Differential Respiratory (PaCO2 > 40) Metabolic PaCO2 <40 Acidosis Hypoventilation Acute Lung Disease Chronic Lung Disease Diarrhea (Normal anion gap) Glue sniffing (Normal anion gap) RTN (Normal anion gap) Hyperchloremia (Normal anion gap) Renal Failure (Inc. anion gap) Lactic acidosis (Inc. anion gap) Ketoacidosis (Inc. anion gap) Aspirin ingestion (Inc. anion gap) Alkalosis Hyperventilation Early Aspirin ingestion Vomiting Diuretic Use Hyperaldosteronism Antacid use Calculation Respiratory acidosis acute appropriate decrease of 0.08 pH for each increase of 10mmHG in PCO2 pH PCO2 PHCOs PO2 7.08 80 PHCOs 45 Respiratory quotient Ratio of CO2 produced per O2 consumed used to estimate basal metabolic rate (BMR) and determine the primary type of metabolism taking place in a patient RQ values associated with different types of metabolism: Carboydrate-predominant diet - RQ = 1.0 Protein-predominant diet - RQ = 0.8-.0.9 Fat-predominant diet - RQ = 0.7 Patient's with COPD who retain CO2 may benefit from higher-fat diet to reduce the amount of CO2 produced and thereby decrease the work of breathing required to breathe off that excess CO2