Patient presented to ED with complaint of vomiting and was found to be hypotensive. Patient sodium was 140meq/l, potassium was 3meq/l, chloride was 92meq/l and HCO3 was 29. On arterial blood gas the patient ph was 7.61 and pCO2 was 30. What is the underlying acid-base disturbance? 

 A) Mixed respiratory and metabolic alkalosis 
 B) Mixed respiratory alkalosis and metabolic acidosis 
 C) Respiratory alkalosis, metabolic acidosis and metabolic alkalosis 
 D) Respiratory acidosis and Respiratory alkalosis 


 Answer: C 

 Rationale: Patient PH is high suggestive of alkalosis. Patient HCO3 is high suggestive of metabolic alkalosis, the PCO2 should be high to compensate, but it is low, suggestive of concurrent respiratory alkalosis. Patient anion gap is 19 suggestive of metabolic acidosis. Hence the picture is consistent with metabolic acidosis, metabolic alkalosis and respiratory alkalosis. Patient cannot have respiratory acidosis and respiratory alkalosis together, as one cannot breath slowly and fast at the same time.