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9780521704632c08a CUFX213A/Peck 9780521618168 December 28, 2007 10:40
Section IICoredrugs in anaesthetic practice
Central nervous system – as PaCO 2 rises so does cerebral blood flow and intracranial
pressure. Beyond 10 kPa narcosis may ensue.Carbon dioxide absorbents
Absorbents consume CO 2 to prevent rebreathing in a circle system. In the UK they
are mainly sodium hydroxide (sodalime) based while in the US they are potassium
hydroxide based (baralyme). There are three steps in the chemical reaction:
H 2 O+CO 2 →H 2 CO 3
H 2 CO 3 +2NaOH→Na 2 CO 3 +2H 2 O
Na 2 CO 3 +Ca(OH) 2 →CaCO 3 +2NaOH.