Overview

Definition:
-Peripherally Inserted Central Catheter (PICC)-related thrombosis refers to the formation of a blood clot within a vein adjacent to or surrounding a PICC line in pediatric patients
-This is a significant complication that can impede catheter function, lead to venous occlusion, and increase the risk of systemic complications like pulmonary embolism.
Epidemiology:
-PICC-related thrombosis is a common complication, with reported incidence rates in pediatric populations ranging from 5% to over 30%, depending on patient population, catheter characteristics, and duration of use
-Risk factors include prematurity, underlying critical illness, prolonged immobility, hypercoagulable states, and catheter dwell time.
Clinical Significance:
-Preventing PICC-related thrombosis is crucial in pediatrics to maintain the efficacy of essential therapies (e.g., antibiotics, parenteral nutrition, chemotherapy), reduce patient morbidity, avoid the need for premature catheter removal, and prevent serious sequelae
-Early recognition and effective management are vital for optimal patient outcomes and successful examination preparation.

Risk Factors

Patient Factors:
-Prematurity and low birth weight
-Underlying malignancy or critical illness
-Sepsis
-Congenital heart disease
-Known or suspected hypercoagulable disorders
-History of previous VTE
-Female sex.
Catheter Factors:
-Catheter material (e.g., polyurethane vs silicone)
-Diameter and length of catheter
-Number of lumens
-Insertion site (e.g., antecubital fossa vs basilic vein)
-Catheter tip malposition
-Dwell time.
Insertion And Maintenance Factors:
-Catheter insertion technique
-Local trauma at insertion site
-Repeated venipuncture attempts
-Poor aseptic technique leading to infection
-Infusion of irritating solutions (e.g., hyperosmolar solutions, chemotherapy)
-Inadequate flushing and locking protocols
-Blood draw frequency and technique.

Prevention Strategies

Catheter Selection And Insertion:
-Use of smallest gauge, single-lumen catheter feasible
-Appropriate tip placement confirmed by imaging
-Insertion in areas with good collateral circulation
-Minimizing manipulation of the catheter during insertion.
Aseptic Technique And Care:
-Strict adherence to aseptic technique for insertion and all subsequent manipulations
-Regular site assessment for signs of infection or inflammation
-Use of sterile dressings and daily site care.
Catheter Maintenance And Flushing:
-Regular and thorough flushing with saline according to institutional protocols, typically using pulsatile technique after each use and at least weekly if not in use
-Proper use of locking solutions (e.g., heparin, citrate) as per guidelines, considering patient age and clinical context
-Avoidance of blood draws from the PICC unless necessary, and then using appropriate technique.
Pharmacological Prophylaxis: Consideration of low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) in high-risk pediatric patients, especially those with known hypercoagulable states or prolonged immobility, based on risk-benefit assessment and consultation with hematology.
Patient And Family Education:
-Educating caregivers about early signs and symptoms of thrombosis and infection, and emphasizing the importance of reporting these promptly
-Instruction on safe catheter care practices.

Clinical Presentation

Signs And Symptoms:
-Swelling of the limb distal to the insertion site
-Erythema and tenderness along the vein
-Pain in the arm or chest
-Palpable venous cord
-Dilated superficial veins
-Restricted range of motion of the affected limb
-Fever or signs of infection which may be attributable to thrombosis.
Diagnostic Approach:
-Clinical suspicion based on the above signs and symptoms
-Doppler ultrasonography is the gold standard for diagnosis, demonstrating non-compressible veins and intraluminal thrombus
-Other imaging modalities like venography are rarely used in pediatrics due to invasiveness.
Differential Diagnosis:
-Cellulitis or local infection at the insertion site
-Phlebitis without frank thrombosis
-Allergic reaction to dressings or infusate
-Nerve compression or injury
-Musculoskeletal pain or injury
-Edema from other causes (e.g., fluid overload, hypoalbuminemia).

Management Of Thrombosis

Initial Steps:
-Discontinue infusion of potentially thrombogenic agents
-Assess patient for signs of systemic embolization
-Consider catheter removal if there is significant thrombus burden, infection, or if the catheter is no longer needed.
Anticoagulation Therapy:
-Initiation of anticoagulation, typically with LMWH or UFH, guided by pediatric hematology recommendations
-Dosing adjusted based on patient weight and renal function
-Close monitoring of coagulation parameters (e.g., anti-Xa levels for LMWH).
Catheter Management Options:
-If catheter is essential, consider thrombolysis with alteplase (tPA) or urokinase instillation to lyse existing thrombus, followed by continued anticoagulation
-If catheter is not essential, removal is often preferred, with anticoagulation continuing until thrombus resolves
-Insertion of a new catheter in an contralateral limb may be necessary.
Supportive Care:
-Pain management
-Elevation of the affected limb if tolerated
-Gentle physiotherapy to maintain range of motion once pain subsides and anticoagulation is established.

Key Points

Exam Focus:
-Understand the multifactorial nature of PICC thrombosis risk
-Recall specific preventive measures: proper catheter selection, meticulous aseptic technique, effective flushing, and appropriate locking solutions
-Be aware of the signs and symptoms and diagnostic modalities, with Doppler US being paramount.
Clinical Pearls:
-Proactive prevention is key
-once thrombosis occurs, management is more complex
-Always consider patient-specific risk factors
-Communicate with vascular access teams and hematology for complex cases
-Emphasize the importance of correct flushing technique to dislodge fibrin sheath.
Common Mistakes:
-Underestimating the risk in pediatric patients
-Inadequate flushing or locking protocols
-Failure to recognize early signs and symptoms
-Inappropriate selection of catheter size or material
-Delay in initiating anticoagulation or thrombolysis.