Imaging in Neurology

 

 

Fig. 29.12. Some reasons for failure of umbilical artery catheterization. A: Sagittal midline section to

show normal anatomy of umbilical artery. B: Catheter has perforated the umbilical artery within the anulus umbilicalis and is dissecting perivascularly and external to peritoneum. C: Catheter has ruptured

through the tunica intima (t.i.) and dissected into subintimal space. D: Catheter invaginating the tunica

intima after stripping it from a more distal point. (Adapted from Clark JM, Jung AL. Umbilical artery catheterization by a cut down procedure. Pediatrics (Neonatol Suppl). 1977;59:1036, with permission of the

American Academy of Pediatrics.)

Chapter 29 ■ Umbilical Artery Catheterization 163

(2) Position infant on side with same side elevated

as artery being catheterized. Flex hip.

(3) Instill lidocaine as for E23b (3). Do not force

catheter.

e. Easy insertion, but no blood return

(1) Catheter is outside vessel in false channel.

(2) Remove and observe infant carefully for evidence of complication.

24. Place marker tape on catheter with base of tape flush

with surface of cord so that displacement of the catheter

may be readily recognized.

25. Remove umbilical tape and place purse-string suture

around base of the cord (not through skin or vessels).

Three bites into cord (with needle facing away from

catheter) are sufficient to include all three vessels

within the suture.

If desired, form marker tape into bilateral wings, and

sew the tails of the purse-string suture through the

wings to anchor the catheter in a symmetrical fashion.

This is a useful method in very small premature infants

because it avoids sticking tape to the abdominal wall

(27). Alternatively, remove needle and wrap ends of

suture in opposite direction around catheter for about

3 cm and tie, taking care not to kink catheter.

26. Secure catheter temporarily by looping over upper

abdomen and taping.

27. Obtain radiographs or ultrasound to check catheter

position.

a. Catheter tip above T6 or between T10 and L2

(1) Measure distance between actual and appropriate position on radiograph.

(2) Withdraw equal length of catheter.

(3) Repeat radiographic study.

(4) Note procedure in chart.

b. Catheter tip below L5

(1) Remove catheter.

(2) Never advance catheter once in situ, because

this will introduce a length of contaminated

catheter into the vessel.

28. If desired, secure catheter with tape bridge (Fig. 38.14).

29. Continue routine cord care with 70% alcohol swab or

other agent of choice.

30. Stabilize catheter, stopcock, and syringe, using tongue

depressor (optional).

a. Reduces risk of air embolus if syringe is maintained

in vertical position

b. Prevents accidental disconnection of catheter

system

F. Alternative Technique:

Umbilical Artery Cutdown

This method is usually successful even after failed insertion

through the umbilical stump, as there is less tendency for

false tracts. The most frequent reason for failed umbilical

artery cutdown is mistaking the urachus for a vessel.

Because of the time and risks associated with the cutdown

procedure, standard insertion should be attempted first.

Indications

1. Failed umbilical artery catheterization through conventional technique described earlier in this chapter

Contraindications

1. Same as for umbilical artery catheterization by conventional technique

2. Bleeding diathesis

Equipment

1. Same as for umbilical artery catheterization by conventional technique.

2. 1% lidocaine HCl without epinephrine in 3-mL syringe

with 25- to 27-gauge needle

3. No. 15 surgical blade and holder

4. Curved delicate dressing forceps, two pairs (1/4 or 1/2

curved)

5. Tissue forceps

6. Self-retaining retractor (such as eyelid retractor)

7. Absorbable suture, plain

8. Absorbable suture on small cutting needle

9. Nonabsorbable suture on a small, curved needle

10. Needle holder

11. Suture scissors

12. Skin-closure tapes

Precautions

 

1. Same as described earlier for conventional technique.

2. If possible, leave catheter from previously attempted standard procedure in place to aid in vessel identification.

3. Ensure that abdominal incision is on abdominal wall

and not too close to umbilical stump.

4. Identify landmarks carefully to avoid cutting or catheterizing urachus.

5. When incising mesenchymal sheath, take care to avoid

transecting vessel.

6. Secure the catheter with an internal ligature that is just

tight enough to prevent accidental removal but loose

enough for elective removal or reinsertion, in case

the catheter becomes occluded by thrombus or precipitate.

Technique (28)

See Fig. 29.13.

1. Insert an orogastric tube to keep the bowel as decompressed as possible.

2. Prepare infant and drape as for umbilical artery catheterization (see earlier in chapter).

3. If catheter has been left in place after previous attempt,

include vessel and catheter in the preparation, leaving

the catheter accessible for removal.

164 Section V ■ Vascular Access

4. Anesthetize area of skin immediately below umbilicus,

at umbilical stump–abdominal wall junction, with

0.5 mL of lidocaine.

5. Prepare UAC as for standard procedure, leaving catheter filled with flush solution. Estimate length for insertion based on patient size. Subtract 1 to 2 cm from that

recommended for standard insertion, as cutdown catheter will enter vessel farther along course.

6. Make a smile-shaped incision from 4 to 8 o’clock

through the skin of the abdominal wall at the junction

with the umbilical stump.

7. Place self-retaining retractor to maintain exposure.

8. Using blunt dissection through the subcutaneous tissue

with mosquito forceps, identify the fascia overlying the

urachus and umbilical vessels.

The mesenchymal sheath is composed of three layers of fascia and is from 1 to 3 mm thick. Although it is

barely perceptible in extremely premature infants, in

term infants it may be thick enough to require making

an incision through the sheath prior to blunt dissection.

9. While elevating the fascia with two forceps, make a

small incision between their tips. Enlarge incision with

scissors to the same size as skin incision. In very immature infants, simple dissection should suffice.

10. With curved mosquito forceps, dissect in the midline

and identify the urachus (Fig. 29.13).

The urachus is a white, glistening, cordlike structure

in the midline. Its position may be confirmed by traction cephalad, pulling the dome of the bladder into

view. The umbilical arteries lie posterolaterally on

either side but not touching the urachus.

11. Identify the umbilical arteries lying to either side of the

urachus.

 

162 Section V ■ Vascular Access

20. Insert catheter into lumen of artery, between prongs of

dilating forceps (Fig. 29.11).

21. Remove curved forceps, having passed catheter approximately 2 cm into vessel with a firm, steady motion.

Grasp cord again with toothed tissue forceps and pull

gently toward head of infant. This mild traction will

facilitate passage of catheter at an angle between the

cord and the abdominal wall.

22. After passing the catheter approximately 5 cm, aspirate

to verify intraluminal position. Clear blood by injecting

0.5 mL of flush solution. Advance catheter to calculated appropriate length.

23. Take appropriate action if insertion is complicated (Fig.

29.12).

a. Resistance before tip reaches abdominal wall

(<3 cm from surface of abdominal stump)

(1) Loosen umbilical tape.

(2) Redilate artery.

b. “Popping” sensation rather than “relaxation”

(1) Catheter may have exited lumen and created a

false channel.

(2) Remove and use second artery.

(3) If unsuccessful, draw 0.5 mL of lidocaine from

vial. Reinsert tip of catheter approximately 2 cm

into UAC and drip lidocaine into vessel. Apply

constant gentle pressure until vessel dilates.

c. Backflow of blood, particularly around vessel

(1) Tighten umbilical tape.

(2) Catheter may be in false channel, with extravascular bleeding.

d. Resistance is encountered at anterior abdominal wall

or sharp turn in vessel as it angles around bladder

toward internal iliac artery (approximately 6 to 8 cm

from surface of umbilical stump in 2- to 4-kg neonate).

(1) Apply gentle but steady pressure for 30 to 60 seconds.

A

D

B

C

 

160 Section V ■ Vascular Access

a. Tighten only enough to prevent bleeding and, if

possible, place around Wharton jelly rather than

skin.

b. It may be necessary to loosen the tie when inserting

the catheter.

9. Cut cord horizontally with scalpel (Fig. 29.8).

a. Approximately 1 to 1.5 cm from skin

b. Avoid tangential slice.

Bloom et al. (25) described an alternative

approach to the artery with lateral arteriotomy. To

perform this method, 3 to 4 cm of cord must be preserved because the cord must be rolled over a Kelly

clamp 180 degrees (25,26).

(1) Clamp across end of cord with a mosquito

hemostat in the nondominant hand and pull

firmly toward the infant’s head.

(2) Roll cord 180 degrees over hemostat toward

abdominal wall.

(3) Identify arteries in superior right and left lateral

aspects of cord.

(4) Approximately 1 cm from abdominal wall,

incise Wharton jelly down to arterial wall, using

a no. 11 scalpel blade.

(5) Incise artery through half of circumference. If

necessary, dilate lumen with iris forceps.

(6) Insert catheter into lumen of artery, directed in a

caudad direction, for predetermined distance.

10. Control bleeding by gentle tension on umbilical tape.

11. Blot surface of cord stump with gauze swab. Avoid rubbing, as this damages tissue and obscures anatomy.

12. Identify cord vessels (Fig. 29.9).

a. Vein is easiest to identify as large, thin-walled, sometimes gaping vessel. It is most frequently situated at

the 12-o’clock position at the base of the umbilical

stump.

b. Arteries are smaller, thick-walled, and white and

may protrude slightly from cut surface.

c. Omphalomesenteric duct is rarely present.

Fig. 29.8. Traction is being placed on cord in direction of the

arrow. Operator is about to make a horizontal cut across cord.

A B

Fig. 29.7. Anteroposterior (A) and lateral (B) radiographs showing satisfactory low position of a UAC.

Catheter tip is at the level of the superior margin of the fourth lumbar vertebral body, which in newborns

usually corresponds to the aortic bifurcation.

 

Chapter 29 ■ Umbilical Artery Catheterization 161

13. Grasp cord stump, using toothed forceps, at point close

to (but not on) artery to be catheterized. If available, it

may be helpful to have an assistant scrub and assist.

a. Apply two curved mosquito hemostats to Wharton

jelly on opposite sides of the cord, away from the

vessel to be cannulated.

b. Apply traction to stabilize cord stump.

14. Introduce one of the points of the curved iris forceps

into the lumen of the artery and probe gently to a depth

of 0.5 cm.

15. Remove forceps and bring points together before introducing them once more into the lumen.

16. Probe gently to a depth of 1 cm (up to the curved

“shoulder” of the forceps), keeping the points together.

17. Allow the points to spring apart, and maintain forceps

in this position for 15 to 30 seconds to dilate vessel

(Fig. 29.10). Time spent in ensuring dilatation prior

to catheter insertion increases the likelihood of

success.

18. Release cord and set aside toothed forceps, while keeping curved forceps within artery.

19. Grasp catheter 1 cm from tip, between free thumb and

forefinger or with curved iris forceps.

Fig. 29.9. The vessels of the umbilical cord. Thin-walled

umbilical vein at 12-O’clock position is indicated by a white arrow.

One of the two umbilical arteries is to the right and directly below

the vein.

Fig. 29.10. An iris forceps is pointed into the umbilical artery

in order to dilate the lumen of the artery.

A B

Fig. 29.11. A: Inserting the catheter into the artery between the prongs of dilating forceps. Note that the

umbilical tape has been tied around the skin of the umbilicus; this should be loosened once the catheter

is secured in place. B: Close-up photo of the umbilical stump with the arterial catheter in place.

 

Chapter 29 ■ Umbilical Artery Catheterization 159

a. High position (14,19): Level of thoracic vertebrae

T6–T9 (Fig. 29.6); catheter tip above origin of celiac

axis

b. Low position (14,19): Level of lumbar vertebrae L3–

L4 (Fig. 29.7)

(1) Catheter tip is below major aortic branches such

as renal mesenteric arteries.

(2) In most newborns, this position coincides with

the aortic bifurcation at the upper end of the

fourth vertebra.

2. Make external measurements as necessary to estimate

length of catheter to be inserted (see Figs. 29.1–29.3)

(20–23).

3. Prepare as for major procedure (see Chapter 5).

4. Attach stopcock to hub of catheter and fill system with

flush solution. Turn stopcock to catheter “off.”

5. Place sterile gauze around umbilical stump and elevate

out of sterile field or have an ungloved assistant grasp

the cord by the cord clamp or forceps and pull the cord

vertically out of the sterile field.

6. Prepare cord and surrounding skin with antiseptic solution to radius of approximately 5 cm. The use of

chlorhexidine in infants <2 months of age is not recommended (24).

7. Drape area surrounding cord.

8. Place umbilical tie around umbilicus and tie loosely

with a single knot.

Fig. 29.5. The aorta and branches.

A B

Fig. 29.6. UAC in satisfactory high position at the level of the ninth thoracic vertebral body on anteroposterior (A) and lateral (B) projections.

 

3. Take time and care to dilate lumen artery before

attempting to insert catheter.

4. Catheter should not be forced past an obstruction.

5. Never advance catheter once placed and secured.

6. Loosen umbilical tie slightly upon completion of procedure and obtain radiographic confirmation of

position.

7. Avoid covering the umbilicus with dressing. Dressing may

delay recognition of bleeding or catheter displacement.

8. Always obtain radiographic (including a lateral view) or

ultrasound (15) confirmation of catheter position.

(16,17).

9. Be certain that catheter is secure, and examine frequently when infant is placed in prone position,

because hemorrhage may go unrecognized.

Fig. 29.1. Graph for determination of length of catheter to be

inserted for appropriate low aortic or venous placement. Length of

catheter is measured from umbilical ring. Length of umbilical

stump must be added. The shoulder–umbilicus distance is the

perpendicular distance between parallel horizontal lines at the

level of the umbilicus and through the distal ends of the clavicles.

(Adapted from Dunn P. Localization of the umbilical catheter

by postmortem measurement. Arch Dis Child. 1966;41:69, with

permission.)

A B

Fig. 29.2. A: Graph for distance of catheter insertion from the umbilical ring for L3, L5, and aortic

bifurcation. Large dots represent catheters positioned at L4. B: Graph for catheter insertion to level T8

using total body length. (From Rosenfeld W, Biagtan J, Schaeffer H, et al. Evaluation of graphs for insertion of umbilical artery catheters below the diaphragm. J Pediatr. 1981;98:628, with permission.)

158 Section V ■ Vascular Access

10. Take care not to allow air to enter the catheter. Always

have catheter fluid filled and attached to closed stopcock prior to insertion. Check for air bubbles in catheter before flushing or starting infusion.

11. When removing catheter, cut suture at skin, not on

catheter, to avoid catheter transection.

E. Technique (See also Umbilical

Catheterization on

the Procedures Website)

Anatomic note: The umbilical arteries are the direct continuation of the internal iliac arteries. Their diameters at

their origins are 2 to 3 mm. As they approach the umbilicus,

their lumina become small and the walls thicken significantly. In a full-term infant, each artery is approximately

7 cm long (Fig. 29.4). A catheter introduced into the umbilical artery will usually pass into the aorta from the internal

iliac artery. Occasionally, it will pass into the femoral artery

via the external iliac artery or into one of the gluteal

arteries. The latter two sites are unsuitable for sampling,

pressure measurement, or infusion.

1. Placement of UAC in high position should be used

exclusively. In rare cases if high position is not successful a low position can be used (Fig. 29.5).

High position is associated with fewer episodes of

blanching and cyanosis of the lower extremities (18).

High catheters were found to have decreased incidence

of clinical vascular complications with a relative risk of

0.53 (95% confidence interval, 0.44 to 0.63) with no

statistically significant increase in any adverse sequelae,

including the incidence of hypertension, intraventricular hemorrhage, hematuria, necrotizing enterocolitis,

or death (19).

 

Fig. 29.3. Estimates of insertion length of umbilical catheters

(umbilical artery catheter tip inserted between T6 and T10;

umbilical vein catheter tip inserted above diaphragm in inferior

vena cava near right atrium) based on birthweight (BW) (with

95% confidence intervals). Modified estimating equations utilizing BW are as follows: umbilical artery length = 2.5 BW + 9.7

(top) and umbilical vein length = 1.5 BW + 5.6 (bottom), where

BW is measured in kilograms and lengths are measured in centimeters. (From Shukla H, Ferrara A. Rapid estimation of insertional length of umbilical catheters in newborns. Am J Dis Child.

1986;140:787, with permission.)

Fig. 29.4. Anatomic relations of the umbilical arteries, showing relationships with major arteries supplying

buttocks and lower limb.

 

g. 5-French (Fr) gauge for infants weighing >1,200 g

h. 3.5-Fr gauge for infants weighing <1,200 g

5. Three-way stopcock with Luer-Lock

6. 10-mL syringe

7. 0.45 to 0.9 normal saline (NS) flush solution (saline

with heparin, 1 to 2 U/mL)

In very small premature infants, particularly in the

first week of life, hypernatremia may result from receiving excess sodium in flush solutions. We recommend

using 0.45 NS rather than more concentrated saline

solutions in these infants. The use of hypotonic (0.25

NS) or dextrose solutions has been associated with

hemolysis of red blood cells and should be avoided if

possible (6). Use of heparinized flush solution is common practice. Rajani et al. and Ankola and Atakent

(7,8) have shown that using a heparinized solution containing 1 U/mL heparin for flushing the umbilical arterial line prolonged catheter life by reducing the

incidence of fibrin thrombus formation in the catheter

lumen. Horgan et al. (9) found that the use of 1 U/mL

heparin did not reduce the incidence of umbilical

artery catheter (UAC)-related thrombi but did lower the

Chapter 29 ■ Umbilical Artery Catheterization 157

incidence of their sequelae. Butt et al. (10) could demonstrate no significant benefit associated with increasing the

rate of infusion from 1 to 2 mL/h (heparin 1 U/mL), and

Bosque and Weaver (11) showed that continuous infusion

of 1 U/mL heparin is more effective than intermittent

infusion in maintaining patency of the UAC. More

recent data have indicated that heparin decreases the

incidence of thrombotic complications (12), and a

Cochrane Database Review found that the use of as little

as 0.25 U/mL heparin in the infusate decreases the likelihood of line occlusion (13).

8. Tape measure

9. 20-cm narrow umbilical tie

10. No. 11 scalpel blade and holder

11. 4- × 4-inch gauze sponges

12. Two curved mosquito hemostats

13. Toothed iris forceps

14. Two curved, nontoothed iris forceps

15. 2% lidocaine HCl without epinephrine

16. 3-mL syringe and needle to draw up lidocaine

17. Small needle holder

18. 4-0 silk suture on small, curved needle

19. Suture scissors

Nonsterile

1. Cap and mask

2. Wooden tongue depressor

D. Precautions

1. Avoid use of feeding tubes as catheter (associated with

higher incidence of thrombosis) (14).

2. Fold drapes so as not to obscure infant’s face and upper

chest.

 

Chapter 28 ■ Management of Extravasation Injuries 155

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neonatal units. Arch Dis Child Fetal Neonatal Ed. 2004;89:F274.

2. Casanova D, Bardot J, Magalon G. Emergency treatment of accidental infusion leakage in the newborn: report of 14 cases. Br J

Plast Surg. 2001;54:396.

3. Friedman J. Plastic surgical problems in the neonatal intensive

care unit. Clin Plast Surg. 1998;25:599.

4. McCullen KL, Pieper B. A retrospective chart review of risk factors for extravasation among neonates receiving peripheral intravascular fluids. J Wound Ostomy Continence Nurs. 2006;33:133.

5. Zenk KE, Dungy CI, Greene GR. Nafcillin extravasation injury.

Use of hyaluronidase as an antidote. Am J Dis Child. 1981;135:1113.

6. Subhani M, Sridhar S, DeCristafaro JD. Phentolamine use in a

neonate for the prevention of dermal necrosis caused by dopamine: a case report. J Perinatol. 2001;21:324.

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approach to management of intravenous infiltration in pediatric

patients. J Infusion Nurs. 2011;34:242.

8. Thigpen JL. Peripheral intravenous extravasation: nursing procedure for initial treatment. Neonatal Netw. 2007;26:379.

9. Doellman D, Hadaway L, Bowe- Geddes LA, et al. Infiltration

and extravasation: update on prevention and management. J

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10. Montgomery LA, Hanrahan K, Kottman K. Guideline for IV infiltrations in pediatric patients. Pediatr Nurs. 1999;25:167.

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13. Fox MD. Wound care in the neonatal intensive care unit.

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14. Gault DT. Extravasation injuries. Br J Plast Surg. 1993;46:91.

15. Kuenstig LL. Treatment of intravenous infiltration in a neonate.

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16. Denkler KA, Cohen BE. Reversal of dopamine extravasation

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17. Wong AF, McCullough LM, Sola A. Treatment of peripheral tissue ischemia with topical nitroglycerine ointment in neonates.

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18. Siwy BK, Sadove AM. Acute management of dopamine infiltration injury with Regitine. Plast Reconstruct Surg. 1987;80:610.

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support wound healing in neonatal patients: an adjunct to nursing care. Neonatal Netw. 2006;25:267.

20. Rustogi R, Mill J, Fraser JF, et al. The use of Acticoat in neonatal

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Surg. 1989;22:146.

22. Tiras U, Erdeve O, Karabulut AA, et al. Debridement via collagenase application in two neonates. Pediatr Dermatol. 2005;22:

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