Skip to content

Category Archives: Mechanical Ventilation

[Clinical Art][Circulation] Interpretation of Hemodynamic Waveforms


Basic Knowledge Mechanism of Hemodynamic Monitoring The rapidly occurring events (represent mechanical forces) of cardiac chambers and vessels during cardaic cycle require conversion to an electrical signal to be transmitted and subsequently translated into an interpretable, graphic format. The pressure transducer is the essential component that translates the mechanical forces to electrical signals. The transducer may […]

Ventilation-Perfusion Relationships


Gas exchange between the alveoli and the pulmonary capillary blood occurs by diffusion. Diffusion of oxygen and carbon dioxide occurs passively, according to their concentration differences across the alveolar-capillary barrier. These concentration differences must be maintained by ventilation of the alveoli and persusion of the pulmonary capillaries. Alveolar ventilation brings oxygen into the lung and […]

[Respiration][Circulation] Blood Flow to the Lung – General and Pulmonary Vascular Resistance


The lung receives blood flow via both the bronchial circulation and the pulmonary circulation. Bronchial blood flow constitutes a very small portion of the output of the left ventricle and supplies part of the tracheobronchial tree with systemic arterial blood. Pulmonary blood flow (PBF) constitutes the entire output of the right venticle and supplies the […]

Effects of Pressure Outside the Heart on Cardiac Output


In the figure cited and the preceding dicussions in thread "Pathophysiology of the Circulation" at, values of Pms and Pra were expressed relative to atmospheric pressure. However, the transmural pressure of the right atrium exceeds the Pra by the subatmospheric value (about -4 mm Hg) of the Ppl surrounding the heart. Consider the effect of […]