Aspirin Desensitisation Protocol for use within Adult Cardiology

Publication: 30/11/2017  
Next review: 21/04/2024  
Clinical Protocol
CURRENT 
ID: 5259 
Approved By: Trust Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2021  

 

This Clinical Protocol is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Oral Aspirin Desensitisation Protocol for use within Adult Cardiology

 

Aims

  • To ensure the safe and successful desensitisation to aspirin within the Cardiology department in patients who require long-term treatment with aspirin.

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Background and indications for protocol

This protocol is NOT suitable for patients with a previous history of bronchospasm or anaphylaxis to aspirin or any of its excipients (World Allergy Organization definition of anaphylaxis below)

Aspirin is indicated in the treatment of coronary artery disease and other cardiovascular disorders.  There are some patients who are unable to receive treatment with aspirin due to a previous history of an adverse reaction to aspirin or non-steroidal anti-inflammatory drugs. 
Aspirin desensitisation has been successfully used to overcome this problem and is used within many centres within the UK.  This procedure sets out the process for desensitisation of cardiology patients at the Leeds Teaching Hospitals Trust.

This protocol is suitable for the following individuals with history of adverse reaction to aspirin:

  1. Patients scheduled for elective percutaneous coronary intervention (PCI)
  2. Patients admitted with non-ST segment elevation acute coronary syndromes scheduled for invasive management including PCI who are clinically stable
  3. Patients admitted with ST segment elevation who have been treated by primary PCI who are clinically stable.
  4. Other patients not scheduled for PCI for whom aspirin therapy is indicated.

An accurate allergy history, from both the patient and medical records, should be undertaken prior to desensitisation to determine the details of previous reaction and therefore suitability for desensitisation.

The World Allergy Organization (WAO) (Cardona et al 2020) state that anaphylaxis is highly likely when any one of the following 2 criteria are fulfilled:

  1. Acute onset of an illness (minutes to several hours) with simultaneous involvement of the skin, mucosal tissue, or both (eg, generalized hives, pruritus or flushing, swollen lips-tongue-uvula)
    AND AT LEAST ONE OF THE FOLLOWING:
    1. Respiratory compromise (eg, dyspnea, wheeze-bronchospasm, stridor, reduced PEF, hypoxemia)
    2. Reduced BP or associated symptoms of end-organ dysfunction (eg, hypotonia [collapse], syncope, incontinence)
    3. Severe gastrointestinal symptoms (eg, severe crampy abdominal pain, repetitive vomiting), especially after exposure to non-food allergens
  2. Acute onset of hypotension or bronchospasm or laryngeal involvement after exposure to a known or highly probable allergen for that patient (minutes to several hours), even in the absence of typical skin involvement.

The WAO guidelines has a useful diagram on page 6, figure 1 which illustrates this definition of anaphylaxis - https://www.worldallergyorganizationjournal.org/action/showPdf?pii=S1939-4551%2820%2930375-6

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Procedure method (step by step)

Important Notes:

  • Desensitisation should take place on a cardiology ward with appropriate nursing cover and monitoring for this procedure. One nurse should be available to complete the full desensitisation on day 1 and a handover should be documented in the patient’s notes for day 2.
  • The patient should be advised to omit the following medications for the 24 hours before the desensitisation procedure:
    • Anticholinergics
    • Antihistamines
    • Cromoglycate
    • Tricyclic antidepressants
    • Beta-blockers
    • Angiotensin converting enzyme inhibitors

      Beta-blockers and angiotensin converting enzyme inhibitors can affect emergency anaphylaxis treatment, resulting in severe and treatment resistant anaphylaxis.  For in-patients, they should be omitted the evening before and on the morning of the day of desensitataton. They can be taken post desensitisation (same day).

      If any of the medications are unable to be omitted please discuss with the Immunology Department prior to undertaking desensitisation.

  • If a patient is taking anti-leuokotriene medication such as Montelukast bronchospasmic responses to oral aspirin may be blocked but exacerbation of cutaneous or rhinoconjunctivitis symptoms should not be.

  • The protocol should be read in full before the desensitisation is started.
  • The procedure should be stopped if any of the following occur:
    • >10% reduction in peak flow
    • Significant drop in blood pressure or oxygen saturation
    • Any signs of adverse reaction
  • Once successfully densensitised, aspirin should be continued without interruption. If a patient misses more than 2 doses (>48hours from last dose) then repeat desensitisation will be required.

Procedure:

  1. The oral aspirin dosing regimen should be prescribed on eMeds
    (Protocols - Adults - Cardiology - Oral Aspirin Desensitisation)
  2. Ensure the following readily available and accessible:
    1. Intravenous hydrocortisone
    2. Intravenous chlorpheniramine
    3. Cetrizine tablets
    4. Salbutamol nebules and nebulizer
    5. 1:1000 (1mg/ml) adrenaline (please note one dose is 500micrograms or 0.5ml of 1mg/ml)
  3. The patient should have intravenous access available prior to the start of the procedure;this is for emergency treatment of anaphylaxis only and not for administration of the desensitisation.
  4. Prepare ‘Solution A’ by dissolving 1 x 75mg aspirin tablet in 75ml water (1mg/ml suspension).
  5. Using a 1ml purple oral syringe withdraw the volumes required for steps 1-3 (0.1ml, 0.3ml and 1ml) and using a 5ml purple oral syringe the volume required for step 4 (3ml); please refer to the table below and eMeds chart.  Each syringe should be labeled with Aspirin 1mg/ml (Solution A), the volume and step number.  Discard the remaining Solution A suspension. The prepared syringes should not be left by the bedside unattended (as per the LTHT Medicines Code) and should be prepared just prior to starting the densensitisation.
  6. Prepare ‘Solution B’ by dissolving 2 x 75mg aspirin tablets in 15ml water (10mg/ml suspension)
  7. Using a 1ml purple oral syringe withdraw the volumes required for step 5 (1ml) and using a 5ml purple oral syringe the volume required for steps 6-7 (3ml and 4ml); please refer to the table below and eMeds chart.  Each syringe should be labeled with Aspirin 10mg/ml (Solution B), the volume and step number.  Discard the remaining Solution B suspension.  The prepared syringes should not be left by the bedside unattended (as per the LTHT Medicines Code) and should be prepared just prior to starting the densensitisation.
  8. Perform baseline monitoring of blood pressure, oxygen saturations and peak flow and record this on the observation sheet (see appendix 1); this will need to be printed out.
  9. With a 15 minute interval in-between each dose, administer by oral administration steps 1 to 7 of the desensitisation protocol (see table below and eMeds chart).
    1. Prior to each step repeat blood pressure, oxygen saturations and peak flow should be performed and recorded.
    2. If there is any alteration in the patient’s condition or monitoring it should be brought to the immediate attention of the doctors.
    3. The oral purple syringe should be inverted several times prior to administration to ensure fully mixed.
    4. The time of administration of each dose should be recorded on the eMeds chart
  10. 15 minutes after step 7 the patient should receive, by oral administration, 1 x 75mg aspirin tablet. Prior to this repeat blood pressure, oxygen saturations and peak flow should be performed. The time of administration of each dose should be recorded on the eMeds chart.
  11. The patient should remain on the ward overnight with regular monitoring.  If there has been no adverse reaction the patient should receive an additional oral aspirin 75mg dose the following morning (repeat baseline observations prior to administration) and be observed for 1 hour before being discharged.
  12. Prior to discharge: the ‘Aspirin Desensitisation Patient Information Leaflet’ should be given to the patient and the importance of not missing doses explained to the patient. The patient should also be discharged with one month’s supply of aspirin 75mg tablets. It should be clearly documented on the discharge summary that the patient has been desensitised to aspirin and for their GP allergy record to be updated accordingly.  This should include a request to add a script note to aspirin on the GP records to state that any break of >48 hours requires the patient requires to be desensitised.

The observation sheet should be scanned to the patients PPM+ record.

Step

Dose of Aspirin
(mg)

Solution

Solutuion
Concentration

Volume of Solution to Administer

1

0.1

A

1mg/ml

0.1ml

2

0.3

A

1mg/ml

0.3ml

3

1

A

1mg/ml

1ml

4

3

A

1mg/ml

3ml

5

10

B

10mg/ml

1ml

6

30

B

10mg/ml

3ml

7

40

B

10mg/ml

4ml

8

75

75mg tablet

N/A

N/A

Please also refer to patients Oral Aspirin Desensitisation eMeds Chart

Provenance

Record: 5259
Objective:

To ensure the safe and successful desensitisation to aspirin within the Cardiology department in patients who require long-term treatment with aspirin.

Clinical condition:
Target patient group:
Target professional group(s): Secondary Care Doctors
Secondary Care Nurses
Pharmacists
Adapted from:

Evidence base

References

  • Chapman A, Rushworth GF & Leslie SJ (2013).  Aspirin desensitization in patients undergoing percutaneous coronary intervention: A survey of current practice.  Cardiology Journal; 20(2): 134-138.
  • Wong et al (2000). Rapid oral challenge-desensitisation for patients with aspirin-related urticarial-angioedema.  Journal of Allergy and Clinical Immunology; 105(5): 997-1001.
  • Rossini R, et al (2017). Aspirin Desensitization in Patients With Coronary Artery Disease: Results of the Multicenter ADAPTED Registry (Aspirin Desensitization in Patients With Coronary Artery Disease). Circ Cardiovasc Interv. 10(2):e004368.
  • Cardona et al (2020). World Allergy Organization Anaphylaxis Guidance 2020. World Allergy Organization Journal; 13:100472 http://doi.org/10.1016/j.waojou.2020.100472

Approved By

Trust Clinical Guidelines Group

Document history

LHP version 2.0

Related information

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