orthodeoxia

orthodeoxia

 [or″tho-de-ok´se-ah]
accentuation of arterial hypoxemia in the erect position.

or·tho·de·ox·i·a

(ōr'thō-dē-oks'ē-ă),
Fall in arterial blood oxygen on assuming the upright posture. Usually caused by right-to-left cardiac or vascular shunting with a posturally induced fall in left-sided pressure permitting a corresponding gradient across the shunt.

orthodeoxia

/or·tho·de·ox·ia/ (-de-ok´se-ah) accentuation of arterial hypoxemia in the erect position.

or·tho·de·ox·i·a

(ōr'thō-dē-oks'ē-ă)
Fall in arterial blood oxygen on standing upright.
References in periodicals archive ?
One unique patient in our study presented with platypnea (dyspnea on standing) and orthodeoxia (hypoxemia on standing) because of pulmonary hypertension from tumor emboli in combination with a patent foramen ovale that created a right-to-left intracardiac shunt and the reduced venous return to the heart on standing left an insufficient amount of unshunted blood to keep him from deoxygenation.
Orthodeoxia, a drop in oxygen saturation associated with vertical posture, is characteristically present in HPS, but not in porto-pulmonary hypertension, which is much more serious, but thankfully a much less common complication of PHT in childhood.
3) Pulmonary symptoms include dyspnea, fatigue, cyanosis, and orthodeoxia (decreased arterial oxygen content while upright), all due to right-to-left shunting of blood through the pulmonary AVM.
Platypnea and orthodeoxia are not pathognomonic for HPS.
Exercise-aggravated hypoxemia and orthodeoxia in cirrhosis.
Lung lesions can lead to hypoxemia, orthodeoxia, or hypocapnia and subsequent clubbing of the fingers and toes.
Acute alveolar hemorrhage and orthodeoxia induced by intravenous amiodarone.
CXR demonstrated a nodular density of the right middle lobe; a subsequent CT scan of the chest revealed several pulmonary AV fistulas in the right middle and lower lobe, likely responsible for her sense of platypnea with accompanying orthodeoxia.
Key Words: orthodeoxia, Parkinson disease, platypnea, pulmonary embolism
It may be associated with a decrease in arterial oxygen saturation when the patient changes from the supine to the upright position, called orthodeoxia, from orthos, meaning upright, and deoxia, meaning desaturation.
The absence of a pressure gradient between the left and right atrium in either the supine or sitting position indicates that the orthodeoxia results from an increase in streaming of blood from the inferior vena cava to the left atrium caused by mechanical distortion of the interatrial septum.
Platypnea without orthodeoxia occurred in a COPD patient during subacute ileus, which rapidly resolved after resolution of the ileus.