hello when treating a pt with adenosine the contra indications are active bronchial constriction on exam, the companion document also states that adenosine can cause bronchial constriction in asthmatic pts. so may question is ... is an asthmatic pt contraindicated for adenosine tx or is more of a relative vs absolute situation
Thank you for your thoughtful question. The short answer is a patient with a history of asthma, with no active signs of bronchoconstriction, but with a symptomatic tachydysrhythmia, can receive adenosine (given they meet all the Conditions and have no Contraindications).
There is very limited evidence, only case reports and small studies using inhaled adenosine that show an association between adenosine and bronchoconstriction. Notably, in some of these case studies the patients who developed bronchoconstriction after adenosine administration had no history of asthma or bronchoconstriction. The mechanism of how adenosine causes bronchoconstriction is unclear. But, may have to do with the release of mast cell mediators, like histamine.
A patient in active bronchoconstriction on exam should not receive adenosine, due to the potential risk for worsening bronchoconstriction. However, the benefit of adenosine outweighs the potential risk in a patient with a history of asthma and no signs of bronchoconstriction on exam.