The most important aspect of the curve is that as the oximeter reading falls below 90%, the PaO 2 drops very rapidly and O 2 delivery to the tissues is reduced and leads to irreversible brain damage and cardiac arrest.

Jun 11, 2023 · Arterial hyperoxemia refers to a high PaO2 in arterial blood. This is defined as a PaO2 of 100 to 300 mm Hg or a PaO 2 of >300 mm Hg post-cardiopulmonary arrest. A high PaO 2 is now considered risky in acute myocardial infarction, as noted in the DETOX-AMI trial (Hofmann et al) and others.

Sep 22, 2019 · To see why this is relevant, look at the oxygen-hemoglobin dissociation curve. The Oxygen-Hemoglobin Dissociation Curve shows the percent of oxygen binding to Hgb per mmHg. An O2 sat of 90% corresponds to a PaO2 of 60 mmHg. …

Jun 7, 2016 · There is often a P50 value expressed on the curve, which is the value that tells us the partial pressure of oxygen at which the red blood cells are 50% saturated with oxygen. At an oxygen saturation of 50%, the PaO2 is approximately 25 mmHg (3.5k Pa).

The oxygen-hemoglobin disassociation curve is a graph that shows the relationship between the partial pressure of oxygen (PaO2) in mmHg and the percentage of oxygen saturation. Body cells use the available O2, and the PaO2 begins to fall.

In many settings an ABG may not be practical or feasible, and thus the established mathematical relationship between SpO2 and PaO2 can be used. There is a distinct relationship between PaO2 and SpO2 which is illustrated by the Oxygen Dissociation Curve (see image).

Feb 22, 2012 · Assuming that PAO2 and arterial partial pressure of oxygen (PaO2) are similar, the oxyhemoglobin dissociation curve is used to correlate FiO2 to SpO2. The border around the simulation becomes red when SpO2 becomes less than 75. The PaO2 (a-A gradient) can be adjusted when FiO2 is air. FiO2 can be adjusted when the a-A gradient is small.

Classically the factors recognised to influence the oxygen dissociation curve (ODC) include the local prevailing CO2 partial pressure (P CO 2), pH and temperature. The curve is shifted to the right (i.e. lower saturation for a given P O 2) by higher P CO 2, greater acidity (lower pH) and higher temperature

Feb 6, 2019 · PaO2 is affected by age (tends to be lower) and altitude (tends to be lower). PaO2 and O2 sat can be related through the oxygen-hemoglobin dissocation curve! See this table for PaO2 to O2 sat conversion. Remember that from first year of med school?

Mar 18, 2025 · In contrast, at lower PaO2 levels, the curve steepens, meaning small PaO2 reductions lead to significant SpO2 drops. The curve shifts in response to physiological conditions that alter hemoglobin’s oxygen affinity. A rightward shift, caused by increased temperature, acidosis, elevated carbon dioxide (PaCO2), and higher 2,3-DPG levels ...