Rosen & Barkin's 5-Minute Emergency Medicine Consult (372 page)

• Cholestyramine: 4 g PO QID
  
• Dexamethasone: 2 mg IV q6h (peds: 0.15 mg/kg q6h)
  
• Esmolol: 500 μg/kg IV over 1 min followed by 50 μg/kg/min IV; titrate to effect
  
• Guanethidine: 30–40 mg PO q6h for 1–3 days
  
• Hydrocortisone: 100 mg IV initially, followed by 100 mg IV q8h for first 24–36 hr
  
• Iopanoic acid: 1 g IV q8h for first 24 hr, then 500 mg IV BID
  
• Lithium carbonate: 300 mg PO QID (peds: 15–60 mg/kg/d div. TID–QID)
  
• Lugol solution: 5 drops (250 mg) PO q6h
  
• MMI: 60–80 mg/d PO (peds: 0.4 mg/kg) (peds: 0.2 mg/kg/d) in 3 div. doses
  
• Propranolol: 0.5–1 mg IV + subsequent 2–3 mg doses over 10–15 min q several hours,
  or
  60–80 mg PO q4h
  
• PTU: 100–150 mg PO q8h initially then 200–250 mg PO q4h (peds: 5–7 mg/kg/d in 3 div. doses)
  
• Reserpine: 1–5 mg IM, then 0.07–0.3 mg/kg in the 1st 24 hr
  

• PTU
  
• Propranolol
  
• Iodine therapy (Lugol), 1 hr after PTU
  

• MMI
  
• Esmolol
  
• Lithium (only with iodine allergy)
  
• Guanethidine (for patients with bronchospasm), reserpine
  

• Physiologic changes associated with pregnancy may resemble many symptoms of hyperthyroidism
  
• Poorly controlled hyperthyroidism during pregnancy may result in:
  
  • Hyperemesis gravidarum
    
  • Premature labor
    
  • Preeclampsia
    
  • Low birth weight
    
  • Spontaneous abortion
    
  • Stillbirth
    
• Thyroid storm often precipitated by stressors including infection, labor, birth
  
• Treatment:
  
  • Initial stabilization as in the nonpregnant patient (ABCs, supportive measures)
    
  • PTU considered safer than MMI. Both cross the placenta. PTU should be ≤ 200 mg/day
    
  • Propranolol may be safely used
    
  • Radioactive iodine absolutely contraindicated when pregnant or nursing
    
  • Thyroidectomy is the only other option if unable to tolerate PTU while pregnant
    
• Postpartum thyroiditis:
  
  • 5–10% of patients within 6 mo of delivery
    
  • May require antithyroid medications
    
  • 50% affected become euthyroid within 1 yr
    
  • Transient hypothyroidism may follow
    

FOLLOW-UP

• Thyroid storm
  
• Requiring IV medications to control heart rate
  
• Significantly symptomatic or unstable patients
  

Minimal symptoms that respond well to PO therapy

• Should have PCP follow-up within a few weeks depending on symptoms
  
• May benefit from endocrinology referral
  

• Thyroid storm can be fatal. Diagnosis requires a high level of suspicion and treatment often needs to be started presumptively
  
• Radioactive iodine is never a treatment option in the pregnant patient with hyperthyroidism
  
• Never give iodine before blocking hormone synthesis with PTU or MMI in thyroid storm
  

• Bahn RS, Burch HB, Cooper DS, et al. Hyperthyroidism and other causes of thyrotoxicosis: Management guidelines of the ATA and AACE.
  Endocr Pract.
  2011;17(3):456–520.
  
• Klubo-Gwiezdzinska J, Wartofsky L. Thyroid emergencies.
  Med Clin North Am
  . 2012;96(2):385–403.
  
• Nayak B, Hodak SP. Hyperthyroidism.
  Endocrinol Metab Clin North Am
  . 2007;36(3):617–656, v.
  

See Also (Topic, Algorithm, Electronic Media Element)

Hypothyroidism

CODES

• 242.20 Toxic multinodular goiter without mention of thyrotoxic crisis or storm
  
• 242.90 Thyrotoxicosis without mention of goiter or other cause, and without mention of thyrotoxic crisis or storm
  
• 242.91 Thyrotoxicosis without mention of goiter or other cause, with mention of thyrotoxic crisis or storm
  

BASICS

• Hyperventilation syndrome describes a constellation of symptoms:
  
  • Most commonly: Dyspnea, chest pain, lightheadedness, and paresthesias
    
• Produced by a nonphysiologic increase in minute ventilation:
  
  • Minute ventilation may be increased by increasing respiratory rate or tidal volume (sighs).
    
• Pathologic or physiologic causes of hyperventilation must be excluded before the diagnosis of hyperventilation syndrome can be assigned.
  
• Prevalence:
  
  • 10–15% in the general population
    
  • More common in women (may be related to progesterone)
    

• Etiology of symptoms is unclear:
  
  • Usually a response to psychological stressors
    
• Controversy exists regarding underlying disorders that may contribute to hyperventilation:
  
  • Hypocapnia
    
  • Hypophosphatemia
    
  • Hypocalcemia
    

DIAGNOSIS

• Past episodes
  
  • Duration
    
  • Triggers
    
  • Past treatment
    
  • Typical time point of onset during the day
    
• Cardiac:
  
  • Chest pain
    
  • Dyspnea
    
  • “Air hunger”
    
  • Palpitations
    
• Neurologic:
  
  • Dizziness
    
  • Lightheadedness
    
  • Syncope
    
  • Paresthesias
    
  • Headache
    
  • Carpopedal spasm
    
  • Tetany
    
• Psychiatric:
  
  • Intense fear, anxiety
    
  • Giddiness
    
  • Feeling of unreality
    
• General:
  
  • Fatigue
    
  • Weakness
    
  • Malaise
    

• Clinical signs are rare and varied:
  
  • Tachypnea most common
    
  • However, tachypnea may not be present. Patient may increase tidal volume rather than respiratory rate.
    
• Carpopedal spasm:
  
  • May be dramatic
    
• Chvostek sign may be present
  

• Diagnosis of exclusion:
  
  • Primary pathologic or physiologic causes of hyperventilation must be investigated and excluded.
    
• Clinical diagnosis based on the history and physical exam
  
• Vital signs including pulse oximetry
  
• Hyperventilation syndrome will not result in hypoxia.
  

• Consider an ABG in any hypoxic patient.
  
• Electrolytes, BUN, creatinine, and glucose levels for suspected acidosis/diabetic ketoacidosis
  
• EKG if chest pain present
  

CXR of any patient with hypoxia or focal findings on lung exam

• Hyperventilation provocation test after resolution of symptoms:
  
  • Forced overbreathing for 3 min may be attempted to reproduce the symptoms.
    
  • Diagnostic accuracy is controversial.
    
  • Reproducibility of the symptoms may help the patient understand the role of overbreathing and help manage future attacks.
    

• Pathologic
  
• Hypoxia:
  
  • Asthma
    
  • CHF
    
  • Pulmonary embolus
    
  • Pneumonia
    
• Severe pain
  
• CNS lesions
  
• Acidosis (DKA)
  
• Pulmonary HTN
  
• Pulmonary embolus
  
• Hypoglycemia
  
• Mild asthma
  
• Drugs:
  
  • Aspirin intoxication
    
  • Withdrawal syndrome (e.g., alcohol, benzodiazepines)
    
• Physiologic
  
• Pregnancy
  
• Pyrexia
  
• Altitude