Acute hyperventilation in emergency room patients

Acute hyperventilation in emergency room patients – Tips from Other Journals

Linz Audain

Little is known about the distribution of clinical etiologies in patients who present to the emergency room with a chief complaint of acute hyperventilation. Saisch and associates studied psychogenic and underlying organic etiologies in patients presenting to the emergency room with acute hyperventilation.

The authors studied 23 consecutive patients who presented to an inner-city emergency room over a one-year period and who were diagnosed with acute hyperventilation by the emergency room physicians. Diagnoses were based on history, observation and examination, although arterial blood gases were measured in five patients. Patients who presented with organic diseases or abnormal test results were not referred to the study investigators. Presenting symptoms included dyspnea, paresthesias, anxiety and panic, and chest tightness.

After patients were referred to the study investigators, more detailed histories and physical examinations were conducted. When necessary, tests performed in the emergency room were also repeated. Additional testing included a complete biochemical profile, thyroid function, full lung function, histamine bronchial provocation, a structured psychiatric interview and partial pressure of end tidal carbon dioxide ([Pet.sub.CO.sub.2]).

Clinical testing by the authors revealed that 78 percent of the patients showed some evidence of airway obstruction; 78 percent showed some evidence of psychiatric disorder, predominantly panic and anxiety disorders, and 57 percent of patients had a positive hyperventilation screen with [Pet.sub.CO.sub.2], levels of 30 mm Hg or less. All but three of the patients misdisattributed their presenting symptoms to a serious or life-threatening condition. The most common misattribution was heart disease or myocardial infarction. Seventy-four percent of these patients had a similar previous incident of acute hyperventilation. Twenty-six percent of the patients had past medical histories that included alcohol and drug abuse.

The authors conclude that acute hyperventilation is multifactorial in etiology. These factors, especially mild asthma, chronic anxiety, and drug or alcohol abuse, combine to lower the partial pressure of arterial carbon dioxide ([Pa.sub.CO.sub.2]) to the point at which symptoms of hypocapnia occur. At this point, misattribution engenders a cycle: it causes the panic and anxiety to increase further, causing more symptoms and more misattribution until the patient ultimately presents to the emergency room in a state of acute hyperventilation. The authors maintain that the best therapy in such cases is for the physician to conduct a search for an organic etiology, explain and reassure the patient regarding the possible presenting sequence of events, and educate the patient regarding possible etiologies. In the emergency room, organic respiratory causes of hyperventilation can best be detected by obtaining arterial blood gas measurements and a chest radiograph in all cases of hyperventilation.

Saisch SG, et al. Patients with acute hyperventilation presenting to an inner-city emergency department. Chest 1996;110:952-7.

COPYRIGHT 1997 American Academy of Family Physicians

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