A 26-year-old woman is brought to the emergency department due to an episode of near-syncope. The patient's husband states that they were at a buffet 20 minutes ago, when she suddenly experienced severe weakness and dizziness. The patient almost fell, so he helped her sit. She also had nausea, abdominal cramping, and a generalized itching sensation but no chest pain or shortness of breath. The patient has no chronic medical conditions and takes no medications. She is menstruating, and her husband says that she usually has heavy periods. Temperature is 36.7 C (98.1 F), blood pressure is 80/50 mm Hg, pulse is 120/min, and respirations are 20/min. On physical examination, the patient is ill-appearing with flushed skin and warm extremities. The lungs are clear to auscultation, and cardiac examination is normal except for tachycardia. The abdomen is soft with mild, diffuse tenderness, and bowel sounds are normal. ECG reveals sinus tachycardia. In addition to intravenous fluids, which of the following is the most appropriate next step in management of this patient?

Question

A 26-year-old woman is brought to the emergency department due to an episode of near-syncope.  The patient's husband states that they were at a buffet 20 minutes ago, when she suddenly experienced severe weakness and dizziness.  The patient almost fell, so he helped her sit.  She also had nausea, abdominal cramping, and a generalized itching sensation but no chest pain or shortness of breath.  The patient has no chronic medical conditions and takes no medications.  She is menstruating, and her husband says that she usually has heavy periods.  Temperature is 36.7 C (98.1 F), blood pressure is 80/50 mm Hg, pulse is 120/min, and respirations are 20/min.  On physical examination, the patient is ill-appearing with flushed skin and warm extremities.  The lungs are clear to auscultation, and cardiac examination is normal except for tachycardia.  The abdomen is soft with mild, diffuse tenderness, and bowel sounds are normal.  ECG reveals sinus tachycardia.  In addition to intravenous fluids, which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d173_6435_bc81_b57f61508446_MD0003_00 This patient with abdominal cramping, pruritus, flushing, and hypotension has anaphylaxis, a life-threatening condition that can develop at any age. Anaphylaxis is caused by sudden, massive degranulation of mast cells and basophils, usually due to an IgE-mediated, type I hypersensitivity reaction to an allergen (eg, food). The trigger is often known; however, there may be no prior allergic history, either because it is the first anaphylactic episode or because prior episodes were unrecognized (eg, nonclassic presentation). nonclassic presentation A variety of presentations can fulfill the diagnostic criteria. In general, anaphylaxis is likely when symptom onset is rapid and ≥2 organ systems are affected. The most commonly used diagnostic criterion involves skin/mucosa (eg, flushing, pruritus) involvement, which occurs in >90% of patients, with cardiovascular (eg, hypotension) or respiratory (eg, stridor, bronchospasm) manifestations. However, patients with exposure to a known allergen require only hypotension for diagnosis. Management requires prompt administration of intramuscular epinephrine, which has alpha-1 and beta-2 agonist effects causing vasoconstriction (↑ blood pressure, ↓ edema) and decreased release of inflammatory mediators from mast cells and basophils (↓ allergic reaction), respectively. Repeat dosing may be required. (Choice A) Staphylococcal toxic shock syndrome can occur in menstruating women who use tampons; it may also cause hypotension, skin manifestations, and gastrointestinal symptoms. However, high fever is expected, onset is typically less abrupt, and the associated rash is typically diffuse and erythematous, involving the palms and soles. (Choices C and F) Intravenous proton pump inhibitors are indicated for upper gastrointestinal bleeding, whereas type O, Rh-negative red blood cell transfusion (uncross-matched blood) is indicated for severe, life-threatening bleeding. Such patients develop hypovolemic shock characterized by cool, pale extremities (as opposed to this patient's warm, flushed extremities) typically with hematemesis or hematochezia. Pruritus would be unexpected. (Choice D) This patient's symptoms fulfill the criteria for anaphylaxis, and she is in shock; therefore, immediate administration of epinephrine is required. Supportive care without epinephrine may result in cardiovascular collapse and cardiac arrest. (Choice E) Synchronized cardioversion is indicated in unstable arrhythmias (eg, supraventricular tachycardia with hypotension). However, this patient has sinus tachycardia, a compensatory mechanism in the setting of anaphylaxis-induced distributive shock that would not improve with cardioversion. Educational objective: Anaphylaxis is a rapid-onset, life-threatening, multisystem disorder that commonly involves the skin/mucosa with cardiovascular, respiratory, and gastrointestinal symptoms. Anaphylaxis should be considered in any patient with symptoms in ≥2 organ systems after exposure to a likely allergen. References: Anaphylaxis (http://www.ncbi.nlm.nih.gov/pubmed/30263034) Time to revisit the definition and clinical criteria for anaphylaxis? (http://www.ncbi.nlm.nih.gov/pubmed/31719946)

A 26-Year-Old Woman Is Brought to the Emergency Department Due