Tests of pulmonary mechanical function may be used in determining the prominent site of pulmonary reaction to intervention. Responses may be localized from a knowledge of changes in lung resistance and compliance. A peripheral airway or parenchymal response is characterized by a decrease in lung compliance. A central airway reaction is characterized by an increase in pulmonary resistance. In mi...

Maintenance of a patent airway is the most important aspect of the safe administration of anesthesia in children. However, in spontaneously breathing, anesthetized children, upper airway obstruction is a frequent problem (1) and failure to maintain a patent airway can rapidly result in hypoxemia, bradycardia or even cardiac arrest. Upper airway narrowing is most likely to appear in pharyngeal s...

Cogswell, J. J. (1973). Archives of Disease in Childhood, 48, 259. Forced oscillation technique for determination of resistance to breathing in children. A method for measuring total respiratory resistance (RT) using a forced oscillation technique was applied to children between 3 and 12 years of age. RT at midinspiration was higher than airway resistance (Raw) measured on the same children by ...

Ideally, the inspired (tidal) volume (V(T)) provided by a volume-controlled ventilation device should not change when the pressure imposed on the ventilator varies. A bench study evaluation of V(T) versus pressure was performed on 10 commercially available devices. The difference between the desired V(T) and the observed V(T) reached 100 mL for some devices when inspiratory resistance was at it...

In asthma, airways constrict in response to emotion and stress, but underlying mechanisms, potential extrathoracic contributions, and associations with airway pathophysiology have not been elucidated. We therefore investigated the role of the cholinergic pathway in emotion-induced airway responses in patients with asthma and the association of these responses with airway pathophysiology. Patien...

5-HT2 receptor activity in the hypoglossal nucleus and hypercapnia is associated with airway dilation. 5-HT neurons in the medullary raphe and hypercapnia are responsible for tidal volume change. In this study, the effects of 5-HT2 receptors in the dorsomedial medulla oblongata (DMM), which receives projections from the medullary raphe, and hypercapnia on airway resistance and respiratory varia...

Assessment of weaning readiness The ability to separate successfully from mechanical ventilation is dependent upon a host of physiologic factors (Table 1). Central ventilatory drive must be adequate; the patient must be able to maintain a patent airway, if extubation or decannulation is contemplated; and the patient must be able to cough and adequately clear secretions. Airway resistance must b...