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Vascular Access in Children  53

          occlude the tip. Ultrasound examination of CVCs shows that more than   istration of drugs as prescribed on time. It reduces patient (and parent)
                                       31
          50% have thrombus at the tip of the line.  However, clinically manifest   anxiety, resulting in a better atmosphere. The price of all these benefits
          thrombosis is rare and occurs mainly in newborns and infants. So far,   is—apart  from  the  financial  burden  [Broviac,  US$200  (150  euros);
          no studies support the use of prophylactic anticoagulants. If thrombosis   Port-a-Cath, US$675 (500 euros); use of operating theatre, US$1350
          is diagnosed, intravenous heparin should be started and anticoagulant   (1000 euros); plus cost of treatment of complications]—also the risk of
          treatment  with  warfarin  continued  for  3  months.  Increasingly  more   potentially life-threatening complications. The balance will have to be
          data have now become available on the long-term sequelae of CVC,   found for each individual centre and patient.
          particularly in oncologic patients. Significant postthrombotic signs and   Evidence-Based Research
          symptoms occur in less than 10%.
                                                                 Table  9.3  presents  a  prospective  Brazilian  study  of  complications  of
          Malposition                                            CVC placement in children.
          Malposition is any tip position other than in the superior or inferior
                                                                 Table 9.3: Evidence-based research.
          vena  cava.  Placement  or  migration  of  the  catheter  tip  into  the  right
          atrium may cause cardiac arrhythmias or myocardial erosion. Damage   Title  Central venous catheter placement in children: a
          to  the  wall  of  the  superior  vena  cava  and  leakage  of  fluid  into  the   prospective study of complications in a Brazilian public
                                                                               hospital
          pericardial  space  resulting  in  tamponade  have  been  reported.  Also,
          catheters in the right atrium may be associated with thrombus forma-  Authors  Cruzeiro PCF, Carmagos PAM, Miranda ME
          tion and valvular damage. If the tip is not in a large vessel (and blood   Institution  Pediatric Surgical Services, Clinics Hospital, Federal
                                                                               University of Minas Gerais, Belo Horizonte, Minas Gerais,
          cannot  be  aspirated  freely),  there  is  a  substantial  risk  of  thrombosis
                                                                               Brazil
          and perforation with extravasation into the pericardial or pleural space.
                                                                   Reference   Pediatric Surg Intl 2006; 22:536–540
          Obstruction of catheter
          Obstruction of the central venous cannula can be caused by administra-  Problem  This study evaluates the complications of percutaneously
                                                                               placed central catheters in a public hospital.
          tion of incompatible mixtures that form debris. Also, the CVC should   Study design  Prospective study.
          be rinsed after withdrawal of blood, and care should be taken to keep
          the CVC open by continuous flow of infusion. If the CVC is not in use,   Length of   Eight months.
                                                                   study
          it should be filled with a heparin solution. If the CVC is blocked, it can
          sometimes be unblocked by pushing normal saline with a small (2-ml)   Results  155 catheters (130 in neck, 25 in groin) were placed in 127
                                                                               patients. The cannulation success rate was 81.9% at the
          syringe. Although this manoeuver can be successful, it may result in   first attempt and 100% at the second attempt.
          rupture of the CVC.
          Pinch-off                                                Complications  Perioperative complications: haematomas, 6 (3.9%);
                                                                               arterial puncture, 3 (1.9%). Complications with catheter in
          The  term  “pinch-off”  refers  to  entrapment  of  subclavian  catheters   situ: mechanical, 51(32.9%); infections, 33 (21.3%).
          between the clavicle and the first rib. Over time, repeated compression
          causes catheter fracture, resulting in extravasation of fluids, or catheter
                                                                   Outcome/    Age, sex, type of catheter, and primary diagnosis
          breakage and embolisation.                               effect      were not associated with complications. There was no
          Ethical Issues                                                       pneumothorax, hemothorax, or hydrothorax, and no
                                                                               mortality.
          The cost-benefit aspect of central venous access in the African setting
          is addressed in this final paragraph. The use of central venous catheters   Conclusions  Knowledge of anatomy and familiarity with the Seldinger
                                                                               technique improve the success rate. Percutaneously
          in the long term is in itself not lifesaving and is potentially dangerous.   placed central venous catheters produce satisfactory
          The advantages are that the caretakers always have CVA, even when    results in paediatric patients.
          the child is asleep. This obviates the need for multiple attempts to set
          up intravenous lines, allowing normal day-to-day activities and admin-



                                                    Key Summary Points

             1.  Virtually every child will need vascular access.  6.  The long saphenous vein at the ankle or at the groin, the
                                                                    femoral vein, antecubital veins, and the cephalic vein are
             2.  Maximum flow is achieved with catheters that are wide and   suitable for venous cutdowns.
                short.
             3.  The umbilical vein can be used for up to 2 weeks in neonates   7.  The intraosseous space is a rich, noncollapsible venous network.
                for administration of colloids or crystalloids, and for exchange   8.  The upper surface of the tibia, iliac crest, lateral malleolus, and
                blood transfusion.                                  upper femur can be used for bone punctures.
             4.  The back of the hand is the most commonly used site for   9.  The internal jugular vein, subclavian vein, and femoral vein are
                venous access in infants.                           suitable for central venous access.
             5.  The antecubital fossa, dorsum of the foot, and snuffbox can be   10. The Seldinger technique is used for inserting central cannulas.
                accessed in older children.                      11. Common complications of vascular access include
                                                                    haemorrhage, line infection, and thrombosis.
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