Chapter 177 - Hemodialysis access dialysis catheters Flashcards
Length of time an acute catheter can be left in
< 4 weeks
Length of time a chronic tunneled catheter can be left in
12 months
Indications for catheter insertion
1) urgent HD while waiting for AVF maturation
2) non-anatomical feasible AVF or not surgical candidate
3) temporary alternative access to avoid usual access complications
Benefit of catheter insertion over other methods
1) Immediate use
2) uncomplicated needle-free access
3) avoid cannulation site complications
4) ease of use
Treatment goals of catheterization
1) high rate 300-340 ml/min
2) avoid recirculation
Arterial lumen and venous lumen definition
Arterial = patient to HD machine Venous = HD machine to patient
Designs of catheters
1) split tip
2) step tip
3) dual catheter
4) tal palindrome symmetrical tip
Benefit of each different designs of catheters
no difference
Pre-operative considerations
1) prior line, avf, avg
2) prior infection
3) pacemaker history
4) coagulation disorders
5) PEX: scars, edema, venous collaterals
Pre-op imaging problems with each modality
US: hard to see central veins
MRI: gadolinium induced nephrogenic systemic fibrosis
CTV: high volume contrast
Catheter based venogram: gold standard
Patency based on location
Right IJ > Left IJ > femoral
Subclavian line downfall
worsen future AVF if fibrosis
optimal Location of cuff
1 cm proximal to exit site on skin
optimal Location of tip
caval-atrial junction at shadow of right main bronchus
Filling of line to prime options
1) citrate sodium
2) low dose heparin < 5000 Units/ml
Unconventional catheter sites
1) translumbar: prone, direct to IVC
2) transhepatic: to right or mid hepatic vein
Problems with unconventional catheters
1) infection
2) migration
3) thrombosis
Central line complication rates overall
7.1%
Complications of central dialysis line
1) pneumothorax
2) hemothorax
3) wire embolism
4) arrhythmia
5) cardiac perforation
6) thoracic duct lasceration
7) nerve injury
8) catheter misplacement
9) air embolism
10) catheter fracture and embolism
Treatment for pneumothorax
1) watchful waiting
2) thoracostomy
3) needle decompression
Reason to treat catheter related pneumothorax
1) tension pneumothorax
2) symptomatic
3) > 20% pneumothorax
Reasons why hemothorax are hard to treat
1) negative pressure of chest
2) lack of tamponade
Treatment for wire or catheter embolism
Snare
Complication rate of arrhythmia needing cardioversion
< 1%
Cardiac perforation signs
All related to tamponade
1) muffled heart sounds
2) tachycardia
3) large globular cardiac silhouette
Thoracic duct laceration treatment
1) remove catheter
2) pressure
Nerve injury
1) Brachial plexus
2) vagus/recurrent laryngeal –> horseness
3) phrenic –> raised hemidiaphragm
4) sympathetic (stellate ganglion) –> horner
Catheter misplacement rate
3.3%
Problem with catheter misplacement in venous system
Intimal damage –> thrombosis or erosion
Management of carotid catheter placement
pressure if <4 hours otherwise explore
Treatment of air embolism
1) cap the line
2) Durant maneuvre: trendelenburg and left lateral decubitus
3) aspirate air in heart using line
Catheter occlusion rate
30-40%
Cause of catheter occlusion
Development of fibrin plug/sleeve at tip
Can infuse but cannot withdraw from a line
sign of impending failure
Evidence on preventing catheter occlusion
no evidence all lock solution same
antiplatelet and anticoag too risky
Treatment of catheter occlusion
1) alteplace
2) snare fibrin sheath
3) balloon fracture
4) replace sheath
Alteplace dose for clearing line
2 mg dwell 2-3 hours
77% success one time, 10% addition success second time
Central venous thrombosis rate
30% of patients with CVC
only 50% are clinically significant
PE from CVC thrombosis rate
0-17%
associated with infections
signs/symptoms of CVC thrombosis
1) edema/swelling
2) prominent collateral veins
3) emboli
4) fever
Treatment of CVC thrombosis
1) anticoagulation
2) catheter removal
Central venous stenosis rate of subclavian vs IJ
42% vs 10%
Treatment of central venous stenosis
1) elevation and compression
2) PTA +/- stent +/- DCB
CVC infection classifications (Tunneled lines)
1) exit site: distal to cuff
2) tunneled infection: superior to cuff
3) catheter related bacteremia
Incidence of catheter related bacteremia
0.6-6.5/1000 catheter days
Usual organism of catheter related infections
Gram + 52-84%
S. aureus 21-45%
Treatment of catheter infection
1) remove
2) antibiotics
Antibiotic duration for catheter infection for Gram +, Gram - and fungi
Gram + 4-6 weeks (S aureus mostly)
Gram - 1-2 weeks
Fungi 2 weeks
KDOQI criteria for stopping antibiotics
Wait 48hours after culture negative then stop antibiotics
Catheter salveage failure rate after infection
> 65%
