Which of the following causes low SpO2 levels, indicating impaired oxygenation?

Hypoventilation is the primary cause of low SpO2 levels, indicating impaired oxygenation. This condition occurs when there is inadequate ventilation, leading to an insufficient exchange of oxygen and carbon dioxide in the lungs. As a result, less oxygen enters the bloodstream, which can cause a decrease in the saturation of hemoglobin with oxygen, reflected in lower SpO2 readings.

In hypoventilation, there may be an increase in carbon dioxide levels that can also lead to respiratory acidosis, further complicating oxygenation. Understanding this mechanism is essential for recognizing when a patient might be experiencing inadequate oxygen delivery, signaling the need for interventions to improve ventilation and oxygenation.

In contrast, hyperventilation typically leads to an increase in oxygen levels in the blood and may actually raise SpO2 readings, even though it can cause other respiratory issues. Normal ventilation maintains adequate oxygen levels, therefore presenting no issues with SpO2. Peripheral vasodilation, while it can affect blood flow especially in cases of shock or sepsis, does not directly cause low SpO2 levels; instead, it may contribute to overall oxygen delivery challenges under certain conditions.