2 Clinical need and practice
2.1 Central venous catheters (CVCs) are inserted for a number of reasons including haemodynamic monitoring, intravenous delivery of blood products and drugs (for example, chemotherapy and antibiotics), haemodialysis, total parenteralnutrition, cardiac pacemaker placement and management of perioperative fluids. Central venous catheterisation may be required for patients undergoing cancer treatment, dialysis, or coronary or other major surgery, and for those admitted to intensive therapy units (ITUs), high dependency units (HDUs) or accident and emergency departments. It has been estimated that about 200,000 CVCs are inserted annually in the NHS.
2.2 Central venous access has traditionally been achieved by puncturing a central vein (venepuncture) and passing the needle along the anticipated line of the relevant vein by using surface anatomical landmarks and by knowing the expected anatomical relationship of the vein to its palpable companion artery. This is known as the 'landmark method'. Direct surgical access to a peripheral vein ('cut-down') is a less frequently used method for central venous access catheter insertion.
2.3 CVCs are inserted in a wide range of clinical settings by a diverse group of clinicians including radiologists, anaesthetists, nephrologists, oncologists, surgeons, general physicians and paediatricians. In the USA and increasingly in the UK, nurse specialists are also undertaking CVC procedures. The range of settings in which CVCs are inserted includes operating theatres, emergency rooms, nephrology, oncology and other wards, radiology departments, ITUs and HDUs.
2.4 Central venous access can be achieved using various puncture sites but the most common are the internal jugular vein (IJV), the subclavian vein (SV), the femoral vein (FV), and the upper limb veins (using peripherally inserted central catheters – PICCs). The choice of access route depends on multiple factors including the reason for CVC insertion, the anticipated duration of access, the intact venous sites available and the skills of the operator.
2.5 Whilst experienced operators using the landmark method can achieve relatively high success rates with few complications, in the literature failure rates for initial CVC insertion have been reported to be as high as 35%.
2.6 The most common complications associated with CVC placement are arterial puncture, arteriovenous fistula, pneumothorax, nerve injury and multiple unsuccessful attempts at catheterisation, which delay treatment. The risks and the consequences of complications vary substantially across different patient groups depending on the patient's anatomy (for example, morbid obesity, cachexia, short neck, or local scarring from surgery or radiation treatment), the circumstances in which CVC insertion is carried out (for example, for a patient receiving mechanical ventilation or during emergencies such as cardiac arrest) and co-morbidities (for example, bullous emphysema or coagulopathy). The National Confidential Enquiry into Perioperative Deaths recently reported that in a survey of over 3000 CVC procedures undertaken in the NHS, one fatality occurred as a result of a procedure-induced pneumothorax.