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CHAPTER 9

Vascular Access in Children

James O. Adeniran
Hugo A. Heij

Introduction Table 9.1: Indications for peripheral vascular access.
Every child presenting to the paediatric surgeon will require vascular Indications Uses
access at one time or another during the management of the child’s
surgical condition. Vascular access becomes critical in patients brought Venous blood sampling For various diagnostic tests
to the hospital as emergencies because many of them may have been Resuscitation Fluids, blood and blood products in:
on treatment in private hospitals for some time, and the obvious veins Intestinal obstruction
have been used already. This common task may be even more daunting Peritonitis
with factors such as restlessness due to the clinical pathology, shock, Trauma
unavailability of appropriate catheters, obese patients, and children Preoperative work-up
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with multiple limb injuries. It is therefore important for the paediatric
surgeon to be familiar with how to gain access to the vascular tree as Administration of other products Drugs during resuscitation
and when necessary. Drugs during anaesthesia
The first part of this chapter considers peripheral vascular access, Correction of anaemia/coagulation defects
and the second part considers central vascular access. Indications, Parenteral nutrition
techniques of catheter insertion, complications and management of Cytotoxic drugs
these complications, and the cost-benefit aspect in the African setting
are discussed. Use as central venous access
Peripheral Vascular Access
Indications for Africa the gastrointestinal tract may need digital substraction angiography
Virtually all patients presenting to a paediatric surgeon need blood tests (DSA) for diagnosis and management. Many advanced liver and renal
for diagnosing their ailments, assessing their fitness for anaesthesia, tumours can now be embolised by using the arterial route with excel-
and use in postoperative management. Accurate figures for Africa are lent palliation.
not known, but in the United States an estimated more than 200 mil- Physiology
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lion peripheral catheters are placed annually. Vascular access is one of The French physiologist Jean Marie Poiseuille in 1839 defined resis-
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the new tools that enables the neonatologist and paediatric surgeon to tance through a vessel as:
provide ongoing therapy for very ill babies, at the same time allowing Resistance = 8 (viscosity) (catheter length) / πr 4
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invasive monitoring of the clinical condition. Many patients present to
the paediatric emergency room with intestinal obstruction as neonates Resistance through the catheter decreases as the length of the
with anorectal malformations, Hirschsprung’s disease, or bowel atre- catheter decreases and the radius r increases. Maximum flow is
sias. Older patients present with peritonitis, usually due to typhoid or therefore best when the catheter is short and wide.
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appendix perforation. Some patients also present with multiple trauma, Sites of Peripheral Vascular Access
and others may present with sickle cell disease in crises. These patients Venepuncture
need urgent vascular access for administration of fluids, blood prod- Umbilical vein
ucts, drugs, and nutritional formulas.
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The umbilical vein may remain patent for up two weeks. It is easily
Venous Access cannulated in neonates and is used extensively in third-world countries
Venous access is needed for administration of drugs during resusci- for venous blood sampling, infusion of crystalloids and colloids,
tation, induction and maintenance of anaesthesia, during cytotoxic administration of drugs, and exchange blood transfusion. The technique
therapy, and in haemodialysis. Stem-cell harvest for research and bone is described below. Portal vein thrombosis can follow prolonged use;
marrow transplantation in cases of leukaemias also need venous access. therefore, a peripheral vein should be secured as soon as possible.
Nutritional support can be given to many patients through peripherally Platelets should not be infused through the umbilical vein.
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inserted central catheters. Other indications and uses for venous access Upper limb
are shown in Table 9.1. The upper limb is the preferred site for cannulation in children. Because
Aterial Access the dorsal venous arch starts from the dorsum of the wrist, this site is
Arterial access is used much less in developing countries, not because most commonly attempted first in most children. Two or three veins
the indications are lacking, but because the necessary equipment is may be found at the radial and ulna borders. The origin of the cephalic
not available. Arterial sampling for O estimation and cardiovascular vein may be seen over the snuff box in older children. The cephalic and
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monitoring in very ill children, especially those who need ventilation, basilic veins and one or two veins crossing them may be visible at the
needs arterial access. Various radiological procedures for diagnosis and cubital fossa.
treatment are becoming popular in children. Children bleeding from