血气分析Arterial Blood Gas Analysis课件.pptVIP

* * * * * * * * * * * * * * * * * * * * * * Arterial Blood Gas Analysis Vanessa Klee MSIV What is an ABG? The Components pH / PaCO2 / PaO2 / HCO3 / O2sat / BE Desired Ranges pH - 7.35 - 7.45 PaCO2 - 35-45 mmHg PaO2 - 80-100 mmHg HCO3 - 21-27 O2sat - 95-100% Base Excess - +/-2 mEq/L Why Order an ABG? Aids in establishing a diagnosis Helps guide treatment plan Aids in ventilator management Improvement in acid/base management allows for optimal function of medications Acid/base status may alter electrolyte levels critical to patient status/care Logistics When to order an arterial line -- Need for continuous BP monitoring Need for multiple ABGs Where to place -- the options Radial Femoral Brachial Dorsalis Pedis Axillary Acid Base Balance The body produces acids daily 15,000 mmol CO2 50-100 mEq Nonvolatile acids The lungs and kidneys attempt to maintain balance Acid Base Balance Assessment of status via bicarbonate-carbon dioxide buffer system CO2 + H2O -- H2CO3 -- HCO3- + H+ ph = 6.10 + log ([HCO3] / [0.03 x PCO2]) The Terms ACIDS Acidemia Acidosis Respiratory ?CO2 Metabolic ?HCO3 BASES Alkalemia Alkalosis Respiratory ?CO2 Metabolic ?HCO3 Respiratory Acidosis ?ph, ?CO2, ?Ventilation Causes CNS depression Pleural disease COPD/ARDS Musculoskeletal disorders Compensation for metabolic alkalosis Respiratory Acidosis Acute vs Chronic Acute - little kidney involvement. Buffering via titration via Hb for example pH ?by 0.08 for 10mmHg ? in CO2 Chronic - Renal compensation via synthesis and retention of HCO3 (?Cl to balance charges ? hypochloremia) pH ?by 0.03 for 10mmHg ?in CO2 Respiratory Alkalosis ?pH, ?CO2, ?Ventilation ? CO2 ? ? HCO3 (?Cl to balance charges ? hyperchloremia) Causes Intracerebral hemorrhage Salicylate and Progesterone drug usage Anxiety ? ?lung compliance Cirrhosis of the liver Sepsis Respiratory Alkalosis Acute vs. Chronic Acute - ?HCO3 by 2 mEq/L for every 10mmHg ? in PCO2 Chronic - Ratio increases to 4 mEq/L of HCO