The amount of carbon dioxide gas dissolved in the blood is an essential stimulus for maintaining respiration. Spontaneous respiration stops below a certain level of carbon dioxide. This value is called the <a class="glossaryLink" style="box-sizing: border-box; background-color: #ffffff; color: #447dd8 !important; text-decoration: none !important; font-size: 16px; border-bottom: 1px dotted #000000; font-family: Montserrat; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal;" href="https://scofa.com/glossary/apneic-threshold/" aria-describedby="tt" data-cmtooltip="<div class=glossaryItemTitle>Apneic Threshold</div><div class=glossaryItemBody>The amount of carbon dioxide gas dissolved in the blood is an essential stimulus for maintaining respiration. Spontaneous respiration stops below a certain level of carbon dioxide. This value is called the apneic threshold. However, this value is not a fixed value in humans but varies in sleep and wakefulness. Apneic threshold values in REM sleep and NREM sleep also differ.</div>" data-mobile-support="0" data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]">apneic threshold</a>. However, this value is not a fixed value in humans but varies in sleep and wakefulness. Apneic threshold values in REM sleep and NREM sleep also differ.