A 24-year-old woman is brought to the emergency department due to sudden-onset difficulty breathing. She is preparing to defend her graduate school thesis at the end of the week. The patient feels that she "can't get enough air" into her lungs. Her fingertips have started tingling. She has no pain. Medical history includes allergic rhinitis and childhood eczema. Medications include nasal fluticasone. Temperature is 36.7 C (98 F), blood pressure is 110/76 mm Hg, pulse is 100/min, respirations are 20/min, and pulse oximetry is 99%. On examination, she is taking deep breaths with occasional audible deep sighs. The lungs are clear to auscultation. Cardiac auscultation is normal. Which of the following is the most appropriate treatment for this patient's condition?

Question

A 24-year-old woman is brought to the emergency department due to sudden-onset difficulty breathing.  She is preparing to defend her graduate school thesis at the end of the week.  The patient feels that she "can't get enough air" into her lungs.  Her fingertips have started tingling.  She has no pain.  Medical history includes allergic rhinitis and childhood eczema.  Medications include nasal fluticasone.  Temperature is 36.7 C (98 F), blood pressure is 110/76 mm Hg, pulse is 100/min, respirations are 20/min, and pulse oximetry is 99%.  On examination, she is taking deep breaths with occasional audible deep sighs.  The lungs are clear to auscultation.  Cardiac auscultation is normal.  Which of the following is the most appropriate treatment for this patient's condition?

Quizplus · Accepted Answer

This patient has subjective shortness of breath with good oxygenation, clear lungs, and a deep breathing pattern punctuated by audible sighs. In addition, she has paresthesias of her hands that presented during a time of significant stress. This is consistent with hyperventilation syndrome, a diagnosis of exclusion characterized by intermittent episodes of hyperventilation without any obvious cardiac or pulmonary etiology. Manifestations develop when alveolar minute ventilation increases enough to decrease the PaCO₂. In some patients, this can be due to tachypnea (ie, increase in respiratory rate); however, the respiratory rate may be near-normal if the depth of breathing is significantly increased (ie, increase in tidal volume), as in this patient (eg, deep breaths, sighs). Neurologic symptoms, including paresthesias, headache, lightheadedness, and carpopedal spasms, are often present and may be related to cerebral vasoconstriction or alkalosis-induced hypocalcemia and hypophosphatemia. Education and reassurance are key components of treatment. Patients should be taught abdominal (diaphragmatic) breathing, a retraining maneuver that involves trying to keep the chest still; this maneuver generally takes some practice but resolves most episodes. If the episode does not improve with breathing retraining, a small dose (not a high dose) of a short-acting benzodiazepine (eg, lorazepam) is appropriate second-line therapy (Choice A). Breathing into a paper bag was previously recommended to improve hypocarbia by rebreathing CO₂; however, this can also result in hypoxia and therefore should not be done (Choice D). There is an overlap between hyperventilation syndrome and panic disorders; however, panic attacks are characterized by an acute onset of intense fear accompanied by 4 out of 13 symptoms (eg, palpitations, chest pain, nausea, sweating) that may not necessarily include respiratory symptoms. (Choice B) Nebulized albuterol is an appropriate treatment for an asthma exacerbation, which presents with acute shortness of breath. However, there would be wheezing (rather than deep sighs), a lower pulse oximetry, and typically no paresthesias. (Choice C) Racemic epinephrine is used most commonly for croup, a viral infection that causes inflammatory narrowing of the subglottic airway. However, croup typically presents in young children (age <3) with stridor (rather than sighing). Educational objective: Hyperventilation syndrome presents with acute onset of deep breathing and/or tachypnea often accompanied by neurologic symptoms. Lung examination is normal. Initial treatment is reassurance with breathing retraining. References: Hyperventilation syndrome in adolescents with and without asthma. (http://www.ncbi.nlm.nih.gov/pubmed/25470247)

A 24-Year-Old Woman Is Brought to the Emergency Department Due