Approach Considerations
Because respiratory distress or chest pain has many potentially serious causes, the diagnosis of hyperventilation syndrome (HVS) should never be made in the field. Even when a patient with these complaints carries a prior diagnosis of HVS, he or she must still be transported to a hospital for a more complete evaluation.
Rebreathing into a paper bag is not recommended. Deaths have occurred in patients with acute myocardial infarction (MI), pneumothorax, and pulmonary embolism (PE) who were initially misdiagnosed with HVS and treated with paper bag rebreathing. [9]
Subspecialty consultation usually is not required for HVS. Patients should be treated by a psychiatrist, psychologist, or family physician with experience and interest in managing HVS. Some physiotherapists and respiratory therapists have extensive experience in retraining patients in proper breathing techniques and should be consulted. Pharmacotherapy may be helpful.
Although inpatient care is not indicated, many patients with chronic HVS are admitted because their symptoms resemble those of many serious organic problems and because there is no simple way of confirming the diagnosis in the emergency department (ED).
Patients may also be referred for treatment with acupuncture. This modality is useful in decreasing anxiety and thereby reducing the severity of the symptoms associated with HVS. Lowering patients’ anxiety levels may also reduce the frequency of symptomatic periods. [10]
Breathing Techniques
ED treatment of hyperventilation syndrome is often ineffective. Rebreathing into a paper bag is no longer a recommended technique, because significant hypoxia and death have been reported. [9]
In patients who are hyperventilating for organic reasons (eg, pulmonary edema, metabolic acidosis), increasing the arterial partial pressure of carbon dioxide (PaCO2) and decreasing oxygen may be disastrous. In addition, paper bag rebreathing is often unsuccessful in reversing the symptoms of HVS, because patients have difficulty complying with the technique. Moreover, carbon dioxide itself may be a chemical trigger for anxiety in these patients.
Once life-threatening conditions are eliminated, simple reassurance and an explanation of how hyperventilation produces the patient’s symptoms are usually sufficient to terminate the episode. Provoking the symptoms by having the patient voluntarily hyperventilate for 3-4 minutes often convinces the patient of the diagnosis, but it is time-consuming and may be ineffective.
Most patients with HVS tend to breathe with the upper thorax and have hyperinflated lungs throughout the respiratory cycle. Because residual lung volume is high, they are unable to achieve full tidal volume and experience dyspnea. Physically compressing the upper thorax and having patients exhale maximally decreases hyperinflation of the lungs. Instructing patients to breathe abdominally, using the diaphragm more than the chest wall, often leads to improvement in subjective dyspnea and eventually corrects many of the associated symptoms.
Diaphragmatic breathing slows the respiratory rate, gives patients a distracting maneuver to perform when attacks occur, and provides patients with a sense of self-control during episodes of hyperventilation. This technique has been shown to be very effective in a high proportion of patients with HVS.
Patients should be referred to a specialist (eg, physiotherapist, psychologist, psychiatrist, family physician, internist, respiratory therapist) who can reinforce this approach.
Pharmacologic Therapy
Several medications, including benzodiazepines and selective serotonin reuptake inhibitors (SSRIs), have been employed to reduce the frequency and severity of episodes of hyperventilation. These agents require prolonged use and are best managed by a consultant on an ongoing outpatient basis rather than through sporadic prescriptions after an ED visit.
Use of benzodiazepines for stress relief and for resetting the trigger for hyperventilation is effective, but again, patients may require prolonged treatment. Although acute chemical sedation may be effective and humane in selected severe cases, prolonged use of these medications should not be initiated in the ED.
Stress reduction therapy, administration of beta blockers, and breathing retraining have all proved effective in reducing the intensity and the frequency of episodes of hyperventilation. If the diagnosis of HVS has been established, the patient should be referred to an appropriate therapist to implement these techniques over the long term.
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Trousseau sign.
