IMPORTANT - Tut 5

• • pH is needed for homeostasis (balance between
  • lungs control co2, which is acid, high acid makes blood more acid which makes ph more acidic, low acid makes blood ore alkaline
  • kidney control bicarb which is an alkaline, high bicarb makes blood/ph more alkaline, less bicarb makes blood/ph more acidic

  
• • if theres a high amount of co2, the pH is acidotic, so the metabolic system release bicarb, which is an alkaline which makes the ph more neutral
  • and vice versa (via lungs, respiratory system releases more co2 in blood to more blood more neutral)

  
• • to get more co2 into blood, decrease tidal volume and decrease respiratory rate
  • to get more co2 out of blood, increase tidal volume and increase respiratory rate
• • high co2 / low HCO3 caused by lungs = respiratory acidosis
  • low co2 / high HCO3 caused by lungs = respiratory alkalosis
  • high co2 / low HCO3 caused by kidneys = metabolic acidosis
  • low co2 / high HCO3 caused by kidneys = metabolic alkalosis
• Compensation:

  • The lungs and kidneys work together to maintain a neutral acid-base balance (pH 7.35-7.45)
  • When there is dysfunction of one system, the other compensates for it
  • The lungs can alter (via changing respiratory rate and tidal volume) levels of CO2 production to compensate for kidney dysfunction within 5 breaths
  • The kidneys take 3 days to alter levels of HCO3 - to compensate for lung dysfunction
• Full or Partial Compensation?

  • Partial compensation is the term used when the other system (not primary) has changed out of normal range, but the pH remains outside of normal range 7.35-7.45
  • Full compensation is the term used when the other system (not primary) has changed out of normal range enough to put pH back in normal range 7.35-7.45
• • If pH is acidic and co2 level is acidic it indicates a respiratory problem
  • If pH is alkalotic and HCO3 level is alkalotic it indicates a metabolic problem
• type 1 respiratory failure - low o2

  type 2 respiratory failure - low/normal o2 , high co2