Artery and Vein Catheterisation
also radiology images of UAC and UVC placement
- Umbilical vessels are relatively accessible in
the newborn infant, particularly the very small and very large
- As a general rule, infants less than 1000g
should have an umbilical venous catheter (UVC) inserted on day 1.
- An umbilical arterial catheter (UAC) may be
indicated if the infant has significant respiratory disease (ventilated or
>40% oxygen) or is likely to require significant blood sampling over the
first few days of life.
- Larger infants with significant respiratory
distress may also require a UAC.
- Larger infants, especially sick infants,
should have a UVC inserted. A double-lumen catheter may be indicated if the
infant requires significant support (see
Umbilical Venous Catheters
- The umbilical vein is 2-3cm long and 4-5mm in
- From the umbilicus, it passes cephalad and a
little to the right. It joins the left branch of the portal vein after
giving off several large intrahepatic branches.
- The ductus venosus arises from the point
where the UV joins the left portal vein.
- It can be difficult to pass the catheter
through the ductus venosus. There are some manoeuvres that can assist
in placement. These include:
- pulling the catheter back to about 4-5cm,
then advancing the catheter whilst rotating the catheter clockwise
- passing another catheter down beside the
already mal-placed catheter. The path of the second catheter may
be through the ductus venosus.
- Do not force a catheter in if there
- In an emergency, a UVC that remains in the
portal circulation may be withdrawn until it lies in the umbilical
vein. Solutions which are not isotonic can be infused through this for
a short period of time until more suitable access is obtained.
For infants who are term or near-term and sick
enough to require central access (for example, sepsis,
PPHN), a 5F
double-lumen UVC should be inserted.
For infants <1000g, a 3.5F double-lumen
catheter should be considered if the infant is likely to need inotropes or
multiple infusions. This will be decided on an individual basis.
- If the shoulder-to-umbilicus distance
is measured, the catheter can be inserted the appropriate distance
according to the graph on the right
- Remember to measure from the
skin at the base of the stump where it connects to the anterior
to add the length of
the umbilical stump to the distance inserted.
- Another method is to calculate the
distance according to the weight of the baby. See the
below to evaluate UVC position.
- An approximation of this is to use
the calculation of: UVC length (cm) = (1.5 x birthweight (kg)) +
or half the UAC length (calculated below) + 1cm
from UVC insertion include
||Catheter Malpostioned in the Heart and
Malpositioned in portal
- Pericardial effusion or cardiac tamponade
- Cardiac arrhythmias
- Thrombotic endocarditis
- Haemorrhagic pulmonary infarction
- Hydrothorax (UVC lodged in or perforating
- Perforation of peritoneum
- Obstruction of pulmonary venous return (in
infants with TAPVD)
- Plasticizer in tissues
- Portal hypertension
- Electrical hazard
(improper grounding of equipment, or conduction of current
through fluid filled catheter).
Umbilical Artery Catheters
- The umbilical arteries are the direct
continuation of the internal iliac arteries.
- A catheter passed into an umbilical
artery will usually (but not always) enter the aorta via the internal iliac
- Occasionally it will pass into the femoral
artery via the external iliac artery or into the gluteal arteries.
- The femoral artery or gluteal artery are
unsuitable sites for sampling, infusion, or blood pressure monitoring.
- There are two potential positions for the
UAC. These are described as "high" or "low".
- The high position is at the level of
thoracic vertebral bodies T6-T9.
3 This position is above the
coeliac axis (T12), the superior mesenteric artery (T12-L1), and the
renal arteries (L1). This position is essentially "above the
- The low position is at the level of lumbar
vertebral bodies L3-L4.
3 This position is below the structures as
above, and is above the aortic bifurcation (L4-L5). The inferior
mesenteric artery arises from L3-L4. This position is essentially
"above the bifurcation".
- Our preference is for UACs to be in the high
position. If this is not achieved, the catheter can always be
withdrawn to a low position.
- There is debate over whether one position is
better. The Cochrane Systematic Review
suggests that a high position is preferred as it is associated with fewer
obvious vascular complications, a probable reduction in the incidence of
aortic thrombus, and longer catheter life.
|Never use an 8F UAC
- If you know the length of the infant,
you can refer to the graph on the right which relates UAC distance
to total body length.
- This will result in placement at
- Note that of all the birth
measurements, length is the least reliable.
- Another option - and one which is
particularly good if you forget to measure the shoulder-to-umbilicus
length - is to calculate the insertion distance using the
birthweight and referring to the graph on the right
or using the formula:
UAC distance (cm) = (birthweight (kg)
x3) + 9.
- The top lines on the graph to the
right are for UAC position.
lines on the graph to the right are for UVC position.
- The curved lines above and below
the straight lines are the 95% confidence intervals.
- It does no harm to insert the line a
centimetre further than calculated, as the line can be pulled back
slightly if needed. However, you should avoid inserting the
UAC so far that it needs to be removed from the carotid or
Complications from umbilical
catheterisation include 3
- Vessel perforation
- Refractory hypoglycaemia
(if catheter tip opposite coeliac axis)
- Peritoneal perforation
- False aneurysm
- Loss of extremity
- Heart failure (from aortic
- Air embolism
- Broken catheter
- Transection of catheter
- Plasticizer in tissues
- Improper grounding of electronic
- Conduction of current through
- Necrotising enterocolitis
- Intestinal necrosis or perforation
- Transection of omphalocoele
- Herniation of appendix through
- Cotton fibre embolus
- Wharton-jelly embolus
DL, Lachman RS, Leake RD, O W. J Pediatr 1972; 81:337
PM. Arch Dis Child 1966;41:71
MA, MacDonald MG, Avery GB. Atlas of procedures in
Neonatology. JB Lippincott Co, Philadelphia 1983.
KJ. Umbilical artery catheters: catheter position (Cochrane
Review). In: The Cochrane Library, Issue 4, 2000: Update Software.
W, Biagtan J, Schaeffer H, et al. Evaluation of graphs for insertion
of umbilical artery catheters below the diaphragm. J Pediatr 1981;
H, Ferrar A. Rapid estimation of insertional length of umbilical
catheters in newborns. Am J Dis Child 1986; 140:786.