Acid-Base Disorders Part 1 (Andelin) Flashcards
72-year-old male with CC of SOB with PMH of COPD.
BP 155/92, RR 28, HR 115, O2 96% on 4 L.
ABG: pH 7.21 pCO2 77 HCO3 30
Respiratory acidosis likely due to COPD exacerbtion
24-year-old with CC of vomiting and confusion with PMH of DM1.
BP 90/55 RR 32 HR 130 O2 100% on RA
ABG: pH 7.18 pCO2 22 HCO3 8
Metabolic acidosis likely due to Diabetic Ketoacidosis
39-year-old male with CC of rapid breathing with PMH of anxiety.
BP 133/85 RR 30 HR 105 O2 100% on RA
ABG: pH 7.55 pCO2 25 HCO3 21
Respiratory alkalosis likely due to a panic attack
81-year-old female with CC of trouble breathing with PMH of CHF. Received furosemide for 3 days.
BP 118/76 RR 14 HR 85 O2 96% on 2L
ABG: pH 7.50 pCO2 48 HCO3 36
Metabolic alkalosis likely due to a loop diuretic
When is it indicated to order an Arterial Blood Gas (ABG)?
Concerned about any acid-base disturbances:
respiratory distress or tachypnea
abnormal serum bicarb
confusion
salicylate overdose/DKA
What is the body’s normal arterial pH?
Arterial pH is maintained between 7.35-7.45
Where is carbonic anhydrase located inside the body?
present in the lung alveoli and renal tubular epithelial cells
What happened to the pH when bicarb is increased?
When bicarb is increased, so is the pH
can lead to alkalosis (think hyperventilation or kidneys compensation)
What happens to pH when PCO2 is increased?
When PCO2 is increased, the pH is decreased.
can lead to acidosis (think hypoventilation - not breathing off the CO2 appropriately or DKA)
How do the lung regulate pH?
by controlling PCO2 concentration
increased RR, increased CO2 blown off, decrease PCO2 in the blood (relieves acidosis, but can lead to alkalosis)
decreased RR, decreased CO2 blown off, increase PCO2 in the blood (relieves alkalosis, but can lead to acidosis)
How do the kidneys regulate pH?
by excreting either acidic or alkaline urine
increased HCO3 excreted, decrease HCO3 in blood, the pH will decrease
increased H+ excreted, decrease H+ in blood, the pH will increase
Normal range for HCO3
24 mEq/L (22-26)
Normal range for PCO2
40 mmHg (35-45)
Low pH and Low HCO3
Metabolic Acidosis (the low HCO3 is causing the low pH) check anion gap; order BMP (Na/Cl/HCO3)
High pH, High HCO3
Metabolic Alkalosis
Low pH, High PCO2
Respiratory Acidosis (the high CO2 is causing the low pH)
High pH, Low PCO2
Respiratory Alkalosis