Positional Pulse Ox Desaturation

[flhtci01]

What could be causes of a person desat'ing from 100% in a supine position to around mid 80's in a sitting position and then returning to 100% when back in the supine position?

Not sure of all the details, jsut seems strange to me.

 

[boingo]

Did you still have a good pleth? Could have been several things, lack of pefusion or inability to expand cx, i.e. morbidly obesity come to mind.

 

[flhtci01]

Wasn't my pt. Got asked by a first reponder a few days after the incident, so I don't have a lot of details. Just got me thinking of the different possiblities.

 

[exodus]

Very low blood pressure? IF there's not adequet perfusion to the limb, then the pulse ox wont' work?

 

[41 Duck]

...or when the PT changes position, they give the probe lead a tug, thereby causing false readings?

 

[VentMedic]

Is the patient symptomatic?

Is the answer is yes then there are several medical reasons for that desaturation.

There may be a presence of lung disease processes, either symmetrical or asymmetric, depending of the lung segments involved that can cause such a change. There can also be changes in intrathoracic pressures from moving that can create pressure changes. The position change can bring about something like a Valsalva maneuver that can affect changes including vagal stimulation as well as increased pressure with the chest which can reduce venous return and alter blood flow and pressure within the cardiopulmonary system. The patient can also have a shunting process occurring from a patent foramen ovale.