<prompt> In a normal healthy person the arterial oxygen is considered satisfactory if SPO2 is more than808590Any of the above  <response>: Ans. c 90 Ref H-17thl590-91; pg. A-15In a normal healthy person the arterial oxygen is considered satisfactory if SP02 is more than 90.Arterial O2 tensionPaO212.7 - 0.7 kPa 95 - 5 mm HgArterial CO2 tensionPaCO25.3 - 0.3 kPa 40 - 2 mm HgArterial O2 saturationSaO20.97 - 0.02 97 - 2Arterial blood pHpH7.40 - 0.02Arterial bicarbonateHCO3-24 2 mEqLBase excessBE0 - 2 mEqLDiffusing capacity for carbon monoxide single breathDLCO0.42 mL COsmm Hg 25 mL COminmm HgDead space volumeVD2 mLkg body wtPhysio dead space; dead space-tidal vol ratioVDVTKnow at rest exercisea Rest 35 VTb Exercise 20 VTAlveolar-arterial difference for O2PA -a O2 2.7 kPa 20 mm HgEducational Point Alveolar hypoventilation exists by definition when arterial PC02 PaC02 increases above the normal range of 37-43 mm Hg, but in clinically important hypoventilation syndromes PaC02 is generally in the range of 50-80 mm Hg. A decrease in the Anion Gap can be due to:- an increase in unmeasured cations;- the addition to the blood of abnormal cations, such as lithium lithium intoxication or cationic immunoglobulins plasma cell dyscrasias;- a reduction in the major plasma anion albumin concentration nephrotic syndrome; A fall in serum albumin by 1 gdL from the normal value decreases the anion gap by 2.5 mEqL.- a decrease in the effective anionic charge on albumin by acidosis; or- hyperviscosity and severe hyperlipidemia. 