Respiratory depression, also called hypoventilation, occurs when ventilation is inadequate to perform needed respiratory gas exchange. It causes an increased concentration of carbon dioxide and respiratory acidosis. It is a precursor to hypoxia and its lethality is attributed to hypoxia with carbon dioxide toxicity.
Respiratory depression is not equal to respiratory arrest, in which breathing ceases entirely and death occurs within minutes due to hypoxia progressing to anoxia.

Some common causes:
• stroke affecting the brainstem;
• medication or drugs, particularly opioids (i.e., oxycodone, hydromorphone) and benzodiazepines (i.e., lorazepam, alprazolam);
• obesity.

See reference for more information.

Adapted from Wikipedia, the free encyclopedia. Internet. Available at https://en.wikipedia.org/wiki/Hypoventilation. Accessed on July 15, 2022.