5/27/2023 0 Comments Polyphonic wheezeInfants & children are prone to wheeze due to different set of lung mechanics ( as compared to older children & adults)Obstruction to airflow airway caliber compliance of lung 1) Resistance = 1/ ( radius of tube)4 In children airways can contribute upto 50% of airway resistanceMarginal additional narrowing can cause further flow limitation & subsequent wheezeĢ) Compliant chest walls, especially in newborns, leads to intra-thoracic airway collapse due to inward pressure produced in expiration3) Differences in tracheal cartilage composition & airway muscle tone causes further increase in airway complianceĪll these mechanisms combine to make the Infant more susceptible to airway collapse Increased resistance Subsequent wheeze Many of these are outgrown in the 1st year of life itself Ĥ) Immunologic & molecular influences:Infants have increased levels of lymphocytes & neutrophils in BAL fluidVariety of inflammatory mediators have been implicated eg. sounds of various pitchesMonophonic wheeze (single pitch) is produced in larger airways during expiration eg. If there is widespread narrowing of airways leading to various levels of obstruction to airflow (eg. IntroductionWheeze is a continuous & musical sound that originates from oscillations in narrowed airwaysMostly heard in expiration due to critical airway obstructionSign of lower (intra-thoracic) airway obstruction Wheezing in childrenDr Divya NairDepartment of Pediatrics,Mahavir Hospital & Research Centre,Hyderabad.
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