Which site is contraindicated for insertion of a central venous catheter?

Peripheral Parenteral Nutrition

When central venous catheterization is undesirable or unavailable, more dilute solutions can be infused into peripheral veins. However, even with final dextrose concentrations of only 10%, the osmolality of the dextrose/ amino acid solution is 900 to 1100 mOsm/kg water, which causes phlebitis and venous occlusion after fairly short periods. To meet energy requirements and reduce osmolality, intravenous (IV) lipid emulsions must be admixed to create total nutrient admixtures (see “2-in-1 versus 3-in-1 Admixtures”) or infused as a “piggyback.” Total volumes of more than 3 L are often required, exceeding the tolerance of some patients. For these reasons, PPN is only feasible for very short periods of time, making its benefits questionable and requiring that careful consideration be given as to whether it is appropriate for each patient. PICCs provide a welcome alternative, allowing CPN to be infused through peripherally inserted catheters.

Complications

Complications of central venous catheterization are related primarily to puncture of the central vein: Hemothorax can be life-threatening, especially in the presence of severe respiratory failure. In the presence of unilateral pathology, the catheter must be introduced on the affected side. Arterial puncture resulting in a local hematoma is not uncommon, but hematoma formation usually is without major consequences. Bedside ultrasonography can help guide the introduction of the catheter into the vein. Excessive advancement of a long catheter in a small patient can result in arrhythmias; such arrhythmias have been described with advancement of the catheter tip into the right ventricle, but this problem can be identified by the presence of an RV trace on the monitor display.

Catheter-related infections constitute the major long-term complication. Adherence to basic hygiene guidelines can decrease the incidence of catheter-related sepsis. Triple-lumen catheters may be associated with a higher incidence of catheter-related infection,10 primarily as a result of increased catheter manipulation. The use of antimicrobial-coated catheters may decrease the risk of infections11 but is associated with the threat of development of resistant organisms.12 Routine replacement of catheters after 3 to 7 days is not recommended.13

Sedation, Analgesia, and Spontaneous Breathing Trials

Endotracheal intubation, central venous catheterization, postoperative pain management, and other ICU procedures require that most patients receive sedation, analgesia, or both. Continuous infusion of sedatives and analgesics is preferable to intermittent boluses, because infusions ensure ongoing tolerance to mechanical ventilation and provide consistent relief of pain and anxiety.

Daily interruption of the infusion of sedatives and analgesics, using protocols that provide an opportunity for the patient to be observed in a less sedated state, is associated with a shorter duration of mechanical ventilation and ICU length of stay.3 A standardized approach to sedation and analgesia, combining a drug titration protocol with a sedation scale, can favorably impact ICU outcomes and resource consumption.

Discontinuation of ventilatory support is affected by sedation and analgesic infusions, and vice versa. A daily sedation vacation followed by a spontaneous breathing test increases the days of breathing without assistance and shortens ICU stay and hospital stay compared with usual sedation management plus a daily spontaneous breathing test.4 Although sedation vacations may theoretically increase the risk of self-extubation, the number of patients requiring reintubation does not appear to be increased. In the year after enrollment, patients who were treated with a “wake up and breathe” protocol, which linked daily sedation vacation periods with daily spontaneous breathing trials, had a 32% better survival rate. Based on these data, a nurse-implemented sedation and analgesic management scale with daily drug interruption and daily spontaneous breathing trials are recommended for mechanically ventilated critically ill patients.

Central Venous Pressure

There are four relative indications for central venous catheterization: inadequate peripheral venous access, central venous pressure monitoring, infusion of hyperosmolar or sclerosing substances, and a planned operative procedure with a high risk for hemodynamically significant venous air embolism. There is no absolute indication for central venous pressure monitoring in pediatrics. Unlike direct systemic arterial pressures, central venous pressure itself rarely provides the sole basis for therapeutic action. It does, however, provide useful information that, taken together with other data, help to form a management plan. The procedures for which this monitoring deserves consideration include large estimated blood loss or fluid shifts (>50% EBV), deliberate hypotension, cardiac surgery with CPB, situations in which the usual signs of hypovolemia are likely to be misleading (e.g., renal failure, congestive heart failure), and procedures with expected moderate blood loss or fluid shifts. The normal values for central venous pressure in children are similar to those in adults (mean, 2 to 6 mm Hg).

Every insertion site that has been used in adults can be used in children. Access to the central circulation can be achieved from the internal and external jugular, subclavian, basilar, umbilical, and femoral veins. The site selected depends on the experience of the operator and the indication for the catheter. If venous access is the only requirement, one might elect to use visible veins (e.g., basilar, external jugular) or those with a lower risk for complications (e.g., femoral). Situations that require true intrathoracic central venous placement also require placement of the catheter into the internal jugular vein or subclavian vein. The umbilical vein can be used in neonates for volume resuscitation, but the high frequency with which these catheters enter the branch portal veins introduces a significant risk for permanent liver injury if sclerosing or hyperosmolar solutions are infused. Because a catheter tip can erode through the wall of the right atrium, care must be taken to avoid intracardiac tip placement. The catheter should be advanced only until the orifice lies in the intrathoracic great vessels, and its position should be confirmed radiographically.

Catheters of various sizes (2.5 to 10 French), lengths, and composition are available for pediatric applications (Cook Critical Care, Bloomington, IN, and other companies). Selection is based on the size of the patient (Andropoulos et al., 2001) and the purpose of the catheter. The composition of the catheter depends on its intended use. Teflon is fairly resistant to thrombus formation, but concerns about perforation by catheters have prompted the development of softer catheter materials, especially for long-term use (e.g., Silastic and polyurethane). The catheters are generally inserted via the Seldinger technique, using landmarks that are similar to those used in adults.

There are no absolute contraindications to placing a central venous catheter, but each site has potential risks. All sites share the common complications of infection (site cellulitis, bacteremia), venous thrombosis with potential emboli, air embolism, catheter malfunction (occlusion, dislodgment, or fractures), dysrhythmias (when the catheter tip is in the heart), and bleeding. Universal precautions and sterile technique should be used when placing a central venous catheter. The risks involved in cannulating the internal jugular vein include carotid artery puncture, Horner's syndrome, pneumothorax, and injury to the thoracic duct when the left internal jugular vein is cannulated. The high approach to the internal jugular vein, at the midpoint of the sternocleidomastoid muscle, results in comparable success with fewer complications than lower approaches (Coté et al., 1979). Two-dimensional ultrasound scanning improves localization of the internal jugular vein and increases the success rate of central venous cannulation in adults and children (Verghese et al., 2002; Hind et al., 2003). Using this device, Alderson and others (1993) reported an 18% prevalence of anatomic variations in children younger than 6 years that would preclude or significantly hinder the successful cannulation of the internal jugular vein using anatomic landmarks alone. In addition, Hong and colleagues (2010) reported that rotating the head away from the neutral position increases the degree of carotid artery and internal jugular vein overlap, and decreases the incidence of lateral positioning of the internal jugular vein to the carotid artery.

Cardiovascular

A major complication of intravenous infusion is thrombophlebitis, which is a principle limitation of peripheral parenteral nutrition. Its precise pathogenesis is unclear, but venospasm has been proposed as the most likely cause. However, in a study with ultrasound techniques to monitor vein caliber, there was no evidence to support this hypothesis, although thrombophlebitis was observed [10]. The author suggested that the initiating event may be venous endothelial trauma, caused by the venepuncture itself, abrasion at the catheter tip, or the delivery of the feeding solution.

Venous reactions could also theoretically be influenced by the composition of the fat emulsion, because long-chain triglycerides, in particular, generate prostaglandin synthesis which can in turn effect vein tolerance. This potentially important issue has been assessed in a randomized, comparative trial of peripheral parenteral nutrition regimens with fat emulsions containing either long-chain triglycerides alone or in equal proportions with medium-chain triglycerides [11]. All other factors were standardized. Long-chain triglyceride-based fat emulsions significantly prolonged the life of the peripheral vein, compared with mixtures of medium-chain and long-chain triglycerides. The authors hypothesized that this effect was due to a reduced reaction of the venous epithelium to the irritating nutritional mixture.

Superior vena cava thrombosis has been described after frequent central venous catheterization and total parenteral nutrition, with eventual partial recovery [12]. The possible etiological factors included the catheter material, catheter-related sepsis, endothelial trauma, osmotic injury, and hypercoagulability. Although thrombosis of the great veins of the thorax is rare, it is life-threatening, characterized by swelling of the head, upper limbs, and torso, and on chest X-ray by mediastinal widening. Confirmation of thrombosis is best achieved by contrast venography or contrast-enhanced CT scan.

Cardiac tamponade is a serious complication of central venous catheterization. A classical case history has been described with detailed discussion of prevention and management [13]. Most serious complications, including air embolism, pneumothorax, hemothorax, chylothorax, chylopericardium, rupture of the right atrium, ventricular dysrhythmias, and cardiac tamponade, are essentially mechanical injuries relating to catheter insertion. Cardiac tamponade can be caused by acute perforation of the superior vena cava during insertion. Alternatively, a delayed event may be due to catheter-related erosion of the vascular wall, either in the vena cava or in the ventricular wall. The consequences are impairment of diastolic filling and a dramatic decrease in cardiac output, with a very high death rate (about 70%).

A 63-year-old man with cancer of the esophagus developed severe dysphagia. A central venous catheter was introduced for presurgical parenteral nutrition and 3 hours later he reported severe epigastric and retrosternal pain. His condition deteriorated rapidly, with loss of consciousness, a weak pulse, hypotension, distant heart sounds, and jugular venous distension. A chest X-ray showed an enlarged mediastinal shadow and an electrocardiogram showed reduced voltage. The catheter was promptly removed. An emergency laparotomy showed only hepatic engorgement and about 100 ml of ascites, but at thoracotomy the pericardial sac was distended by about 500 ml of clear fluid. There was no apparent injury to the right subclavian artery or evidence of pleural hemorrhage.

The authors concluded that the right ventricle had been perforated by the catheter and they pointed out that these events can be insidious, and can take several months before symptoms suddenly start, requiring quick diagnosis and immediate intervention. This includes immediate removal of the catheter and often also emergency surgical intervention.

SURGICAL TECHNIQUE

After intubation, attachment of appropriate monitoring leads, establishment of large-bore intravenous access, and arterial and central venous catheterization, the patient should be placed prone on a radiolucent table or four-post frame. Care should be taken to ensure that all bony prominences are well padded and that the abdomen hangs free. The hips can be allowed to gently flex with knee and thigh support to passively correct lumbar hyperlordosis. Intraoperative traction has been described to correct pelvic obliquity, but this is rarely necessary.

A standard posterior exposure of the spine from T1 to the sacrum is performed. Each vertebra must be exposed subperiosteally out to the transverse process. At the inferior margin of the incision, the outer wing of the ilium is subperiosteally exposed down to the sciatic notch. The right and left drill guides for the unit rod are placed in the respective sciatic notch; care should be taken to ensure that the drill guide is as far inferior as possible along the posterior superior iliac spine. The handles of the drill guide are the reference points for alignment; the lateral handle should be parallel with the pelvis, and the axial handle should be parallel with the sacrum. The drill hole is next made by utilizing the guide using a 3/8-inch drill to the predetermined depth; the hole is palpated with a ball-tipped feeler to confirm that there has been no breach of the cortex. Gelfoam should be inserted into the drill holes, and sponges should be packed out over the pelvis to maintain hemostasis.

The spinous process of each level is removed to expose the ligamentum flavum. Care must be taken to preserve the laminae, as they are key to the strength of fixation, especially the supralaminar cortex, which even in osteoporotic bone can be strong. The orientation of the cut will change from lumbar to thoracic vertebrae; this must be recognized to avoid resection of the edge of the lamina. The ligamentum is now opened at each level to expose the sublaminar space and epidural fat.

After removal of all spinous processes and exposure of the sublaminar space, the sublaminar wires are passed at each level. A 16-gauge double Luque wire is passed at each level from T2 to L4, and two wires are placed at T1 and L5. The wire is passed from inferior to superior. After the wire has been passed, it is contoured back over the lamina, and the ends of the wire are contoured to the edges of the incision; this will maintain the intraspinal portion of the wire against the undersurface of the lamina as the remaining levels are instrumented. In passing the wire, care must be taken to avoid levering off the lamina and impinging against the cord; the diameter of the contoured bend should approximate the length of the lamina. In passing the wire, if resistance is felt, remove the wire and alter its curvature.

The length of the rod is measured from T1 to the pelvis. Note that correction of a kyphotic deformity will shorten the spine and correction of a lordotic deformity will lengthen the spine. This can be confirmed by placing the rod upside down with the top of the rod at T1 and confirming that the corner of the rod is at the level of the pelvic drill holes. Intraoperatively, if the rod is noted to be too long (i.e., superior to T1) the limbs at T1 can be secured with cross connectors and the excess rod can be cut. If the rod is noted to be too short, the end can be cut and a piece of another rod can be joined with rod-to-rod connectors to achieve the necessary length. Both scenarios, however, will weaken the unibody construction of the rod and decrease the ability to generate sufficient cantilever moment.

Facetectomies and decortication are performed, and a preliminary grafting of the area under the rod is performed. After the proper length unit rod has been selected, the pelvic limbs of the rod are crossed and inserted into their respective drill holes. Each limb should be advanced alternatively in 1-cm increments with an impactor. Care must be taken to maintain control of the rod and to ensure that it does not penetrate either table of the pelvis. In the setting of hyperlordosis, the marked anterior inclination of the pelvis increases the risk of the pelvic limb perforating the inner cortex during insertion. The pelvic ends of the rod need to be directed in a more posterior direction to accommodate this angulation; rod placement is facilitated by manual correction of the lordosis prior to rod insertion. In instances of marked lordosis, the pelvic limbs of the rod can be cut and inserted separately and then attached to the rod with rod-to-rod connectors. (Alternatively, iliac screws can be used with modular connectors.)

The spine is manually corrected to the rod, and the wires are tightened sequentially. Pushing the rod to the spine can generate substantial force at the lever arm of the pelvic insertion with subsequent fracture, so a few of the lumbar levels should be wired prior to generating substantial cantilever forces. After the wires have been tightened and retightened, the wires are cut to be 1 cm long and are bent down to the lamina to avoid implant prominence. Copious crushed cancellous allograft is packed, and the wound is meticulously closed. A drain might or might not be used.

Dabney and colleagues noted that when there is marked lordotic deformity, better fixation and correction were achieved with pedicle screws in the lordotic segment. A cadaveric biomechanical study has confirmed that the use of L5 pedicle screws significantly increases the lateral and oblique stiffness of the unit rod construct. McCall and Hayes retrospectively examined a cohort of patients with neuromuscular scoliosis in whom those with a stable lumbosacral articulation were instrumented with a U-rod (unit rod without the pelvic limbs) with L5 pedicle screw fixation. The L5-S1 interspace mobility was assessed on the basis of L5 tilt; patients with more than 15 degrees of L5 tilt were instrumented with a standard unit rod construct. McCall and Hayes found that in follow-up, the patients who were instrumented to L5 with the U-rod had results similar to those of patients who were fused with the standard unit rod construct.

COMPLICATIONS

I.

Infectious complications, including site infection, bacteremia, and infection of remote sites (e.g., endocarditis), occur with relative frequency in patients who undergo central venous catheterization. Sterile technique, optimal site selection, and frequent reevaluation of the insertion site may reduce the risk of infection. Routine line changes increase the likelihood of both mechanical and infectious complications and therefore are not recommended.

Technical complications include arterial catheter placement, hematoma formation, pneumothorax, hemothorax, arrhythmia, and air embolism. Pneumothorax is most often associated with SC catheter placement, but may result from IJ cannulation as well. A postoperative chest radiograph should be obtained after attempted SC and IJ catheterization, and postprocedure respiratory distress or hemodynamic instability should raise suspicion for the development of a tension pneumothorax. Air embolism results from entry of air into the central venous circulation and subsequent embolization to the pulmonary vasculature. In the presence of a patent foramen ovale, air may also occlude the cerebral circulation and cause an ischemic stroke. Like tension pneumothorax, air embolism may present with dyspnea or hypotension. The incidence of air embolism may be minimized through preventive practices; these include Trendelendurg positioning, limiting the intervals during which an introducer needle and catheter are open to the air, and having the patient perform the Valsalva maneuver or exhale selectively during such intervals.

Thrombotic complications are most common after femoral vein catheterization and lowest after SC vein catheterization. Thrombosis may occur as early as 1 day after insertion; therefore, catheters should be removed as soon as they are no longer needed.

What's the contraindications of central venous catheterization?

What are 3 common insertion sites for a central venous catheters?

When placing a central venous catheter which insertion site is preferred?

Where should a central venous catheter be placed?