{"id":"pco2-arterial","name":"Arterial pCO2","shortName":"Arterial pCO2","aliases":["pCO2, Arterial","PaCO2","pCO2 (ABG)","Carbon Dioxide Partial Pressure, Arterial","Arterial pCO2","pCO2 (Arterial)","Arterial carbon dioxide tension","Carbon dioxide tension, arterial","Partial Pressure of Carbon Dioxide, Arterial","ABG pCO2","pCO2 arterial"],"abbreviations":["PaCO2"],"loinc":[{"code":"2019-8","primary":true},{"code":"11557-6","primary":false},{"code":"2020-6","primary":false}],"specimen":"whole-blood","units":[{"ucum":"mm[Hg]","display":"mmHg"},{"ucum":"kPa","display":"kPa"}],"referenceRanges":[{"population":"Adults","low":35,"high":45,"unit":"mm[Hg]","unitDisplay":"mmHg","note":"Adult arterial interval of 35 to 45 mmHg (4.7 to 6.0 kPa), the same in MedlinePlus and two reviews. Lab directories print slightly wider limits: 35 to 48 mmHg at Penn State Health and 32 to 46 mmHg at Northwell Health. The venous interval is higher (41 to 50 mmHg in one review), so venous gases have their own marker. In some healthy groups the average sits below 40: the mean was about 35.8 mmHg in 194 healthy nonsmokers aged 40 to 90, women averaged lower than men in two studies of healthy volunteers (20 young adults and 182 adults), and healthy people living at altitude run lower (median 33.5 mmHg at 3,164 m in 46 residents). Use the range on your own report first. Adults only; newborn and child ranges differ and are not included.","sources":[{"title":"Arterial Blood Gas (ABG) Test","url":"https://medlineplus.gov/lab-tests/arterial-blood-gas-abg-test/","publisher":"MedlinePlus, National Library of Medicine"},{"title":"Mastering blood gas interpretation: A practical guide for primary care providers","url":"https://doi.org/10.4102/safp.v67i1.6058","publisher":"South African Family Practice","year":2025},{"title":"Blood gas analysis: Clinical applications, interpretation and future directions (Review)","url":"https://doi.org/10.3892/mi.2025.291","publisher":"Medicine International","year":2026},{"title":"Arterial blood gas standards for healthy young nonsmoking subjects","url":"https://pubmed.ncbi.nlm.nih.gov/6789666/","publisher":"American Journal of Clinical Pathology","year":1981},{"title":"Reference values of arterial oxygen tension in the middle-aged and elderly","url":"https://pubmed.ncbi.nlm.nih.gov/7663806/","publisher":"American Journal of Respiratory and Critical Care Medicine","year":1995},{"title":"Arterial blood analysis of healthy residents in Huamachuco, Peru (3,164 m): a cross-sectional study","url":"https://doi.org/10.12688/f1000research.134567.2","publisher":"F1000Research","year":2023},{"title":"Blood Gas, Arterial","url":"https://pennstatehealth.org/pathology-test/blood-gas-arterial","publisher":"Penn State Health"},{"title":"Blood Gas Arterial","url":"https://labs.northwell.edu/epic/test/114134","publisher":"Northwell Health Laboratories"},{"title":"Reference intervals and age and gender dependency for arterial blood gases and electrolytes in adults","url":"https://pubmed.ncbi.nlm.nih.gov/21619466/","publisher":"Clinical Chemistry and Laboratory Medicine","year":2011}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"How much carbon dioxide is dissolved in your arterial blood. It shows how well your breathing clears this waste gas.","url":"https://bloodtesttracker.com/markers/pco2-arterial","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}