A 56-year-old woman in the emergency department waiting room develops shortness of breath and generalized itching. She was eating a cookie when the symptoms started. The patient is allergic to peanuts and believes the cookie contained them. She has a history of emphysema and a 20-pack-year smoking history. Temperature is 36.7 C (98.1 F), blood pressure is 88/60 mm Hg, pulse is 124/min, and respirations are 26/min. Pulse oximetry is 92% on room air. The patient is using the accessory muscles of her neck and shoulder girdle and is exhaling through pursed lips. There is no tongue swelling or stridor. Bilateral wheezes are present on lung auscultation. Skin examination is shown in the exhibit. The patient is given an intramuscular injection of epinephrine. Ten minutes later, there is no significant change in her condition. Which of the following is the best next step in management of this patient?

Question

A 56-year-old woman in the emergency department waiting room develops shortness of breath and generalized itching.  She was eating a cookie when the symptoms started.  The patient is allergic to peanuts and believes the cookie contained them.  She has a history of emphysema and a 20-pack-year smoking history.  Temperature is 36.7 C (98.1 F), blood pressure is 88/60 mm Hg, pulse is 124/min, and respirations are 26/min.  Pulse oximetry is 92% on room air.  The patient is using the accessory muscles of her neck and shoulder girdle and is exhaling through pursed lips.  There is no tongue swelling or stridor.  Bilateral wheezes are present on lung auscultation.  Skin examination is shown in the exhibit.  The patient is given an intramuscular injection of epinephrine.  Ten minutes later, there is no significant change in her condition.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_bdcf_4340_8f63_c93fcd09c7c8_MD0005_00 This patient with urticaria, respiratory distress, and hypotension is experiencing anaphylaxis. First-line treatment is immediate administration of intramuscular (IM) epinephrine, a beta-2 and alpha-1 adrenergic receptor agonist that typically causes bronchial smooth muscle relaxation (decreasing wheezing and work of breathing) and vasoconstriction (increasing blood pressure and decreasing edema), respectively. However, some patients experience refractory symptoms (eg, no significant change after 10 minutes). These patients require additional IM doses of epinephrine or even intravenous epinephrine to achieve significant symptom resolution. When intravenous epinephrine is required, slow infusion is preferred to bolus dosing due to the risk of cardiovascular side effects (eg, ventricular arrhythmias, myocardial infraction). Adjunct management of anaphylaxis includes circulatory support measures such as large-volume fluid resuscitation in hypotensive patients; patients should also be positioned (eg, supine, semirecumbent) with the lower extremities elevated to improve venous return to the heart. Other medications (eg, albuterol, glucocorticoids, antihistamines) may be given to address isolated symptoms. However, titrating epinephrine administration to achieve symptom improvement and/or resolution always takes priority because these other medications do not address the broad-ranging systemic effects of anaphylaxis or prevent hypotension, cardiovascular collapse, and death. (Choice A) The beta-2 agonist effect from albuterol can relieve bronchoconstriction (eg, wheezing) but does not treat other dangerous symptoms of anaphylaxis such as hypotension. (Choice C) The antihistamine effect of intravenous diphenhydramine can help relieve symptoms of pruritus and urticaria. However, it does not treat bronchospasm or shock, which are ongoing in this patient. (Choice D) Glucocorticoids such as methylprednisolone may be helpful (although evidence is limited) in preventing prolonged or biphasic reactions. However, glucocorticoids need several hours to take effect and do not provide the immediate action required in this emergency situation. (Choice E) IM epinephrine administration into the thigh is the preferred route and location because peak plasma concentration (and therefore medication effect) is achieved faster than with subcutaneous injection, which has delayed absorption. Educational objective: Immediate administration of intramuscular epinephrine is the first-line treatment for anaphylaxis, and additional epinephrine administration (eg, intramuscular, intravenous) may be required for symptom resolution in some patients. Fluid resuscitation, bronchodilators, antihistamines, and glucocorticoids may be adjunct therapies but do not take priority over epinephrine. References: Management and Prevention of Anaphylaxis (http://www.ncbi.nlm.nih.gov/pubmed/26918144) 2012 update: World Allergy Organization guidelines for the assessment and management of anaphylaxis. (http://www.ncbi.nlm.nih.gov/pubmed/22744267)

A 56-Year-Old Woman in the Emergency Department Waiting Room Develops