catheter tip should lie about 1 cm below this landmark, and above the right upper cardiac silhouette to ensure placement outside of the pericardium [33].

Large-vessel perforations secondary to CVCs are uncommon and often not immediately recognized. Vessel perforation typically occurs 1 to 7 days after catheter insertion. Patients usually present with sudden onset of dyspnea and often with new pleural effusions on chest radiograph [34]. Catheter stiffness, position of the tip within the vessel, and the site of insertion are important factors causing vessel perforation. The relative importance of these variables is unknown. Repeated irritation of the vessel wall by a stiff catheter tip or infusion of hyperosmolar solutions may be the initiating event. Vascular erosions are more common with left IJV and EJV catheters, because for anatomical reasons the catheter tip is more likely to be positioned laterally under tension against the SVC wall [35]. Positioning of the catheter tip within the vein parallel to the vessel wall must be confirmed on chest radiograph. Free aspiration of blood from one of the catheter ports is not always sufficient to rule out a vascular perforation.

Significant air and catheter embolism are rare and preventable complications of CVC. Catheter embolism can occur at the time of insertion when a catheter-through- or over-needle technique is used and the operator withdraws the catheter without simultaneously retracting the needle. It more commonly occurs with antecubital or femoral catheters after insertion, because they are prone to breakage when the agitated patient vigorously bends an arm or leg. Prevention, recognition, and management of catheter embolism are covered in detail elsewhere [36].

Air embolism is of greater clinical importance, often goes undiagnosed, and may prove fatal. This complication is totally preventable with compulsive attention to proper catheter insertion and maintenance. Factors resulting in air embolism during insertion are well known, and methods to increase venous pressure, such as use of the Trendelenburg position, should not be forgotten. Catheter disconnection and passage of air through a patent tract after catheter removal are more common causes of catheter-associated air embolism. An air embolus should be suspected in any patient with an indwelling or recently discontinued CVC who develops sudden unexplained hypoxemia or cardiovascular collapse, often after being moved or transferred out of bed. A characteristic mill wheel sound may be auscultated over the precordium. Treatment involves placing the patient in the left lateral decubitus position and using the catheter to aspirate air from the right ventricle. Hyperbaric oxygen therapy to reduce bubble size has a controversial role in treatment [37]. The best treatment is prevention which can be effectively achieved through comprehensive nursing and physician-in-training educational modules and proper supervision of inexperienced operators [38].

Central venous access in the patient with a bleeding diathesis can be problematic. The SCV and IJV routes have increased risks in the presence of coagulopathy, but the true risk is frequently overestimated and it is not known at what degree of abnormality it becomes unacceptable. A coagulopathy is generally defined as an international normalized ratio (INR) greater than 1.5 or platelet count less than 50,000. Although it is clear that safe venipuncture is possible (even with the subclavian approach) with greater degrees of coagulopathy [39], the literature is also fraught with case reports of serious hemorrhagic complications. In patients with severe coagulopathy, IJV cannulation under ultrasound guidance has proven to be very safe, while the FV offers a viable alternative for general-purpose venous access. In nonemergent patients, peripherally inserted central venous catheters (PICC) can be used.

Catheter-related thrombosis is very common but usually of little clinical significance. The spectrum of thrombotic complications includes a fibrin sleeve surrounding the catheter from its point of entry into the vein distal to the tip, mural thrombus, a clot that forms on the wall of the vein secondary to mechanical or chemical irritation, or occlusive thrombus, which blocks flow and may result in collateral formation. All of these lesions are usually clinically silent; therefore, studies that do not use venography or color flow Doppler imaging to confirm the diagnosis underestimate its incidence. Using venography, fibrin sleeve formation can be documented in a majority of catheters, mural thrombi in 10% to 30%, and occlusive thrombi in 0% to 10% [40,41,42,43,44,45]. In contrast, clinical symptoms of thrombosis occur in only 0% to 3% of patients. The incidence of thrombosis probably increases with duration of catheterization but does not appear reliably related to the site of insertion. However, the clinical importance of femoral vein catheter-associated thrombosis compared to upper extremity thrombosis caused by IJ and SCV catheters is unknown [46]. The presence of catheter-associated thrombosis is also associated with a higher incidence of infection [47].

The antecubital veins are used in the ICU for CVC with PICC and midline catheters. Use of PICCs in critically ill adults is becoming increasingly important. Specialized nursing teams are now able to insert PICCs at beside with use of real-time ultrasonography and sterile technique thereby increasing safety and reducing the potential for infection. There are now triple lumen catheters that may be inserted with this approach. PICCs may be useful in ICU patients undergoing neurosurgery, with coagulopathy, or in the rehabilitative phase of critical illness for which general purpose central venous access is required for parenteral nutrition or long-term medication access (Table 2.1) [48,49]. Although many hospitals have a designated “PICC” insertion team, they may have significant work hour limitations that delay insertion of catheters and result in significant delays in delivery of care or throughput. For that reason, we believe intensivists should be familiar with the antecubital route, and as a result, the technique of percutaneous insertion of catheters using the basilic vein is described later.

The IJV has been used for venous access in pediatric and adult patients for many years but its use in some circumstances has been limited by a relatively lower rate of success due to its compressibility and propensity to collapse in hypovolemic conditions. In our opinion, ultrasound has had its greatest impact by improving the efficiency of IJV cannulation, since real-time direct visualization of the vein is easily obtained. This minimizes the impact of hypovolemia or anatomical variations on overall success, and has rendered the need for EJV catheterization almost extinct. Furthermore, under ultrasound guidance, the central approach is almost always used, and as a result, we will no longer review the anterior or posterior approaches. In general, these techniques will differ only in the point of skin puncture (Fig. 2.2), and readers are referred to previous editions of this text for a thorough description of these approaches.