Atlas of Procedures in Neonatology, 4th Edition

Vascular Access

32

Extracorporeal Membrane Oxygenation Cannulation and Decannulation

Khodayar Rais Bahrami

Gary E. Hartman

Billie Lou Short

Extracorporeal membrane oxygenation (ECMO) is defined as the use of a modified heart–lung machine combined with a membrane oxygenator to provide cardiopulmonary support for patients with reversible pulmonary and/or cardiac insufficiency in whom maximal conventional therapies have failed (1,2,3). After decades of laboratory and clinical research, ECMO is now well accepted as a standard of treatment for neonatal respiratory failure refractory to conventional techniques of pulmonary support (4,5,6,7). Most causes of neonatal respiratory failure are self-limited, and ECMO allows time for the lung to recover from the underlying disease process and for reversal of pulmonary hypertension, which frequently accompanies respiratory failure in the newborn.

Venoarterial Extracorporeal Membrane Oxygenation—Cannulation

  1. Indications

Placement of carotid arterial and internal jugular venous catheters for use in venoarterial ECMO. Venoarterial ECMO should be used in patients with significant cardiovascular instability.

  1. Relative Contraindications for Extracorporeal Membrane Oxygenation in the Neonatal Period (5,7)
  2. Gestational age <34 weeks
  3. Birthweight <2,000 g
  4. Uncontrolled coagulopathy or bleeding disorders
  5. Congenital heart disease without lung disease. Exception: Postoperative cardiac patients, a topic that will not be covered in this chapter
  6. Irreversible lung pathology
  7. Intracranial hemorrhage >Grade I to II
  8. Major lethal congenital anomaly
  9. Duration of maximum ventilatory support, >10 to 14 days
  10. Significant positive response to ventilator management and/or inhaled nitric oxide (iNO)
  11. Precautions
  12. Ensure that the patient is paralyzed before placing the venous catheter, to prevent air embolus.
  13. Recognize that:
  14. Internal jugular lines placed for intravenous access prior to ECMO may cause clot formation, resulting in the need for thrombectomy before placement of the venous ECMO catheter.
  15. Excessive manipulation of the internal jugular vein may cause spasm and inability to place a catheter of appropriate gauge.
  16. A lacerated vessel may result in the need for a sternotomy for vessel retrieval.

Appropriate instruments should be on the bedside tray or cart. A backup unit of blood should be available in the blood bank.

  1. Blood loss sufficient to produce hypotension can occur during a difficult cannulation.

Emergency blood should be available at the bedside (10 to 20 mL/kg).

  1. The vagus nerve is located next to the neck vessels and may be injured or manipulated during isolation of the vessels. Manipulation can cause bradycardia or other arrhythmias.
  2. Vital signs and pulse oximetry values must be monitored at all times because clinical observation of the infant is prevented by the surgical drapes.
  3. If the patient has been hand bag–ventilated for stabilization, do not place the Ambu bag on the bedside when surgical drapes are placed. The bag may entrap oxygen, which can result in a fire when electrocautery is used.

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  1. Personnel, Equipment, and Medications (8)

Personnel

  1. Surgical team
  2. A senior surgeon (pediatric, cardiovascular, or thoracic) with assistant
  3. A surgical scrub nurse and a circulating nurse
  4. Medical team
  5. A physician trained in management of ECMO patients and cannulation techniques, who will administer anesthetic agents and manage the infant medically during the procedure
  6. A bedside intensive care (neonatal or pediatric intensive care unit) nurse, who will monitor vital signs, record events, and draw up medications as needed by the ECMO physician
  7. A respiratory therapist, who will change ventilator settings as necessary
  8. Circuit specialists
  9. A cardiovascular perfusionist, nurse, or respiratory therapist specially trained in this procedure, who will prime the pump
  10. A bedside ECMO specialist (nurse, respiratory therapist, or cardiovascular perfusionist with special training in ECMO management), who will manage the ECMO system after the patient is on ECMO

Equipment (Fig. 32.1)

Sterile

  1. Arterial and venous catheters (9)
  2. Arterial
  3. The size of the arterial catheter determines the resistance of the ECMO circuit, because it is the part of the ECMO circuit with the smallest internal diameter and thus the highest resistance.
  4. This catheter should be as short as possible, with a thin wall and a large internal diameter (resistance is related directly to the length of the catheter and inversely to the diameter). An example of a suitable catheter is the Bio-Medicus Extracorporeal Circulation Cannula, 8 to 10 French (Fr) (Bio-Medicus, Minneapolis, MN, USA).
  5. Venous
  6. The venous catheter should have as large an internal diameter as possible to allow maximal blood flow (the patient's oxygenation is related directly to the rate of blood flow).
  7. Should be thin walled with a large internal diameter. An example of a suitable catheter is the Bio-Medicus Extracorporeal Circulation Cannula, 8 to 14 Fr. (Bio-Medicus, Minneapolis, MN, USA).
 

FIG. 32.1. Schematic diagram of venoarterial extracorporeal membrane oxygenation circuit, showing the drainage from the right atrium into the bladder of the circuit, with flow through the membrane lung, heat exchanger, and return flow to the arch of the aorta via the carotid artery catheter. (From 

Polin RA, Fox WC, eds. Fetal and Neonatal Physiology, Vol. 1. Philadelphia: WB Saunders; 1992:933

, with permission.)

  1. Surgical instruments required are listed in Tables 32.1 and 32.2.
  2. Sterile gowns and gloves
  3. Sterile saline for injection
  4. Syringes (1 to 20 mL) and needles (19 to 26 gauge)
  5. Povidone–iodine solution
  6. Povidone–iodine ointment
  7. Semipermeable transparent membrane-type dressing
  8. Absorbable gelatin sponge, for example, Gelfoam (Upjohn, Kalamazoo, MI, USA)
  9. Surgical lubricant, bacteriostatic

Nonsterile

  1. Surgical head covers and mask
  2. Pulse oximeter
  3. Surgical head light
  4. Electrocautery
  5. Wall suction
  6. Shoulder roll, for example, a small blanket, to place under infant's shoulders
  7. Tubing clamps

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Medications

  1. A long-acting paralyzing agent, for example, pancuronium bromide (0.1 mg/kg)
  2. Fentanyl citrate (10 to 20 mcg/kg)
  3. Sodium heparin (75 to 150 U/kg)
  4. Topical thrombin/Gelfoam
  5. Xylocaine, 0.25%, with epinephrine
  6. Xylocaine, 1%, plain (without epinephrine)
  7. Cryoprecipitate, thawed, or commercially available fibrin sealant (optional)

TABLE 32.1 Surgical Instruments for ECMO Cannulation

Number

Item

Place in a 12 × 18-in mayo tray with a Huck towel on the bottom of the tray.

2

Custard cup (place on inside of other cup with a 3 × 4-in sponge)

1

Medicine cup (place inside of custard cup with a 3 × 4-in sponge)

2

Straight bulldog clamps

1

Sauer eye retractor

1

Alm retractor

1

Mastoid Jansen retractor

2

Vein retractors

2

Octagonal forceps

2

7-in Gerald forceps

2

6-in DeBakey forceps

1

Adson forceps, plain

2

Adson forceps with teeth

2

No. 3 knife handles

1

Castroviejo needleholder

2

Right-angle retractors

2

Chops retractors

1

Set of Garrett dilators, nine pieces (sizes 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0)

String the following instruments from left to right on two 9-in sponge sticks or instrument stringer. Then place on top of a rolled Huck towel.

4

9-in sponge stick

1

Tonsil clamp (bleeder)

1

612-in crile

1

534-in crile

1

Baby right-angle clamp

4

Straight mosquitoes

6

Curved mosquitoes

3

Fine curved mosquitoes

2

Tubing clamp with guard

1

Ryder needleholder

1

Webster needleholder

1

Straight mayo scissor

1

534-in Metzenbaum scissor

1

Curved Steven scissor

1

Straight Iris scissor

4

Small towel clips (nonpenetrating)

1

Baby Satinsky clamp

1

Curved bulldog clamp

1

Straight bulldog clamp

1

Disposable ECMO tray (Table 32.2)

ECMO, extracorporeal membrane oxygenation. For information on suture material, see Appendix B2.

TABLE 32.2 Contents of Disposable Extracorporeal Membrane Oxygenation Tray

Number

Item

2

1-mL syringe

1

20-mL syringe

1

6-mL syringe

1

3-mL syringe

1

Needle adapter

3

Single-cavity tray

2

Gauze packages

1

Betadine ointment

1

Surgical blade no. 15 carbon

2

Semipermeable transparent dressings

1

Handle, suction frazier, 8 Fr

1

Xylocaine insert

1

Mini yellow vessel loops

1

Hand-control cautery

1

Suture, 4-0 Vicryl

1

Suture, 2-0 silk

1

Suture, 6-0 Prolene

4

Forceps, sponge

1

25-gauge needle

1

NaCl, 5-mL amp

1

3-g foil package of Surgilube

1

Surgical blade, no. 11 carbon

2

Steri-Drapes

2

Connectors, straight 14 × 14 in

1

Xylocaine 1%

1

Suction tubing, 316 in × 10 ft

1

Package sterile towels (14)

  1. Technique—Preparation for Cannulation
  2. Place infant with head to “foot” of warmer.
  3. Anesthetize the patient with fentanyl (10 to 20 mcg/kg).
  4. Paralyze the patient with pancuronium (0.1 mg/kg).
  5. Hyperextend the patient's neck with a shoulder roll, and turn the head to the left (Fig. 32.2). Make sure that the Bovie ground pad is placed at this time.

Observe closely for hypotension.

  1. Monitor vital signs and give additional fentanyl and/or pancuronium as needed (see Chapter 5).
  2. Clean a wide area of the right neck, chest, and ear with Betadine solution.
  3. Drape the infant and entire bed with sterile towels.

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  1. Use Steri-Drapes (3M Health Care, St. Paul, MN, USA) to secure the towels to the skin.
 

FIG. 32.2. Infant positioned for cannulation with shoulder roll present and head extended to the left. Position of neck incision is indicated.

  1. At the point of incision, infiltrate the skin with Xylocaine (AstraZeneca, Wayne, PA, USA) (0.25%, with epinephrine) (Fig. 32.2).
  2. Wait at least 3 minutes for anesthesia to be effective.
  3. Make a 1- to 2-cm vertical incision over the right sternocleidomastoid muscle, starting approximately 1 cm above the right clavicular head, using the electrocautery set on cutting current (Fig. 32.3).
  4. Continue to use the electrocautery to cut through the subcutaneous tissue.
 

FIG. 32.3. Landmarks over the sternocleidomastoid muscle for making the incision with electrocautery.

  1. Coagulate all visible bleeding sites.
  2. Spread the fibers of the sternocleidomastoid muscle apart with a hemostat and retract using hemostats clamped onto the muscle (Fig. 32.4).
  3. Open the carotid sheath, taking care to avoid the vagus nerve.
  4. Irrigate both the common carotid artery and internal jugular vein with 1% plain Xylocaine to vasodilate the vessels.
 

FIG. 32.4. Split sternocleidomastoid and open carotid sheath.

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  1. Encircle the artery with silicone loop, and proximal and distal 2-0 silk ties held with clamps but not tied. Avoid “sawing” the ties on the artery.
  2. Avoid excessive handling of the internal jugular vein. Some isolate the vein after cannulation of the carotid artery to avoid spasm.
  3. Estimate the length of the cannula to be inserted.
  4. Identify the sternal notch and the xiphoid process.
  5. The arterial catheter is inserted approximately one third of the distance between the sternal notch and the xiphoid process. This is typically between 3 and 4 cm.
  6. The venous catheter is inserted approximately one half the distance between the sternal notch and the xiphoid process. This is typically between 7 and 7.5 cm.
  7. Mark these distances on the catheters with a 2-0 tie, or note the distance if the cannula is marked.
  8. Heparinize the patient with a bolus of 75 to 150 U/kg of heparin, depending on the estimated risk of bleeding, and wait 60 to 90 seconds before proceeding with cannulation.
 

FIG. 32.5. A: Carotid artery isolated with vessel clamp in place and with arteriotomy site showing the placement of the 6-0 Prolene traction sutures. B (inset): Magnified view of (A).

Arterial cannulation

  1. Tie the distal ligature on the carotid artery, and place a bulldog clamp on the proximal portion of the artery.

Allow blood to dilate the artery before placing the bulldog clamp.

  1. Make an arteriotomy using a no. 11 scalpel blade, and place two traction sutures of 6-0 Prolene (Ethicon, Somerville, NJ, USA) on the proximal side of the arteriotomy (Fig. 32.5).

Always use traction sutures, to prevent intimal tears.

  1. If desired, lubricate Garrett dilators with sterile surgical lubricant and dilate the artery to the approximate size of the catheter.
  2. Place a sterile tubing clamp on the catheter. Lubricate the catheter and insert the catheter into the vessel as the bulldog clamp is removed.
  3. Secure the catheter with a 2-0 silk ligature tied over a 0.5- to 1-cm vessel loop (“bootie”) (Fig. 32.6).
  4. Place a second 2-0 silk ligature. Tie the distal tie around the catheter, and then tie the distal and proximal ties together. Some surgeons place two ties proximally and one distally for added security.
  5. Allow blood to back up into the catheter to remove air.

Venous cannulation

  1. Dissect the vein free and isolate with two 2-0 silk ties.

Do not apply traction to the vein with the ties, to avoid spasm.

  1. Place a bulldog clamp on the proximal end of the vein, allowing blood to distend it. Then tie the distal end of the vein with the 2-0 silk ligature.
  2. Make a venotomy with a no. 11 scalpel blade, and place two stay sutures of 6-0 Prolene as traction sutures, as for arterial cannulation.
  3. Lubricate the venous catheter, place a sterile tubing clamp on the catheter, and dilate the venotomy.

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  1. Insert the catheter as an assistant places traction on the proximal tie, and apply pressure over the liver to increase the backflow of blood out of the catheter (to decrease the risk of an air embolus).

There will be a slight impedance to catheter advancement at the thoracic inlet—pushing against resistance will tear the vein. Use gentle downward and posterior pressure.

 

FIG. 32.6. A: Securing the catheter with proximal and distal ties onto a “bootie.” B (inset): Magnified view of (A).

  1. Secure, as for the artery, and back blood into the catheter by pressing gently on the liver.
  2. If desired, pack the wound with absorbable gelatin sponge soaked in topical thrombin or commercially available topical fibrin sealant, to assist in hemostasis.

Cryoprecipitate and topical thrombin can be used to form a fibrin clot if dropped onto the field from separate syringes in a one-to-one concentration. Note: If they are mixed together in one syringe, they will form a solid clot in the syringe. A similar product is now commercially available as Tisseel-HV Fibrin Sealant (Baxter Hyland Division, Glendale, CA, USA).

  1. Confirm catheter placement by chest radiography and/or cardiac echocardiography, if the patient is stable (Fig. 32.7) (10). If the patient is unstable, he or she can be placed on ECMO and the radiograph taken when adequate oxygenation is achieved but prior to closing the surgical wound.
 

FIG. 32.7. Radiograph at cannulation, showing proper placement of the arterial and venous catheters. Note the radio-opaque dot indicating the end of the Bio-Medicus venous extracorporeal membrane oxygenation catheter (arrow).

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Venovenous Extracorporeal Membrane Oxygenation—Cannulation

More than 60% of neonatal ECMO patients reported in the ELSO registry have received treatment with venoarterial bypass (11). In neonates with respiratory failure, venoarterial ECMO is gradually being replaced by a venovenous (VV) technique, which uses a single double-lumen catheter (Fig. 32.8). The catheter is placed in the right atrium, where blood is drained and reinfused into the same chamber, thus requiring cannulation of only the right jugular vein, thus sparing the carotid artery. Other advantages of VV ECMO include maintenance of normal pulsatile blood flow, and the theoretical advantage that particles entering the ECMO circuit enter by way of the pulmonary rather than the systemic circulation. The design of the original VV catheter resulted in significant recirculation, limiting its use when ECMO flows >350 mL/min were required. Research by Rais-Bahrami et al. resulted in development of a new catheter design that significantly lowers the degree of recirculation (12). The double-lumen catheter should be placed within the right atrium, directing the oxygenated blood from the return lumen through the tricuspid valve to minimize recirculation. This catheter design in 12-, 15-, and 18-Fr sizes allows the use of VV ECMO in a greater number of infants (13).

 

FIG. 32.8. Schematic of the venovenous extracorporeal membrane oxygenation catheter placed in the mid-right atrium. (From Short BL. CNMC ECMO Training Manual. 2005, with permission).

  1. Double-Lumen Venovenous Catheters
  2. Kendall 14-Fr catheter (Kendall Health Care Products, Mansfield, MA, USA)
  3. OriGen 12-, 15-, and 18-Fr catheters (OriGen Biomedical, Austin, TX, USA)
  4. Advantages of Venovenous Bypass
  5. Provides excellent pulmonary support
  6. Avoids carotid artery ligation
  7. Oxygenated blood enters pulmonary circulation.
  8. Particles coming from the ECMO circuit enter the venous circulation instead of the arterial circulation.
  9. Disadvantages of Venovenous Bypass
  10. Lack of cardiac support
  11. ECMO support is dependent on the patient's cardiac function.
  12. Catheter position and rotation are extremely critical.
  13. Amount of recirculation
  14. Cannulation Technique

The cannulation technique for venovenous ECMO is essentially the same procedure as venous cannulation for venoarterial ECMO, with the following exceptions:

  1. Both internal jugular vein and carotid arteries are identified and dissected free, although the internal jugular vein is the only vessel cannulated with the double-lumen venovenous catheter. A silastic loop may be tied loosely around the artery to facilitate potential conversion to venoarterial flow.

Both vessels are isolated in case a rapid conversion to venoarterial bypass becomes necessary.

  1. The catheter is advanced in a direction with the arterial side upward and anterior to the venous limb of the double-lumen cannula.

Caution: Avoid bending the catheter or creating a “crimp” in the catheter.

Correct positioning of the catheter helps direct the oxygenated blood return toward the tricuspid valve, thus minimizing the recirculation of the oxygenated blood back to the ECMO circuit.

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  1. The proximal end of the internal jugular vein is also cannulated for cephalad drainage, that is, a jugular bulb catheter. This catheter is connected to the venous tubing of the ECMO circuit via a Luer connector. For this, we use a custom-made Carmeda heparin-coated Bio-Medicus venous catheter, made specifically for use as a cephalad catheter.

This allows additional venous drainage to the ECMO circuit, prevents venous congestion, and also allows for cephalic venous saturation measurement.

  1. If using a jugular bulb catheter to measure cerebral saturations, care should be used when entering the circuit; air will draw into the venous side of the circuit rapidly if a stopcock is loose or is left open.
  2. Placing Patient on the Extracorporeal Membrane Oxygenation Circuit

The circuit has been previously primed with packed cells/albumin. The priming procedure and the surgical placement of the ECMO catheters should be timed so that the two are completed at the same time. Priming of the circuit is beyond the scope of this chapter.

  1. Fill catheters with sterile saline. Connect them to the ECMO circuit by inserting the ¼X¼-in connectors into the tubing as the assistant drips sterile saline into the ends of the circuit tubing and the catheter, to ensure that all residual air is eliminated prior to connection.
  2. Do not squeeze the tubing while attaching; air will enter when the tubing is released.
  3. If air is seen in the tubing, the catheters must be disconnected from the circuit. Prior to reconnection, air is removed, and the catheters are reconnected as described in E.1.
  4. Remove all sterile tubing clamps from the catheters, and have a nonsterile assistant hold the catheters. Nonsterile tubing clamps remain in place on the arterial and venous sides of the circuit at this juncture.
  5. Place the patient on ECMO by removing the arterial clamp, placing a clamp on the bridge (Fig. 32.9a), and removing the venous clamp. This will remove all nonsterile clamps from the circuit.
  6. Increase ECMO flow in 50-mL increments over 20 to 30 minutes, until adequate oxygenation is achieved (usually at 120 mL/kg/min).

Transfusion may be needed if hypotension occurs at this stage.

  1. Decrease the ventilator settings and oxygen concentration gradually as the ECMO flows are increased.

Typical resting ventilator settings for venoarterial ECMO are at a rate of 10 to 15 breaths/min, a peak pressure limit of 15 to 20 cm H2O, and FiO2 of 0.21 to 0.30. For venovenous ECMO, it is recommended to keep ventilator settings at a rate of 20 to 30 breaths/min, a peak inspiratory pressure of 20 to 25 cm H2O, and FiO2 of 0.30 to 0.50.

  1. Closure of the Neck Wound
  2. Obtain radiographic confirmation of appropriate catheter position and achievement of an adequate flow rate through the ECMO circuit prior to closure of the neck wound.
  3. Cut and remove traction sutures.
  4. Approximate the skin with a running 4-0 Vicryl (Ethicon) suture on an atraumatic needle.
  5. Tie the Vicryl suture, and use the tails of the suture to secure each catheter.
  6. Tie catheters together with another silk tie.
  7. Anesthetize the area behind the ear with 0.25% Xylocaine with epinephrine.
  8. Use 2-0 silk suture on a noncutting needle to place a stitch behind the ear and tie around the catheter to secure in place. Place a separate stitch for each catheter.
  9. Tie catheters together, dress the incision with povidone–iodine ointment, and cover the area with semipermeable membrane dressing.
  10. Tape the circuit tubing securely to the bedside to reduce traction on the catheters.
  11. Complications
  12. Torn vessels, more commonly the vein
  13. This risk is decreased if 6-0 Prolene stay sutures are always used.
  14. Do not attempt to use too large a catheter.
  15. Aortic dissection associated with arterial cannulation (14)
  16. Blood loss, particularly during the venous cannulation, when side holes in the catheter are outside the vein
  17. Venous spasm, resulting in inability to place a large enough venous catheter to meet the required ECMO flow to support the patient adequately

The rate of blood flow is impeded by the small gauge of the catheter, requiring that a second venous catheter be placed in the femoral vein. The two catheters must be Y-connected together into the ECMO circuit.

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  1. Arrhythmias and/or bradycardia can occur, owing to stimulation of the vagus nerve
  2. Hypotension, due to an increase in the intravascular space when the patient is connected to the ECMO circuit
  3. Conversion to venoarterial from venovenous ECMO. This will occur if:
  4. The patient remains hypoxic despite adequate ECMO flow.
  5. The patient remains hypotensive despite vasopressor support.
  6. Cerebral venous saturations remain persistently <60% after adequate flows and ventilator management have been undertaken.

Converting from venovenous to venoarterial ECMO requires cannulation of carotid artery with a Biomedicus arterial catheter, and the double-lumen venovenous catheter must be “Y'd” in together to make a double-lumen venous drainage catheter (Fig. 32.9).

Extracorporeal Membrane Oxygenation—Decannulation

 

FIG. 32.9. Schematic view of converting from venoarterial (A) to venovenous (B) ECMO. The double-lumen venovenous catheter is “Y'd” together to make a double-lumen venous drainage catheter.

  1. Indications
  2. Removal from ECMO after lung recovery

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  1. Removal from ECMO because of a complication such as uncontrolled bleeding or failure of lung recovery
  2. Contraindications

All intensive support is being withdrawn, and permission for autopsy is obtained. It is usually optimal to remove the catheters during the autopsy.

  1. Precautions
  2. The patient must be paralyzed during the removal of the venous catheter to avoid an air embolus.
  3. The vessels are fragile and may tear. A backup unit of blood should be available at the bedside.
  4. Delay removing catheter for 12 to 24 hours in cases in which there is a high risk of reoccurrence of pulmonary hypertension—for example, severe congenital diaphragmatic hernia.
  5. Personnel, Equipment, and Medications

Personnel

Same as for cannulation, with the exception of the primer, which is not required

Equipment

Sterile

  1. Surgical tray with towels and suture as for cannulation
  2. Semipermeable transparent dressing
  3. Povidone–iodine ointment
  4. Syringes (1 to 20 mL) and needles (18 to 26 gauge)
  5. Unit of blood
  6. Absorbable gelatin sponge

Nonsterile

Same as for cannulation

Medications

  1. Fentanyl (10 to 20 mcg/kg)
  2. Vecuronium bromide (0.2 mg/kg)

A short-acting paralyzing agent is preferred because of the relatively short duration of the procedure. This allows the infant to breathe spontaneously as soon as possible after decannulation, which facilitates rapid weaning from ventilator support.

  1. Xylocaine, 0.25%, with epinephrine
  2. Topical thrombin
  3. Protamine sulfate (1 mg only)
  4. Technique

Postdecannulation vessel reconstruction is beyond the scope of this chapter.

  1. Place the neck in an extended position, using the shoulder roll.
  2. Give fentanyl for relaxation, prior to giving vecuronium.

Because of the risk of air embolism during the removal of the venous catheter, the infant must not be allowed to breathe during decannulation. If two doses of vecuronium do not produce paralysis, give pancuronium.

  1. Increase ventilator setting to a rate of 40 to 50 breaths/min, a peak inspiratory pressure of 20 to 25 cm H2O (depending on chest movement), and FiO2of 0.30 to 0.40 after paralytic agent is given.
  2. Clean the neck, and drape as for cannulation.
  3. Anesthetize with 0.25% Xylocaine with epinephrine.
  4. Cut and remove the Vicryl suture.
  5. Remove absorbable gelatin sponge packing, exposing the catheters and vessels.

If a jugular bulb catheter is in place, it is usually removed first to allow better visualization for removal of the venovenous ECMO catheter.

  1. The jugular bulb catheter should be clamped off before its removal, after the patient is taken off bypass. Be aware that removing the catheter while on bypass without a clamp in place will result in the introduction of air into the circuit.

In case of venoarterial ECMO, the venous catheter is usually removed first because it is most readily accessible.

  1. Separate the catheter from surrounding tissue by blunt dissection.
  2. Encircle the vein with a 2-0 silk tie, which is used for traction and hemostatic control.
  3. Place a Satinsky clamp around the vein to stabilize the catheter (Fig. 32.10).
  4. Place a 2-0 silk tie proximal to the clamp.
  5. Cut the silk ties securing the catheter in the vein with a no. 11 scalpel blade. The two proximal ties should be cut where they cross the vessel loop (“bootie”).
  6. Ask the ECMO specialist to remove the patient from the ECMO circuit.
  7. Monitor vital signs and oxygen saturation as an indication that ventilator settings are appropriate. Settings may have to be increased when the patient is removed from the circuit.

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  1. Provide an inspiratory “hold” on the ventilator while the surgeon places pressure on the liver and removes the catheter. Failure to do this can result in air embolus.
  2. Replace any significant blood loss.
  3. Cut the 2-0 silk traction suture and tie the suture proximal to the Satinsky clamp. Remove the Satinsky clamp.
  4. Isolate the arterial catheter, dissect free, and remove.

The decannulation procedure is the same as for the arterial catheter, with the exception that an inspiratory hold is not required.

  1. Give protamine (1 mg IV) after removal of both catheters.

Administration of protamine is not mandatory if there is no significant bleeding.

  1. Irrigate the wound with sterile saline and cauterize any bleeding sites.
  2. If desired, pack the wound with a thrombin-soaked absorbable gelatin sponge and close the neck incision using subcuticular horizontal sutures of 4-0 Vicryl.
  3. Remove the sutures holding the cannula behind the right ear.
  4. Place povidone–iodine ointment over the incision and cover with semipermeable transparent dressing.
 

FIG. 32.10. Placement of Satinsky vessel clamp prior to removal of extracorporeal membrane oxygenation catheter.

  1. Complications
  2. Vessel laceration, which may require a sternotomy for correction
  3. Excessive blood loss
  4. Venous air embolus

References

  1. O'Rourke PP, Crone RK, Vacanti JP, et al. Extracorporeal membrane oxygenation and conventional medical therapy in neonates with persistent pulmonary hypertension of the newborn: a prospective randomized study. Pediatrics.1989;84:957.
  2. UK Collaborative ECMO Trial Group.UK Collaborative Randomised Trial of Neonatal Extracorporeal Membrane Oxygenation. Lancet.1996;348:75.
  3. Elbourne D, Field D, Mugford M.Extracorporeal membrane oxygenation for severe respiratory failure in newborn infants. Cochrane Database Syst Rev. 2002:CD001340.
  4. Kanto WP, Shapiro MB.The development of prolonged extracorporeal circulation. In: Zwischenberger JB, Steinhorn RH, Bartlet RH, eds. Extracorporeal Cardiopulmonary Support in Critical Care. 2nd ed. Ann Arbor, MI: Extracorporeal Life Support Organization; 2000:27.
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