44: Venous Access: Umbilical Vein Catheterization

1. Immediate, primarily postnatal access for intravenous (IV) fluids or emergency medications.

2. Central venous pressure monitoring (if UVC passed through the ductus venosus).

3. Exchange or partial exchange transfusion (catheter tip should not be in the intrahepatic venous system or the portal system).

4. Long-term central venous access in extremely low birthweight infants or sick infants for administration of IV fluids, total parenteral nutrition, medications.

5. Delivery of blood and blood products.

6. Other reported indications include general venous access in difficult peripheral IV access, administration of fluids and total parenteral nutrition, infusion of hypertonic solutions (>12.5% only if catheter tip in inferior vena cava), infusion of vasoactive drugs, antibiotics, and medications.

7. Secondary aid in the diagnosis of cardiovascular or other anomalies by an unusual course of the umbilical venous catheter or the blood gas samples are suspicious.

   1. Congenital diaphragmatic hernia. Umbilical venous catheter (UVC) is left of the midline because of the anomalous positioning of the liver in the chest.

   2. Persistent left superior vena cava. Diagnosed by the path of a UVC. UVC catheter extended beyond the lung (it had entered the persistent left superior vena cava and entered the left jugular vein).

   3. Congenital absence of the ductus venosus. This can cause an abnormal path of UVC. (Caudal loop is seen on radiograph in a UVC.)

   4. Infracardiac total anomalous pulmonary venous return. Diagnosed by high partial pressure of oxygen in a UVC below the diaphragm.

1. Basic. Identical to umbilical artery catheterization (see Chapter 24).

2. UV catheters

   1. Types. Single lumen: 2.5F, 3.5F, 5.0F; dual lumen: 3.5F, 5.0F; triple lumen: 5.0F, 8.0F.

   2. Size guideline. Preterm: 3.5F; term and late preterm: 5F. Other guidelines: 3.5F or 5F catheter <3.5 kg, 5F or 8F >3.5 kg. An 8F catheter is recommended for exchange transfusion or a large volume replacement. Dual-lumen catheters are sometimes recommended in infants <28 weeks and <1000 g, in infants that need inotropes or insulin, and any critically ill neonates such as persistent pulmonary hypertension or meconium aspiration syndrome.

1. Important UVC tips

   1. There is only 1 umbilical vein, and it remains open and viable for cannulation for up to 1 week after birth. The umbilical vein carries oxygenated blood from the placenta to the fetus. The UVC passes into the umbilical vein through the umbilicus and follows this path: junction of the right and left portal vein in the liver, the ductus venosus, crosses at the level of the right and left hepatic vein, and enters the inferior vena cava up to the junction of the inferior vena cava and right atrium.

   2. In an emergency postnatal situation (delivery room). The UVC can be rapidly inserted only until adequate blood return is obtained (usually 2–4 cm in a term infant, less in preterm) as an emergency venous access. Resuscitation medications, volume, and blood can be given.

   3. Cochrane review does not make any recommendations on using single- versus multiple-lumen catheters. Double-lumen catheters decreased the number of additional venous lines during the first week of life, but double-lumen catheters broke, leaked, and clogged more (smaller diameter). No difference in catheter placement difficulty, misplacement, catheter-related infections or blood clots, or rate of infant mortality was noted. More studies are needed; consider using the least amount of lumens required.

   4. Suspect cardiac tamponade in a neonate with a UVC (even if properly placed) who develops a sudden unexplained clinical deterioration in cardiopulmonary status. Urgent echocardiography or pericardiocentesis should be considered. Routine radiography to verify tip placement is recommended by some to check for tip migration.

   5. Catheter duration recommendations. Centers for Disease Control and Prevention, 14 days; others sources: 7 days, up to 28 days if absolutely necessary. The American Academy of Pediatrics (AAP) states catheters can be used up to 14 days if used aseptically.

   6. Heparin use in UVCs is controversial. The literature is conflicting since there are recommendations for and against its use. The majority of NICUS use heparin in UVCs. Our recommendation: heparin (lowest dose at least 0.25 U/mL) in all fluids via the UVC. Use of heparin flushes only are not effective in maintaining patency. The American College of Chest Physicians Evidence-Based Clinical Practice Guidelines study does recommend heparin in central venous access devices. They recommend UFH continuous infusion at 0.5 U/kg/h to maintain CVAD patency.

   7. Blood cultures can be obtained from the UVC right after placement (venipuncture preferred).

   8. Ultrasound guidance. Faster and results in fewer manipulations and x-rays as compared with conventional placement.

2. Determine the length of UVC needed. There are multiple methods reported; refer to institutional guidelines if possible.

   1. Dunn method. Measures the shoulder-umbilicus length and uses a nomogram to determine the insertion length. This method was more accurate than the Shukla method in one study. The catheter tip should be placed between the level of the diaphragm and the left atrium on the graph (Figure 44–1).

   2. Shukla method. Based on birthweight (BW):

      1. Modified BW equation. UAC line calculation divided by 2 + 1 cm (UAC: BW in kilograms × 3 + 9).

      2. Exact BW equation. 1.5 × BW in kilograms + 5.6.

   3. Measure from the xiphoid to the umbilicus and add 0.5–1.0 cm. This number indicates how far the venous catheter should be inserted.

   4. UVC length (in centimeters) = shoulder (distal end of clavicle) to umbilicus length × 0.66

3. Pain management. Since the umbilical cord is denervated, pain may be minimal. No formal anesthesia is usually needed if you avoid using a hemostat to grab the skin or avoid putting sutures through the skin around the umbilicus. Use any nonpharmacologic pain prevention and relief techniques if possible.

4. Technique

   1. Place the infant supine with a diaper wrapped around both legs for stabilization.

   2. Prepare the area around the umbilicus with povidone-iodine solution. Use a gown, gloves, and mask.

   3. Prepare the tray as you would for the umbilical artery catheterization. (See Chapter 24, Technique) Fill the lumen with infusion solution so it is air free.

   4. Place sterile drapes, leaving the umbilical area exposed. Use gown, mask, and gloves.

   5. Tie a piece of umbilical tape or a purse string suture around the base of the umbilicus.

   6. Cut the excess umbilical cord with a scalpel or scissors, leaving a stump of ∽0.5–1.0 cm. Identify the umbilical vein. The umbilical vein is thin-walled, larger than the 2 arteries, and close to the periphery of the stump (see Figure 24–3B).

   7. Grasp the end of the umbilicus with the curved hemostat to hold it upright and steady. (Figure 44–2A).

   8. Open and dilate the umbilical vein with the forceps. If a later insertion, remove any visible clots in the lumen with the forceps. Once the vein is sufficiently dilated, insert the catheter (Figure 44–2B) the desired length. Direct the catheter toward the head/cephalad with a hand providing liver immobilization, as this improves the rate of insertion of the UVC into the inferior vena cava. Some units use ultrasound to help guide the catheter, and this has been found to reduce complications during UVC insertion.

   9. Occasionally, a catheter enters the portal vein. (Figure 44–3) Suspect portal vein entry if you meet resistance and cannot advance the catheter the desired distance or if you detect a “bobbing” motion of the catheter. Several options are available to correct this.

      1. Withdraw the catheter 2–3 cm, rotate it, and try to reinsert it.

      2. Try injecting flush as you advance the catheter. Sometimes this makes it easier to pass the catheter through the ductus venosus.

      3. Double-catheter technique is based on the fact that once the first catheter occupies the wrong vessel, the second catheter will have to enter the correct vessel because the wrong one is blocked. Leave the misplaced catheter in and pass another catheter through the same opening. Sometimes this allows one catheter to go through the ductus venosus while the other enters the portal system. The one in the portal system can then be removed (reported 50% success rate).This technique increases the risk of perforation.

   10. Connect the catheter to the fluid and tubing.

   11. Secure the catheter just like the UAC. (See Figure 24–4). Never advance a catheter once it is secured in place.

   12. Confirm placement. Incorrect UVC placement is associated with a higher complication rate. The UVC should be placed in the inferior vena cava below the level of the right atrium and above the level of the ductus venosus. Recently, some centers have used ultrasound combined with radiography for catheter placement and to verify position.

       1. Anteroposterior (AP) and lateral “babygram” (includes the abdomen and chest) are the radiographs of choice for catheter placement to confirm the position (see Figure 11–10). The UVC should be above the diaphragm but below the right atrium of the heart. The correct UVC position is catheter tip 0.5–1.0 cm (reported ranges 0–2 cm) above the right diaphragm (UVC tip at thoracic vertebrae 8–9 corresponding to the junction of the right atrium [RA] and inferior vena cava [IVC]). The lateral image is necessary to show the exact location and will show the course of the umbilical vein and ductus venosus in relation to the liver. Note: On the radiograph, sometimes air can be seen in the portal venous branches immediately after UVC insertion. As an isolated transient finding, it should not be confused with portal air due to necrotizing enterocolitis.

          1. Thoracic level on CXR did not accurately predict catheter position. UVC lines were found to be located at a wide range of vertebral bodies (T6-T11) by echocardiogram. Recommendations vary on what thoracic level the UVC line should be at T8-T9, T9, or T9-T10.

          2. Some clinicians suggest radiography is unreliable in confirming catheter tip position. Lateral CXRs were found to not accurately predict catheter placement. The AP underestimates the incidence of left atrial placement and lateral radiograph overestimates left atrial placement.

          3. Bedside ultrasound/echocardiography is an option. Ultrasound more accurately confirms the position of the catheter tip than x-ray and reduces the exposure of ionizing radiation.

       2. Venous Po₂ and saturation can be obtained, but only has a sensitivity of 45% and specificity of 95%.

       3. Gold standard is considered echocardiography with saline contrast injection to document distal catheter location.

       4. If bright red blood (arterial blood) is obtained, then the UVC has crossed the foramen ovale, and the catheter needs to be pulled back.

   13. There is insufficient evidence to support or refute the routine use of prophylactic antibiotics with UVC (Cochrane reviews). Do not use topical antibiotic ointment or creams at umbilical catheter insertion sites, as these will promote fungal infections.

UVC removal should be as soon as possible because of the higher risk of colonization and infection with longer indwelling times. Compare the markings on the UVC to another catheter of the same size and review placement to determine the distance needed to pull the UVC to the 2-cm mark.

1. Make sure the umbilical tie is loosely tied and remove any sutures or tape.

2. Withdraw the catheter slowly until about 2-5 cm remains.

3. Tighten the umbilical tie and stop the infusion.

4. Pull the rest of the catheter out slowly (rate of 1 cm/min).

5. Apply pressure and once bleeding has stopped, loosen the umbilical tie.

6. Send tip for culture if suspect infection. Observe stump for excessive oozing or hemorrhage.

Risk of complications is high (10–50%). Keep the catheter tip in the ductus venosus or inferior vena cava and not at the foramen ovale, portal vein, or hepatic vein. Remember, you can have complications from appropriately placed UVC.

1. Infection. The most commonly reported adverse effect. Minimize the risk by strict sterile technique, never advancing a catheter that has already been positioned, and limiting indwelling time. Sepsis is the most common, cellulitis, omphalitis, endocarditis, septic emboli, liver abscess, and lung abscess (with malposition of UVC into right pulmonary vein). AAP recommends to remove and not replace the line if any signs of central line–associated bloodstream infection are present.

2. Cardiac complications. Pericardial effusion is the second most common complication. It can be asymptomatic and suspected in infants with catheters and progressive cardiomegaly. Right atrial arrhythmias can be caused by a UVC inserted too far and irritates the heart. Cardiac tamponade, cardiac perforation, pneumopericardium, and thrombotic endocarditis have also been reported.

3. Thrombotic or embolic phenomenon. The most important risk factor is placement of central catheters. Never allow air to enter the end of the catheter. A nonfunctioning catheter should be removed. Never try to flush clots from the end of the catheter. Emboli can be in the lungs (if catheter passes through ductus venosus), liver, (catheter at portal system and ductus venous is closed), or anywhere in systemic circulation (catheter is through the ductus venosus, and there is right to left shunting through the ductus arteriosus or foramen ovale). Careful monitoring is indicated in very low birthweight infants who have a hematocrit >55% in the first week of life, as there is an increase in UVC-associated thrombosis in this group. AAP recommends removing the line if thrombosis is present.

4. Blood loss/hemorrhage. Occurs if tubing becomes disconnected (use Luer lock connections).

5. Retroperitoneal fluid extravasation (genital, buttocks, thigh, abdominal), total parenteral nutrition/IV fluid, ascites, hemoperitoneum.

6. Necrotizing enterocolitis. Thought to be a complication of UVCs, especially if left in place for >24 hours.

7. Fungal infections of the right atrium. Reported complication of 13%.

8. Pulmonary edema, hemorrhage, infarction (with/without hydrothorax), hydrothorax can occur from a catheter lodged in or perforated pulmonary vein.

9. Portal vein hypertension. Caused by a catheter positioned in the portal system.

10. Hepatic complications include necrosis, calcification, laceration, abscess, biliary venous fistula formation, infusate ascites, subcapsular fluid collections, and portal venous air/hematoma/erosion. Do not allow a catheter to remain in the portal system. In case of emergency placement, the catheter should be advanced only 2–3 cm (just until blood returns) to avoid hepatic infusion. If the UVC perforates an intrahepatic vascular wall, a hematoma may result.

11. Other rare complications. Creation of a false luminal tract, vessel perforation, hydrothorax, hepatic cyst, digital ischemia, perforation of the peritoneum, hemorrhagic infarction of the lungs, colon perforation, perforation of the Meckel diverticulum (UVC inserted through a narrow lumen in the umbilical cord mistaken for an umbilical vein), persistent neonatal hypoglycemia, ascites with peritoneal perforation), fluid in the peritoneal cavity from a perforated umbilical vein, Wharton jelly embolism, gangrene of the extremity (UVC placed in iliac artery branches).