This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
Anewlypostedjuniordoctorhaddifficultyinfindingoutbasedeficit/excessforbloodinagivenpatient.Anexperienced senior resident advised a quick method to determine acid-base composition of blood-based on pCO2. Which of the following is the likely method he suggested to predict acid base composition of blood 
Select and explain. 
A. Red ford nomogram, B. DuBio's nomogram, C. Goldman constant field equation, D. Siggard-Andersen nomogram
D: Siggard-Andersen nomogram
Answer: D: Siggard-Andersen nomogram 
Explanation: Siggard-Anderson nomogram: plots the acid-base charecteristics of aerial blood PCO2 is placed on the veical axis and pH on the horizontal axisVeical line through pH 7.40: any point to the left denotes acidosis & any point to right denotes alkalosisHorizontal line through p CO2 of 40 mmHg: point above or below this line defines the effective degree of hypo or hyperventilationRef: Ganong 19/e p703 fig 39.8