Due to different mechanisms of ventilation, changes in the intrathoracic pressures
during the respiratory cycle are totally opposite in these two ventilation modes (Bellamy & Mercurio, 1986).
Table One: Conditions associated with pulsus paradoxus Causes of Pulsus Paradoxus Rationale * Asthma The narrowing of airways creates a more negative intrathoracic pressure
during * Exacerbation of chronic inspiration, which increases the pooling obstructive pulmonary of blood in the pulmonary vessels disease (COPD) (Darovic, 2002).
Similar to this finding, it has been showed that also the BP increase can be attenuated by pharmacological blockade of the autonomic nervous system with hexamethonium, indicating that it is mediated by the SNS rather than by mechanical factors related to changes in intrathoracic pressure
4) The Use of Pleth Variability Index (PVI) to Detect Changes in Intrathoracic Pressure
If we let [the mother] go with her instinct, she's going to do a much better job of coordinating her intraabdominal and intrathoracic pressures
to make a more forceful push.
increased negative intrathoracic pressure
during inspiration in an obstructed laryngeal airway could predispose a patient to GERD by trying to overcome the lower esophageal sphincter.
Impact of CPAP on the negative intrathoracic pressure
The latter was used as an indicator of the intrathoracic pressure
because of the potential of the thoracic packing to raise this parameter and produce barotrauma.
The pathogenesis in this context is likely to be multifactorial process including large negative swings in intrathoracic pressure
, intermittent hypoxemia and hypercapnia, increased sympathetic nervous system activity, vascular endothelial dysfunction, oxidative stress, systemic inflammation, excessive platelet activation as well as metabolic dysregulation.
4) Due to negative intrathoracic pressure
, thoracic esophageal perforations are more likely to disseminate fluid and bacteria throughout the mediastinum.
And for all mammals, laryngeal occlusion permits the increase in intrathoracic pressure
necessary for coughing and sneezing.
The IJV tends to expand in the inspiratory phase during mechanical ventilation, due to changes in intrathoracic pressure
Valsalva maneuver can be used to assess the reversibility of this pattern by increasing intrathoracic pressure
and decreasing preload, hence attempting to cause a shift from type III to type II (11).
The rapid spread of infection has been attributed to dependent drainage from the neck into the mediastinum, negative intrathoracic pressure
, and synergistic bacterial growth.
The Valsalva maneuver associated with high-resistance instrument playing is thought to be responsible, because it causes a rise in intrathoracic pressure
and compression of the intrathoracic venous system.