Dear All Blood gas analysers measure pH and PCO2 using specific electrodes and calculate actual bicarbonate using various algorithms (based on Henderson Hasselbalch equation). It is unclear to me how the calculation of actual bicarbonate varies during acute vs chronic vs mixed acid base disturbances, if it is based on the Henderson equation only? Also can manufacturer's have built in software to provide an interpretation guide for a given set of blood gas readings, or is this considered too risky by them? thanks Mohammad Dr. M A Al-Jubouri Consultant Chemical Pathologist Send instant messages to your online friends http://uk.messenger.yahoo.com ------ACB discussion List Information-------- This is an open discussion list for the academic and clinical community working in clinical biochemistry. Please note, archived messages are public and can be viewed via the internet. Views expressed are those of the individual and they are responsible for all message content. ACB Web Site http://www.acb.org.uk List Archives http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html List Instructions (How to leave etc.) http://www.jiscmail.ac.uk/