vasc access & feeding tubes (Lanaux)

Question 1

Meds with > 600 mOsm

Answer 1

• should only be admined through central line
  
  • total parenteral nutrition
  • CRI dextrose > 5%

*meds < 600 mOsm can give in peripheral vein

Question 2

Poiseuille’s law

Answer 2

• radius⁴ big variable in determing flow of something

Question 3

Which will cause greatest decrease in flow through a catheter?

TQ

a. doubling diameter of catheter
b. halving diameter of the catheter
c. doubling the length of the catheter
d. halving the length of the cath

Answer 3

b. halving diameter of catheter

Question 4

Sites of access

Answer 4

• cephalic vein
• lateral and medial saphenous veins
• jugular vein
• auricular veins (Dog)

Question 5

central line placement

sites of access

Answer 5

• Jugular vein
• Medial and lateral saphenous veins

*PIC lines

Question 6

Types of catheters

Answer 6

• Winged or Butterfly needle
  
  • SQ fluids
  • short term admin
  • blood draws
• Over-the-needle
  
  • normal ones
• Through-the-needle
  
  • push pops
• single or multilumen
  
  • long terms

Question 7

Complications catheterization

Answer 7

• Phlebitis
  
  • inflammation of vessel wall
  • from endothelial lining damage
  • CS
    
    • swelling
    • tenderness
    • erythema over vessel
      
      • mech damage
      • admin of hyperosmotic fluids
      • infection
• Thrombosis
• Catheter embolism
  
  • Fragment of cath breaks off and enters circulation
• SQ fluid infiltration into tissue
  
  • backed out
  • upstream venous thrombosis
• Infection
  
  • local cellulitis/phlebitis
  • systemic
• Hemorrhage

Question 8

Placement of peripheral catheters

Answer 8

• shave, aseptic scrub
• occlude vein upstream
• insert bevel up 15 deg angle
• after flash advance 1-4 mm more
• advance cath off needle
• cap, flush
• secure

Question 9

Facilitative incision/relief hole

Answer 9

• small incision through tough skin
  
  • # 11 scalpel blade
  • cutting edge of 20 guage needle
  • prevents flaring of cath tip

Question 10

Venous cut down

Answer 10

• aseptic prep, local anesthetic
  
  • NOT IV
• 1-2 cm skin incision parallel to vein
• Dissect out vein and isolate w/ hemostats/suture
• place cath directly through superficial vessel wall

Question 11

Central venous cath

Answer 11

• Terminate in cranial/caudal vena cava
• Uses
  
  • hemodynamic monitoring (CVP)
  • admin meds and fluids
  • seriel blood sampling
  • allows longer term venous access
• Maintenance
  
  • inc severity of complications
  • aseptic technique
    
    • foreign material
    • infectious agents
• Open air ports => air embolism
  
  • one-way locking valves to cap ports
• Inadvertent disconnections => hemorrhage

Question 12

Seldinger technique

Answer 12

• Use smaller introducing cath/trochar and guidwire
• Can be used to replace existing cath in same location
• Technique
  
  • Clip and aseptic prep
  • drape using sterile technique
  • surgeon/assistants wear sterile gloves, gown, cap, mask
  • relief incision with scalpel
  • cath wtih short over needle cath
  • guidewire threaded through over needle cath
    
    • J-tip protects against puncture
    • always hold guidwire
  • remover over needle cath, stabilize guidewire
  • vessel dilate used over guidewire
  • large bore cath threaded onto guidewire, advance into dilated vessel
  • guidewire removed, aspirate larger cath to remove air, flush and secure (suture)

Question 13

IO catheterization

Answer 13

• access to capillaries in bone marrow
• useful in neonates, or vasc collapse
• Can cause discomfort

Question 14

Mean IO flow rates crystalloid solns delivered under pressure (300 mmHg) limited to approx ?????? in puppies?

Answer 14

29 mL/min

Question 15

IO contraindications

Answer 15

• Don’t do in recently fractured bones
• Don’t do in pneumatic bones of birds
  
  • will drown them
• Inc risk extravasation if in same bone as failed earlier attempt where cortex has been penetrated

Question 16

IO cath placement

Methods

Sites

Answer 16

• Manually place hypdermic needles or bone marrow needles
  
  • automatic delivery systems exist
• Sites
  
  • flat medial surface of proximal tibia
  • tibial tuberosity
  • trochanteric fossa of femur
  • alternative sites
    
    • wing of ileum, ischium, greater tubercle of humerus

Question 17

IO complications

Answer 17

• Fat embolism
• Infection
• extravasation fluids
• compartment syndrome
  
  • inc pressure and necrosis if admin at high rates
• bone fractures

Question 18

Cath care

Answer 18

• change bandage daily or if soiled
• clean site povidone iodine/chlorhex soln
• cath should be flushed Q 4-6hours
  
  • prevents thrombosis w/in cath
• Peripheral caths should be removed after 72 hours OR if signs of
  
  • infection
  • phlebitis
  • thrombosis

Question 19

Advantages of nasoesophageal/gastric tubes

Answer 19

• Placement only requires local anesthetic or minimal sedation
• does not require special equipment
• excellent for short term feeding (1-2 weeks)
• NG tube allows for gasric decompression

Question 20

Disadvantages of nasoexophageal/gastric tubes

Answer 20

• Limited to liquid diets
• may be poorly tolerated
• patient may vomit or sneeze out tube
• NG tube may create incompetance of lower esophageal sphincter

Question 21

NG/Gastric tubes

TQ

Answer 21

• Limit number of people working with the pet
  
  • label everything
  • label food as not for IV use
• Stress to staff that they need to verify food is correctly attached to feeding tube
  
  • not IV cath
• always confirm placement with radiographs or endoscopy

Question 22

Advantages of Esophageal tubes

Answer 22

• Allows long-term feeding of canned gruel diets
• Relatively easy to place
• Does not require special equiptment
• Can be removed at any time with ease

Question 23

Disadvantages of esophageal tubes

Answer 23

• Requires general anesthesia
• Patient may vomit tube
• Risk of infection
• Esophageal irritation or reflux
• must wrap neck

Question 24

When placing esophageal tubes ALWAYS

Answer 24

intubate a patient