Acid Base

Question 1

Consequences of Acidosis

Answer 1

1. Cardiovascular: decrease contractility and cardiac output - hypotension and arrhythmia’s
2. Metabolic: Insulin resistance, hyperkalemia - ketoacidosis
3. CNS - coma and altered mental status

Question 2

Consequences of alkalosis

Answer 2

1. CNS- decreased blood flow to the heart leading to constrictions
2. Metabolic: decreased Mg, Ca, and K
3. CNS: Decreased cerebral blood flow, seizures

Question 3

Causes of Non-anion gap metabolic acidosis

Answer 3

1. GI bicarb loss: diarrhea, pancreatic fistula
2. renal bicarb loss
   - Type II: proximal - Reabsorption of bicarb is decreased in the proximal tubule
   - Type I RTA: distal tubule - caused by sickle cell, myeloma - leads to hypokalemia
   - Type IV RTA - Hypoaldosteronism and hyperkalemia seen here
3. TPN messed up

Question 4

Causes of anion gap metabolic acidosis

Answer 4

Methanol intoxication
Uremia
Lactic acidosis - most common cause
Ethylene glycol
Paraldehyde ingestion
Aspirin - causes metabolic acidosis and respiratory alkalosis
Ketoacidosis

Question 5

Treatment for metabolic acidosis

Answer 5

Treat the underlying cause

If patient has a pH <7.10, or cardiac arrest use bicarb therapy
(0.5L/KgIBW) x (12 - Bicarb level) = dose
starting dose is 1/3 or 1/2 of what you calculated

if cardiac arrest start with 1mEq/kg

Question 6

Adverse reactions to bicarbonate therapy

Answer 6

Overalkanization - reduces cerebral blood flow and can cause shift to the left on oxygen-hemoglobin saturation curve (Hemoglobin is hanging onto oxygen and not going to body)

Hypernatremia

CSF acidosis

Electrolyte shift - decrease in potassium and calcium

Question 7

Saline responsive metabolic alkalosis causes

Answer 7

1. Diuretic therapy
2. Vomiting and NG suction
3. Exogenous HCO3 or blood transfusion

Question 8

Treatment of Saline responsive metabolic alkalosis caused by diuretic therapy

Answer 8

Stop the diuretic
get this person some fluids

Question 9

Treatment of Saline responsive metabolic alkalosis caused by vomiting and NG suction

Answer 9

Fluids
Treat the vomiting

Question 10

Treatment of Saline responsive metabolic alkalosis for those who cannot tolerate excess fluids or sodium

Answer 10

Carbonic anhydrase inhibitors

Question 11

Saline resistant metabolic alkalosis causes

Answer 11

1. Increased mineralcorticoid activity
2. Hypokalemia
3. Renal tubular chloride wasting

Question 12

Saline resistant metabolic alkalosis treatment

Answer 12

if patients alkalosis is caused by mineralcorticoid decrease the dose - best to go with Methylprednisolone or Dexamethasone

always correct hypokalemia with potassium sparing diuretic - spironolactone

correct hyperaldosteronism

if potassium is K<3 supplement with oral or IV potassium

Question 13

Respiratory acidosis causes

Answer 13

1. obstruction of airway: asthma, COPD, choking
2. CNS depression: overdose, paralysis, sleep apnea
3. Neuromuscular disorders: ALS
4. Heart and lung problems: PE, cardiac arrest
5. mechanical ventilation

Question 14

Treatment of respiratory acidosis

Answer 14

Correct the underlying symptom

• can give patient oxygen or mechanical ventilation to breath for them in states where they cannot or they has a disorder that causes them to forget
• slowly titrate up a COPD patients oxygen if we go too fast we can kill them

Question 15

Respiratory alkalosis causes

Answer 15

1. Central stimulation of breathing: anxiety, pain, injury, trauma
2. Peripheral stimulation of breathing: hypotention, CHF, hypoxemia
3. Mechanical ventilation
4. Pulmonary: edema, PE
5. aspirin - causes metabolic acidosis and respiratory alkalosis

Question 16

Respiratory alkalosis treatment

Answer 16

treat the underlying cause

if patient needs ventilation give ventilation

if patient is anxious and hyperventilating can give sedation to call that down. Can also do paralysis but need a mechanical ventilator to do the breathing for the patient