Arterial Blood Gas (1) Indications of ABG

BY

[01]. [02]. (CO2 retention, sugar) [03]. ventilatory (PaCO2), acid-base (pH & PaCO2), gas exchange (A-aDO2), and/or oxygenation (PaO2) status [04]. [05].

(2) Reference Range PH PO2 (110Age/2) PaCO2 Arterial O2SAT HCO3 BE SaO2 PH PO2 Venous PaCO2 O2SAT HCO3 pH 0.3 [H+] 7.35-7.45 80-100 mm Hg 40 4 mm Hg 95-100 mmol/L 24 4 mmol/L 0 2 mEq/L 97-98% 7.33-7.43 35-40 mmHg 404 mmHg 70-75 % 24-28 mmol/L Critical Value 7.60 12 Urine Anion Gap(UAG)= UNa+UK-UCl0 (RTA primary aldosteronism) (hyperchloremic) DURHAM a. Diarrhea b. Ureteral diversion c. Renal tubular acidosis

Renal failure: GFR5.5+ K+: Type 1 RTA [04]. a. DKA(hydration+insulin),(),() b. PH 45-55mmHg PH 40 mmHguncommon

pCO2 < 40 mmHg

Respiratory Acidosis

Metabolic Alkalosis w/ Compensation

Respiratory Alkalosis

Compensation can produce a 2 process

Compensate: met. alkalosis (hrs/days) Compensate: resp. alkalosis (now) Acute (1:10) [HCO3] ~10% of pCO2 pCO2 by 1-1.5 x [HCO3] (1:1) Chronic (4:10) [HCO3] ~10% of pCO2

Compensate: resp. acidosis (now) Compensate: met. acidosis (hrs/days) pCO2 by 1-1.5 x [HCO3] (1:1) Acute & Chronic (4:10) [HCO3] ~40% of pCO2

Hypoventilation (CO2 retention) - Acute lung disease - Chronic lung disease (COPD) - Opioids, narcotics, sedatives - Weakening of respiratory muscles

Check Anion GapAG can cause a 3 process

-

Vomiting Diuretic use/abuse Antacid use Hyperaldosteronism

- Hyperventilation - Aspirin ingestion (early)

Anion Gap MUDPILES see next page - Renal failure - Ketoacidosis (diabetes mellitus) - Lactic acidosis - Ethylene glycol (antifreeze) - Salicylates (aspirin) ingestion

Normal Anion Gap (must be Cl) - Diarrhea - Glue sniffing - Renal tubular acidosis (RTA) (*NO glucose like you see w/ DM) - Hyperchloremia - Diuretics - IV fluids (too much)

Anion Gap = Na+ (Cl + HCO3) Normal AG = 12 3 mEq/L

5~ 6 PCO2 50mmHg

(20) + + + + () COPD

COPD + ()

(21) ABG H-diagram

H-diagramRespiratory 80pH

Metabolic 48

60

36 pH=7.4Normal

PaCO2 40 mmHg30

24

HCO3mEq/L

18

20

12

[01]. pH lines acidosis [02]. pH lines alkalosis [03]. pH lines H crossbar primary crossbar disturbancePaCO2 (respiratory) or HCO3[04]. pH lines H crossbar mixed [05]. pH lines crossbar crossbar, partially compsensated disturbance [06]. PaCO2 (respiratory) or HCO3- (metabolic) crossbar disturbance [07]. pH lines crossbar, total compensated disturbance with a normal pH

(22)

[01]. SaO2:Arterial oxyhemoglobin saturation SaO2 [02]. SpO2:Oxyhemoglobin saturation by pulse oximetry SpO2 (pulse oximetry) 1980 CaO2 = PaO2 mmHg x 0.003 ml (dissolved O2)+ SaO2% x Hb gm/dL x 1.34 ml