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Hyperventilation Syndrome, Emergency Medicine

Basics

Description

- Controversy exists regarding underlying disorders that may contribute to hyperventilation: - Hypocapnia - Hypophosphatemia - Hypocalcemia

- Past episodes - Duration - Triggers - Past treatment - Typical time point of onset during the day

- Psychiatric: - Intense fear, anxiety - Giddiness - Feeling of unreality

  • 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 populationMore common in women (may be related to progesterone)

Etiology

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

Diagnosis

Signs and Symptoms

History

  • Past episodesDurationTriggersPast treatmentTypical time point of onset during the day
  • Cardiac:Chest painDyspnea"Air hunger"пїЅPalpitations
  • Neurologic:DizzinessLightheadednessSyncopeParesthesiasHeadacheCarpopedal spasmTetany
  • Psychiatric:Intense fear, anxietyGiddinessFeeling of unreality
  • General:

Physical Exam

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

Essential Workup

  • 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.

Diagnosis Tests & Interpretation

Lab

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

Imaging

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

Diagnostic Procedures/Surgery

  • 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.

Differential Diagnosis

  • Pathologic
  • Hypoxia:AsthmaCHFPulmonary embolusPneumonia
  • Severe pain
  • CNS lesions
  • Acidosis (DKA)
  • Pulmonary HTN
  • Pulmonary embolus
  • Hypoglycemia
  • Mild asthma
  • Drugs:Aspirin intoxicationWithdrawal syndrome (e.g., alcohol, benzodiazepines)
  • Physiologic
  • Pregnancy
  • Pyrexia
  • Altitude

Treatment

Pre-Hospital

  • Patients with abnormal vital signs require IV access and pulse oximetry.
  • Supplemental oxygen if hypoxic

Initial Stabilization/Therapy

  • Patients with abnormal vital signs require IV access and pulse oximetry.
  • Initiate therapy for pathologic or physiologic cause of hyperventilation.

Ed Treatment/Procedures

  • Initiate treatment of hyperventilation syndrome if initial workup does not support a pathologic or physiologic cause, and history and physical exam findings suggest the diagnosis of hyperventilation syndrome.
  • Reassurance, calming, and explanation of the voluntary component of the patients symptoms often have immediate dramatic results.
  • Do not use paper bag rebreathing to increase the PCO2. This has not been supported in the literature:It may be dangerous in patients with hypoxia or a pathologic or physiologic cause for hyperventilation.
  • Clarification of the psychological stressors helps the patient avoid further attacks.
  • Assess for need of psychiatric evaluation (i.e., suicidal ideation).
  • Anxiolytics:Benzodiazepine if symptoms persist to break the cycle of anxiety and hyperventilationShort course of anxiolytics may benefit patients with definable temporary stressors.

Medication

  • Alprazolam 0.25-0.5 mg PO
  • Lorazepam: 1-2 mg PO or IV
  • Diazepam: 2-5 mg PO or IV
  • Outpatient treatment:Buspirone: 5 mg PO TIDDiazepam: 2-5 mg PO BID-QID

Follow-Up

Disposition

Admission Criteria

Hyperventilation syndrome does not require admission. пїЅ

Discharge Criteria

  • Exclusion or successful treatment of primary pathologic or physiologic causes of hyperventilation
  • No acute psychiatric issues
  • Adequate follow-up with a primary care physician

Follow-Up Recommendations

  • Follow-up with primary care physician
  • Assess the need for psychiatric follow-up.

Pearls and Pitfalls

  • Exclude pathologic or physiologic causes of hyperventilation.
  • Hyperventilation syndrome will not result in hypoxia.

Additional Reading

  • Gardner пїЅWN. The pathophysiology of hyperventilation disorders. Chest. 1996;109:516-534.
  • Nardi пїЅAE, Freire пїЅRC, Zin, пїЅWA. Panic disorder and control of breathing. Respir Physiol Neurobiol. 2009;167(1):133-143.
  • Niggerman пїЅB. How to diagnose psychogenic and functional breathing disorders in children and adolescents. Pediatr Allergy Immunol. 2010;21:895-899.
  • Rizzolo пїЅCL, Taylor пїЅJE, Cerciello пїЅRL. Anxiety and anxiety-related disorders in the adolescent population: An overview of diagnosis and treatment. Adolesc Med State Art Rev. 2009:20(1):188-202.
  • Saisch пїЅSG, Wessely пїЅS, Gardner пїЅWN. Patients with acute hyperventilation presenting to an inner-city emergency department. Chest. 1996;110(4):952-957.

Codes

ICD9

306.1 Respiratory malfunction arising from mental factors пїЅ

ICD10

F45.8 Other somatoform disorders пїЅ

SNOMED

  • 191956005 Psychogenic hyperventilation (finding)