Overview
Definition:
Dialysis catheters are essential vascular access devices used in pediatric patients requiring renal replacement therapy (RRT) via hemodialysis (HD) or peritoneal dialysis (PD)
These catheters facilitate the removal of waste products and excess fluid from the blood when the kidneys are unable to perform these functions adequately
Proper care is crucial to prevent complications and ensure effective therapy.
Epidemiology:
The incidence of pediatric end-stage renal disease (ESRD) requiring RRT is low but growing, with an increasing reliance on both HD and PD
Catheter-related complications, particularly infections, remain a significant cause of morbidity and mortality in these vulnerable patients
Catheter failure due to occlusion or malfunction also impacts treatment efficacy and patient well-being.
Clinical Significance:
Effective dialysis catheter care directly impacts the success of RRT in pediatric patients
Poor catheter management can lead to severe infections (e.g., sepsis), catheter dysfunction (occlusion, kinking), venous stenosis, thrombosis, and delays in therapy, all of which can have profound negative effects on a child's growth, development, and overall health outcomes
Mastering these principles is vital for pediatric residents preparing for DNB and NEET SS examinations.
Types Of Pediatric Dialysis Catheters
Hemodialysis Catheters:
Temporary or tunneled catheters, typically dual-lumen, inserted into large central veins (e.g., internal jugular, subclavian, femoral)
Temporary catheters are used for acute dialysis needs, while tunneled catheters (e.g., Hickman, Broviac) are for long-term use, featuring a dacron cuff for tissue ingrowth to stabilize the catheter and reduce infection risk.
Peritoneal Dialysis Catheters:
These are surgically implanted catheters with one or two lumens, placed in the peritoneal cavity
They allow for the exchange of dialysis fluid
Common types include Tenckhoff catheters, which often have subcutaneous domes and dacron cuffs to promote healing and prevent infection.
Age And Size Considerations:
Catheter selection is based on patient's age, weight, body size, venous anatomy, and the intended duration of therapy
Pediatric catheters are designed with smaller diameters and lengths appropriate for children to minimize trauma and improve patient comfort
Specialized pediatric dialysis centers utilize a range of catheter sizes.
Catheter Insertion And Initial Care
Insertion Techniques:
Hemodialysis catheters are typically placed percutaneously under image guidance (ultrasound) and local anesthesia, with sterile technique being paramount
Peritoneal dialysis catheters are usually inserted surgically, often laparoscopically, into the rectus muscle sheath for better anchoring and outflow
Ultrasound is frequently used for PD catheter placement in neonates and infants.
Aseptic Technique:
Strict adherence to aseptic technique during insertion is critical to minimize the risk of introducing pathogens
This includes proper hand hygiene, use of sterile gloves and drapes, and appropriate antiseptic preparation of the insertion site.
Dressing And Securing:
A sterile, semi-occlusive dressing is applied after insertion to protect the exit site from contamination
Catheters are securely anchored to prevent dislodgement, which can lead to bleeding, pain, and increased infection risk
For tunneled catheters, the dacron cuff should be allowed to heal in place without tension.
Hemostasis And Flushing:
Adequate hemostasis is ensured post-insertion
For HD catheters, lumens are flushed with saline and then filled with a heparin solution to prevent clotting
PD catheters are typically flushed with saline and then filled with dialysate to check for proper flow and drainage.
Ongoing Catheter Care And Maintenance
Exit Site Care:
Daily or as-needed cleaning of the exit site with antiseptic solutions (e.g., chlorhexidine, povidone-iodine) by trained personnel or caregivers
The site should be inspected for redness, swelling, tenderness, or drainage
Dressings should be changed if soiled or wet, using sterile technique.
Dressing Changes:
Regular dressing changes (e.g., every 48-72 hours for semi-occlusive dressings, or weekly for more secure dressings) are performed using aseptic technique
The skin around the exit site is cleaned, and a new sterile dressing is applied
The integrity of the dacron cuff (if applicable) should be monitored.
Flushing And Locking Protocols:
For HD catheters, regular flushing with saline and locking with heparin or citrate solutions is essential to maintain patency and prevent thrombus formation
The specific lock solution and frequency depend on institutional protocols and patient factors
For PD catheters, proper inflow and outflow of dialysate are monitored during exchanges.
Activity And Lifestyle Modifications:
Children with dialysis catheters should avoid activities that could lead to trauma to the catheter or exit site, such as rough sports or swimming
Caregivers should be educated on safe handling and positioning to prevent accidental dislodgement.
Complications And Troubleshooting
Catheter Related Infections:
Infections can be local (exit site infection, tunnel infection) or systemic (catheter-related bloodstream infection - CRBSI)
Symptoms include fever, chills, erythema, purulent discharge at the exit site, and hypotension
Diagnosis often involves blood cultures from the catheter and a peripheral vein
Management includes antibiotics, and potentially catheter removal if severe or unresponsive to treatment.
Catheter Occlusion And Thrombosis:
Inability to aspirate or infuse blood (HD catheters) or poor inflow/outflow (PD catheters)
Causes include fibrin sheath formation, thrombus, or kinking
Management involves gentle flushing with saline and appropriate locking solutions
Urokinase or tPA may be used to dissolve thrombi in HD catheters
PD catheter occlusion may require surgical revision.
Mechanical Complications:
Includes catheter kinking, dislodgement, leakage from the exit site, or catheter fracture
Dislodgement requires immediate attention to secure the catheter and assess for bleeding
Leakage may indicate infection or poor wound healing.
Venous Stenosis And Thrombosis:
Long-term HD catheter use can lead to stenosis or thrombosis of the central vein, making future vascular access difficult
This is often diagnosed with venography
Management may involve angioplasty, stenting, or catheter repositioning
Prevention strategies include using appropriate catheter sizes and avoiding venous stasis.
Prevention Strategies
Strict Aseptic Technique:
Consistent application of aseptic technique during all catheter manipulations (insertion, dressing changes, flushing, dialysis treatments) is the cornerstone of infection prevention.
Patient And Caregiver Education:
Comprehensive education for patients and their families on proper catheter care, recognizing signs of infection or malfunction, and when to seek medical attention is critical for successful home management.
Antimicrobial Strategies:
Use of antiseptic agents for exit site care, antimicrobial lock solutions (where appropriate and guided by local resistance patterns), and prophylactic antibiotics for certain procedures can reduce infection rates.
Regular Monitoring And Assessment:
Frequent assessment of the exit site, catheter function, and patient's overall condition by healthcare professionals helps in early detection and management of potential complications.
Timely Catheter Replacement:
Considering catheter replacement or conversion to a more permanent access (e.g., AV fistula or graft) when the need for long-term RRT is established can reduce the risk of complications associated with indwelling catheters.
Key Points
Exam Focus:
DNB/NEET SS examiners frequently test on differentiating exit site infections from CRBSI, management of catheter occlusion, importance of aseptic technique, and indications for catheter removal or replacement
Understanding different catheter types and their specific care is crucial.
Clinical Pearls:
Always confirm catheter patency before initiating HD
Use gentle flushing techniques to avoid damaging the catheter or vessel
Educate caregivers on \"red flags\" for immediate medical attention
Consider the patient's age and size when choosing catheter size and care protocols.
Common Mistakes:
Failure to use strict aseptic technique, inadequate education of caregivers, over-reliance on antibiotics without addressing mechanical issues for occlusion, and delaying catheter removal in the presence of severe infection are common pitfalls to avoid.