IR Flashcards
how is size measured for puncture needles, catheters, dilators, sheaths, wires.
- puncture needle- Gauge. Outer
- catheter/dilator- French. Outer
- sheath- F. inner (Shy and stays in Shell)
- wires: outer diam (inch), length (cm). standard=0.035in and 180cm
T or F: larger the gauge, smaller the wire. Larger the F, larger the catheter.
True
how many inch = 1 mm. How many F = 1 mm
- 0.039 inch
- 3F
how are wires sized? what is the standard wire size for general purposes
- outer diam=inch. Standard= 0.035 inch
- length =cm, standard=180 cm
size of microwires
0.018, 0.014 inches
What size catheter will the standard 0.035 wire fit through?
4F (or bigger)
when are sheaths used? How are they sized?
- cases that require exchange of multiple catheters w/o losing access
- sized via inner lumen. Chosen according to largest catheter they will accommodate
- outer diameter usually 1.5-2F larger than inner lumen, ieL add 2F for outer diam (if you want to know how big the hole in the skin will be)
some conversions… How many F?
- 16G needle has outer diam of 1.65 mm
- 20G needle has outer diam of 0.97 mm
- 5F
- 3F
18G, 19G (seldinger technique) and 21G (micro puncture) needles accept what size guide wire?
- 0.038 in
- 0.035 in
0. 018 in (micropuncture)
when is micro puncture good and bad?
- Good-tough access (Ex: antegrade femoral puncture), lack of experience, anatomically sensitive (internal jugular, dialysis access)
- bad: scarring, obesity, flimsy 0.018 inch guide wire doesn’t give enough support for dilator when upsizing
2 flavors of guidewires
- non-steerable (supportive raises for catheters)
- steerable-tight spots, ex: hydrophilic
“long wire” length and uses
- 260 cm
- upper extremity from groin access, visceral circulation and need to exchange catheters, guide catheter >90cm, through and through situation (body flossing)
minimal guidewire length
-length of catheter + length of guide wire in pt
what’s more likely to cause dissection: short or long floppy tip guidewire
shorter
which guide wire for “tight spots”
hydrophilic
how should stiff guide wires be introduced?
through a catheter
Advantage of J tip guidewires. Significance of number associated with it?
- Don’t dig up plaque and miss branch vessels
- radius of curve (smaller miss small branch vessels, larger miss large branch vessels)
guidewire stiffness: noodle-like, normal, supportive, stiff, hulk smash
- Bentson (floppy tip) (BENdy)
- hydrophilic (standard 0.35 J or straight)
- stiff hydrophilic (heavy duty J or straight)
- flexfinder. Abplatzen stiff or extra stiff. 0.018 platinum plus. V18 shapeable tip
- hulk smash-lunderquist, back up Meier.)
more guide wire stiffness, more…
dissection
use of lunderquist (super stiff) guide wire?
-aortic stent grafting
catheter types
- nonselective (medium and large vessels)
- selective (diff shapes/angles for “selecting” branch vessel)
nonselective catheter types
- pigtail
- straight
selective catheter types
- end hole
- side + end hole
- acute angle (<60˚), curved (60-120˚), obtuse (>120˚)
what happens if you consistently inject through a pigtail
contrast goes out proximal side holes and not the tip –> con’t injection=clot in tip