Asma
AsmaJavier Orlando Quintero ArdilaEstudiante de
MedicinaUniversidad Nacional de ColombiaDefinicinEl asma es una
enfermedad heterognea, usualmente caracterizada por inflamacin
crnica de las vas areas. Se define por historia de sntomas
respiratorios como sibilancias, disnea, opresin en el pecho y tos
que varan en el tiempo e intensidad, junto a una limitacin que
varia del flujo de aire espiratorio.Global Strategy for Asthma
Management and Prevention, Global Iniciative for Asthma(GINA 2014).
www.ginasthma.orgEpidemiologiaPrevalencia mundial de entre el 7 y
10%, con mas de 300 millones de personas afectadas.250 mil muertes
anuales por asma en el mundo.Corresponde al 0,4% de las causas de
muerte. Prevalencia de sntomas 12% en Colombia, 7% con diagnostico
de asma.Nadels & MurrayDennis et al. BMC Pulmonary Medicine
2012, 12:17FisiopatologaWeinberger ST, Cockrill BA, Mandel J.
Principles of Pulmonary Medicine. Elsevier, 6 ed.
PredisposicinWeinberger ST, Cockrill BA, Mandel J. Principles of
Pulmonary Medicine. Elsevier, 6 ed.
Kumar V, Abbas AK, Fausto N, Aster JC. Robbins y Cotran -
Patologa estructural y funcional. Ed. Elsevier, 8
ed.DesencadenatesAlrgenosIrritantes inhaladosInfecciones de va
respiratoriaEjercicioCambios de climaCambios emocionales
fuertes
Weinberger ST, Cockrill BA, Mandel J. Principles of Pulmonary
Medicine. Elsevier, 6 ed.
6Fisiologa
Weinberger ST, Cockrill BA, Mandel J. Principles of Pulmonary
Medicine. Elsevier, 6 ed.
This sensory information not onlyis communicated to the central
nervous system via the afferent vagal fibers but isalso responsible
for activation of local reflexes causing release of mediators
calledtachykinins from nerve endings in the airway wall. The
tachykinins, which includesubstance P and neurokinin A, can cause
bronchoconstriction, increased submucosalgland secretion, and
increased vascular permeabilit7Fisiopatologa
Corrigan C, Mechanics of Asthma, Medicine, 36:4 177-180,
2012.
Corrigan C, Mechanics of Asthma, Medicine, 36:4 177-180,
2012.
8Fisiopatologa
Corrigan C, Mechanics of Asthma, Medicine, 36:4 177-180,
2012.
Th2-type, CD4+ T cells are activated by allergens and perhaps
other antigens following presentation of specific epitopes by
dendritic cells (DC). The T cells producethe cytokines
interleukin-4 (IL-4), IL-5 and IL-13. IL-5 promotes eosinophil
recruitment to, and survival in, the airways mucosa. IL-4 and IL-13
contribute and also act onepithelial cells (Epi), fibroblasts (Fib)
and airways smooth muscle cells (ASM) to cause remodelling changes.
Eosinophils damage the mucosa through the release of basic proteins
and exacerbate bronchospasm, vascular leakage and oedema through
the release of leukotrienes. They also contribute to re modelling
through release of pro-fibrotic mediators, such as transforming
growth factor (TGF)-. IL-4 and IL-13 cause IgE switching in B
cells, promoting their secretion of allergen-specific IgE.
Cross-linking of this IgE by allergens on the surface of mast cells
in atopic subjects causes degranulation, with release of mast cell
mediators (histamine, prostaglandins and leukotrienes). This is a
mechanism for acute exacerbation of symptoms superimposed on the
chronic inflammatory background created by T cells and their
cytokines. AHR, airwayshyperresponsiveness.9Remodelacin
KUMAR V, ABBAS AK, FAUSTO N, ASTER JC. Robbins y Cotran -
Patologa estructural y funcional. Ed. Elsevier, 8 ed.Weinberger ST,
Cockrill BA, Mandel J. Principles of Pulmonary Medicine. Elsevier,
6 ed.10Funcin PulmonarDisminucin del dimetro de las vas por
broncoespasmo, secrecin mucosa y engrosamiento de la
pared.Disminucin del dimetro y rea de superficieMayor resistencia
al flujo de aireMenor flujo, de predominio espiratorio.Atrapamiento
areoWeinberger ST, Cockrill BA, Mandel J. Principles of Pulmonary
Medicine. Elsevier, 6 ed.
Espirometria
Johnson JD, Theurer WM. Am Fam Physician 2014
Mar;89(5):359-66Manifestaciones clnicasHistoria de sntomas
intermitentes, a veces mas nocturnos, puede asociarse algun
precipitante, mas desde la niez:DisneaSibilanciasTosOpresin en el
pecho
Examen fsicoTiempo de espiracin forzado a la auscultacin mayor a
9 segundosSibilancias a la auscultacinTaquipnea
Weinberger ST, Cockrill BA, Mandel J. Principles of Pulmonary
Medicine. Elsevier, 6 ed.
Diagnostico
Global Strategy for Asthma Management and Prevention, Global
Iniciative for Asthma(GINA 2014). www.ginasthma.orgClasificacin
segn gravedad
Clasificacin control
TratamientoGlobal Strategy for Asthma Management and Prevention,
Global Iniciative for Asthma(GINA 2014). www.ginasthma.org
Dosis Corticoesteroides Inhalados
Global Strategy for Asthma Management and Prevention, Global
Iniciative for Asthma(GINA 2014). www.ginasthma.orgGracias
