Consequences of Acidosis
- Cardiovascular: decrease contractility and cardiac output - hypotension and arrhythmia’s
- Metabolic: Insulin resistance, hyperkalemia - ketoacidosis
- CNS - coma and altered mental status
Consequences of alkalosis
- CNS- decreased blood flow to the heart leading to constrictions
- Metabolic: decreased Mg, Ca, and K
- CNS: Decreased cerebral blood flow, seizures
Causes of Non-anion gap metabolic acidosis
- GI bicarb loss: diarrhea, pancreatic fistula
- 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 - TPN messed up
Causes of anion gap metabolic acidosis
Methanol intoxication
Uremia
Lactic acidosis - most common cause
Ethylene glycol
Paraldehyde ingestion
Aspirin - causes metabolic acidosis and respiratory alkalosis
Ketoacidosis
Treatment for metabolic acidosis
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
Adverse reactions to bicarbonate therapy
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
Saline responsive metabolic alkalosis causes
- Diuretic therapy
- Vomiting and NG suction
- Exogenous HCO3 or blood transfusion
Treatment of Saline responsive metabolic alkalosis caused by diuretic therapy
Stop the diuretic
get this person some fluids
Treatment of Saline responsive metabolic alkalosis caused by vomiting and NG suction
Fluids
Treat the vomiting
Treatment of Saline responsive metabolic alkalosis for those who cannot tolerate excess fluids or sodium
Carbonic anhydrase inhibitors
Saline resistant metabolic alkalosis causes
- Increased mineralcorticoid activity
- Hypokalemia
- Renal tubular chloride wasting
Saline resistant metabolic alkalosis treatment
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
Respiratory acidosis causes
- obstruction of airway: asthma, COPD, choking
- CNS depression: overdose, paralysis, sleep apnea
- Neuromuscular disorders: ALS
- Heart and lung problems: PE, cardiac arrest
- mechanical ventilation
Treatment of respiratory acidosis
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
Respiratory alkalosis causes
- Central stimulation of breathing: anxiety, pain, injury, trauma
- Peripheral stimulation of breathing: hypotention, CHF, hypoxemia
- Mechanical ventilation
- Pulmonary: edema, PE
- aspirin - causes metabolic acidosis and respiratory alkalosis
Respiratory alkalosis treatment
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
