See the relevant sections in the ‘Complications’ section under ‘Peripheral cannulation’ above.

See ‘Phlebitis’ in the ‘Complications’ section under ‘Peripheral cannulation’ above.

A venous thrombosis is a clot of blood that can be present at the tip of a catheter or can surround the catheter, for example a thrombosis in the upper arm caused by the presence of a PICC (Dougherty [128]). A SVC thrombus occurs when a catheter chronically rubs against the wall of the SVC, provoking a thrombosis at the site, and is often associated with a fibrin sheath. In order for a thrombosis to develop, three factors are required, known as Virchow's triad:

The incidence of thrombotic catheter disfunction can be 3–7% (Dougherty [128]), with rates in PICCs normally ranging from 4% to 5% (Aw et al. [14], Chopra et al. [77], [78], Lobo et al. [274]). A review of the literature by Fallouh et al. ([142]) showed that the incidence could be as high as 75%. The risk is highest with suboptimal tip position in the high SVC and the brachiocephalic vein, and there are lower risks with small‐bore catheters, basilic rather than cephalic vein and a secure fixation (Bodenham and Simcock [44], Chopra et al. [77], Garrino [169]). Thrombosis may initially present as partial withdrawal occlusion, inability to aspirate blood or resistance to flushing (Bodenham and Simcock [44]). Symptoms can be very acute or vague. The majority of cases of catheter‐related thrombosis (two‐thirds) are asymptomatic, which can make diagnosis difficult (Wall et al. [459]). When symptoms are present, the patient will usually complain of pain in the area (such as the arm or neck); oedema of the neck, chest and upper extremity; periorbital oedema; facial tenderness; tachycardia; shortness of breath and sometimes a cough; signs of a collateral circulation over the chest area; jugular venous distension; and/or discoloration of the limb (Bodenham and Simcock [44], Qinming [378], Wall et al. [459]).

Thrombosis can be prevented by correct placement of the tip in the lower third of the superior vena cava, cavo‐atrial junction, inferior vena cava or right atrium (Bodenham and Simcock [44]), monitoring the catheter's function and flushing with pulsatile positive pressure flush (Dougherty [128], Mayo [301]). The use of prophylactic anticoagulants, such as low‐dose warfarin, has been shown to be of no apparent benefit (Couban et al. [91], Wall et al. [459], Young et al. [479]). Full anticoagulation may be necessary if the patient has had previous thromboembolic events (Bishop [37], Dougherty [128], Wall et al. [459]).

If a thrombosis is suspected, the patient should have a Doppler ultrasound. A venogram should be performed if suspicion of thrombosis is high despite a negative Doppler ultrasound (Dougherty [123], Wall et al. [459]). Treatment can be either catheter removal or leaving the CVAD in situ and commencing anticoagulation, as thrombolytic therapy has proved successful in extreme cases and is often dependent on the size of the clot and the area of impaired circulation (Bodenham and Simcock [44], Gorski et al. [182], Wall et al. [459]). The current recommendations state that if the catheter is still required and functioning well, it does not need to be removed provided that it is well positioned, is infection free and demonstrates good resolution of symptoms on surveillance (Debourdeau et al. [111], Wall et al. [459]). If the catheter is to be removed, patients will be prescribed injectable low‐molecular‐weight heparin for 6 weeks to 6 months and up to 3 months following removal (Gorski et al. [182], Wall et al. [459]) (see Figure 17.32).

Infection is one of the most common and most serious complications associated with a central venous catheter (Dougherty [123]). Colonization by micro‐organisms primarily occurs via two mechanisms: extraluminal and intraluminal (Scoppettuolo [406]). The catheter provides the ideal opportunity for micro‐organisms to either track along the outside of the catheter (extraluminal) or be administered via the hub (intraluminal) internally into the central venous system. Infections can occur locally on the skin at the insertion site, in the skin tunnel or port pocket, or systemically (Wilkes [472]). Signs of infection at the insertion site include erythema, oedema, tracking along the length of the catheter, tenderness at the site, exudate (such as pus) and offensive smell (Wilkes [472]).

Septicaemia is a systemic infection that is usually characterized by pyrexia, flushing, sweating and rigors (rigors occur particularly when the catheter is flushed) (Wilkes [472]). The aim of extraluminal prevention is to lower the microbial load present on the patient's skin and on the hands of people who manipulate the catheter insertion site (i.e. via effective hand washing, skin antisepsis at insertion and after insertion, good aseptic non‐touch technique (ANTT) for dressing changes and catheter maintenance). Intraluminal prevention focuses on good ANTT, and proper disinfection of the hub or needle‐free connectors (Scoppettuolo [406]). Further means of preventing catheter‐related bloodstream infections (Scoppettuolo [406]) include:

If a patient develops symptoms of an infection, then site swabs should be taken along with blood cultures (from the device and peripheral veins). The needle should be removed from the port if there is a skin infection and the port should not be reaccessed until the skin infection has cleared (Wilkes [472]). Depending on the clinical condition of the patient, the CVAD may be removed and/or intravenous antibiotics may be commenced (Gorski et al. [182]).