Catheters

Question 1

What is the only thing a general practitioner needs to know about Art lines?

Answer 1

It is a highly specialized piece of equipment not commonly used in GP
- needs to be sterilely prepped
- needs to be removed before patient is standing or they will exsanguinate themselves

Question 2

What are the main indications for placing peripheral venous catheters?

Answer 2

• to provide emergency medications
• to allow for fluid administration
• to sedate
• to euthanize

Much more challenging in exotics

Question 3

What are the main locations utilized for peripheral venous catheters?

Answer 3

Cephalic, saphenous, auricular (good for GDVs) and pedal

Question 4

Describe the various techniques for inserting peripheral catheters

Answer 4

-Percutaneous, pilot hole/relief hole or venous cutdown
- utilization of larger bore, shorter catheters are best for fluid administration and blood products, especially in patients in shock

Question 5

What are the contraindications for inserting peripheral catheters?

Answer 5

-fractious patients in respiratory distress or patient in such severe distress that the catheter may push them into CPA
- suspected cutaneous infections of catheter sites may necessitate placement of the catheter in alternative sites
- avoidance of limbs containing fractures

Question 6

When should you utilize venous cutdown?

Answer 6

-utilized in very small patients or those in shock
-it is a temporary utilization of the vein to provide fluid resuscitation until routine peripheral venous catheter can be more readily placed (due to the contaminated nature of this catheter placement, after removal it will need to be treated like a fresh laceration, lavaged and closed aseptically
-preferred location in dog is lateral saphenous, in cat is medial saphenous

Question 7

What are some common complications with peripheral venous catheters?

Answer 7

-phlebitis*
-catheter site infection*
-extravasation of fluids or other medications
-thrombosis
-catheter embolism

*most common

Question 8

What are signs of phlebitis?

Answer 8

• pain on palpation, pain during injection administration, swelling and erythema of the skin, fever
  -ultrasound has recently been described in the literature for diagnosis
  -incidence is 3-22% of catheters placed

Question 9

What is the incidence of infection from peripheral venous catheters?

Answer 9

-up to 24%
-does not appear to increase in catheters left in place for more than 72 hours
-more recent reports describe 14% of positive cultures- most common enterobacter

Question 10

If a patient spikes a fever after a GI exploratory or GDV, what should you check?

Answer 10

First check for dehiscence- free fluid, check lactate, overall well being

ALSO check the catheter site - change if there is no explanation for why that patient has a fever

Question 11

How should catheter sites be maintained?

Answer 11

Monitor routinely for complications
- cleanliness of catheter site and associated bandages is important to prevent infection- check these periodically

Question 12

What are the main indications for intraosseous catheters?

Answer 12

-similar as for peripheral venous catheters
-can use when there is a failure to place a peripheral catheter
-consider for small and neonatal patients, exotics

Sites for placement: femur, humerus, sometimes tibia

Question 13

What are the contraindications of IO catheters?

Answer 13

Birds- bones are hollow and light
-do not place through infected tissue
-bones with fractures should be avoided

Question 14

What should be considered when thinking about using an IO catheters?

Answer 14

• slower onset of drug administration (can be improved with fluid boluses- but still a slower response to these)
• IO can allow for fluid resuscitation slowly so that peripheral venous access can be reattempted (fluid delivery rates depend on gauge of needle placed)
• blood sampling can be performed, but some lab tests may not be accurate (blood gas analysis will appear similar to a mixed venous-arterial sample)
  -potassium and blood glucose should be interpreted with caution
  -less time needed to place compared to venous cutdown
  -dont want to leave these in more than 24 hours

Question 15

T/F: you should use lidocaine prior to placing an IO catheter

Answer 15

True- this is often missed
- push needle until you hit bone and inject as you are coming out

Question 16

What are the main complications associated with IO catheters?

Answer 16

Infection, fat embolism, extravasation of fluids/medications, nerve injury, compartment syndrome, fractures

Question 17

What is the incidence of infections/compartment syndrome with IO catheters?

Answer 17

Infections: reported in 0.6% of cases with sterile technique followed and IO catheter removal within 72 hours

Compartment syndrome: documented in less than 1% of human patients, unknown in veterinary patients

Question 18

What are the indications for central lines/sampling catheters/picc lines?

Answer 18

-frequent blood glucose or blood gas monitoring
-multiple fluid types desired but not compatible within other peripheral lines
-high osmolality medications or fluids that may be necessary to administer continuously
-administration of total parenteral nutrition
-venous pressure monitoring
-other locations for catheter placements have skin infections or they are at a high risk of contamination

Question 19

What are the common sites for central lines?

Answer 19

Jugular* (which terminates in cranial vena cava) or saphenous (which terminates in caudal vena cava)

Question 20

What are the main indications for urinary catheters?

Answer 20

-De-obstruction or urinary retention disorders
-urine output monitoring
-post operative urinary procedures or urinary system trauma
-infectious zoonotic disease control
-immobilized patients that may develop urine scalding or those with wounds that may become contaminated
-contrast studies

Question 21

When should you use an indwelling vs an intermittent catheter?

Answer 21

Intermittent is best utilized for contrast procedures or to relieve an obstruction whether mechanical or functional that an indwelling catheter has not been elected
- or when you want to collect urine intermittently

Question 22

What are the contraindications for urinary catheters? Complications?

Answer 22

Contraindications: Inadequate nursing staff to manage if left to remain indwelling- referral facility recommended for these patients

Complications: catheter associated infections, physical trauma to urethra or bladder, sedation/anesthesia related complications

Question 23

Describe infections due to urinary catheters

Answer 23

-catheter associated UTIs are usually bacterial, but fungal has been reported
-recent investigations show an incidence of 10% for up to 3 days- increases with longer use
-older veterinary literatures reports higher incidence of UTIs- but we have better techniques now
-collection system does not appear to increase positive cultures or the presence of UTIs

Prevention: limit duration, catheters coated with antibacterial products (not available in vet med), aseptic technique with SOPs (clean prepuce well, clean vaginal vestibule)

Question 24

How can you prevent urethral or bladder tears with urinary catheters?

Answer 24

• caution with stylet containing catheters
  -LOTS of lube
  -avoid force

Always warn owners about the risk
- consider cystocentesis in full bladders (to decrease pressure you are working against)

Question 25

What urinary catheters are ideal for cats? Dogs?

Answer 25

Cats: 3.5 fr typically appropriate. Tomcat with stylet can be utilized to de-obstruct and remain indwelling, slippery sam is rigid and can be left in place, red rubber not as rigid for obstruction but can be left indwelling

Dogs: 5-8 fr
-red rubbers often not rigid enough
-foley catheters with stylets are a reasonable option in most dogs but rigidity is also an issue

Question 26

What suture is recommended for holding indwelling catheter in place?

Answer 26

Nylon