low PH, high CO2, high HCO3 = RESP. ACIDOSIS
high PH, low CO2, low HCO3 = RESP. ALKALOSIS
low PH, low CO2, low HCO3 = METABOLIC ACIDOSIS
high PH, high CO2, high HCO3= METABOLIC ALKALOSIS
Note: everything is low in Metabolic acidosis and everything is high in Metabolic Alkalosis. Of course, try to remember the normal values.
Hope it helps.