Epinephrine

INTRODUCTION

Indications

SCbcut, IV, Inhalation: Management of reversible airway disease due to asthma or COPD. SC, IV: Management of severe allergic reactions. IV, Intracardiac, Intratracheal, Intraosseous (part of advanced cardiac life support [ACLS] and pediatric advanced life support [PALS] guidelines): Management of cardiac arrest (unlabeled). Inhalation: Management of upper airway obstruction and croup (racemic epinephrine). Local/Spinal: Adjunct in the localization/prolongation of anesthesia.

Action

Results in the accumulation of cyclic adenosine monophosphate (cAMP) at beta-adrenergic receptors. Affects both beta₁ (cardiac)–adrenergic receptors and beta₂ (pulmonary)–adrenergic receptor sites. Produces bronchodilation. Also has alpha-adrenergic agonist properties, which result in vasoconstriction. Inhibits the release of mediators of immediate hypersensitivity reactions from mast cells. Therapeutic Effects: Bronchodilation. Maintenance of heart rate and blood pressure (BP). Localization/prolongation of local/spinal anesthetic.

Adverse Reactions/Side Effects

CNS: nervousness, restlessness, tremor, headache, insomnia. Resp: paradoxical bronchospasm (excessive use of inhalers). CV: angina, arrhythmias, hypertension, tachycardia. GI: nausea, vomiting. Endo: hyperglycemia.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• In patients with airway disease, assess pulmonary function at rest and during exercise (See Appendices I, J, K) to document effectiveness of medication in controlling bronchospasm.

• Monitor signs of increased (paradoxical) bronchospasm such as wheezing, cough, dyspnea, and tightness in chest and throat. These signs are more common at high or excessive inhaled doses. If condition occurs, advise patient to withhold medication and notify physician or other health care professional immediately.

• Assess BP periodically and compare to normal values (See Appendix F). Report a sustained increase in BP (hypertension) to the physician.

• Assess heart rate, ECG, and heart sounds, especially during exercise (see Appendices G, H). Report any rhythm disturbances or symptoms of increased arrhythmias, including angina, palpitations, shortness of breath, fainting, and fatigue/weakness.

• Monitor and report signs of CNS toxicity, including nervousness, restlessness, insomnia, or tremor. Sustained or severe CNS signs may indicate overdose or excessive use of this drug.

• Monitor signs of hyperglycemia (drowsiness, fruity breath, increased urination, unusual thirst). Patients with diabetes mellitus should check blood glucose levels frequently.

Interventions

• When implementing airway clearance techniques or respiratory muscle training, attempt to intervene when the airway is maximally bronchodilated. Drug effect is usually very rapid (within 1 min) after inhalation, so chest physical therapy interventions can begin soon after drug administration.

• Because of the risk of cardiovascular stimulation, use extreme caution during aerobic exercise and endurance conditioning. Cardiovascular effects such as arrhythmias, angina pectoris, or increased BP occur more commonly with epinephrine compared to other bronchodilators because epinephrine stimulates beta_...