Asthma - SpeedyLook encyclopedia

Clinical demonstrations

The asthma attack is characterized by:

breathing difficulty or Dyspnea;
a Tachypnea or conversely a Bradypnée, i.e. an increase or a reduction in the respiratory frequency;
a whistle with the expiry and/or the inspiration (one speaks about breathing sibilante);
a reduction in the saturation of oxygen hemoglobin;
a Tachycardia;
a pulling;
a Cough which can be chronic or prevail during the night.
of the crises which can appear after an unsuited physical-activity (one speaks then about asthma of effort or more precisely of broncho-spasm post-exercise)

The muscles of breathing, which usually are requested only during the filling (Inspiration), must also provide an effort during their draining (active Expiration).

The intermittent asthma definite arbitrarily by occurred, to the maximum, of two short crises per night week, and/or two episodes per month, and a EPD higher than 80%.

The persistent asthma is defined when there exists more than two episodes per week, and/or more than two night episodes per month, with repercussion on the current activities. It can be light, moderate or severe.

The acute asthma engraves brings into play the vital prognosis. It requires a dealt with urgent in hospital medium (for example, in France approximately 2.000 people per annum die of asthma, that is to say 3,2 cases for 100.000 inhabitants). Clinically, there exists at least one of the following signs:

feeling of unusual crisis;
difficulty of speaking (a word speaks at the same time)
Cyanose
deceleration about the cardiac rhythm (Bradycardie)
turbid of the conscience (confusion, Coma)
“silence auscultatoire” (absence of murmur vésiculaire to the sounding);
a reduction in the EPD (expiratory flow of point or Peak Flow) reduced by half compared to the best score of the patient, or of his theoretical value; the EPD is only the average objective of evaluation of the intensity the asthma attack
a resistance to the treatment of the crisis (fast Bronchodilatateur of action);
a respiratory frequency higher than 25/mn in the adult, 30/mn in the child of more than 5 years, 50/mn in the children from 2 to 5 years; even a weak breathing with respiratory pauses
a arterial Hypotension

It is advisable to dissociate from it the' asthma of the Nourrisson , which is defined by the appearance of at least three episodes of Sibilance before the three years age. An asthma of the infant generally disappears before the five years age.

Recent expansion of asthma

Asthma largely spread these last 40 years in the countries with Western lifestyle. It is still not very present in the countries to which the lifestyle dominating is closer to the ground, and shows a clear division between the rich and poor countries. Running to West Germany, it was quasi non-existent in East Germany before the fall of the Berlin Wall. In 1999 of the researchers (International Study off Asthma and Allergies in Childhood) some data concerning asthma quantified, by measuring the percentage of asthma and allergies among the 13-14 years in various countries:

- Sweden and Finland: between 10 % and 20 %;

- Albania, Romania, Russia, Georgia and Ouzbékistan: <6 %;

- RU: >30 % (asthma is the second of the most fatal diseases there).

The monitoring of the evolution of the incidence in France is carried out by the Réseau Sentinels of the Inserm.

Diagnosis

Examinations of respiratory functional exploration or EFR;
Test of reactivity to a bronchodilatator (pre expiratory flow and post salbutamol);
bronchial Test of provocation.

Treatment

The asthma attack
The first and therapeutic independent measurement are the administration of a Bronchodilatateur (developed by professor Dusan Mandic) of short duration of action, often the Salbutamol or the Terbutaline, drugs known as béta-mimetic which cause a “relaxation” of the bronchial muscles and the reopening of the bronchi (Bronchodilatation).
The administration is done primarily by inhalation: dosing aerosols or poudres.
The technique of use of the dosing aerosols must imperatively be known by the patient for a maximum.
effectiveness The use of specific devices “Chambre of inhalation” facilitates the administration of the dosing aerosols largely, in particular in the child but also at the adulte.
Any crisis which does not yield to beta-mimetic quickly must involve the patient to consult a doctor, to even call the emergency helps in the event of unusual crisis or with signs of gravity.

The asthma engraves
A medicalized transfer and a hospitalization in urgency are essential. The treatment of first intention rests on an oxygen treatment with strong flow (6 to 8 liters/mn), associated with the catch of beta 2-stimulant of short action inhaled, with raised posology, and the corticoid administration per oral or intravenous way.

If the Intubation trachéale and the mechanical Ventilation become necessary, it will be probably necessary to compose with very strong resistances which will complicate ventilation considerably. However, it is important to understand that because of these strong resistances, the alveolar pressures are much lower than the pressures measured in the respiratory circuit. One will be able to thus tolerate very high pressures of point in so far as the pressure of plate (or pressure of pause) remains acceptable.

In addition, as in several cases of difficult ventilation, the permissive Hypercapnie is an approach recommended by several authors.

Treatment of maintenance of persistent asthmas

Bronchodilatateur (β2 mimetic) - Attention: the bronchodilatateurs of fast, standard action Salbutamol, should be regarded only as one specific treatment of the crisis, but in no case like a basic treatment. Indeed, as their name indicates it, they are satisfied to force the bronchus to remain dilated (open) in spite of its inflammatory state; if they make it possible the organization to breathe, they leave the bronchus in a state of suffering; to the limit, used only, without associated local corticoid treatment, they contribute to worsen the disease since the bronchus, which only required to be put at rest, (thus to close itself because of its suffering), continuous with being exposed with the agent irritating present in the ambient air: allergen, pollutant or other… ;
often necessary, a Anti-inflammatory drug Glucocorticoïde - which perhaps associated with a bronchodilatator (β2 mimetic) known as “of long life of action” in opposition to the precedents, fast but short action. Recent studies however showed a surmortality among asthmatic patients treated by stimulating beta-2 of long life of action, leading the professionals to limit the use of it;
treatment of the cause, for example Antihistamine in the event of allergic asthma - by knowing that the antihistamines, often useful, in particular in the event of nasal allergy or eyepiece associated, are not sufficient alone to look after asthma;
for a few years, one has been able to also use antagonists of the receivers of the Leucotriène S (for example Montélukast, Zafirlukast).

the therapeutic assumption of responsibility also rests to the following measures:

réentraînement with the effort (adapted Physical-activities) to push back the threshold of intensity of exercise causing the appearance of the broncho-spasm post-exercise; to minimize the ventilatory adaptation necessary for a given intensity (less breathlessness with the exercise); to increase the bronchial flows… to fight against déconditionnement of a population which minimizes its physical-activities by fear of the crisis.
to act on the cause of asthma if it is of allergic origin, either by carrying out the ousting (= separation) of the allergen (for example to separate from its pet), or by trying a desensitizing with the allergen in question. The results are good with the acarina, pollens - less good with the animals.
In order to prevent with the asthmatic people making asthma attacks which can be serious (2000 deaths per annum), it is important that those follow their basic treatment correctly (anti-inflammatory drugs in particular).
In order to be able to prevent the crises, the asthmatic ones can use an apparatus (peak-flow) which makes it possible to measure their expiratory flow of point, witness of the obstruction of the bronchi and thus to adapt their treatment to the result obtained (taken of bronchodilatator of action fast for example or modification of the basic treatment in collaboration with the doctor.)
In 1950 professor J. Turiaff prescribed an autovaccination which gave results of final cure on certain patients. ! |date=

Differential diagnosis

See the asthma equivalent, associated pathology expressing themselves by a bronchial hyper-reactivity, causing spasmodic and night coughs, without causing clinically detectable reduction in the expiratory flow.

The fight against asthma: directions of research

Allergens and pollution

At the beginning of the year 1960, one blamed the allergens, acarina and others. Resulting hunting for the allergens (using products various possibly allergens themselves for the majority) helped certain patients but not others.

The evolution in time between asthma and allergy is not always symmetrical: this correlation was shown in Great Britain, but neither in Germany, nor in Italy, where the frequency of the allergies increased but not that of asthma.

Tobacco

Stephen Holgate considers that the smoke of tobacco is by far the identified leading cause of asthma. He and its team proved that the tobacco smoke modifies pulmonary genes of cells of mouse, and could cause genetic changes in the lungs of the fetuses, making them thus vulnerable to asthma. The same thing could be true for the unhealthy food modes and even the Paracétamol (a powerful antioxydant which recently was related to asthma).

The active nicotinism as well as passive can be in question.

Hygiene

Since the years 1990, one started to stress the absence of cohabitation between the human ones and the bacteria in the countries particularly touched by the disease. Thus are blamed the “surhygiene” with its products of cleaning at the antibactériens, as well as the generalization of antibiotics with broad spectrum and systematic vaccinations - the whole involving a lack of autoimmunization per absence of exposure to the surrounding bacteria. One wonders why, for example, in an Indian hospital one finds a group of children coming from districts poor and afflicted with pneumonias and other infections, whereas the group of children coming from rich districts is that reached of asthma. This “assumption of hygiene” is supported by obviousnesses such as the least occurrence of allergies in the alive children in farms or in contact with animals, at those which nourish not-pasteurized milk, or at 3rd or 4th or 5th children of a family - who are exposed as of their young age with all the pathogenic ones and other micro-organisms that their elder can bring back school. Researchers explore the possibilities of causing the same answer in the immune system of a child as that caused by the infection by the parasites of the bilharzia. On another side, “the assumption of hygiene” justifies more the rise of the allergies than that of asthma, which do not go inevitably together (one can have one without the other, in one or more forms).

Food

It is to some extent an extension of the preceding theory, applied to food and extending to the bacteria normally contained in the human body. The conservatives and pesticides, and sterilization even (Irradiation and other means usually employed in food industry), are severely called in question by certain scientists like Tony Frew, professor of medicine allergenic and respiratory at the university of Southampton (the U.K.). He and others stresses the major changes in the intestinal total colony count, mainly the reduction of the diversity of the types of bacteria populating the intestines in the rich countries. One sees a strong growth of the consumption of the dairy products known as “probiotic”, i.e. containing active bacteria duly selected for their beneficial actions. Given the expectant mothers this food seems to push back the development of allergies and asthma in their once born children - from where an obviousness which the mode of the expectant mothers plays a role in the occurrence of asthma in their children. However one does not know why the food within the infants reduces the occurrence of asthma at the time same as it reduces also the quantity of infectious organizations in the intestines. One puts also questions concerning the elements normally present at the state of traces in healthy food: for example, is the absence of Sélénium to be called into question, since it was introduced regularly in Great Britain until the politico-economic movements decide to buy the European corn instead of Canadian corn like previously?

Genetics

In the recent last years of the researchers showed that the respiratory tracts of the patients suffering from chronic asthma are is faded in a permanent way by the disease, or - possibly - develop differently in the uterus. Stephen Holgate, one of the researchers on asthma in Great Britain, published in the newspaper Nature the results of a search for five years blaming the Gène ADAM33 . This is the first gene discovered for asthma, and would control the way in which the muscle develops in the respiratory tracts. Holgate also thinks that the environmental factors could influence the things much earlier than one thought it in the development of the disease: they could influence the form of genes in the development of the fetus, thus contributing to a genetic modification supporting the disease. Holgate and its team already showed the modification of the gene ADAM33 by the tobacco smoke in pulmonary fabric cultures of mouse. In October 2005 they as published a showing report as when the fabrics of the respiratory tracts of asthmatic are inflammés, they produce a molecule called TNF alpha, or Tumor Necrosis Factor alpha. However the gene ADAM33 , implied in asthma, behaves in a way very similar to the gene ADAM17 responsible for the production of TNF alpha. One finds also this molecule TNF alpha in ignited fabrics of the patients suffering from other chronic respiratory diseases, like arthritis rhumatoïde (?) or the Disease of Crohn. After six years of fight near the drug companies to carry out these tests, Holgate succeeded in convincing them to endorse an experiment which goes against the general tendency take asthma for an allergenic disease. In October 2004, it and its team injected 15 volunteers with Etanercept, a soluble receiver for TNF alpha which intercepts this molecule and prevents it binding with the cells of fabrics and from irritating the bronchi. The results are for the moment very satisfactory, with clear and persistent improvements at each of the 15 volunteers. On this date of November 2005 three of these patients have not used any steroid for the 12 weeks of weekly injections a little more than twelve months before.

Asthma and influenza

The asthmatic ones, like other weakened people, can be victims of complications exacerbated and serious in the event of influenza.
Le Vaccin seasonal anti-influenza their is recommended (as from 6 months, dealt with at 100% for the asthmatic ones) in France by the Superior council of public health of France, and by equivalent organizations in the majority of the other industrialized countries (European Union, the United States). Vaccination decreases at asthmatic the risk of hospitalization and need increased for drugs.
Mais on the three million French victim of asthma (especially of the children and teenagers), only 32% were made vaccinate the winter 2006-2007; and less than one quarter of less than 65 years were vaccinated (and 14% only of less than 15 years), against 77% at those 65 years and more. The Allergie to egg (rare and detectable by cutaneous test) is the only counter-indication, if the subject is unscathed of evolutionary infection, fever and/or instability of asthma. The asthmatic ones vaccinated have significant or particular side effect in the fifteen days which follow (no change in respiratory flow, neither increased need bronchodilateurs, nor increase in the corticoid doctor visits or consumption).

See too

pulmonary Medicine
Ventilation
human Breathing
List of the principal allergens

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