Respiratory FailurePaO2<60mmHg respiratory failureNotice: sea level, quiet, inspire air rule off other causes ( heart disease)
Classification of Respiratory FailurePaCO2: The carbon dioxide partial pressure of arterial bloodNormal: 35-45mmHg (4.7-6.0kPa) mean: 40mmHg
Classification of Respiratory Failure Type Ⅰ TypeⅡPaO2 (mmHg) <60 <60PaCO2 (mmHg) ≤50 >50
Other ParametersSaO2: Saturation of arterial blood oxygenNormal: 0.95-0.98Significance: a parameter to evaluate hypoxia, but not sensitiveODC ( Dissociation curve of oxygenated hemoglobin): “S” shape
PH 2,3DPG temperature CO2 ODC to right deviation Oxygenated hemoglobin release oxygen to tissue, prevent hypoxia of the tissue. But absorbed oxygen of hemoglobin is decreased from the alveoli.Bohr effect: movement of ODC place is induced by PH.
PA-aO2: Difference of alveoli-arterial blood oxygenic partial pressure.Normal: 15-20mmHg (<30mmHg in the old)Significance: a sensitive parameter in gas exchange
PvO2: Oxygenic partial pressure of mixed venous blood.Normal: 35-45mmHg mean: 40mmHgSignificance: Pa-vO2 is to reflect the tissue absorbing oxygen.
CaO2: The content of the oxygen of the arterial blood.Normal: 19-21mmol/LSignificance: a comprehensive parameter to evaluate arterial oxygen.
Parameters in acid-basic disorder evaluation PH: negative logarithm of Hydrogen ion concentration. Normal: 7.35-7.45 mean: 7.4 〔 HCO3- 〕 PH=Pka+log 0.03PaCO2 20 ＝ 1 6.1+log
HCO3- (bicarbonate): SB (standard bicarbonate) AB (actual bicarbonate)SB: the contents of HCO3- of serum of arterial blood in 38℃ , PaCO2 40mmHg, SaO2 100%. Normal: 22-27mmol/L mean: 24mmol/LAB: The contents of HCO3- in actual condition. In normal person: AB=SB
AB and SB are parameters to reflect metabolism, regulated by kidney. Difference of AB-SB can reflect the respiratory affection on serum HCO3- . Respiratory acidosis: AB>SB Respiratory alkalosis: AB<SB Metabolic acidosis: AB ＝ SB<Normal Metabolic alkalosis: AB=SB>Normal
Buffer bases （ BB) ： is the total of buffer negative ion of blood.BB: HCO3- hemoglobin plasma proteins HPO42- (phosphate)Normal: 45-55mmol/L mean: 50mmol/LSignificance: Metabolic acidosis: BB Metabolic alkalosis: BB
Bases excess （ BE): the acid or bases used to regulate blood PH 7.4 . ( in 38℃ ， PaCO2 40mmHg, SaO2 100%)Normal: 0±2.3 mmol/LSignificance: add acid: BE(+), BB add base: BE(-), BB
Total plasma CO2 (T-CO2) ： total content of the CO2 .Normal: HCO3- >95%
Anion gap (AG): the difference of undetermined anion and undetermined cation in serum.AG=Na+ － (Cl-+ HCO3- )Normal: 8-16mmol/LSignificance: AG acidosis: ketoacidosis, kidney failure AG normal acidosis: Cl , diarrhea, fixed acid decrease to evaluate mix acid-basic disorder
Regulation of Acid-basic Balance Chemical buffer Dielectric changes of incells and excells H+---K+, HCO3- ---Cl- Physiology regulation of the lung and kidney
Classification of Acid-basic Disorder Complementary: PH is normal Dis-complementary: PH is abnormal. PH,PaCO2, HCO3- are three important parameters in acid-basic disorder evaluation.
Classification of Acid-basic Disorder Mixed acid-basic disorder Complementary formula example: original disorder: chronic respiratory acidosis ⊿ HCO3- =⊿ PaCO2 ×0.35±5.58 complementary limit: 45mmol/L
Classification of Acid-basic Disorder Respiratory acidosis with metabolic acidosis Respiratory acidosis with metabolic alkalosis Respiratory alkalosis with metabolic acidosis Respiratory alkalosis with metabolic alkalosis