Arterial blood gas test

An arterial blood gas (ABG) test, or arterial blood gas analysis (ABGA) measures the amounts of arterial gases, such as <a href="/facts/Oxygen/acyn6o8r">oxygen</a> and <a href="/facts/Carbon_dioxide/xGzpppEp">carbon dioxide</a>. An ABG test requires that a small volume of blood be drawn from the <a href="/facts/Radial_artery/aRw0Rqy3">radial artery</a> with a <a href="/facts/Syringe/8m937D8m">syringe</a> and a thin <a href="/facts/Hypodermic_needle/EJEUNyRK">needle</a>, but sometimes the <a href="/facts/Femoral_artery/qL6wx3T9">femoral artery</a> in the <a href="/facts/Groin/49jqnbc3">groin</a> or another site is used. The blood can also be drawn from an <a href="/facts/Arterial_catheter/2pBw0wN1">arterial catheter</a>.
An ABG test measures the <a href="/facts/Blood_gas_tension/8SIHAoI6">blood gas tension</a> values of the <a href="/facts/Oxygen/acyn6o8r">arterial partial pressure of oxygen</a> (PaO2), and the <a href="/facts/PaCO2/3jPc7ToV">arterial partial pressure of carbon dioxide</a> (PaCO2), and the <a href="/facts/PH/RnSv8D7y">blood's pH</a>. In addition, the arterial <a href="/facts/Oxygen_saturation_(medicine)/9cfum2Yl">oxygen saturation</a> (SaO2) can be determined. Such information is vital when caring for patients with critical illnesses or respiratory disease. Therefore, the ABG test is one of the most common tests performed on patients in <a href="/facts/Intensive-care_unit/j77VBgtt">intensive-care units</a>. In other <a href="/facts/Therapy/2ytkGbgT">levels of care</a>, <a href="/facts/Pulse_oximetry/2xMWwKzK">pulse oximetry</a> plus transcutaneous carbon-dioxide measurement is a less invasive, alternative method of obtaining similar information.
An ABG test can indirectly measure the level of <a href="/facts/Bicarbonate/zzSVVAl1">bicarbonate</a> in the blood. The bicarbonate level is calculated using the Henderson-Hasselbalch equation. Many blood-gas analyzers will also report concentrations of <a href="/facts/Lactic_acid/BsVRFx7s">lactate</a>, <a href="/facts/Hemoglobin/RsD1MzYA">hemoglobin</a>, several <a href="/facts/Electrolyte/4YE8bIVa">electrolytes</a>, <a href="/facts/Oxyhemoglobin/RsD1MzYA">oxyhemoglobin</a>, <a href="/facts/Carboxyhemoglobin/pzv2kCQe">carboxyhemoglobin</a>, and <a href="/facts/Methemoglobin/eTPQFl0A">methemoglobin</a>. ABG testing is mainly used in <a href="/facts/Pulmonology/k0hUHBhu">pulmonology</a> and critical-care medicine to determine <a href="/facts/Gas_exchange/3vUewPNH">gas exchange</a> across the alveolar-capillary membrane. ABG testing also has a variety of applications in other areas of medicine. Combinations of disorders can be complex and difficult to interpret, so calculators, <a href="/facts/Nomograms/ysXLNuVY">nomograms</a>, and rules of thumb are commonly used.
ABG <a href="/facts/Sampling_(medicine)/RpgWjpj9">samples</a> originally were sent from the clinic to the <a href="/facts/Medical_laboratory/ov10GjQD">medical laboratory</a> for analysis. Newer equipment lets the analysis be done also as <a href="/facts/Point-of-care_testing/llrrlXHb">point-of-care testing</a>, depending on the equipment available in each clinic.

Arterial blood gas test open-in-new

Arterial blood gas test