Kawasaki Disease or Incomplete Kawasaki Disease Clinical Pathway — Emergency Department and Inpatient

Aspirin (ASA)

Aspirin has been used in the treatment of KD for its anti-inflammatory activity at high doses and anti-platelet activity at low doses. There is no evidence that aspirin decreases the incidence of coronary artery abnormalities, and there is no data to suggest that a high vs. moderate dose of aspirin is superior. The AHA guidelines state it is reasonable to administer moderate- or high-dose aspirin until the patient is afebrile, although there is no evidence it reduces coronary artery aneurysms.

This pathway does not recommend high-dose aspirin in those already receiving steroids, since steroids offer a powerful anti-inflammatory effect. This pathway suggests transitioning to low-dose ASA after 24 hours to allow for better assessment of fever and treatment resistance prior to discharge.

  • Patients not receiving steroids:
    • High dose x 24 hours (80-100 mg/kg/day divided Q 6 hours)
    • Discontinue high-dose ASA after 24 hours and start on low-dose ASA (3-5 mg/kg given daily, max 325 mg)
  • Patients receiving steroids:
    • Low-dose ASA (3-5 mg/kg given daily, max 325 mg)
  • Patients with G6PD:
    • Avoid high-dose aspirin and administer low-dose aspirin only
2nd Line Thrombosis Prevention
  • With rapidly expanding aneurysms or z score > 10, systemic anticoagulation with LMWH or warfarin is reasonable.
  • If systemic anticoagulation is started, Cardiology should contact the Cardiac Anti-Coagulation and Thrombosis Team to help manage these patients.
  • For patients with increased risk of thrombosis (large or giant aneurysms and recent h/o coronary artery thrombosis), triple therapy with ASA, 2nd antiplatelet agent and anticoagulation may be considered.
  • Ibuprofen and other NSAIDs may be harmful in patients taking ASA for its antiplatelet effects and should be avoided.
Special Considerations
  • Avoid ibuprofen or other NSAID (antagonizes anti-platelet effect of aspirin)
  • Adverse effects (rare): GI bleed, tinnitus, Reye’s syndrome
    • Reye’s syndrome – rare, but increased risk with aspirin and viral infection.
    • Consider inactivated influenza vaccine (avoid live vaccines (e.g. varicella) until off aspirin or discuss risk benefit when on low-dose aspirin).
    • No cases of Reye’s syndrome have been reported for patients on low-dose ASA according to latest AHA KD guidelines.
  • Note:
    • There is no evidence that ASA decreases aneurysms or that outcomes are different with low- vs. high-dose ASA.
    • High-dose ASA may help with inflammation initially.
    • Low-dose ASA is necessary for thrombosis prevention until follow-up echocardiograms show no aneurysms.

American Heart Association. 2017 Mar: Circulation 135:00-00. Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association. McCrindle et al.