1. Vascular Access The Alpha and Omega of CRRT
Rick Hackbarth MD
Division of Pediatric Critical Care
Grand Rapids, Michigan

2. Vascular Access Wisdom
“If you don’t have good access you might as well go home!”

3. Vascular Access The portal from patient to circuit
Affects circuit life
Lost circuits may expose patients to more transfusions and frustrates staff
Affects clearance
Lower blood flow rates and hemofiltration rates
More downtime

4. Vascular Access Two questions to be answered-
What size catheter to use?
Where to put it?

5. Vascular Access Wisdom
“Size matters!”

6. Vascular Access 8l Pousielle’s Law- Q = ∆Pπr4
Smaller diameters offer greater resistance to flow
Longer lengths offer greater resistance to flow
Decreasing the diameter by 1/5th is the same as doubling the length (roughly a 2 French size difference)
Q = ∆Pπr4
8l

7. Vascular Access ppCRRT Registry Access Study 13 Pediatric Institutions
376 patients
1574 circuits
Circuit survival by Catheter size, site, and modality
Hackbarth R et al: IJAIO 30: , 2007

8. Vascular Access
Hackbarth R et al: IJAIO 30: , 2007

9. Hackbarth R et al: IJAIO 30:1116-21, 2007

10. Vascular Access 1st 72 hrs of circuit life only Shorter life span
for 7 and 9 French
catheters (p< 0.002)
Hackbarth R et al: IJAIO 30: , 2007

11. Hackbarth R et al: IJAIO 30:1116-21, 2007

12. Vascular Access Wisdom
“Location, location, location!”

13. Vascular Access “Location, location, location!” Options: Femoral vein
Subclavian vein
Internal Jugular vein

14. Vascular Access “Location, location, location!” Femoral Vein Pros:
Accessible under almost any conditions
Easier to maintain hemostasis
Cons:
Potential for kinking
More recirculation
Thrombosis
Problematic flow with increased abdominal pressures

15. Vascular Access “Location, location, location!” Subclavian Vein Pros:
Shorter catheter/better flow
Less recirculation
Cons:
Potential for kinking
Difficult hemostasis
Potential for venous narrowing
Less accessible with cervical trauma

16. Vascular Access “Location, location, location!” Internal Jugular Vein
Pros:
Shorter catheter/better flow
Less recirculation
Cons:
Difficult hemostasis
Less accessible with cervical trauma
Catheter length problematic in small infants

17. Vascular Access Highly variable position of the IJ vein
Ultrasound can be quite helpful
Maecken T et al: CCM 35: S178-85, 2007

18. Hackbarth R et al: IJAIO 30:1116-21, 2007

19. Vascular Access Survival favors IJ Location (p< 0.05)
Hackbarth R et al: IJAIO 30: , 2007

20. Vascular Access Wisdom
“It’s déjà vu all over again.”

21. Vascular Access Recirculation
More of an issue in femoral catheters especially shorter than 20 cm
Is this really a practical concern with 24/7 clearance?
Catheter proximity may be a bigger issue

22. Vascular Access
Note the relationship of the line tips.

23. Vascular Access Catheter proximity Inadvertent removal of infusions
Circuit clotting with platelet transfusions
Entraining calcium into the circuit

24. Vascular Access Wisdom
“You can’t always get what you want, but you might get what you need!”

25. Vascular Access Catheter Specifications French Size 5 7 8 10 12
Flow Rate
(ml/min) ?
80-100

26. Vascular Access Catheter Specifications French Size 5 7 8 10 12
Diameter
(mm)
1.67
2.3
2.7
3.3
4.0

27. Vascular Access
Steinberg et al: Catheterization and Cardiovascular Diagnosis 27: , 1992

28. Vascular Access
Pousielle’s Law-
Q = ∆Pπr4
8l

29. Vascular Access

30. Vascular Access

31. Vascular Access Differing Perspectives on the ICU Patient
It was six men of Indostan
To learning much inclined,
Who went to see the Elephant
(Though all of them were blind),
That each by observation
Might satisfy his mind.
John Godfrey Saxe
The Blind Men and the Elephant

32. Vascular Access Differing Perspectives on the ICU Patient
And so these men of Indostan
Disputed loud and long,
Each in his own opinion
Exceeding stiff and strong,
Though each was partly in the right,
And all were in the wrong!
John Godfrey Saxe
The Blind Men and the Elephant

33. Vascular Access

34. Vascular Access

35. Vascular Access

36. Vascular Access

37. Vascular Access Two questions to be answered-
What size catheter to use?
Where to put it?

38. Vascular Access What size catheter should we use?
Don’t use a 5 French catheter.
Choose the largest diameter that is safe for the child.
Choose the smallest catheter that will achieve the necessary flow easily.
Choose the the minimum length to position the tip for optimal flow.
In the femoral position, longer catheters will minimize recirculation

39. Vascular Access Where should the catheter go?
What sites are available?
Are there anatomic or physiologic constraints?
Which vessel is optimal for the catheter size?
Is the patient coagulopathic?
Consider patient mobility and risk of kinking.
Is there elevated intra-abdominal pressure?

40. Vascular Access Where should the catheter go?
Answer: Internal Jugular vein if possible

42. Disney Wisdom
“I would rather entertain and hope that people learned something than educate people and hope they were entertained.”