<prompt> Which of the following correlates well with the severe type of bronchial asthma exacerbation: March 2011Bradycardia with HR less than 100 minPulsus paradoxus less than 10minTachypnea with RR less than 30minUsual use of accessory muscles of respiration  <response>: Ans. D: Usual use of accessory muscles of respiration Bronchial asthma: Hyper-responsiveness of airways with bronchoconstriction Increased leukotrienes Histology: Creola bodies, - Charcot Layden crystals, - Curschmanns spiral FEV1 is the parameter to improve maximum on bronchodilator therapy 