CO2 + H2O<—> H2CO3<—>H + HCO3
Carbonic acid buffering system First part!
CO2(150ml/day)
When body makes too much acid, bicarb ions act as a base , accepting H ions to form carbonic acid, which exhaled as CO2.
When body alkaline, carbonic acid dissociates to release more H ions = maintain Ph
2nd Part of Buffering System
LUNGS
Our lungs recognize too much bicarb(H+) when gets CO2 we exhale. It adjust amt of carbonic acid by blowing off or holding co2
Buffer system #3
RENAL
holding or eleminating bicarb.
For ever 10meq change bicarb thePH will change by 0.15mmhg in same direction
Ie pH=7.40 ,HCO310 now phis ? And bicarb is 20. The PH will be 7.55
For every change in pH of 0.10, the K+ will change by ___ in the OPPOSITE direction
K will change by 0.6
K norm- 3.5-5.5
For every 10meq/l change in HCO3, the pH will change by _____ in the ___ direction
pH will change by 0.15mmhg in the SAME direction
For every 10mmhg change in PCO2, the PH will change by ___ in the ___ directions
pH change by .08 in the opposite direction. ie: pH is 7.1, CO2 54, HCO3 24, etco2 50. Now etco2 =30. What is change in PH? Etco2 50-30=20 so pH 7.10+.08=7.18+.08= 7.26. pH is 7.26
What can cause metabolic ALKILOSIS? What about Respiratory alkilosis
Metobolic- tums od, lasix dropping K+, lots of v/d, ng SX
Respiratory - 1st stage of shock, pulm embolism, pregnancy (Dec. Functional residual capacity. High altitude.
If kidneys are showing acidosis
We can assume the respiratory is alkilosis
Normals
PH
PaCO2
HCO3
PaO2
BE
pH 7.35-7.45
PaCO2. 35-45
HCO3. 22-26
PaO2. 80-100
BE. -2/+2 if -2= 2 extra acids, +2= 2 extra base.
BE of -10 is too many acidd
Uncorrected anion gap
Na - (Cl + Hco3)
If > 12 you have metabolic Acidosis
Corrected anion gap
Na - (Cl + HCo3) + K
If > 20 you have metabolic Acidosis
