Indwelling Vascular Access Devices: Emergency Access and Management

Cuffed, Tunneled Right Atrial (RA) Catheters (Broviac, Hickman, Hemocath, Leonard, Raaf)

Several cuffed, tunneled RA catheters are available, each with differences tailored to specific applications ( Fig. 24.1A ). The Broviac (Bard Peripheral Vascular, Tempe, AZ) is an all-Silastic, single-lumen catheter, with a 1.0-mm internal diameter (ID). It is 90 cm long with a thin intravascular segment (55 cm). The Hickman (Bard), also a Silastic catheter, has a 1.6-mm ID. It allows more frequent blood sampling without jeopardizing luminal patency. Single-, double-, and triple-lumen variations exist. Hemocath/Permacath has the largest bore of the RA catheters, with an ID of 2.2 mm. Quinton Instrument Company (Bothell, WA) manufactures these catheters for HD, plasmapheresis, long-term nutritional support, and pain control. The main advantage of these catheters is that they can be used immediately as a bridge to longer-term devices. They are not recommended for long-term access in patients undergoing dialysis if an AV fistula or graft ( Video 24.2 ) is possible, as long-term dialysis with tunneled catheters has been associated with an increased risk for death, a five- to tenfold increase in the risk for infection, and a decreased likelihood of adequate dialysis.

Nonemergency insertion of RA catheters is typically done in an operating room or interventional radiology suite. The device is introduced via the arm, upper anterior chest wall, or neck, and tunneled subcutaneously to enter the superior vena cava (SVC) system via the cephalic, subclavian, internal, or external jugular vein ( Fig. 24.2 ), advancing the distal tip of the flexible catheter to the distal SVC or into the mid-RA area. The subcutaneous tunnel isolates the venous puncture site from the skin and decreases the potential for bacterial contamination. Dacron cuffs (one near the venous entrance site and one near the skin exit site) anchor the catheter and are believed to inhibit colonization of the SVC by skin organisms. However, no study has been able to support this belief. Advantages of an RA catheter include ease of insertion and use, minimal interference with patient activity, low incidence of major complications or unintended dislodgment, ease of removal, and potential repair via a kit. Disadvantages include the need for regular maintenance and the potential for unacceptable cosmesis.

Groshong Catheter

In contrast to the Broviac and Hickman catheters, the Groshong (Bard) catheter has slit-like openings just proximal to the end of the intravascular portion of the catheter (see Fig. 24.1B ). This functions as a one-way valve to stop backbleeding and prevent air entry and embolism from the negative intrathoracic pressure. This feature obviates the need to use a heparin lock (saline may be used). In addition, external catheter clamping is not necessary. Disadvantages are its high cost and requirement for pressurized infusion systems.

TIVADs/Ports

(Port-A-Cath, Proport, Infuse-A-Port, Mediport)

Since 1983, implanted ports have become the mainstay for long-term cancer therapy. TIVADs are tunneled RA catheters, but they differ from Broviac and Hickman catheters in that they have a subcutaneous titanium or plastic portal with a self-sealing septum ( Fig. 24.3 ) that may be accessed by puncturing a specially designed needle (90-degree angled Huber needle) through intact skin ( Fig. 24.4 ). Cosmetically, they are superior to external tunneled catheters, require less maintenance, and afford patients greater freedom of movement and activities, such as swimming or bathing.

TIVADs may be inserted on an outpatient basis under local anesthesia via a subcutaneous tunnel or open cutdown. The cutdown technique offers potential speed (mean placement time, 15 minutes), safety (negligible risk for pneumothorax), and avoidance of early and late complications. Placement is typically in the nondominant arm, with the portal in the upper part of the arm or chest, unless a vein is occluded or radiation therapy is planned on that side.

Disadvantages of this type of device include increased cost, the need for a specific non-coring Huber access needle, and the small gauge (20 to 22) of the access needle, which limits fluid infusion rates. Typical TIVADs do not have the capability to withstand the pressure required for power injection. Power­Port by Bard is an implantable port that allows for venous access and power injections required for contrast-enhanced computed tomography scans.

Peripherally Inserted Central Catheter (PICC) (Nontunneled, Noncuffed)

PICC lines are centrally placed lines that were first described in the 1970s and originally developed for the neonatal population. Subsequently, their use expanded into the adult arena for prolonged antibiotic therapy, IV fluids, chemotherapy, TPN, and delivery of medications that are irritating to peripheral vessels. PICCs ( Fig. 24.5 ) are made of two substances, either polyurethane (Intracath) or silicone (Intrasil), are radiopaque, and measure 50 to 60 cm in length, with an outside diameter of 2 to 7 Fr. The catheter may have a single- or double-lumen configuration and can be open- or close-ended or valved (e.g., Groshong). An open-ended PICC cannot prevent feedback of blood into the catheter and therefore must be flushed one or more times daily with heparinized saline. The Groshong valve reduces backup of blood into the catheter and therefore requires flushing as infrequently as once a week.

Selection of the device should be based on the number of lumens necessary for therapy. Selection of the access site depends on many factors including: the suitability of target vessels, body habitus, handedness, ability to manage self-care, comorbid conditions, desired infusion rate, number and compatibility of concurrent infusions, infusate characteristics, and the estimated duration of therapy. Infusate that is hyperosmolar (e.g., TPN) or vesicant requires rapid dilution. Accordingly, the tip must be in the SVC, where the estimated flow rate is 2000 mL/min. PICC lines are most frequently placed in the superficial veins proximal to the antecubital fossa (usually the basilic or cephalic vein) ( Fig. 24.6 ). However, they may also be placed via a transhepatic or translumbar approach when the SVC is thrombosed or occluded.

Advantages of PICC lines include usefulness in a wide variety of clinical situations, ease of placement, and ease of use and maintenance. They do not require surgical insertion and may be placed in an outpatient setting. A PICC line is an excellent vehicle for medium- to long-term IV therapy. With proper care, PICCs can remain in place for long periods, even months to years. To remove a PICC line, simply withdraw it from the vein, and apply pressure and a sterile bandage.

Midline Peripheral Catheters

Midline catheters are often confused with PICC lines. They are also placed peripherally in the superficial veins of the antecubital fossa or upper part of the forearm. They differ from PICCs in that they are peripheral, not central catheters. Midlines are typically shorter (20 cm), with the tip terminating near the axillary vein. Placement above the axillary vein results in a higher risk for thrombosis . They are designed for short- to medium-term use, a shorter period than with a PICC. Because midline catheters do not enter the central circulation with high flow, delivery of medication and infusion types are limited, and routine blood withdrawal is not recommended. Differentiating between these two catheters in situ may be difficult because their outward appearance is similar. Obtaining an x-ray film for visualization of tip placement will help in determining catheter type.

Hemodialysis (HD) IVADs

Vascular access for dialysis, which is often referred to as the Achilles heel of patients with end-stage kidney disease, remains problematic. From the moment that the first access is created, an ongoing process is started that will end with the loss of all access sites if the patient survives long enough. Clinical practice guidelines of the National Kidney Foundation—Disease Outcomes Quality Initiative (NKF-DOQI) recommend early construction of an AV fistula and avoidance of catheters for permanent or prolonged vascular access, except in rare circumstances where AV graft or fistula formation is not feasible because of a lack of acceptable anatomic sites or limited life expectancy of the patient. However, close to 70% of patients in the United States begin dialysis with a central catheter because a well-developed AV fistula is not available at the time of the initial catheter requirement.

Temporary Dialysis Catheters (Quinton, Mahurkar, Tessio, Vascath, Uldall)

Temporary vascular access catheters ( Fig. 24.7 ) are used for emergency HD or for temporary HD access if a more permanent dialysis route (AV fistula or graft) is not available, or has recently been placed and has not matured yet. The advantage of tunneled catheters is the ability to provide immediate access or temporary access while a more permanent structure matures, but this carries an increased long-term risk for infection, dysfunction, and central venous stenosis. The majority of bacteremia episodes in patients undergoing HD are caused by HD catheters, with an approximate 20% to 25% risk over the average duration of use.

These large-bore catheters allow the necessary blood flow rate of 300 mL/min for dialysis. The Quinton catheter has two ports, one to deliver the patient's blood to the dialysis machine, and another to return the blood to the patient's circulation (see Fig. 24.2B ). These catheters are placed in a central vein, either the internal jugular, subclavian, or femoral. The right internal jugular approach is preferred, even if permanent access is to be created on the right side, because it has the lowest thrombosis rate. The NKF-DOQI recommends avoiding the subclavian vein unless no other options exist or the ipsilateral arm has no more permanent access sites. For patient comfort a special 180-degree catheter can be used ( Fig. 24.8 ). There are two avenues to place this catheter: percutaneous or surgical. Emergency percutaneous placement may be performed by the emergency clinician at the bedside. Using sterile technique and after injection of a local anesthetic, insert the catheter by following the same procedure for placing a central line into one of the central veins.

The second technique uses a slightly larger catheter (Quinton, Hickman) and is performed in the operating room under local anesthesia, with or without general sedation. This catheter is placed in much the same fashion as the tunneled RA catheters described previously. Surgically implanted catheters are preferred if more than temporary use is anticipated because the risk for infection is decreased and they can be used for a longer time.

Chronic HD Vascular Access

The goal of chronic HD vascular access is to provide safe, effective, and repeated easy access to the circulation. The three principal types of access are native AV fistulas, synthetic grafts, and double-lumen tunneled cuffed catheters (described previously). Fistulas and grafts are collectively termed shunts. It may be difficult to distinguish a fistula from a graft by gross inspection alone. Hints to identification include location and shape. Grafts are rarely placed in the forearm, which is the preferred site for fistulas. Fistulas tend to be more tortuous and serpentine, whereas synthetic grafts are straighter or C shaped.

HD access types differ in failure rates, patency, complications, and other morbidity. Both grafts and fistulas are subject to vascular perturbation and integrity issues from the high flow rates and repeated access. Grafts are subject to pseudoaneurysms when there is a breach in the integrity of the graft and they are more likely to rupture. Fistulas, also subjected to bulging of the vessel walls, may form a true aneurysm. Dilated veins in a fistula can simulate an aneurysm. Both types of vascular deformities can rupture. Multiple defects may require a replacement access.

Both fistulas and grafts must mature before they can be used for HD, a process that may take several weeks to several months. HD is often performed via a Quinton catheter during this hiatus, so a patient in the emergency department (ED) with both a catheter and a shunt either has a nonfunctioning fistula or graft, or an access site that is still immature.

Complications common to both grafts and fistulas are thrombosis, infection, steal syndrome, venous hypertension, bleeding ( Video 24.3 ), seromas, and aneurysms ( Fig. 24.9 ). Overall, grafts are more likely to experience infection and thrombosis requiring thrombectomy or require other types of access intervention.

Arterial Venous (AV) Fistulas

In general, fistulas are preferred over grafts because of superior long-term patency and lower complication rates. An AV fistula is a direct subcutaneous anastomosis of an artery and vein without prosthetic material and is the preferred means of vascular access for HD (see Fig. 24.9 ). The minimum time for fistula maturation is at least 1 month, much longer than required for graft cannulation.

Historically the percentage of patients with AV fistulas fell well below the recommended goal, with most patients receiving AV grafts or long-term vascular access catheters. In recent years there has been a concerted effort to increase the utilization of AV fistulas, most notably the National Kidney Foundation's Fistula First Breakthrough Initiative. The most recent data from the Dialysis Outcomes and Practice Patterns Study (DOPPS) show that from 2002 to 2011 AV fistula use in the United States almost doubled (32% to 62%), and AV graft use fell by more than 50%. Use of an autogenous fistula is associated with the longest period of patency with relative freedom from thrombotic and infectious complications.

Fistulas have a 15% rate of primary failure, defined as being unable to provide reliable access as a result of early thrombosis or failure to mature. However, once a fistula matures, long-term patency is high (48% of AV fistulas versus 14% of AV grafts at 5 years), with low infection rates relative to grafts.

An autogenous AV fistula is constructed by anastomosing an artery to a vein (see Fig. 24.9 ), preferably a nearby one. Various configurations are possible, but AV fistulas are typically an end-to-side, vein-to-artery anastomosis. The radial-cephalic (Brescia-Cimino) fistula in the forearm is the most frequently used ( Fig. 24.10 ), with the brachial-cephalic, brachial-basilic, and rarely the proximal part of the thigh being alternatives. Over time, the venous portion of the shunt is subjected to high pressure, and the fistula becomes arterialized (hypertrophied and dilated), which renders it suitable for repeated vascular access. Full epithelialization of the shunt does not occur for 3 to 6 months, thus necessitating anticipatory placement as renal function worsens.

AV Grafts

If a forearm radiocephalic fistula cannot be constructed or has failed, an AV bridge graft using a donor vein or synthetic material is a well-accepted alternative. Several synthetic materials are used for grafts. Grafts can usually be cannulated earlier than fistulas, often within weeks of placement. Polytetrafluoroethylene (PTFE) is most commonly used, but takes 3 weeks to mature. An available polyurethane graft (Vectra [Bard]) has the ability to be accessed within 24 hours. A standard graft is 6 to 8 mm in diameter and usually positioned in a U-shaped subcutaneous tunnel in the forearm. The graft is attached by end-to-side anastomoses to the brachial artery and antecubital vein. If no suitable antecubital vein is available, a straight bridge graft between the brachial artery and either the axillary or the basilic vein is often used. Multiple configurations are possible ( Fig. 24.11 ). A jump graft between opposite extremities with creation of a loop across the chest or anastomosis of the axillary artery to the iliac vein is a possibility, if all other sites have been exhausted.

When compared with AV fistulas, AV grafts have a significantly higher incidence of thrombosis, infection, pseudoaneurysm formation, and limb loss. The risk for infection with HD grafts is approximately 10% over prolonged use and 1% with HD fistulas. Graft infection requires complete excision to eradicate an infection of the foreign material, whereas fistula infections may resolve with IV antibiotic use. AV grafts have a low primary patency rate (31% at 1 year according to one study). However, they have a low incidence of aneurysm formation and are comparatively easy to revise. The estimated life span of an AV graft in clinical practice is often less than 2 years.

Accessing Long-Term Venous Access Catheters

To access the catheter (with the exception of Groshong catheters, which have backflow valve protection), first clamp it to prevent air embolism. Patients usually carry their own clamps, but a hemostat with teeth will suffice in an emergency. In this case, wrap sterile tape or tubing around the teeth of the hemostat. Remove the cap of the catheter and withdraw any mobile clots with a syringe. Remove approximately 3 to 5 mL of blood and then attach a 10-mL syringe to a single-dose vial of sterile normal saline. Smaller syringes generate greater amounts of pressure for infusion, which can lead to increased intraluminal pressure and rupture of the catheter. Inject 3 to 5 mL of solution and then again withdraw it to ensure patency. Flush again with saline. More pronounced infusion might be necessary to ensure the patency of Groshong catheters.

To accomplish phlebotomy, withdraw the dead space solution, reclamp it, and use a separate syringe to remove the desired amount of blood. If clots are withdrawn, continue withdrawing blood until it is clot free. Inject bolus medications and infuse IV solutions through the catheter, and clamp it whenever it is unattached. Do not administer medications concurrently that are known to be incompatible when mixed (e.g., calcium and bicarbonate), even through separate ports of multilumen catheters. Deliver a 5-mL normal saline flush between medications through a 10-mL syringe. On completion of either blood withdrawal or medication infusion, inject 3 to 4 mL of saline to flush it and then inject 3 to 5 mL of heparin (1000 Units/mL). Clamp the line and reposition the cap. Note that 1000 Units/mL of heparin should be used; less concentrated solutions may promote clotting. Do not inject larger amounts because it can systemically heparinize the patient. Groshong catheters need not be flushed with heparin but instead may be flushed briskly with 5 to 10 mL of saline. Multilumen central catheters have one port for each lumen, so access each one in the same manner. After antiseptic preparation, gain access either by inserting a needle or a syringe into the protective cap or by removing the cap entirely. Flush with 5 mL normal saline or sterile water, and verify backflow before all subsequent procedures. Perform phlebotomy through the proximal lumen to prevent mixing with medications being delivered through the other ports. Deliver IV infusions in similar fashion, and inject a normal saline flush between medications. Following the procedure, flush 3 to 5 mL of heparin (1000 Units/mL) through each port.

Accessing TIVADs

The procedure for accessing TIVADs is unique because these devices are not external. Instead, a circular reservoir (cylinder) lies subcutaneously on the anterior chest wall. First, palpate the cylinder and then prepare the overlying skin with povidone-iodine solution. Fill a 10-mL syringe with normal saline and attach it to connecting tubing. Attach this to a 19- to 22-gauge, 90-degree tapered (Huber) needle. The Huber needle is a specialized needle designed for use with TIVADs to prevent damage to the portal septum. It has a 90-degree bend with a slightly curved tip and the opening on the side rather than on the end. Most importantly, the Huber is a noncoring needle. This avoids damage to the Silastic septum and allows up to 2000 punctures. Do not access the TIVAD with a standard needle unless an arrest is in progress and a Huber needle is not immediately available. Apply a clamp to the connecting tubing whenever the system is open. Expel the air and insert the Huber needle through the septum of the reservoir. Insert the needle slowly and steadily through the diaphragm until it contacts the back of the reservoir. Be aware that although incomplete perforation of the septum will block flow, substantial pressure may also damage the back of the device and bend the tip of the needle. Remove the clamp slowly and inject 5 mL of solution to ensure patency. If patency is not easily demonstrated, consider using alteplase (recombinant tissue plasminogen activator) as a fibrinolytic agent for catheter occlusion.

Once the solution has been injected, apply gentle negative pressure to demonstrate backflow of blood. Stabilize the Huber needle by building a 4- × 4-inch gauze pad about the needle and further reinforce it with 2.54-cm (1-inch) silk tape. First, remove 8 to 9 mL of blood with a separate syringe and waste it, and then perform phlebotomy through the extension tubing. If necessary, deliver IV solutions through extension tubing, but remember that the rate of flow will be limited by the smaller radius of the Huber needle. Deliver a 5-mL sterile normal saline flush between medications. Complete the procedure with a 3- to 5-mL heparin (1000 Units/mL) flush and remove the Huber needle.