2. Acidemia: blood pH < 7.35 Acidosis: a primary physiologic process that, occurring alone, tends to cause acidemia. Examples: metabolic acidosis from decreased perfusion (lactic acidosis); respiratory acidosis from hypoventilation. If the patient also has an alkalosis at the same time, the resulting blood pH may be low, normal, or high. Alkalemia: blood pH > 7.45 Alkalosis: a primary physiologic process that, occurring alone, tends to cause alkalemia. Examples: metabolic alkalosis from excessive diuretic therapy; respiratory alkalosis from acute hyperventilation. If the patient also has an acidosis at the same time, the resulting blood pH may be high, normal, or low.

3.  Aids in establishing a diagnosis  Helps guide treatment plan  Aids in ventilator management  Improvement in acid/base management allows for optimal function of medications  Acid/base status may alter electrolyte levels critical to patient status/care

4.  Start with the pH  Note the PCO 2  Determine compensation

5.  pH 45 (Normal: 35 – 45)  a. depression of the Respiratory Center (sedatives, narcotics, drug overdose, CVA, cardiac arrest, MI)  b. Respiratory muscle paralysis (spinal cord injury, Guillian-Barre, paralytics)  c. Chest wall disorders (flail chest, pneumothorax)  d. Disorders of the lung parenchyma (CHF, COPD, pneumonia, aspiration, ARDS)  e. Alteration in the function of the abdominal system (distension)

6.  Respiratory Alkalosis: pH > 7.45 (Normal: 7.35 - 7.45) CO2 < 35 (Normal: 35 – 45)  a. Psychogenic (fear, pain, anxiety)  b. CNS stimulation (brain injury, ETOH, early salicylate poisoning, brain tumor)  c. Hypermetabolic states (fever, thyrotoxicosis)  d. Hypoxia (high altitude, pneumonia, heart failure, pulmonary embolism)  e. Mechanical overventilation (ventilator rate too fast)

7.  Metabolic Acidosis pH < 7.35 (Normal: 7.35 - 7.45) HCO3- < 22 (normal: 22 – 26)  a. Overproduction of organic acids (starvation, ketoacidosis, increased catabolism)  b. Impaired renal excretion of acid (renal failure)  c. Abnormal loss of HCO3- (diarrhea, biliary fistula, Diamox)  d. Ingestion of acid (salicylate overdose, oral anti-freeze)

8.  Metabolic Gap Acidosis  M - Methanol  U - Uremia  D - DKA  P - Paraldehyde  I - INH  L - Lactic Acidosis  E - Ehylene Glycol  S - Salicylate  Non Gap Metabolic Acidosis  Hyperalimentation  Acetazolamide  RTA (Calculate urine anion gap)  Diarrhea  Pancreatic Fistula

9.   pH,  HCO 3   PCO 2 by 0.7 for every 1mEq/L  in HCO 3  Causes  Vomiting  Diuretics  Chronic diarrhea  Hypokalemia  Renal Failure

10.  Metabolic acidosis: pCO 2 = 1.5 x HCO 3 + (8 + 2)  Metabolic alkalosis: pCO2= 40 +[( HCO3 – 24) x 0.6] +2  Respiratory Acidosis: HCO3 = (CO 2 - 40) (0.3) +24  Respiratory alkalosis: HCO3 = 24- [(40-pCO2)](0.4)

11.  METABOLIC ACIDOSIS  pCO 2 = 1.5 x HCO 3 + (8 + 2)  Uncompensated metabolic acidosis, adequate oxygenation

12.  RESPIRATORY ALKALOSIS  HCO3 = 24- [(40-pCO2)](0.4)  Compensated respiratory alkalosis with adequate oxygenation

13.  NORMAL

14.  VENOUS BLOOD GAS

15.  METABOLIC ACIDOSIS  pCO 2 = 1.5 x HCO 3 + (8 + 2)  Compensated Metabolic Acidosis with adequate oxygenation

16.  METABOLIC ACIDOSIS  pCO 2 = 1.5 x HCO 3 + (8 + 2)  Compensated Metabolic Acidosis with inadequate oxygenation  Anion gap?  Na 139 Cl 105

17.  METABOLIC ALKALOSIS pCO2= 40 +[( HCO3 – 24) x 0.6] +2  Partially Compensated Metabolic Alkalosis with Respiratory Acidosis with adequate oxygenation

18.  METABOLIC ACIDOSIS  pCO 2 = 1.5 x HCO 3 + (8 + 2)  Combined Metabolic Acidosis and Respiratory Acidosis with inadequate oxygenation

19.  RESPIRATORY ALKALOSIS  HCO3 = 24- [(40-pCO2)](0.4)  Compensated Respiratory Alkalosis with inadequate oxygenation

20.  RESPIRATORY ACIDOSIS HCO3 = (CO 2 - 40) (0.3) +24  Partially Compensated Respiratory Acidosis with hypoxemia