Page 14 - 59peadiatric-surgery-speciality8-14_opt

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.