Physiology - Acid-Base Compensation PDF

Right graph: L1 (from non-carbonic acid) + L2 (from carbonic acid) = base deficit Would be base excess if above the line Lecture 79: Physiology - Acid-Base II, Acid-Base Compensation Acidemia: pH is less than 7.40 Alkalemia: pH is over 7.40 Can be respiratory or metabolic imbalance Simple A-B Diso...

Right graph: L1 (from non-carbonic acid) + L2 (from carbonic acid) = base deficit Would be base excess if above the line Lecture 79: Physiology - Acid-Base II, Acid-Base Compensation Acidemia: pH is less than 7.40 Alkalemia: pH is over 7.40 Can be respiratory or metabolic imbalance Simple A-B Disorders: Hypercapnia (resp. acidosis), Hypocapnia (resp. alkalosis), metabolic acidosis, metabolic alkalosis The bodies response to the above disorders is called compensation Diagnosis: arterial blood sample → get pH, pCO2, [HCO3-] → Davenport diagram positions are based diagnosis Solid arrows: indicate the primary disorder Dashed arrows: indicate compensation that occurs Inc. carbonic anhydrase (CA), inc. pCO2, inc. and HCO3- filtered all increase HCO3- reabsorption Respiratory acidosis (hypercapnia): primary problem is excess H2CO3, buffered by Hgb-Im → bicarb - Biochemical (buffering) response is an increase in [HCO3-], it is the much faster of the two - Physiological (compensatory) response is kidney reabsorbs more HCO3-, secrete more NH4+ - Common causes include asthma, COPD, obesity, sedatives, and narcotics Respiratory alkalosis (hypocapnia): primary problem is low H2CO3 - Biochemical response is a decrease in H2CO3, which leads to less buffering by bicarbonate - Cells will also increase lactic acid production (LA + HCO3- ←→ CO2 + H2O) to generate CO2 - Physiological response involves less HCO3- reabsorption and less NH4+ secretion - Common causes include early phase asthma and anxiety Metabolic acidosis: primary problem is excess non-carbonic acid present - Sources of this acid include addition via metabolism, and loss of alkaline fluid (base) - Buffering occurs via NaHCO3, physiological response involves inc ventilation and acid excretion - Common causes include diarrhea and ketoacidosis (diabetic) Metabolic alkalosis: primary problem is loss of non-carbonic acid or addition of HCO3- - Buffering occurs in ECF, H+ pumps also move H+ out of the cell - Physiological response involves decreased RR along with less acid excretion from the kidneys - Common cause is vomiting (body losing Cl-, HCO3- is generated as result due to coupling) Region 1: primary metabolic acidosis compensatory hypocapnia