Panic frequently accompanies asthma exacerbations.The goal of this study is to evaluate airflow obstruction (forced expiratory volume in one second [FEV1] and peak expiratory flow rate [PEFR]), inspiratory reserve (inspiratory capacity [IC]) and panic (acute panic inventory [API]) during an acute asthma exacerbation. Panic may be triggered by either airflow limitation or loss of inspiratory reserve. We hypothesize that API and IC but not FEV1 will correlate.
This is a prospective observational study of 14 acutely ill asthmatic patients. Before treatment in the emergency room subjects performed spirometry, completeted an API and evaluated their dyspnea(Borg). At follow up after stabilization, subjects repeated the earlier studies and responded to questionnaires concerning anxiety (Speilberger [STAI inventory])and somatization(Barsky [SSAS]).
Patients presented with severe asthma (FEV1 = 39 + 22 SD % predicted; PEFR = 37 + 23 %; Borg = 5 + 2 scale units). IC on admission = 50 + 23%. API correlated strongly with the Borg score (F = 5.92; p = 0.032) but did not correlate with any measure of lung function. Multiple regression analysis showed that when IC was entered as a second independent variable both Borg score and IC made independent contributions to the prediction of API: API = −8.4 + 2.9 (Borg) + 0.2 (IC % pred); F (for IC) = 5.68: P = 0.036 No similar relationship could be identified for either FEV1 or PEFR with Borg scores and API. Adjusting for age, final (stable) API or BMI did not alter this relationship.
No pulmonary function measure alone was a predictor of panic; IC, however, made an independent contribution the measure of panic when added to a measure of dyspnea.
IC is easily measured in the emergency setting and as a sign of loss of respiratory reserve may be a more helpful index of lung dysfunction than the traditional spirometric measures.
Irram Hamdani, No Financial Disclosure Information; No Product/Research Disclosure Information