Three types of asthmatic patients can be identified during periods of clinical stability: “poor perceivers,” “normal perceivers,” and “over perceivers.” When asthmatics undergo bronchial challenge in the laboratory, the same distinctions in type of perception can be observed. The aim of the present study was to determine the level of agreement between the 2 situations.
Patients and methodsA total of 93 patients with persistent moderate asthma (36 men and 57 women; mean age 40 years) were studied. We asked them to assess their dyspnea on a modified Borg scale when stable and after each histamine dose in a bronchial provocation test. When a patient's Borg scale assessment in stable situation was below the 25th percentile, that patient was classified as a poor perceiver. Patients were considered over perceivers if their score in stable situation was in the 75th percentile. Others were labeled normal perceivers. Type of perception during acute bronchoconstriction was defined in function of the change in Borg assessment once forced expiratory volume in the first second had decreased 20%: poor perceivers were those whose change in Borg assessment was in the 25th percentile, over perceivers were in the 75th percentile, and normal perceivers in the middle percentiles.
ResultsIn stable situation, 23 patients were poor perceivers, 58 were normal perceivers, and 12 were over perceivers. During bronchoconstriction, there were 23 poor perceivers, 47 normal perceivers, and 23 over perceivers. Agreement was estimated by a kappa index of 0.0574 for poor perception, 0.1521 for over perception, and 0.3980 for normal perception.
ConclusionsAsthmatics' perception of dyspnea during periods of stability and during acute bronchoconstriction are independent phenomena. It is therefore not possible to infer how a patient will perceive an asthmatic attack by evaluating only how he or she perceives breathlessness during stable periods.
Durante la estabilidad clínica se pueden distinguir 3 tipos de asmáticos: hipoperceptores, normoperceptores e hiperperceptores. Cuando a esos mismos pacientes se les provoca una broncoconstricción aguda, también existen hipo, normo e hiperperceptores de disnea. El objetivo del presente trabajo ha sido comprobar la concordancia entre ambas situaciones.
Pacientes y métodosSe ha estudiado a 93 pacientes con asma persistente moderada (36 varones y 57 mujeres; edad media de 40 años). Se les pidió que estimaran su disnea (es-cala modificada de Borg) en situación de estabilidad y después de cada dosis de histamina en una prueba de broncoprovocación. Cuando la puntuación de Borg en situación estable era menor del percentil 25, se consideró hipoperceptor; si era superior al percentil 75, hiperperceptor, y normoperceptor al grupo restante. En función del cambio de disnea al descender un 20% el volumen espiratorio forzado en el primer segundo se distinguieron los perceptores agudos: hipoperceptores (cambio en Borg inferior al percentil 25), hiperperceptores (cambio superior al percentil 75) y normoperceptores (cambio entre los percentiles 25 y 75).
ResultadosEn situación estable 23 pacientes fueron hipoperceptores, 58 normoperceptores y 12 hiperperceptores, mientras que durante la broncoconstricción hubo 23 hipoperceptores, 47 normoperceptores y 23 hiperperceptores. El análisis de concordancia mostró un índice kappa de 0,0574 para la hipopercepción, de 0,1521 para la hiperpercepción y de 0,3980 para la normopercepción.
ConclusionesLas percepciones de disnea de los asmáticos en situación estable y durante una broncoconstricción aguda son fenómenos independientes. Por ello, no es posible inferir cómo un paciente va a percibir una crisis de asma va-lorando únicamente cómo percibe su enfermedad durante la estabilidad clínica.
This study was partially funded by Red Respira-ISCIII (RTIC-03-11).