This page focuses on explaining the different results that are provided on an ABG printout slip. They are explained further on the 'causes of disruption' page. Please note, the printout slip layout and contents, as well as normal values provided may differ with each analyser.
Components of the ABG
Analysis information
Measurement report
dd/mm/yyyy hh:mm
Serial number: ....
Unique serial number of the analyser
Instrument ID: ....
Assigned name of analyser i.e. A & E
Operator ID: ....
Unique ID of operator ID
Hospital Location: ....
Name of the hospital
Patient information
Patient ID: ....
Usually patient NHS number
Patient Name: ....
Date of Birth: ....
Remark: ....
i.e. on 2L/min nasal cannula
FiO2: ....
Fraction of inspired oxygen i.e. 0.21 for room air, 0.28 with a controlled venturi mask
Temperature: ....
Recorded patient temperature (may affect analysis)
Blood type: ....
Arterial or venous sample provided?
Figure 1: Exemplar ABG printout
Blood gas values
pH .... [7.350 - 7.450]
pH is defined as the negative log of the hydrogen ion activity: This means that when the concentration of H+ goes up, and the solution becomes more acidic, the pH goes down, and vice versa
pCO2 .... [4.27 - 6.40]
Partial pressure (number of molecules of a particular gas in a mixture of gases) of carbon dioxide in arterial blood
pO2 .... [11.07 - 14.40]
Partial pressure of oxygen in arterial blood
Acid base status
cHCO3- .... [22.0 - 26.0]
Concentration of bicarbonate (HCO3-), a marker of metabolic disturbance
BE .... [-2.0 - +2.0]
The base excess is another marker of metabolic disturbance. The predominant base contributing to base excess is bicarbonate, therefore, derangement in BE usually mirrors cHCO3-. However, base excess is a more comprehensive measurement, encompassing all metabolic contributions. For simplicity however, it is not considered in this guide, as very rarely adds extra information
Electrolyte status
Na+ .... [136.0 - 145.0]
K+ .... [3.50 - 5.10]
Ca2+ .... [1.150 - 1.330]
Cl- .... [98.0 - 107.0]
A venous or arterial blood gas is a good way to quickly check electrolyte status
Oxygen status and co-oximetry
Hct (%) .... [36.0 - 53.0]
Haematocrit (volume percentage of red blood cells in blood)
tHb (g/L) .... [115.0 - 178.0]
Total haemoglobin; includes the values below. Haemoglobin acts as a guide but is notoriously inaccurate in an ABG
COHb (g/L) .... [0.0 - 3.0]
Concentration of carboxyhemoglobin. Elevated in carbon monoxide poisoning, as well as in tobacco smokers
O2Hb (g/L) .... [97.0 - 98.0]
Concentration of oxyhemoglobin
MetHb (g/L) .... [0.0-1.5]
MetHb is an oxidized form of haemoglobin, which may be abnormally raised in methaemoglobinaemia
SO2 .... [94.0-98.0]
Commonly referred to as O2 saturations, ratio of oxyhaemoglobin, to total Hb
Metabolite values
Glu .... [3.5 - 5.3]
Glucose level; important in DKA and sepsis
Lac .... [0.6 - 2.5]
Lactate level; important in sepsis, and also hypoperfusion. Often in sepsis, an ABG is often the fastest and easiest way of determining lactate
This page focuses on explaining the different results that are provided on an ABG printout slip. They are explained further on the 'causes of disruption' page. Please note, the printout slip layout and contents, as well as normal values provided may differ with each analyser.
Components of the ABG
Analysis information
Measurement report
dd/mm/yyyy hh:mm
Serial number: ....
Unique serial number of the analyser
Instrument ID: ....
Assigned name of analyser i.e. A & E
Operator ID: ....
Unique ID of operator ID
Hospital Location: ....
Name of the hospital
Patient information
Patient ID: ....
Usually patient NHS number
Patient Name: ....
Date of Birth: ....
Remark: ....
i.e. on 2L/min nasal cannula
FiO2: ....
Fraction of inspired oxygen i.e. 0.21 for room air, 0.28 with a controlled venturi mask
Temperature: ....
Recorded patient temperature (may affect analysis)
Blood type: ....
Arterial or venous sample provided?
Blood gas values
pH .... [7.350 - 7.450]
pH is defined as the negative log of the hydrogen ion activity: This means that when the concentration of H+ goes up, and the solution becomes more acidic, the pH goes down, and vice versa
pCO2 .... [4.27 - 6.40]
Partial pressure (number of molecules of a particular gas in a mixture of gases) of carbon dioxide in arterial blood
pO2 .... [11.07 - 14.40]
Partial pressure of oxygen in arterial blood
Acid base status
cHCO3- .... [22.0 - 26.0]
Concentration of bicarbonate (HCO3-), a marker of metabolic disturbance
BE .... [-2.0 - +2.0]
The base excess is another marker of metabolic disturbance. The predominant base contributing to base excess is bicarbonate, therefore, derangement in BE usually mirrors cHCO3-. However, base excess is a more comprehensive measurement, encompassing all metabolic contributions. For simplicity however, it is not considered in this guide, as very rarely adds extra information
Electrolyte status
Na+ .... [136.0 - 145.0]
K+ .... [3.50 - 5.10]
Ca2+ .... [1.150 - 1.330]
Cl- .... [98.0 - 107.0]
A venous or arterial blood gas is a good way to quickly check electrolyte status
Oxygen status and co-oximetry
Hct (%) .... [36.0 - 53.0]
Haematocrit (volume percentage of red blood cells in blood)
tHb (g/L) .... [115.0 - 178.0]
Total haemoglobin; includes the values below. Haemoglobin acts as a guide but is notoriously inaccurate in an ABG
COHb (g/L) .... [0.0 - 3.0]
Concentration of carboxyhemoglobin. Elevated in carbon monoxide poisoning, as well as in tobacco smokers
O2Hb (g/L) .... [97.0 - 98.0]
Concentration of oxyhemoglobin
MetHb (g/L) .... [0.0-1.5]
MetHb is an oxidized form of haemoglobin, which may be abnormally raised in methaemoglobinaemia
SO2 .... [94.0-98.0]
Commonly referred to as O2 saturations, ratio of oxyhaemoglobin, to total Hb
Metabolite values
Glu .... [3.5 - 5.3]
Glucose level; important in DKA and sepsis
Lac .... [0.6 - 2.5]
Lactate level; important in sepsis, and also hypoperfusion. Often in sepsis, an ABG is often the fastest and easiest way of determining lactate
Figure 1: Exemplar ABG printout