Teaching the distribution of pulmonary blood flow using a Starling resistor model and turbine flowmeters.

The distribution of pulmonary blood flow is uneven and can be described as a three-zone model, the West zones: zone 1 occurs whenever alveolar pressure exceeds arterial pressure; zone 2 when the arterial pressure is greater than alveolar but the alveolar pressure exceeds the venous pressure; and finally zone 3 when both arterial and venous pressures exceed alveolar pressure. Consequently, the blood flow is almost determined by the difference between the arterial and venous pressures in zone 3 and between arterial and alveolar pressures in zone 2 and ceases in zone 1. The understanding of this subject may be difficult to some medical students.

Right ventricular contractility decreases during exercise in patients with non-advanced idiopathic pulmonary fibrosis.

Early right ventricular dysfunction in patients with non-advanced idiopathic pulmonary fibrosis (IPF) has not been fully elucidated. Thus, we aimed to assess right ventricular functions in IPF patients and controls by speckle-tracking strain echocardiography at rest and peak exercise.We screened 116 IPF patients from February to August 2019 to include 20 patients with no history of oxygen therapy, peripheral saturation levels ≥92% at rest, Gender-Age-Physiology Index score ≤5, and modified Medical Research Council score ≤3.

Right ventricular dysfunction in patients with non-severe idiopathic pulmonary fibrosis: a cross-sectional prospective single-center study.

Background: Little is known about right ventricular dysfunction in non-advanced idiopathic pulmonary fibrosis (IPF) patients without hypoxemia at rest. We evaluated it at rest and during exercise.

Research Design And Methods: 123 IPF patients were evaluated, and 27 met all the following criteria: Gender-Age-Physiology Index score ≤5, modified Medical Research Council dyspnea score ≤3, peripheral oxygen saturation ≥92% at rest, and no history of oxygen therapy.