Mendelson's syndrome refers fo-
Ans. is 'a' i.e., Aspiration of gastric contentso Mendelson 's syndrome is chemical pneumonitis caused by aspiration of gastric contents during anaesthesia.Classification of aspiration pneumoniao Aspiration pneumonia is characterized by:o The character of the inoculum, pathogenesis of the pulmonary conditions, presentation, and management guidelines. All these features assist in distinguishing clinical syndromes within the category of aspiration pneumonia.o The three syndromes that are most frequently seen clinically and best studied are -# Chemical pneumonitis,# Bacterial infection, and# Airway obstruction.Chemical pneumonitiso The term chemical pneumonitis refers to the aspiration of substances that are toxic to the lower airways, independent of bacterial infection.o The prototype and best studied clinical example is chemical pneumonitis associated with the aspiration of gastric acid first described by Mendelson and sometimes referred to as Mendelson's syndrome.The production of chemical pneumonitiso Require an inoculum that has a pH of < 2-5 and that is relatively large (usually I to 4 mL/kg).o This would translate to an inoculum of at least 25 mL of gastric acid in adult humans. It is probable that smaller volumes produce a more subtle process that either escapes clinical detection or causes a less fulminant form of pneumonitis.o The clinical observation that patients with esophageal or gastric reflux experience frequent bouts of recurrent pneumonitis, often accompanied by pulmonary fibrosis, supports this concept.Clinical featureso The following clinical features should raise the possibility of chemical pneumonitis# Abrupt onset of symptoms with prominent dyspnea# Fever, which is usually low grade# Cyanosis and diffuse crackles on lung auscultation# Severe hypoxemia and infiltrates on chest imaging involving dependent pulmonary segments. The dependent lobes in the upright position are the lower lobes. However, aspiration that occurs while patients are in the recumbent position may result in infection in the superior segments of the lower lobes and the posterior segments of the upper lobes.
Aspiration of gastric content
Rupture of bronchial tuberculoma.
Transient pneumonitis of allergic origin
Tracheal compression due to nodal enlargement
Respiratory