The investigation of bronchospasm during induction of anaesthesia.

BACKGROUND: The aim of this study was to ascertain whether anaesthetic induction-related anaphylactic bronchospasm could be distinguished from other types of bronchospasm by clinical features and response to treatment. Such features could then be used to identify a group of patients in whom skin testing is indicated. METHODS: We retrospectively studied data from 183 patients referred to an anaesthetic allergy clinic because of bronchospasm during induction. For the analysis, the patients were divided into two groups depending on whether there was evidence suggesting immunological anaphylaxis. RESULTS: When the patients in whom intradermal tests were positive were compared with those in whom intradermal tests were negative, the skin test-positive patients had significantly more severe reactions, and they were more commonly associated with other clinical signs. Mast cell tryptase (MCT) was an excellent discriminator between reactions likely to be allergic and those unlikely to be allergic. CONCLUSIONS: Anaphylactic bronchospasm related to induction of anaesthesia is more likely to be severe than bronchospasm due to non-immune causes. An allergic cause is more likely if there are associated features of anaphylaxis (skin changes, hypotension, angioedema) or elevated MCT. Patients with any of these features should undergo immuno-allergolical investigation.

A new modified classification of bronchial asthma based on clinical symptoms.

The clinical features of four asthma types, Ia-1 (bronchospasm with 0-49 ml/day of expectoration), Ia-2 (with 50-99 ml/day), Ib (over 100 ml/day), and II (bronchiolar obstruction), as classified by the clinical symptoms, were compared in 119 patients with bronchial asthma. The age of onset characteristic symptoms of each asthma type was in the 20's in types Ia-1 and Ia-2, in the 30's in type Ib, and in the 40's in type II patients. A significant increase in the number of neutrophils in bronchoalveolar lavage (BAL) fluid was found in type II patients. The proportion of BAL eosinophils was significantly higher in types Ia-2 and Ib asthma patients compared with that in type Ia-1 patients. The BAL eosinophil count was significantly higher in type Ib than in type Ia-2 patients. The FEV1.0% and %V25 values were significantly lower in patients with type II asthma than in the patients with the other asthma types. Steroid-dependent intractable asthma (SDIA) was more often observed in patients with type Ib or type II asthma.

Reassessment of the temporal patterns of bronchial obstruction after exposure to occupational sensitizing agents.

Typical asthmatic reactions after exposure to common or occupational allergens have been classified as isolated immediate, early late, late, and dual (Pepys and Hutchcroft, 1975). Atypical reactions can also occur, but their temporal behavior and frequency are unknown. We analyzed 69 bronchospastic reactions after exposure to three types of occupational sensitizers in the laboratory: isocyanates, western red cedar, and IgE sensitizing agents. Graphs of the reactions were presented to three observers in a blind, randomized way. Reactions were defined as follows: (1) typical patterns, that is, isolated immediate, early late, late, and dual, as put forward by Pepys and Hutchcroft, and (2) atypical patterns including progressive (onset, during, or minutes after exposure, progressing to a maximum reaction 5 to 6 hours later) and square waved (similar to a dual reaction but with only partial recovery [less than 10%] between the immediate and late falls in FEV1). Some curves were also analyzed by polynomial regression. The three observers agreed in 59/69 cases (86%), and a consensus was reached after discussion for the remaining subjects. Fifteen of 63 (22%) reactions were atypical. IgE-mediated reactions and reactions to red cedar were, respectively, mainly of the immediate and late types. The distribution of reactions to isocyanates, however, was significantly different (chi-square, 6.1; p = 0.01), the "progressive" pattern occurring in 7/23 instances (30%). There was a satisfactory concordance between visual assessment and polynomial fit analysis in distinguishing dual from square-waved reactions. We conclude that isocyanates frequently cause atypical progressive bronchospastic reactions that are rarely observed after exposure to IgE agents and western red cedar.

Classification of asthma based on clinical symptoms: asthma type in relation to patient age and age at onset of disease.

Seventy-one cases of bronchial asthma were classified into three types: bronchospasm, bronchospasm-hypersecretion and bronchiolar obstruction types. The characteristics of each type were studied in relation to patient age and age at onset of the disease. In the 71 subjects studied, the most frequent type was the bronchospasm type followed by the bronchospasm-hypersecretion type and bronchiolar obstruction type. Intractable asthma was most frequently observed in the bronchiolar obstruction type and least in the bronchospasm type. Most of the patients under 50 years of age showed the bronchospasm type. The bronchospasm-hypersecretion type was characteristically accompanied by blood eosinophilia when the patient age was under 50 years. In the bronchospasm-hypersecretion type, the incidence of intractable asthma was high in patients under 50 years of age, but not remarkable in those over 50. A large proportion of the patients over 50 years of age were of the bronchiolar obstruction type. There was no difference in the incidence of intractable asthma between the two groups classified by age at onset.