Acid Base Balance

Acid/Base Balance: Made Easy To Understand

Wed 9/1/10

• Normal Values

o pH (7.35-7.45) perfect avg is 7.40 (7.35 is more acidic, 7.45 is more alkaline)

o PO2 (80-100 mm Hg) presence of O2 in bloodstream (best measure is O2 sat)

o values vary w/ age (ventilation & metabolism decline)

o Drops 5mm Hg/yr after age 20 but varies with condition of lungs

o PCO2 (35-45) becomes an acid when mixed w/water (ex. blood)

o Breathe to keep CO2 levels balanced – if hypoventilated, keep CO2 in bloodstream, which becomes acid, which = acidic PH

o PH & PCO2 go hand in hand, when one increases or decreases then the other one does also

o HCO3 (22-26 meq) bicarb measured in mEq – an electrolyte – a buffer to neutralize acid

o O2 Sat. (93-100%) measures the amount of O2 hemoglobin is up taking

o Hemoglobin is like a sponge for O2 because of iron (ladies are at risk for low O2 sats when menstruating because of low iron) this is also why anemic individuals are weak, they don’t have sufficient O2 levels

• Extra notes

o If PO2 decreases then so does O2 – they move incrementally with each other

o Acid base balance deals with core essence of maintaining life – everything affects acid base balance (anything from a cold to pregnancy)

o Pulse ox is the specific gravity but when you need to know the exact amount, then we check arterial blood gas (ABG) – INCLUDE ALL ABG LABS VALUES FOR INTERPRETATION!!!

o Blood gases measured with arterial blood (oxygenated blood)

▪ Cannot treat arterial sticks like venous sticks (hold pressure on venous stick for 1 min to stop bleeding unless anticoagulants are used – with arterial sticks hold for 5 minutes

• Coagulation from platelet aggregation which means they come together and clump to...