View source for Serum CO2

{{Data_element
| field_name = Ap_SerCO2
| CCMDB_tab = Apache
| element_description = The patient's {{#show: Serum CO2 | ?AP phys name}} level in {{#show: Serum CO2 | ?AP phys unit}}.
| in_table = L_Log table
| data_type = number
| datafield_length = single
| program_collecting = CC
| created_raw = Raw
| data_element_sort_index = 71
}}

== Collection instruction ==
Collect Serum CO2 '''only if an [[Arterial blood gas (APACHE)]] is not available'''. An '''ABG is preferred''', but if no ABG available during the first 24 hours in ICU then collect serum CO2. 

If '''no ABG and no serum CO2''' available assume normal and record serum CO2 as '''25.0'''.

''' Do not use venous gases.'''

{{APACHE physiological variable
|AP phys name=Serum CO2
|AP phys unit=mmol/L
|AP phys absMax= 440
|AP phys warnMax= 285
|AP H4= ≥52
|AP H3= >=41 and <52
|AP H1= >=32 and <41 
|AP 0= >= 22 and <32
|AP L2= >=18 and <22
|AP L3= >=15 and <18 
|AP L4= <15 
|AP phys warnMin= 2
|AP phys absMin= 2
}}

== Background == 
For APACHE II scoring: the serum CO2 replaces [[pH]] and assumes normal oxygenation.

Serum CO2 is really a measure of '''serum HCO3-''', also '''called bicarbonate'''. The procedure used to measure HCO3- in the laboratory first converts it to CO2. In the body, 95% of the CO2 is present as HCO3-, so most of what is measured in the laboratory represents HCO3-.

== Data Integrity Checks ==
{{Data Integrity Check List}}

== Related articles ==
{{Related Articles}}

[[Category:APACHE II Physiological Variables]]