Procedure for Rush and Cluster Immunotherapy

Rush and Cluster Immunotherapy represent accelerated schedules of immunotherapy. They are designed to allow a patient to reach a maintenance dose in a shorter time that the more traditional weekly immunotherapy. Though this may provide improved convenience, it also is associated with an increased risk of allergic reactions. There a number of advantages and disadvantages to using an accelerated immunotherapy schedule:

Advantages
  • May be more convenient if the duration of weekly visits is shortened
  • Improved adherence
  • Clinical benefit may occur more rapidly
  • May be safer because the number of vials being used is reduced once a maintenance dose is reached

Disadvantages
  • There is an increased risk of systemic reactions during the procedure
  • Increased time and resources are needed in the health facility to give multiple injections

Indications

While there are no firm indications for accelerated schedules, the following patients and/or situations may benefit from such schedules:
  • Patients who have not been able to reach a maintenance dose on weekly immunotherapy due to systemic reactions or due to sub adherence
  • Patients whose schedule precludes weekly injections for a prolonged time
  • Patients with asthma that cannot be adequately controlled but who can be controlled long enough to reach a maintenance dose with an accelerated schedule

Consent for accelerated schedules

When an accelerated schedule is used then additional informed consent should be obtained in which the additional procedures, risks and benefits are disclosed. This may be obtained using a separate consent form designed for accelerated immunotherapy in addition to a form designed for weekly immunotherapy.

Premedication

Premedication is given in an attempt to reduce the risk and severity of a systemic reaction during the procedure. Factors that increase the risk of a systemic reaction include:
  • Poorly-controlled asthma
  • Extremely high sensitivity to the allergens
  • Poor suppression of skin reactivity with premedication

Cluster Immunotherapy
  • It may be desirable to have the patient take an H1 and H2 antagonist on the day that they will receive cluster injections, however, there is no evidence that doing so reduces the likelihood or severity of a local or systemic reaction.
Rush Immunotherapy
  • Patients should receive prophylaxis starting 2 days prior to the procedure to reduce the likelihood of a systemic reaction.
  • Prophylaxis should include cetirizine or benadryl, rantidine, prednisone, and montelukast.

Schedules

Cluster Immunotherapy (example)
cluster_schedule.png

Rush Immunotherapy (1-day schedule)
rush_schedule.png
This should be followed by 8 weekly injections building up to and at the maintenance dose. The frequency can then be reduced to every 2 weeks.


Other points

Rush Immunotherapy
  • An IV with a heparin lock often is inserted as a precaution prior to the procedure.
  • It may be necessary to stop giving injections if the patient develops a large local reaction or evidence of a systemic reaction.
  • For extremely sensitive individuals it may be desirable to stop giving injections after the 1:10 (v/v) vial to avoid inducing a systemic reaction.
  • Patients should be observed for at least 2 hours after the last injection during the rush day.

Billing

  • It is best to obtain prior authorization if possible
  • An appropriate CPT code to use is 95180 which is billed on an hourly basis. This should billed for the preapproved amount.

References