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Intravascular lines are indicated when access to the venous or arterial circulations is necessary. An IV line may be positioned in peripheral veins (scalp, hand, forearm, foot, ankle, axilla, thigh) or central veins (superior vena cava via the internal jugular, axillary, superficial temporal, posterior auricular, or subclavian venous approach (36) (37) and the inferior vena cava via the umbilical or femoral venous approach) (Fig. 18-9) . Likewise, intra-arterial lines may be positioned peripherally (radial, posterior tibial, dorsalis pedis, or superficial temporal arteries) or centrally (abdominal or thoracic aorta via an umbilical or femoral artery approach). Techniques to secure access to these intravascular spaces are discussed in the following sections (see Chapters 19 and 20) . Note that 50% nitrous oxide in oxygen administration to the patient (see Chapter 35) may facilitate these vascular procedures by reducing pain and anxiety. (38) The use of lidocaine-prilocaine (Emla) cream has been shown to decrease the pain associated with venipuncture and venous cannulation in children as well. (39) (40)
Figure 18-9 Technique for peripheral venous
catheterization. A, The catheter is directed
at a 10° to 20° angle toward the insertion site and advanced until
blood return is seen in the catheter and hub. The stylet is removed, and
the T-extension tubing is attached. B, Taping
technique for butterfly and intravascular catheters using a crisscross pattern.
C, Hand and forearm secured to an arm board.
D, Covering with the plastic wrapper from
the T-extension tubing for protection.
In general, peripheral IV lines are indicated when the patient is unable to attain medical and nutritional goals with enteral therapy. These lines provide maintenance fluids to support adequate hydration and serve as a route for administering medications. In the acute setting, peripheral IV lines provide a route for administering resuscitative medications and fluids as well as antibiotics.
Materials needed for placement of a peripheral IV line in an infant are listed in Table 18-4 . The 2 devices commonly used for peripheral IV insertion are the butterfly needle and the plastic over-the-needle catheter. The former ranges in size from 21 to 27 ga. Butterfly needles are used primarily for infusions of short duration and are removed after completion. Examples of such use include certain chemotherapeutic agents as well as single-dose antibiotic administration. Due to their rigid nature, they tend to infiltrate very easily in the active child. Placement in a vein close to a flexor surface is contraindicated. For the most part, over-the-needle catheters, such as Angiocath, Medicut, or Quikcath, have become the mainstay of peripheral venous catheterization. These thin-walled, flexible catheters range in size from 14 to 24 ga. For infants, a 22- or 24-ga catheter will suffice in most cases. The selection of catheter size is dependent on the catheter s intended purpose. In general, the smallest gauge appropriate for the clinical situation should be used. Larger diameter catheters allow for rapid administration of fluids in emergency situations. The use of T-connector extension tubing connected to the catheter after insertion facilitates withdrawal of blood for specimen collection, makes flushing the catheter and maintaining patency easier (especially while taping and securing the IV), and allows for dressing changes without disturbing the IV dressing. (41)
The clear plastic wrapper of the extension tubing package can be taped
over the hub of the catheter as a protective covering to prevent accidental
dislodgment when snagged on clothing or bed linen or subjected to the wandering
| 22- or 24-ga venous catheters |
| Tourniquet (rubber band for infants) |
| IV solution and tubing |
| T-connector extension set |
| Pretorn tape (½-, 1-, and 2-inch) |
| Alcohol pads |
| Povidone-iodine swabs (for blood culture) |
| Arm or leg board |
| Non-sterile examination gloves |
| Sterile 2 × 2-in. or 4 × 4-in. gauze pads |
| Protective covering (container from IV catheter or T-extension set) |
| IV fluid chamber with microdrip |
| A continuous infusion pump |
| Saline flush solution |
| 3- or 5-mL syringes |
A number of IV sites are available for placement of a peripheral IV needle or catheter in the infant (see Fig. 18-2) . (36) (37) The most common sites chosen for IV insertion in infants and children are the superficial veins of the dorsum of the hand; the antecubital fossa; the dorsum of the foot; and, in newborns and small infants, the scalp. The veins of the dorsum of the hand are the most often used. These vessels are relatively straight and lay flat on the metacarpals and therefore are stabilized without undue difficulty. If the hand is chosen, one should take into consideration the age and hand preference of the patient. Veins in the antecubital fossa (cephalic and basilic veins) are easily accessible; however, their angulation across the fossa may make advancement of the catheter difficult. These veins may not be easily visible and yet may be palpable. It is recommended to select the most distal vein that is large enough to accommodate the catheter and leave the larger, more proximal veins in case (1) initial attempts are unsuccessful or (2) prolonged IV therapy may be needed and percutaneous central venous catheter placement is contemplated. Tributaries of the dorsal venous arch on the dorsum of the foot, like those on the dorsum of the hand, are relatively straight, and the extremity is easily immobilized after insertion. Because indwelling catheters in this location will prevent mobility, this site should be considered only in preambulatory patients or after attempts at other sites have been unsuccessful. The scalp veins are probably the easiest to cannulate, but their use is primarily limited to infants <1 year of age. If a peripheral vein on the hands, feet, or antecubital fossa is being used, the extremity can first be immobilized by taping it to an arm board, a padded splint, a full plastic IV fluid bag, or a sandbag. The particular site is a matter of preference, and the physician should choose the vein that appears to be the easiest to cannulate.
With few exceptions, the same techniques used for IV insertion in adults may be used in infants and children, especially in the veins of distal extremities. If a peripheral extremity is used, a tourniquet may be placed proximal to the planned site of entry. Although not in widespread use, nitroglycerin ointment (0.4-0.8 mg) is advocated by some physicians to induce local vasodilation, thereby aiding venous cannulation. (42) The tubing of the butterfly infusion set or the T-extension set should be flushed before venipuncture with a sterile IV solution, such as normal saline, to prevent air embolism. If a plastic catheter is used, the catheter with stylet in place is directed through the skin at a 10° to 20° angle (see Fig. 18-9 A). (43) The catheter with stylet is slowly advanced until blood return is noted. One then advances
The catheter is fixed to the skin with a piece of 0.5 in. tape passed around and over the catheter hub and fixed to the skin. A second piece of tape is placed adhesive side uppermost under the catheter hub and crossed over the catheter in a V shape (see Fig. 18-9 B). The tubing of the T-extension set is looped back, and a piece of tape is placed midway over the tubing and secured to skin. This ensures against accidental dislodgment if the IV tubing is suddenly pulled. The hand and forearm are securely taped to the arm board for immobilization (see Fig. 18-9 C). The clear plastic wrapper of the extension tubing package is then taped over the hub of the catheter as a protective covering (see Fig. 18-9 D). Occasionally the flow rate of the infusion may be positional, especially if the catheter spans a joint or abuts a venous valve. Careful repositioning or adjustment of the hand position or catheter with strategically placed sterile gauze or slight withdrawal of the catheter may be all that is required to remedy the problem.
If blood specimens and blood cultures are needed, one can obtain these simultaneously during IV insertion and spare the child an additional needlestick. The procedure is similar to venipuncture, with the following exceptions. The T-extension tubing and attached syringe should not contain any flush solution. After appropriate preparation of the insertion site and successful placement of the catheter into the vein, the T-extension tubing and syringe are connected to the hub of the catheter, and the blood is aspirated into the syringe. After the desired quantity is obtained, the syringe is removed, and the T-extension tubing is connected to the IV infusion tubing, and the infusion pump is set at the desired rate.
If the scalp veins are used, the area surrounding the planned site of insertion should be shaved and cleansed with an iodine solution. Arteries and veins can usually be differentiated on the scalp by the fact that arteries are more tortuous than veins. In addition, the flow of blood is away from the heart in arteries and toward the heart in veins. If an artery is entered during placement of the needle and fluid is infused, blanching will occur in the area. If this happens, the catheter or needle should be removed, light pressure should be maintained for several minutes, and the procedure should be repeated at another site. A rubber band may be used as a tourniquet around the scalp (never the neck) to produce venous dilation. One should always ensure that the rubber band is removed after venous cannulation. When removing this rubber band, it should be carefully slipped over the catheter or butterfly needle or cut with a pair of scissors. Although cutting the rubber band with scissors is often the easiest technique, the clinician must take care to hold both ends of the cut rubber band to avoid having the infant ""snapped"" by one or both ends of the rubber band. Placing a piece of tape on the rubber band before placement on the scalp will facilitate lifting the rubber band away from the scalp.
If a scalp vein butterfly infusion set is used, the wings of the butterfly are grasped between the thumb and forefinger, and the needle is introduced beneath the skin approximately 0.5 cm distal to the anticipated site of vein entrance (Fig. 18-10) . The needle is advanced slowly toward the
Figure 18-10 Using a rubber band as a tourniquet to distend the scalp veins, the
needle is introduced approximately 0.5 cm distal to the anticipated site
of the vessel puncture. Gloves should be worn.
After the wings are secured with tape, the tubing of the butterfly set should be taped in a loop on the scalp so that it is not inadvertently pulled. A wisp of cotton may be placed under the wings of the butterfly if the infusion is positional. A small plastic medicine cup or half of a paper cup may be taped over the wings and the needle to protect the IV line (Fig. 18-11) . The catheter of the butterfly set should then be connected to the tubing from the IV system, and the IV pump should be started.
Complications of IV fluid therapy include infection (44) ; injection of sclerosing agents into the SQ space, with resultant necrosis and sloughing of the skin (especially in small infants) (45) ; air embolism (46) ; and administration of inappropriate volumes of fluid. The incidence of infection secondary to peripheral IV therapy may be decreased by routine periodic replacement of the needles. (47) Because the life span of an IV needle or catheter is usually fairly short (<72 hours) in the small infant, the decision concerning elective removal and replacement of the IV system is not usually a problem. Of course, it is important to pay meticulous attention to sterility during insertion and maintenance of the IV system to decrease the risk of infection.
A simulator (Medical Plastics Laboratory, Gatesville, TX) is available to demonstrate and practice the proper technique for placement of peripheral IV needles in infants. (48)
With the development of small IV catheters and butterfly needles and the rapidity and safety of intraosseous (IO)
Figure 18-11 Protecting the IV line with a plastic
medicine cup.
Successful venous catheterization in the small infant requires sterile instruments, an assistant, good lighting, and a selection of catheters. The use of self-retaining retractors is a personal preference. Because of temperature instability, a warming light or an overhead radiant warmer is frequently useful. Silastic catheters, which can be obtained in 2, 3, and 4 Fr sizes (Dow-Corning Company), seem to remain patent longer, and can be sterilized with the instruments to make a ""cutdown tray."" Standard 18- to 22-ga IV catheters (Angiocath, Deseret Medical, Inc., Sandy, Utah) are also useful.
The clinician should begin with complete immobilization of the thigh, leg, ankle, and foot by taping them to a padded arm board, which in turn is attached to the table or bed where the procedure is being performed (see Fig. 18-12 A). The area around the medial malleolus is prepared with a povidone-iodine solution and draped with sterile towels. Local anesthesia is accomplished by superficial infiltration with 0.25 to 1% lidocaine in an area proximal and anterior to the superior portion of the medial malleolus. Fortunately, there are no major nerves or tendons that accompany the vein in this location (see also Chapter 22) .
A tourniquet is placed in the midleg, and a transverse skin incision is made; a small mosquito hemostat is inserted into the wound, with the concavity of the clamp upward. The tip of the hemostat is advanced to the bone in one corner of the wound, and all tissues lying against the bone and in the SQ region are ""scooped up"" with the hemostat (see Fig. 18-12 B). This will invariably lift the vein out of the wound along with surrounding tissues. A fine forceps or a mosquito hemostat is used to separate and remove all nonvenous structures, leaving only the saphenous vein tented over the hemostat (see Fig. 18-12 C). To avoid injury to the vein during dissection, one spreads the ends of the hemostat parallel to the direction of the vein, never transversely.
Two 4-0 silk sutures are passed under the vein; one silk suture is pulled distally to stabilize the vein, and the other suture is pulled proximal to the site of venipuncture. The distal suture may be tied, but if left untied, it can still be used for stabilization of the vein. Removal of the untied distal suture following vein cannulation may allow for subsequent vein recannulation following eventual catheter removal. If the distal suture is left untied, longitudinal traction on it permits hemostasis and continued exposure of the vein above the wound. Fine scissors or a scalpel blade may be used to make an oblique or V-shaped incision in the anterior (superficial) vein wall between the sutures (see Fig. 18-12 D). The catheter (beveled at its tip) is then filled with saline.
The catheter is grasped with forceps and is advanced into the vein for a distance of 2 to 3 cm (see Fig. 18-12 E and F). This is usually the most difficult and time-consuming portion of the procedure. A vein dilator or forceps may be used to hold open the incision in the vein (see Fig. 18-12 G). Downward pull on the distal tie will give countertraction and will stabilize the vein during catheter advancement. The tourniquet is then removed. One ties the proximal suture around the vein with the catheter inside, taking care not to occlude the catheter by tying the suture too tight. If the distal suture was tied, the free ends of the suture can be tied around the catheter, providing additional stability to the catheter. If the distal suture was not tied, it is now removed. When the distal suture is left untied, the proximal suture is still tied to secure the catheter, but the ends are left long so that the suture can be pulled out of the incision and removed to allow recannulation once the infusion catheter is removed.
Continued infusion of saline through the catheter from an attached syringe will ensure patency. The catheter is oriented into either corner of the incision, and the incision is closed with interrupted 4-0 nylon sutures. The skin suture nearest the catheter is wrapped around the catheter and tied to hold the catheter in place. Bleeding can be controlled with direct pressure. Antibiotic ointment is placed over the wound, and a sterile occlusive dressing is applied. The IV tubing is connected and taped securely to the foot board to prevent inadvertent removal of the catheter (see Fig. 18-12 H).
One should change the dressing carefully every day, using sterile technique with reapplication of antibiotic ointment. When cared for properly, catheters can remain in place for as long as 7 to 10 days. Generally, though, a line is replaced, using another site, after 3 to 4 days. Obviously, at the first sign of infiltration or infection the catheter must be removed. Unfortunately, once the vein has been used for a cutdown, it is usually rendered useless for future venous cannulation.
Figure 18-12 Venous cutdown (saphenous
vein). A, Immobilization of the ankle and
the site of skin incision. B, A curved hemostat
scoops up the vein. The point of the hemostat should be kept against the
bone. C, The vein is dissected free. D, With a proximal and distal tie to stabilize the vein
and control bleeding, an incision is made in the upper one third of the vein.
E and F,
The infusion catheter is threaded into the vein lumen and advanced. A vein
lifter/dilator facilitates placement of the catheter into the vein lumen.
H, The incision is sutured, and the catheter
is secured. ( C from Suratt PM, Gibson
RS: Manual of Medical Procedures. St. Louis, CV Mosby, 1982. Reproduced by
permission.)
Figure 18-13 The mini-cutdown procedure
using a standard IV catheter over-the-needle system is technically easier
than the full cutdown and may be preferred in an emergency.
The cannulation of a small vein with a catheter or tube may be difficult and very time consuming if one is not experienced in the technique. As an alternative, the mini-cutdown procedure may be used. Once the vein is exposed through a skin incision and SQ dissection, it is cannulated directly with a standard IV catheter (Medicut, Angiocath) rather than nicked with a scalpel (Fig. 18-13) . A silk suture or hemostat may be placed under the vein to immobilize it during puncture, but with the mini-cutdown technique, the vein is not tied off after being cannulated. The catheter will not be as secure with this modification, but the technique is useful when time is critical. The vein is not destroyed with this technique. In essence, the mini-cutdown uses the percutaneous technique of cannulation, except that venipuncture is performed through a skin incision under direct visualization (see Chapter 22) .
In an emergency situation, if a percutaneous peripheral or central venous access is not available within several minutes, a saphenous cutdown should be performed (see previous discussion). The technique requires practice and may consume 5 to 15 minutes of resuscitation time. One common error is making an improper skin incision. The incision must be made through all layers of the skin without severing the vein. SQ fat should be visible through the incision. The SQ incision should be carried to the end of the skin incision so that the clinician can take full advantage of the skin incision. A 2-cm incision is usually required, and one should not try to work through a skin incision that is too small.
One should perform dissection only with a blunt technique, spreading the hemostat parallel to the course of the vein. Inadvertent severance of the vein may occur during dissection, and one can best control bleeding by pulling the silk ties taut. The incision in the vessel may be a source of frustration. One must incise completely into the lumen of the vessel; a superficial nick, although it will bleed, will not allow for catheter passage. If the vein is severed completely, it will retract from view and will be difficult to find. Generally an incision should include one third of the vessel diameter. Placing the catheter into the vessel lumen is usually the most difficult part of the procedure, and it is easy to create a false lumen. Small plastic vein dilators are available to facilitate entering into the lumen. If a valve is encountered during passage, one should increase the rate of fluid administration while gently advancing the catheter.
In addition to the problems discussed previously, venous cutdowns can result in wound infections and phlebitis. Adjacent structures may be injured during the incision and subsequent blunt dissection. When the mini-cutdown technique without ligatures is used, extravasation of infusate may result. Light pressure on the closed wound will generally prevent continued extravasation.
Percutaneous placement of central venous lines (CVLs) has become the technique of choice of many clinicians for securing central venous access in neonates and young infants (see Chapter 24) . (49) (51) (52) This technique has largely supplanted the conventional technique of venous cutdown catheterization. Both percutaneous and venous cutdown catheterization require central venous catheters, which can be purchased separately or within self-contained kits (Arrow International, Inc., Reading, PA; Gesco International, San Antonio, TX). However, CVL placement requires little additional equipment, whereas venous cutdown catheterization requires a set of sterile instruments. Percutaneous CVL placement also preserves the access veins for repeated use, whereas the venous cutdown technique has traditionally included ligation of the access vein. Finally, the percutaneous approach avoids the tissue injury associated with surgical incision and dissection. (53) It may be used for rapid venous access in emergency situations, as well as to secure central venous access when peripheral venous access is limited (e.g., in low-birth-weight infants). (49) (54) (55)
Percutaneous central venous cannulation is indicated to secure vascular access (1) when peripheral venous access is limited or impossible, (2) for emergency drug and fluid administration during cardiac arrest and shock, (3) when hyperalimentation and IV infusions are required for days to weeks, (4) when low-birth-weight neonates and young infants require central venous access, and (5) when precise hemodynamic monitoring is needed in a critically ill or injured child. Contraindications to percutaneous placement of central venous catheters include an uncorrected coagulopathy; local infections or burns at insertion sites; malformations or deformations that may distort vascular anatomy; vascular insufficiency of an extremity; obstruction or compression of the access veins by tumor, abnormal vessels, hematoma, thrombus, abscess, or malformation; absence of access veins; or a planned future transfemoral cardiac catheterization. (55) Bacterial septicemia is a relative contraindication, and delaying placement of central venous access until cultures have been sterile for 48 hours is generally recommended.
Percutaneous central venous catheterization in infants and children can be performed using any of a number of sterile over-the-needle catheters ranging in size from 22 to 16 ga
Other necessary equipment includes sterile forceps and scissors, povidone-iodine solution, gauze pads, sterile drapes, gowns, gloves, caps and masks, syringes (3 mL, 5 mL, and 10 mL), Tegaderm (Medical Products, Inc., St. Paul, MN), Op-Site (Smith and Nephew Medical, Massilon, OH), or other sterile transparent skin coverings, Luer-Lok three-way stopcocks, 0.25 to 1.0% lidocaine, flush solution (1 to 2 U heparin per mL normal saline or D5 W), and IV tubing with a T-connector extension. Depending on the access vein to be used, restraint of the extremity, pelvis, or head may require a padded support, an assistant, or both.
Percutaneous placement of central venous catheters can be accomplished using 2 methods that differ only in the use of a guide wire. The guide wire (Seldinger) technique is preferred when catheters are inserted into the femoral vein or subclavian vein. When using the basilic or cephalic vein of the forearm and antecubital space, axillary vein, or superficial temporal or posterior auricular scalp vein, we prefer to insert the catheter through an introducer needle. Some investigators may use the saphenous vein as an access vein. Details of the pediatric femoral, external and internal jugular, and subclavian and antecubital approaches follow.
Previously, central venous catheters were most commonly inserted by cutdown on the external or internal jugular vein or high saphenous vein or by percutaneous cannulation of the subclavian or internal jugular vein. (56)
The safety and efficacy of percutaneous femoral venous catheterization have been demonstrated. (21) (52) (57) Femoral venous catheterization is the central venous access route most commonly used in infants and children in emergency situations. Advantages of this technique are several. The femoral anatomy is easily learned, and the arterial pulse provides a landmark for catheter insertion. In case of inadvertent arterial puncture or venous laceration, hemostasis can be achieved by application of direct pressure. Also, femoral catheterization is less likely to interfere with emergency procedures in the region of the head, neck, and chest during medical or trauma resuscitations. (21) In addition, the specific risks associated with subclavian and internal jugular vein catheterization (pneumothorax and carotid or subclavian artery puncture) are avoided. Risks of the procedure include thrombosis and infection; these can occur with any type of venous catheters.
The child must be adequately restrained to permit exposure of the inguinal region; sedation may be useful. It may be helpful to use an ultrasonic Doppler flow detector to locate the femoral artery and then place a heavy ink mark on the abdomen in the line of the femoral artery. This may be useful if edema makes palpation of the artery difficult or if the artery is difficult to locate when wearing gloves. Note that during CPR, palpable pulsations or Doppler tones in the femoral vein may be detected. (58) Hence, if the vein is not found medial to the pulsations, catheterization of the pulsating vessel during cardiopulmonary resuscitation (CPR) may be considered as a last resort when other options for vascular access or drug delivery are unavailable. Both groins are generally prepared with povidone-iodine in the event that the initial attempt is unsuccessful.
The introducer needle supplied with the kit can be used with or without a syringe to enter the femoral vein. The femoral artery is palpated with 1 finger, and the needle is placed in the skin just medial to the artery. One enters the skin at a 30° to 45° angle approximately 1 cm below the inguinal ligament. The general course of the needle is in a line directed toward the umbilicus. When blood return is noted, the wire is gently passed through the needle into the proximal vein. An alternative method that may be useful when placing the 4 Fr double-lumen Arrow catheter is to remove the tubing from a 21-ga butterfly needle (Abbott Hospitals, Inc., North Chicago, Ill) and use the needle to enter the vein (Fig. 18-14 A). The butterfly needle is very easy to hold in a stable position and is also shorter than the needles supplied with the assembled kits. When blood return is obtained, the wire is passed through the butterfly needle into the proximal vein.
A small incision (1 to 2 mm) is then made along the wire to allow passage of the vein dilator (Fig. 18-14 B). The dilator is removed; the catheter, which has been flushed with saline, is advanced over the wire into the vein; and the wire is then removed (Fig. 18-14 C). (59) Occasionally it is useful to rotate and advance the catheter simultaneously as it enters the vein. Blood return is noted from the catheter ports, which are then flushed with a heparinized saline solution (10 U/mL). The catheter is subsequently secured with silk or nylon sutures (Fig. 18-14 D). A sterile transparent skin covering placed over the exit site may be used as an impermeable dressing.
This technique is useful in children as small as 1000 gm. When one is placing femoral venous catheters in children <1500 gm, a smaller single-lumen catheter (3 Fr or 24 ga) should be used, because a larger catheter may occlude blood flow in the femoral vein. (4)
The external jugular vein is superficial and easily visible. This site should be selected for catheterization only after catheterization of other, more peripheral sites has been unsuccessful. Also, the external jugular vein should not be chosen as a primary catheterization site during resuscitative efforts, since manipulation of the head and neck may compromise management of the airway. In young infants, use of the Seldinger technique is difficult due to the short length of the infant s neck, as well as the low success rate of central venous catheter placement resulting from the acute angle of entry of the external jugular vein into the subclavian vein. (60)
The external jugular vein lies in a line from the angle of the jaw to the middle of the clavicle and is
Figure 18-14 Technique for inserting a femoral venous catheter.
A, A 21-ga butterfly catheter is used to
enter the femoral vein, and the guide wire is passed through the butterfly
needle into the proximal vein. Note that the tubing has been removed from
a standard butterfly set. B, A small incision
is made alongside the wire, and the dilator is advanced over the wire and
into the vein. C, The catheter is advanced
over the wire and into the vein. D, The wire
is removed and the catheter secured. Note that many commercial kits have
a self-contained 21-ga needle, making modification of a butterfly needle
catheter unnecessary.
Using an 18- to 22-ga catheter with a syringe, the catheter is aligned parallel to the vein, and the skin is punctured approximately one half to two thirds of the distance from the angle of the jaw to the clavicle. The catheter is advanced slowly until the jugular vein is entered. The syringe is connected to the catheter at all times to maintain a constant negative pressure and avoid an air embolism. After the appropriate amount of blood is obtained, the catheter is advanced and secured in place. If the Seldinger technique is used, proceed as described for femoral catheterization. The catheter should be passed far enough to reach the superior vena cava-right atrium junction. The catheter is checked for blood return, and the line is secured with sutures and a sterile occlusive dressing applied. (61) A chest radiograph is warranted to assess the proper location of the catheter, as well as to rule out the possibility of an iatrogenically induced pneumothorax.
The internal jugular veins lie within the carotid sheath containing the carotid artery and vagus nerve. The lower part of the veins lies within the triangle formed by the sternal and clavicular heads of the sternocleidomastoid muscle and becomes more lateral and anterior to the artery as the veins join the subclavian
Three approaches (the anterior, medial or central, and posterior approaches as discussed in Chapter 24) to internal jugular catheterization are possible. The medial or central approach is recommended in pediatric patients and will be described here. The child is positioned in the same fashion as that described for external jugular venous catheterization. The medial or central approach uses the apex of the angle formed by the sternal and clavicular heads of the sternocleidomastoid muscle as the entry site. The skin surrounding the area to be punctured is cleansed with alcohol. The area is covered with a sterile drape, and 1% lidocaine may then be infiltrated into the skin. Using an 18- to 22-ga needle with a syringe, the needle is introduced at the apex of the triangle at an angle of 30° downward relative to the coronal plane and directed caudally toward the ipsilateral nipple (Fig. 18-15) (Figure Not Available) . The needle is advanced slowly until the jugular vein is entered. The syringe is connected to the needle at all times to maintain a constant negative pressure and avoid an air embolism. After blood flow is obtained, the syringe is removed, and a finger is placed over the hub of the needle. A guide wire is then inserted during a positive-pressure breath or exhalation, the needle is removed, and a catheter is introduced using the Seldinger technique (see Chapter 21) . The catheter should be passed far enough to reach the superior vena cava-right atrium junction. The catheter is checked for blood return, the line is secured with sutures, and a sterile occlusive dressing is applied. (61) A chest radiograph is warranted to assess the proper location of the catheter, as well as to rule
Figure 18-15 (Figure Not Available) Technique for internal
jugular venous catheterization (medial or central approach). The needle is
inserted at the apex of the triangle formed by the sternal and clavicular
heads of the sternocleidomastoid muscle. The needle is angled 30° downward
relative to the coronal plane and directed toward the ipsilateral nipple.
(From Textbook of Pediatric Advanced Life Support, 1994. Reproduced
with permission. Copyright American Heart Association.)
The subclavian vein is a popular route of central venous access in the adult patient but is used far less frequently in children. The technique is more difficult in the child because of the vessels smaller size, as well as their more cephalad location under the clavicles. An infraclavicular approach to the subclavian vein has been used, but due to the high risks of pneumothorax and hemothorax, especially when performed during emergencies, this approach should be considered only if other peripheral or central venous access sites are unobtainable. (62) (63) The younger the patient, the higher the risks of these complications. Also, subclavian venous access may interfere with resuscitative efforts, and except in very small infants and obtunded children, heavy sedation and adequate restraint are often required.
The technique for subclavian venous catheterization differs from that for the adult in that the approach to the vein is more lateral in children. The equipment needed is the same as that used for femoral catheterization. The patient is placed in the Trendelenburg position with the head turned away from the side to be punctured and a towel roll placed under the shoulders (Fig. 18-16) (Figure Not Available) . The right side is preferred, since the dome of the lung is more cephalad on the left side. The needle insertion site is at the distal one third of the clavicle in the depression created between the deltoid and pectoralis major muscles. If the patient is awake, sedation should be administered. The skin is prepped with antiseptic solution, the area covered with a sterile drape, and the skin infiltrated with 1% lidocaine.
An entry point is created at this location using a scalpel blade. The catheter needle is introduced and advanced slowly while negative pressure is applied with the attached syringe. The syringe and catheter needle should be parallel to the frontal plane and directed medially and slightly cephalad, beneath the clavicle toward the posterior aspect of the sternal end of the clavicle (i.e., with the lower end of the fingertip placed in the sternal notch). (64) The needle is advanced until blood return is obtained. The catheter can be advanced a few more millimeters further to ensure its position in the vein. Catheter functioning can be assessed by the ability to withdraw blood and flush saline without difficulty. At this point, a large-bore catheter can be inserted using the Seldinger technique as previously described for femoral catheterization. Auscultation of bilateral breath sounds should be performed and a chest radiograph obtained to confirm the proper positioning of the catheter in the superior vena cava, as well as to rule out procedural complications such as pneumothorax or hemothorax. The catheter is then secured in place with sutures, and a sterile, occlusive dressing is applied.
Percutaneous insertion of central catheters by way of peripheral antecubital veins is used most frequently to obtain central venous access in patients with very small caliber vessels (e.g., low-birth-weight neonates and very young infants). These peripherally inserted central catheter (PICC) lines are small Silastic catheters ranging in size from 23 to 16 ga. (55) (65) (66) The catheter is inserted through a peripheral vein through a 19-ga butterfly needle or 20-ga angiocatheter. The most common sites include scalp, neck, and arm veins. The catheter is then threaded centrally. PICC lines offer several advantages over conventional peripheral
Figure 18-16 (Figure Not Available) Technique for subclavian venous catheterization. The needle is inserted
at the distal one third of the clavicle in the depression created between
the deltoid and pectoralis major muscles. The needle should be parallel to
the frontal plane and directed medially and slightly cephalad toward a fingertip
placed in the sternal notch. The patient is shown in a 30° Trendelenburg
position. (From Textbook of Pediatric Advanced Life Support, 1994.
Reproduced with permission. Copyright American Heart Association.)
The vessel to be cannulated is initially stabilized using a support board or the help of an assistant. The remainder of the procedure requires sterile technique. Povidone-iodine is used to cleanse the skin overlying the vessel to be cannulated, and 0.25% to 1% lidocaine is infiltrated at the skin site to be punctured. This skin site is punctured with an 18-ga needle to ease insertion of the introducer through the skin. The catheter to be inserted is chosen based on the size of the access vessel.
Typically a 23-ga silicone elastomer catheter with other needed accessories is used, as in a kit prepared by Gesco International, Inc. (San Antonio, Texas). Advantages of this catheter include (1) a double-wing silicone adapter, which precludes the need to make homemade blunt-end adapters to fit small cannulas and simplifies the taping procedure, and (2) a breakaway introducer needle that can be peeled off the catheter, thereby precluding the need for sliding the introducer off the catheter and placing an adapter. Because the length of this catheter (33.5 cm) is longer than needed in low-birth-weight neonates and young infants, the distance from the insertion site to the superior vena cava-right atrium junction is estimated (i.e., by measuring the distance between insertion site and the right nipple (Fig. 18-17 A)), and the catheter is cut 1 to 3 cm longer than the estimated distance to compensate for variability between the estimated and actual needed length of the catheter. The end of this catheter is then connected to a Luer-Lok stopcock and syringe and filled with flush solution; the catheter is then ready for use.
Figure 18-17 Techniques for insertion
of central catheters from peripheral veins. A,
A tape measure is used to determine the catheter length. B, Placement of the catheter through the specialized breakaway
butterfly-type introducer needle.
The 20-ga breakaway introducer needle (Gesco International, Inc.) is also filled with flush solution and then directed slowly through the insertion site and into the access vein. When blood return occurs, the catheter is picked up approximately 1 cm from its tip and guided into the introducer needle (Fig. 18-17 B). The catheter is advanced in 1-cm increments until the previously estimated distance is reached (i.e., the catheter tip is at the superior vena cava--right atrium junction). The breakaway introducer needle is then withdrawn several centimeters from the insertion site before peeling the introducer off the catheter to avoid inadvertent catheter laceration. If accidental laceration occurs, blunt-end adapters should be readily available.
Immediately after catheter placement and withdrawal of the introducer needle, the clinician will be able to manipulate the position of the catheter. Once clotting occurs around the catheter at the insertion site, however, the catheter becomes difficult to manipulate. In addition, after the sterile field is discontinued, the catheter should never be advanced. The function of the catheter is checked by withdrawing blood, by noting the presence of residual air bubbles within the catheter, or both. After the clinician is assured that no air bubbles remain in the line, the catheter is flushed. This catheter should be ""easy"" to flush; if it is not, the clinician should reposition the catheter and recheck its function. If the catheter remains difficult to flush, it should be considered clotted and should be removed. Alternatively, position may be confirmed by chest radiograph and fibrinolytic therapy used, if considered appropriate.
A transparent skin covering is placed and is removed only when the catheter is removed; it is not routinely removed as are coverings of some surgically placed central venous catheters. Stabilization sutures are not routinely placed during this procedure. Occasionally a small amount of bleeding occurs at the insertion site; this generally stops spontaneously or with gentle pressure. With the three-way stopcock in place, central venous pressure measurement and infusion of medications, IV fluids, and hyperalimentation solutions can be performed.
The incidence of complications from central venous catheterization ranges from 10% to 50%. (65) (68) (69) (70) Infection and thrombosis are the major risks associated with these catheters. (53) (71) (72) Other complications include accidental displacement, phlebitis, hemorrhage, hematoma, dysrhythmia, air embolus, vascular obstruction or perforation, right atrial perforation, and localized edema. Blood sampling from indwelling central venous lines must be performed with caution, because the risk of contamination increases each time the system is opened. Morbidity from complications can be minimized by removing catheters as soon as they are no longer needed. Occasionally infections associated with central venous lines can be successfully treated with antibiotics alone. In the majority of catheter-associated infections, however, the catheters must be removed to resolve the infection. Colonization of the catheter tip is related to in situ time, younger age, and inotropic support. (73) Central venous catheters are generally free of colonization if used for no more than 3 days in infants under 1 year and no more than 6 days in older children. Right atrial and major vessel thrombus formation can be monitored using echocardiography; treatment with fibrinolytic agents is occasionally successful in restoring catheter patency. (74) These types of catheters have been used for up to 80 days, with a mean duration as long as 34 days, in very-low-birth-weight neonates. (53) (55) Most clinicians find that the majority of these catheters are discontinued because they are no longer needed. (49)
The first steps in managing pediatric resuscitations are to establish an adequate airway, ensure adequate ventilation, and enhance blood circulation. Maintaining or reestablishing adequate circulation often requires prompt access to the intravascular space for administration of fluids and/or medications. The difficulty of obtaining venous access during pediatric resuscitations can be considerable. (75) (76) In the review by Rossetti and colleagues, IV access required 10 or more minutes in 24% of the cases. Only 6% of cases had no IV line established before attempts at resuscitation were halted. The average time required for a cutdown was 24 minutes. Children who were successfully resuscitated had vascular access achieved significantly sooner than those who were not resuscitated. Emergency IV access was most prolonged in children <2 years of age. (75) This last finding is important, since the majority of cardiopulmonary arrests in children occur in this younger age group.
If no IV line is available, appropriate drugs can be given via the endotracheal tube (see Chapter 27) while attempts at venous access are initiated. The initial attempts at venous access should consist of peripheral placement by percutaneous venipuncture; however, if such placement is unsuccessful within the first 1 to 2 minutes, an IO line should be started in children <6 years of age, and percutaneous central venous cannulation or saphenous venous cutdown should be performed in children older than 6 years of age. (64) The femoral vein is often the central vein of choice in emergencies, because its consistent anatomic location and large size make it the safest and easiest central vein to catheterize. The femoral vein also can be accessed with minimal interference to resuscitative efforts. However, pulsations may be present in the vein during CPR, thus making the distinction between femoral vein and femoral artery challenging. (58)
An IV protocol for resuscitations helps eliminate the common mistake of persisting with futile attempts at peripheral sites and wasting precious time (Fig. 18-18) (Figure Not Available) . (54) If experienced personnel are available, a simultaneous cutdown of the greater saphenous vein at the ankle or the groin can be performed. One advantage of a cutdown at the groin level is that the saphenous vein can be cannulated and a double-lumen catheter advanced into the femoral vein for rapid fluid infusions through one port and medication administration through the other port. Depending on the experience of the physicians involved in the resuscitation effort, a subclavian or internal jugular catheter insertion may be attempted; however, these are not easy procedures, and attempts may interfere with chest compressions and securing of the airway. One group reported a 92% success rate with percutaneous subclavian vein catheterization in critically ill infants using a Seldinger technique. (63)
The major indication for umbilical vein catheterization is access to the vascular system for emergency resuscitation
Figure 18-18 (Figure Not Available) Priorities for emergency vascular
access in infants and children. (From Textbook of Pediatric Advanced
Life Support, 1994. Reproduced with permission. Copyright American Heart
Association.)
The supplies and equipment for catheterization are listed in Table 18-5
. Although unlikely to be needed
for most emergency
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Infusion solution (usually D5-10
W with electrolytes. Some physicians also add 1 unit heparin per milliliter
of fluid to ""prevent"" clotting in the catheter) Fluid chamber,
IV tubing, infusion pump, filter (0.22 mum), short length of IV tubing,
three-way stopcock Umbilical artery catheter (3.5 to 5 Fr) 3-0 silk suture on a curved needle Curved iris forceps without teeth Small clamps, forceps, scissors, needle holder Sterile drapes Light source 10 mL of heparinized solution for flush (1 to 2 units heparin per milliliter of fluid) Surgical cap, mask, gown, and gloves |
The infant s extremities are restrained using gauze wrapped around the ankles and wrist and pinned to the bed. An assistant is used to hold the umbilical stump up. The cord is scrubbed with a bactericidal solution. Pooling of liquid at the infant s side should be avoided, because this may be associated with blistering of the skin under a radiant warmer. The umbilical area is draped in a sterile fashion, with the infant s head left exposed for observation.
To provide hemostasis and to anchor the line after placement, a pursestring suture is placed at the junction of the skin and the cord (Fig. 18-19) . Alternatively, a constricting loop of umbilical tape in the same position may be used. The cord is cut about 1 cm from the skin, and the vessels are identified. The vein is usually located at 12 o clock and has a thin wall and large lumen and may continue to bleed after cutting, whereas the two arteries have thicker walls and smaller lumina, and constriction prevents bleeding after being cut. Occasionally a persistent urachus may be mistaken for the umbilical vein, but the return of urine should identify the mistake.
The catheter (3.5 Fr (preterm infants) to 5.0 Fr (term infants)), which has been flushed with heparinized saline
Figure 18-19 When placing an umbilical vein catheter, a pursestring
suture or umbilical tape is passed around the base of the cord to provide
hemostasis and to anchor the line.
The inferior vena caval site may be a desirable location in some newborn infants in whom peripheral vascular access is limited and for whom central venous access is desired for central venous pressure monitoring or infusion of medications, high concentrations of glucose (>10%), IV fluids, and hyperalimentation solutions. The catheter must be inserted approximately 10 to 12 cm in a term-sized infant to reach the inferior vena cava. The portal vein site can be verified by radiographs that document the placement of the catheter. Note that an umbilical venous catheter will proceed directly cephalad (without making a downward loop) until it passes through the ductus venosus (Fig. 18-20) (Figure Not Available) . Of course, in a resuscitation, radiographic documentation may not be possible. Therefore, it is generally recommended that the catheter be inserted approximately 4 to 5 cm to minimize the risk of injecting sclerosing solutions into the liver.
Air embolism may occur at the time of catheter removal if the infant generates sufficient negative intrathoracic pressure (as during crying) to cause air to be drawn into the patent umbilical vein. Therefore, caution must be used during catheter removal to ensure that the vein is promptly occluded (by tightening a pursestring suture or applying pressure on or just cephalad to the umbilicus).
Complications of umbilical venous catheters include hemorrhage, infection, injection of sclerosing substances into the liver (resulting in hepatic necrosis), air embolism, and vessel perforation. It is most important that one follow careful technique in insertion and maintenance of catheters to minimize such complications.
Umbilical artery catheterization is a useful procedure in the care of newborn infants who require frequent monitoring of arterial blood gases and arterial blood pressure, fluid and medication administration, and exchange transfusions. It is imperative for the clinician to remain aware of potential complications. (78) (79) (80) One of the two umbilical arteries may be cannulated for resuscitation purposes, but an umbilical vein is generally technically easier to cannulate and may be preferred in an emergency.
The equipment required for umbilical artery catheterization is identical to that used for umbilical venous catheterization. Additional equipment needed for continuous arterial pressure monitoring and infusion should be readily available.
The technique of umbilical artery catheterization is similar to that
described for umbilical vein catheterization in the preceding section. After
the umbilical arteries have been located, the cord is grasped with a curved
hemostat near the selected artery (Fig. 18-21)
. This maneuver is important, because it provides clear visualization
and stabilization of the vessel. Using the curved iris forceps without teeth,
one gently dilates the artery. Umbilical artery spasm may make the procedure
difficult. A 3.5 to 5 Fr catheter is attached to a three-way stopcock and
is flushed with sterile heparinized solution. The catheter may then be introduced
into the dilated artery. A 3.5 to 4 Fr catheter is recommended for infants
weighing <2 kg and a 5 Fr catheter for those weighing 2 kg.
When the catheter is being inserted, tension should be placed cephalad on the cord, and the catheter should be advanced with slow, constant pressure toward the feet (Fig. 18-22) . Resistance is occasionally felt at 1 to 2 cm and should be overcome by gentle, sustained pressure. If the
Figure 18-20 (Figure Not Available) An umbilical vein catheter is directed toward the head and remains anterior
until it passes through the ductus venosus into the inferior vena cava. (From Ludwig S, Fleisher GR: Textbook of Pediatric Emergency Medicine. Baltimore,
Williams & Wilkins, 1994.)
Figure 18-21 The umbilical cord is grasped with a curved hemostat near the selected
artery. The umbilical artery is then dilated with curved iris forceps.
The optimal position of the catheter tip in the descending aorta remains the subject of much debate. (81) (82) (83) If a low (L3 to L4) position is desired, the catheter may be advanced 7 to 8 cm in a 1-kg premature infant or 12 to 13 cm in a full-term infant. Graphs are available to estimate the proper length of insertion for a high or low catheter location. (84) (85) Once sterile technique is broken, the line may not be advanced. It is therefore preferable to position the catheter too high and to withdraw as necessary according to the location on a radiograph. After it has been positioned appropriately, the catheter should be tied with the previously placed suture (Fig. 18-23) and taped to the abdominal wall. A radiograph should be obtained and the catheter repositioned, if necessary, with the tip at the lower border of the L3 vertebra. Some clinicians prefer to place the catheter high (T6 to T9 vertebrae). There are no unequivocal data to support either preference. (86) (87)
Radiographs of an arterial catheter (Fig. 18-24) will show the catheter proceeding from the umbilicus down toward the pelvis, making an acute turn into the internal iliac artery, continuing toward the head into the bifurcation of the aorta, and then moving up the aorta slightly to the left of the vertebral column. (88)
Most unsuccessful umbilical artery catheterization attempts fail because the catheter perforates the arterial wall approximately 1 cm below the umbilical stump, where the umbilical artery begins curving toward the feet. (89) In this instance, the catheter is advanced in the extraluminal space, and resistance is met at 4 to 6 cm. The following maneuvers make it possible to avoid perforating the umbilical arterial wall in most cases:
The use of a placenta or a commercially available simulator
Figure 18-22 The catheter is introduced into the
dilated artery and advanced toward the feet. The suture placed around the
base of the cord is tied to the catheter.
Figure 18-23 The tape is pleated above and below the catheter.
If the catheter becomes plugged or fails to function properly or if there is blanching or discoloration of the buttocks, the heels, or the toes, then the catheter should be removed at once. Umbilical arteries are most easily cannulated in the first few hours of life but may provide a viable vascular route as late as 5 to 7 days of age.
Complications include hemorrhage, (92) infection, (93) (94) (95) thromboembolic phenomena (especially to the kidneys, the gastrointestinal tract, and the lower extremities), (96) (97) (98) aortic thrombosis, (99) aortic aneurysm, (100) vasospasm, air embolism, vessel perforation, peritoneal perforation, hypertension, (101) (102) and possible effects of plasticizers. (103)
Despite the growing use of noninvasive devices for monitoring transcutaneous oxygen and carbon dioxide, percutaneous
Figure 18-24 The umbilical artery catheter makes a loop downward before
heading cephalad (schematic drawing of a radiograph interpretation).
Percutaneous radial artery catheterization has become widely accepted and has been shown to be a safe method in infants and children. (110) The catheter allows for preductal blood gas determinations if placed in the right radial artery. Only the procedure for radial artery catheterization is described here, but catheterization of other vessels is similar.
The following are contraindications to peripheral arterial catheterization:
The equipment needed for arterial catheterization is essentially the same as that required for percutaneous peripheral venous catheterization (see Table 18-4) . The catheters used are usually 22- or 24-ga over-the-needle catheters, a T-piece connector, and a stopcock. One should connect the T piece and the stopcock and then fill them with normal saline solution. An infusion pump with heparinized saline (1 to 5 U/mL) should be readied. (111)
The procedure should be performed with good lighting and an adequate work area, with the infant s heart and respiratory rates monitored closely. The radial artery may be palpated proximally to the transverse wrist crease on the palmar surface of the wrist, medial to the styloid process of the radius. The artery is then compressed, and the hand and
A fiberoptic transilluminator may be used to localize the artery. With the overhead lights off, the transilluminator head (with a rubber shield or filter to prevent overheating the skin) is positioned beneath the wrist, and the artery is visualized as a dark, pulsatile shadow. (112) (113)
The infant or child s hand and lower forearm are secured to an arm board with the wrist dorsiflexed 45° to 60° with the aid of a roll of gauze placed underneath. Care must be taken to leave the fingers exposed to assess the peripheral circulation. The radial artery is palpated at the point of maximal impulse and can be marked with a gentle indentation by one s fingernail. The area over the radial artery is prepared with a povidone-iodine solution and washed with alcohol. A local anesthetic such as 1% lidocaine without epinephrine may be used at the planned insertion site. The catheter with stylet is inserted through the skin just proximal to the transverse wrist crease at a 10° to 20° angle (Fig. 18-25) . The catheter with needle is advanced slowly until blood appears in the catheter hub, signifying puncture of the anterior arterial wall. The catheter is slowly advanced further until blood appears in the needle and then the needle angle is carefully lowered to approximately 10°. The catheter is slowly advanced over the needle into the lumen of the artery, and the needle is removed. The stopcock and T-piece connector are attached to the catheter hub. The stopcock is opened to the syringe to confirm pulsatile blood return. It is then flushed with 0.5 mL heparinized flush solution very gently to clear the catheter while the fingers and the hand are observed for evidence of blanching or cyanosis.
The puncture site is then covered with antibiotic ointment, and the catheter is fixed to the skin by a thin piece of tape placed adhesive side uppermost under the catheter hub and crossed over the catheter in a V shape. A second piece of tape is passed around and over the catheter hub and is fixed to the wrist (Fig. 18-26) . A small piece of tape is used to attach the T-piece connector to the wrist area or to the splint. The fingers should be easily visible.
Only heparinized normal or half-normal saline is used for infusion. Some clinicians prefer to add 1 to 5 U of
Figure 18-25 The catheter assembly is introduced into the radial artery
through skin at a 10° to 20° angle. This is a smaller angle than
is used for simple arterial puncture. Gloves should be worn.
Figure 18-26 One technique of taping the arterial catheter. The arm board should
be well padded and secured.
The catheter must be removed when there is evidence of blanching or cyanosis or when it is impossible to withdraw blood from the catheter or difficult to flush the catheter.
Complications, which have been reported with every type of arterial catheter, include hemorrhage, thrombosis, spasm, infection, scars, air embolism, retrograde blood flow, transient elevation in blood pressure with rapid (<1 second) infusion, and nerve damage. Thrombosis or spasm may result in blanching or cyanosis of the extremity or skin. (114) (115) (116) There is potential for loss of digits, an entire extremity, or large areas of skin, as well as cerebral infarction with temporal artery catheters. (117) (118) (119) Malposition of the catheter such that infusion of a glucose solution flows into the celiac artery may also precipitate hypoglycemia on discontinuation of the glucose infusion. Saladino and colleagues note that complications from emergency department-placed arterial lines are uncommon and generally minor. (120)
Figure 18-27 Anatomy of the posterior tibial
artery and surrounding structures.
Figure 18-28 Posterior tibial artery cutdown
technique. With the foot prepared and immobilized, a 5- to 7-mm incision
is made in the skin posterior to and at the midline of the medial malleolus.
Curved forceps and a silk suture are inserted beneath the posterior tibial
artery, which courses just posterior to the medial malleolus.
Arterial catheterization by cutdown on the posterior tibial artery, radial artery, and temporal artery may be indicated when the need exists for frequent monitoring of arterial blood gases or blood pressure and when percutaneous access is not possible. (109) (121) Arterial cutdowns are contraindicated when (1) adequate peripheral blood gas samples can be obtained by percutaneous punctures or catheterization, (2) circulation of the extremity to be catheterized is compromised, or (3) occlusion of the vessel to be catheterized results in compromised perfusion of that extremity.
Successful arterial cutdown catheterization in the small infant requires sterile instruments, an assistant, good lighting, and a selection of catheters. Previous clinical experience is helpful. The use of self-retaining retractors is a personal preference. Because of temperature instability, a warming light or an overhead radiant warmer is frequently useful. The equipment required for performing an arterial cutdown catheterization can be found on a cutdown tray, available in most emergency departments. Also needed are a 22- or 24-ga over-the-needle catheter, T-extension connector tubing, stopcock, a 5- or 10-mL syringe filled with flush solution (normal saline with 1 to 5 U heparin/mL) and silk suture ties.
The anatomy and technique for posterior tibial arterial cutdown are described in detail (Fig. 18-27) . The same technique is applicable for the radial artery. The clinician stabilizes the foot in a neutral position by taping the externally rotated lower leg to a splint. The posterior tibial artery is then localized by Doppler ultrasound just posterior to the medial malleolus. The operator prepares for the procedure by scrubbing and donning a gown and gloves; the foot is prepared with a povidone-iodine solution.
Following SQ injection of 1% lidocaine, a 5- to 7-mm transverse incision is made in the skin over the artery posterior to and at the midlevel of the medial malleolus (Fig. 18-28) . Using blunt dissection in a vertical direction (parallel to the vessels), the tissue is separated with a small, curved forceps, and the artery is identified. The artery courses with the vein just anterior and superficial to the nerve and is usually pulsatile. One isolates the artery by sliding a small, curved forceps beneath it and gently elevating the vessel (see Fig. 18-28) . Excessive manipulation of the artery can cause spasm; if this occurs, a few drops of 1% lidocaine applied locally may result in dilation. A silk tie (without a needle) is then placed beneath the artery to stabilize it during cannulation.
Figure 18-29 Technique of inserting the
arterial catheter. A silk tie is used only to stabilize
the artery during cannulation. It is never tied. The catheter is
inserted under direct vision without making an incision in the vessel.
Figure 18-30 The skin incision is closed,
and the catheter and connector are secured to the heel with tape.
At a 10° angle, a 22-ga Angiocath with the catheter bevel down is inserted into the artery over the surface of the forceps. When blood return is seen, the catheter is advanced over the stylet to its full length (Fig. 18-29) . The needle stylet is then removed, and the catheter is connected to the T-connector tubing and a three-way stopcock that has been prefilled with heparinized flush solution. Patency is checked by observation of blood return with pulsations; the catheter is then flushed slowly and gently. The silk suture is removed, and the skin incision is sutured. The catheter is sutured to the skin over the heel. The catheter and connector are then secured to the heel with tape (Fig. 18-30) . The stopcock is then connected to the infusion line.
The complications of arterial cutdown are similar to those of percutaneous arterial catheterization. They include hemorrhage, thrombosis, or spasm resulting in loss of tissue; infections; permanent scars; and nerve damage. Complications have been reported with all types of arterial cutdown. Follow-up data and computed tomography data suggest an association between temporal artery catheterization by the cutdown technique and cerebral infarct that may result in hemiparesis. (122) Therefore, temporal artery catheterization should be the last choice for arterial catheterization.
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