[Occurrence of delayed symptoms after a challenge test with methacholine]. / Survenue de symptômes tardifs après un test de provocation par la méthacholine.

There are few prospective studies available on the development of delayed symptoms following challenge tests with methacholine (MCT) at the currently recommended doses. The objective of this study was to describe the nature and frequency of respiratory symptoms suggestive of bronchospasm developing within 24hours after a MCT. The study was offered to adult patients who underwent MCT seen consecutively between June and October 2015. Following the test, a questionnaire adapted from the GINA asthma control questionnaire bearing on diurnal and nocturnal symptoms (cough, dyspnoea, wheeze and tightness), was delivered to the patient and the replies collected by telephone 24hours later. Of the 101 patients included (initial FEV1 2.82±0.79L), 46 (46 %) were MCT+ and 55 (54 %) MCT-. Among the MCT-, 4 (7 %) presented with immediate symptoms (S+) and 4 (7 %) with delayed symptoms. Among the MCT+ patients, 36 (78 %) presented with immediate symptoms (P<0.001 compared with the MCT- patients), and 39 (85 %) with delayed symptoms (P<0.001 compared with the MCT- patients). Delayed symptoms developed with a mean of 5h30 after the provocation test. Immediate and delayed symptoms were more frequent in subjects having significant non-specific bronchial hyper-reactivity. Informing patients of the risk of developing delayed symptoms seems useful and allows optimization of their management after a MCT.

[Measuring and speaking about respiration. Role and ethical function of a psychopathological interview in a medical service]. / Mesurer et dire le souffle. Place et fonction éthique d'un entretien psychopathologique dans un service de médecine.

On the occasion of a respiratory function exploration, it was given to the patient the possibility of evoking, in respect of freely association, the psychical sense assumed by his symptom in his history. The unity of time, place and methodology, clinical psychopathology, defined our "experimental device". When the patient of this study, with SAS, said to the physician "I forget myself" with regard to ther apneas, the symptom, spoken, referred to a construction, "complementary" (Bohr, 1927) to another one described and objectivated by medicine. Each interpretation of the somatic phenomenon is related to the occurrence of speaking in the context of discursive associations and transference coordinates. The symptom is related to psychical reality, conflicts and desire of the patient. By the relations established between the advent of the spoken symptom and other events, the patient considers it as a response to a personal question. Then, he can reach a fragment of his verify, hear himself and hear the effects of his speaking. Without this possibility of reappropriating subjectively and intersubjectively the suffering in its irreducible singularity, he would remain alienated from his suffering, as to a trauma. Our approach gives evidence of the methodological as well as praxeological revision of the psychopathology contribution to the medicine.

Comparisons among external resistive loading, drug-induced bronchospasm, and dense gas breathing in cats: roles of vagal and spinal afferents.

In anesthetized cats, breathing spontaneously, increase in lung resistance (RL) was induced by either external resistive loads (ERL) or internal loading produced by dense gas breathing (sulfur hexafluoride, SF6) or serotonin (5-HT)-induced bronchoconstriction. The 3 test agents were used in each animal. Arterial blood gases were maintained in the normal range. Ventilatory and cardiovascular responses were studied in 3 groups of animals: intact, vagotomized, or spinalized at C8 level, a condition that preserved diaphragmatic afferents. In intact or spinal animals, ERL as well as SF6 inhalation lengthened the inspiratory and/or the expiratory periods, whereas 5-HT injections elicited rapid shallow breathing. The changes in ventilatory timing with either type of load were not observed in vagotomized cats. In all animals, ERL breathing or 5-HT injections increased the moving-time average of diaphragmatic EMG measured at constant time (Edi 0.1 and 0.5 secs), but this was not observed during SF6 inhalation, a condition in which the magnitude of RL increase was less than in the 2 other situations. The changes in systemic arterial blood pressure and/or cardiac frequency were mostly associated with 5 HT-induced bronchoconstriction. They persisted in spinalized cats, but were not observed or reversed in vagotomized ones. These observations demonstrate that vagal afferents play a major role in the changes in ventilatory timing and cardiovascular function in response to both external or internal moderate resistive loading. The existence of Edi changes in the 3 groups of cats suggests also that diaphragmatic afferents, preserved in both situations, are involved in this response.

The respiratory sensation at high altitude.

The respiratory sensation was studied in Nepal at four different altitudes, 1377 m before and after the ascension, 2800 m, 3900 m and 530 m. Dyspnea was noted at each altitude for the nine subjects. They had to rate 4 external resistive loads between 2.5 and 13 cm H2O.l-1.s, presented in 2 pairs, a low and a high one. The discrimination between the loads i.e. the subject's sensitivity was obtained from Sensory Decision Analysis. These subjects were compared to six normal ones observed at sea level while breathing air, an hypoxic mixture (FIP2:11%) and air in a cold environment (-6 degrees C). In these protocols, the load perception was not modified. The 2 populations exhibited a similar sensitivity when observed in normal conditions. At exertion and with altitude, the nine subjects demonstrated a progressive increase in dyspnea, rated with visual analog scales. At rest, the perception of the loads was not altered but slightly improved with altitude for 6 subjects. The other 3 subjects (2 subjects with clinical impairment, important dyspnea and pulmonary oedema) showed an impairment of the perception. The sensitivity to the loads was similar before and after the ascension for the well adapted subjects to altitude. In conclusion, the respiratory sensation is not impaired with altitude in well adapted subjects and transient hypoxia does not result in change in load perception. An impairment in load perception observed in some subjects is probably related to the secondary effects of chronic hypoxia, i.e. cerebral and/or pulmonary suboedema.