Central Venous Catheterization & Arterial Catheterization

James Allen, MD

I. Central venous cannulation

A. flow rates

1. depends on both diameter & length

2. peripheral IVs often equal in flow rates compared to CVCs

3. actual rates (Pediatr Emerg Care 1986; 2:153):

a) 14g/2 inch: 93 ml/min

b) 16g/2 inch: 75 ml/min

c) 16g/5.25 inch: 64 ml/min

d) 18g/2 inch: 62 ml/min

e) 18g/8 inch: 13 ml/min

f) 20g/2 inch: 42 ml/min

g) 24g/.75 inch: 14 ml/min

B. indications for CVCs:

1. inadequate peripheral veins

2. CVP monitoring

3. administration of phlebitic medications

4. rapid fluid replacement

5. CPR (medications reach the heart unpredictably from peripheral veins during cardiac arrest with CPR)

6. frequent phlebotomy

7. long term IV therapy

8. dialysis

9. TPN

10. vasoactive drug administration

C. specific sites:

1. general contraindications

a) physician inexperience

b) coagulopathy

c) thrombolytic therapy

d) severe thrombocytopenia

e) inability to identify landmarks

f) infection or burn at planned site

g) uncooperative patient

2. internal jugular vein

a) contraindications

(1) SVC thrombosis

(2) COPD

(3) high levels of PEEP

(4) tracheostomy with excessive secrestions

(5) intracranial pressure elevation

b) advantages

(1) pneumothorax uncommon

(2) high success rate

(3) head of bed access

(4) control of bleeding easy

(5) right IJ represents straight path to the right atrium (malposition unlikely)

(6) less failure with inexperience

c) disadvantages

(1) not ideal for prolonged central venous access

(2) uncomfortable

(3) dressings difficult to maintain

(4) left IJ has risk of thoracic duct injury

(5) poor landmarks in obese patients

(6) not ideal for temporary dialysis access

(7) difficult access with tracheostomies

(8) difficult to establish access during emergent intubation

(9) higher incidence of infection

3. subclavian vein

a) contraindications

(1) SVC thrombosis

(2) upper extremity trauma

(3) COPD, asthma

(4) high levels of PEEP

(5) coagulopathy

b) advantages

(1) comfortable

(2) easy to maintain dressings

(3) better landmarks in obesity

(4) vein less collapsable in hypovolemia or shock

(5) better access when airway control is being established

(6) lower incidence of infection

c) disadvantages (New Engl J Med 1994; 331:1735-8)

(1) higher risk of pneumothorax (1.5%)

(2) compression difficult if bleeding occurs

(a) artery puncture in 3.7%

(b) mediastinal hematoma in 0.6%

(3) requires experience for success

(a) 32% failure rate for interns

(b) 10.5% failure rate for residents

(c) 11.7% failure rate for attendings

(4) catheter malposition frequent

(5) inaccessible from head of bed position

(6) difficult to place during CPR

4. femoral vein

a) contraindications

(1) IVC filter

(2) femoral or vena caval thrombosis

(3) absent femoral pulse

(4) penetrating abdominal trauma

(5) cardiac arrest or low flow rates

(6) requirements for patient mobility

b) advantages

(1) fast & easy with high success rate

(2) does not interfer with CPR

(3) does not interfer with airway placement

(4) no risk of pneumothorax

c) disadvantages

(1) takes longer for drugs to reach central circulation during CPR

(2) complications possible in patients with abdominal pathology

(3) prevents patient mobilization

(4) difficult to keep site sterile

(5) difficult to pass PA catheter

(6) high incidence of DVT

(a) reported to be 25% when patients are prospectively evaluated by duplex ultrasound (Crit Care Med 1995; 23:52-9)

(b) in a randomized trial of 289 patients, femoral lines were associated with a 21.5% incidence of thrombosis compared to a 1.9% incidence of venous thrombosis with subclavian lines (JAMA. 2001;286:700-707)

(7) high incidence of infection

(a) in a randomized trial of 289 patients, femoral lines were associated with a 19.8% incidence of infection compared to a 4.5%% incidence of infection with subclavian lines (JAMA. 2001;286:700-707)

D. positioning (Chest 1995; 107:1662-4):

1. catheter tip position is optimally in the SVC and not in the heart

a) cardiac perforation can occur by tip erosion

b) cardiac arrhthmias can occur by tip irritation

2. positioning equations to insure SVC tip position:

a) right subclavian:

(1) (height/10) - 2 cm

b) left subclavian:

(1) (height/10) + 2 cm

c) right internal jugular:

(1) (height/10) - 1 cm

d) right subclavian:

(1) (height/10) + 4 cm

3. average length of catheters appropriately placed:

a) males:

(1) right subclavian: 15.6 cm

(2) left subclavian: 19.5 cm

(3) right internal jugular: 17.1 cm

(4) left internal jugular: 21.1 cm

b) females:

(1) right subclavian: 14.1 cm

(2) left subclavian: 17.9 cm

(3) right internal jugular: 15.7 cm

(4) left internal jugular: 19.2 cm

E. infection:

1. whether to routinely replace CVCs at set time periods is uncertain

a) routinely replacing CVCs every 3 days had an equal number of line infections as replacing when clinically indicated (fever, malfunction, site infection; average = 6 days) in one study of 160 patients (New Engl J Med 1992; 327:1062-8)

b) one study found that there was an equal incidence of infection in lines that were replaced either at a new site OR guidewired at the original site. Both forms of line replacement had a higher incidence of infection than "de novo" lines at any given time point after placement of the line. The overall incidence of infection was 2% of all lines. (Mayo Clin Proc 1996; 71:838-46)

c) the incidence of catheter-related infections rises with the number of days the cathter is in place beyond 3 days

d) the issue of whether CVCs should be routinely changed is controversial and there is no definite recommendation at this time (Federal Register, 1995; 60:49978-50006)

e) the incidence of infection in antiseptic coated catheters is 4-fold reduced (Maki, et. al., ICAAC Clinical Infection Abstacts, 1991 & Bach, et. al., J. Antimicrob. Chemo. 1994, 33:969-78)

2. the role of re-guiding CVCs is also uncertain

a) re-guiding CVCs has a lower incidence of mechanical complications but a similar incidence of catheter infection compared to placing a new line at a new site (New Engl J Med 1992; 327:1062-8; Crit Care Med 1992; 20:1426-30)

3. types:

a) site infection

(1) purulence around the catheter insertion site

b) tunnel infection

(1) cellulitis involving the subcutaneous tunnel of long-term catheters (Hickmans, Groshongs)

c) catheter colonization

(1) generally defined as > 15 colony forming units on a catheter segment using a "roll plate" techinque (N Engl J Med 1977; 296:1305-9)

d) catheter sepsis

(1) defined as clinical sepsis with positive blood cultures and > 15 CFU on the CVC quantitative culture

(2) often presumptively diagnosed when no organism is grown from the blood despite fever

4. etiology:

a) skin insertion site

(1) most important site of infection

(2) careful decontamination of the site with topical disinfectants and antibiotics decrease CVC infections

(3) transparent plastic dressings increase catheter infection (JAMA 1992; 267:2072-6)

(4) usually Staphylococcus aureus, S. epidermidis, & candida

b) catheter hub

c) infusate

(1) usually gram negative bacteria

d) hematogenous seeding of the catheter

(1) rare

5. prevention (Ann Intern Med 2000; 132:391-402):

a) chlorhexidine prep is associated with a 4-fold decrease in catheter infection than 70% alcohol or povidone-iodine prep (Lancet 1991; 338:339-43)

b) povidone-iodine ointment at the insertions site does not reduce the probability of infection but topical polymyxin-neomycin-bacitracin does (Am J Med 1981; 70:739-44); a new chlorhexidine "sponge" (Biopatch) is currently the optimal antimicrobial dressing

c) antibiotic coated catheters have a 50% lower incidence of infection

d) perform a > 15 second hand wash with chlorhexidine (or equivilent) before placing the catheter

e) use a gown, gloves, mask, and hat

f) if using povidone-iodine, allow it to dry for full antibacterial effects

g) provide a large enough sterile area using drapes so as to minimize the chance of contamination; a full sterile barrier sheet is preferred over the smaller sterile drapes normally contained within the CVC kits

h) do not routinely use antibiotic ointment at the catheter insertion site after the line is placed; povidone-iodine ointment does reduce infection of hemodialysis catheters when administered at the catheter insertion site and should be additionally used in immunosuppressed patients receiving CVCs in whom there is a high likelihood of Staph. aureus carriage

i) specialized catheter hubs filled with iodinated alcohol or hub-protective povidone-iodine-saturated sponges can reduce catheter infections but are not yet available in the United States

j) the subclavian approach has a lower incidence of infection than the IJ approach (An J Med 1991; 91:197S-205S)

k) stopper on hubs should be adequately cleansed with alcolhol pads before inserting needles

6. current OSU catheter policy:

a) do not routinely change CVCs

b) a CVC may be re-guided only for mechanical failure

c) use antiseptic-coated catheters if anticipated duration of use is > 3 days (there are many such catheters available; the Arrow catheter kit is preferable at this time)

d) TPN ports must be dedicated as such and not used for other purposes

e) replace non-sterile lines and "code blue" lines at the earliest convenience

f) replace tubing every 72 hours

(1) tubing used for blood, TPN, or lipid emulsions (ie, propofol, amphotericin B, etc.) should be changed every 24 hours

g) remove line as soon as it is no longer needed

h) convert IV meds to oral as soon as possible to minimize the number of times the tubing circuit must be opened

i) catheter tips should not be routinely cultured but do send the tip (removed and cut under sterile conditions) when line infection is suspected

(1) send a concurrent pediatric blood culture tube with 3 cc of blood drawn from the line

(2) send a concurrent standard blood culture tube from a peripheral site

F. thrombosis

1. mural thrombosis very common (38% of CVCs) although clinical DVT is less frequent (JAMA 1994; 271:1024-6)

2. femoral sites should be avoided except under circumstances that prevent use of alternative access sites

II. Arterial line placement

A. sites:

1. radial artery first choice

a) contraindication = absence of collateral ulnar flow

(1) occurs in Å 15-20% of patients

(2) assess with Allen's test first

(a) occlude both ulnar & radial arteries

(b) have patient open and close the hand until blanching occurs

(c) release ulnar pressure

(d) color return to entire hand should occur in < 7 seconds

(e) color return in > 14 seconds is abnormal

(f) color return in 7-14 seconds is indeterminate

b) after lidocaine anesthesia, introduce the needle at 45°

c) pentration of both sides of the artery is frequent; therefore, withdraw the needle slowly since you may atain good bevel position during withdrawl

d) do not alter the angle or direction of the needle while the needle is still under the skin but not in the vessel since the artery can be lacerated

e) reducing the angle of the needle to Å 15-20° after penetration of the artery allows easier threading of the guidewire

f) if difficulty is encountered, measures which can occasionally be helpful include:

(1) wrapping the wrist and hand in a warm towel

(2) increasing intravascular volume with isotonic solution

(3) placing a small amount of topical nitroglycerin over the artery

(4) identifying the artery by doppler flow prior to preping the entrance site

2. femoral artery second choice

a) can use a larger (18g) catheter

b) shave the groin first

c) approach 1-3 cm below the inguinal ligament to prevent perforation of the peritoneum or a smaller iliac artery branch

d) contraindications = severe atherosclerosis or absence of a femoral pulse

3. dorsalis pedis third choice

a) modified Allen's test can be performed using the posterior tibial artery but this has not been validated as effective; the patient should at least have a posterior tibial pulse

b) if there is peripheral vascular disease, the true central BP may be underestimated

c) because of wave mechanics, the systolic BP may be overestimated and the diastolic BP may be underestimated; the mean arterial pressure should be correct and is the preferable parameter to follow when using dorsalis pedis lines

d) this site has an increased incidence of thrombosis (Br J Anaesth 1987; 59:482)

4. brachial artery should not be used because of potential thrombosis

B. complications:

1. bleeding

a) most risky in femoral artery cannulation since pressure within the pelvis cannot be applied

2. distal ischemia

a) partial obstruction occurs in 20-48% of cannulations

b) incidence decreases with smaller gauge catheters (non-tapered 20g catheters better than 18 g catheters)

c) catheter placed by cut down have a higher incidence of occlusion

d) permanant ischemia is rare, occurring in 0.5% of cannulations

3. infection

a) incidence (2-8%) is reported to be similar to that of CVCs (J Crit Ill 1989; 63:381) although in our experience it is lower

b) infection is minimized by limiting stopcock manipulation, limiting phlebotomy through the arterial line, and changing line every 4 days

c) the current recommendations by the CDC includes routine changing of the a-line every 4 days

 

last updated 8-19-2001

 

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