Related Experiment Video
Updated: Jun 1, 2026
A Model to Simulate Clinically Relevant Hypoxia in Humans
Published on: December 22, 2016
["On and off" hypoxaemia]
E Magois1, P Aubry, C Andrejak
1Unité de Réanimation Respiratoire, Service de Pneumologie, CHU Sud, Avenue René-Laennec, 80054 Amiens cedex 1, France. Magois.Eline@chu-amiens.fr
Introduction:
A right to left shunt caused by a patent foramen ovale (PFO) must be considered when patients present with symptoms of platypnoea-orthodeoxia. The most useful investigation is saline contrast transthoracic or transoesophageal echocardiography.
Case Report:
We report a case of an eighty-year-old woman with the platypnoea-orthodeoxia syndrome, but without signs of a right to left shunt caused by a PFO. (99m)Tc-macroaggregated albumin lung scintigraphy and saline contrast transthoracic echocardiography were considered normal in the supine position. The clinical suspicion of PFO was so strong that the examinations were repeated in the upright position. This revealed a systemic uptake of the isotope on lung scintigraphy, confirmed by saline contrast echocardiography. The atrial septal defect was due to displacement of the interatrial septum by an aneurysm of the ascending aortic. In the upright position blood flowed directly from the inferior cava vena through a PFO into the left atrium.
Conclusion:
The diagnosis of PFO may be difficult and it is important to repeat saline contrast echocardiography in the upright position when it is negative supine. It is possible to confirm the diagnosis by contrast infusion through the femoral veins.
More Related Videos
05:45Delivery of In Vivo Acute Intermittent Hypoxia in Neonatal Rodents to Prime Subventricular Zone-derived Neural Progenitor Cell Cultures
Published on: November 2, 2015
05:45Experimental Approach to Examine Leptin Signaling in the Carotid Bodies and its Effects on Control of Breathing
Published on: October 25, 2019
Related Concept Videos
01:23Hypoxia
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
01:21Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
01:19Respiratory Assessment: Purpose and Indications
Objectives and Importance:
The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a...
01:25Hyperpnea and Hyperventilation
01:23Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
01:27Oxygen Transport in the Blood