Q: 60-year old patient presented with the compliant of shortness of breath. Patient has 60 pack-year history of smoking. Patient
sodium is 140meq/l,
potassium is 4meq/l,
chloride is 94meq/l, and
HCO3 is 36meq/l.
Patient abg revealed
pCO2 is 70 and
pH is 7.31.
What is the acid base disturbance.
A) Metabolic acidosis
B) Acute Respiratory acidosis
C) Chronic Respiratory acidosis
D) Mixed Metabolic and Respiratory acidosis
Rationale: Patient anion gap is 10 that rules out metabolic acidosis. For every 10 Torr change in CO2 change in ph is 0.3 for chronic and 0.8 for acute. Since the change in torr of CO2 in this case is 30, and ph is 7.31 that makes it chronic respiratory acidosis. If it would have been acute that the ph should have been 7.16 (0.08x3=0.24; 7.4-.24=7.16)