<prompt> pH is 7.2; PCO2 12; PO2 55 most likely cause is -Metabolic acidosis and respiratory alkalosisMetabolic alkalosisRespiratory acidosisRespiratory alkalosis  <response>: In this patientpH Decreased Normal 7.4PCO2 Decreased.First stepDetermine whether it is acidosis or alkalosis.The decrease in pH suggests acidosis.Second stepObserved HCO3-PCO2 to determine the cause of acidosis or alkalosisOnly one value is mentioned and that too is not in sync with the pHPCO2 value of 12 indicates respiratory alkalosisBut the pH of the serum indicates acidosis, this suggests the presence of some other disorder besides the respiratory alkalosis which must be producing acidosisOption a appears to be appropriate because the coexisting metabolic acidosis will cause a decrease in pH. 