ABG v.1
Arterial Blood Gas Analyser (ABG) helps to calculate the acid/base disturbances that can be ascertained from a patient's arterial blood gases/electrolytes and albumin.
This tool calculates the AG (Anion gap) the corrected Anion Gap (cAG), the primary acid/base disturbance of blood PH and the compensatory - if any - reaction by utilising the various blood gas/electrolytes values found in a patient's record. Increased Anion gap is measured in the presence of a metabolic acidosis with a corrected gap in the presence of albumin values.
According to the US National Library of Medicine (NIH) on their MedlinePlus health information platform (3) reference ranges at sea level used are: Arterial PH normal range: 7.38-7.42 PH (but with an extreme deviation in either bicarb or PaCO2 if the Ph is between above or below 7.4, even if the value is within this normal range, it will be moving in the direction of the disturbance). Bicarb (HCO3-) normal range: 22-28 mmol/L (mEq/L) PaCO2: 38-42mmHg (5.1-5.6kPa) Na: 136-145mmol/L Cl: 98-107mmol/L Albumin: 40 g/L The picture is also contextualised in terms of acute or chronic. To ascertain whether the picture represents a metabolic or respiratory acidosis or alkalosis, the PH, PaCO2 and bicarbonate are looked at: 1-Is the PH normal? 2-Is the PaCO2 normal? 3-Is the HCO3 normal? 4-Match the direction of difference of the PaCO2 or HCO3 with the PH 5-Does the PaCO2 or the HCO3 move in the opposite direction to the PH?
Do not use in isolation of a thorough clinical evaluation of the patient's state
Ref. 1: Baillie JK. Simple, easily memorised 'rules of thumb' for the rapid assessment of physiological compensation for respiratory acid-base disorders. Thorax 2008;63:289-290 doi:10.1136/thx.2007.091223 Ref. 2: Kaufman DA. Interpretation of Arterial Blood Gases (ABGs). Written for Thoracic.org. Retrieved 12/9/2014. Ref. 3: NIH: US National Library of Medicine: Accessed at: https://medlineplus.gov/ency/article/003855.htm
OBSERVATION.abg_analyser.v1, OBSERVATION.lab_test-blood_gases.v1, OBSERVATION.lab_test-urea_and_electrolytes.v1, OBSERVATION.lab_test-serum_albumin.v1
