nurs320 - acid base imbalance

normal values for pH

7.35 - 7.45

lower - acidosis

higher - alkalosis

normal values for paCO2

35-45 mm Hg

normal values for paO2

80 - 95 mm Hg

normal values for HCO3-

22 - 26 meq/L

metabolic acidosis

• low bicarbonate, high acid

• mostly from diarrhea

• decrease in pH

• HCO3- deficit or H+ excess

metabolic acidosis causes

• CRF - chronic renal failure

• DKA - diabetic ketoacidosis

• diarrhea

metabolic acidosis manifestations

• headache, altered LOC (confusion, increase drowsiness)

• increase in RR - earliest symptom

• weakness, muscle twitching

• vasodilation - warm flushed skin

• Kussmaul Respirations - hyperventilation

metabolic acidosis interventions

• correct underlying problem

• IV bicarb

• observe for hyperkalemia

metabolic alkalosis

• low acid, high bicarbonate

• mostly from vomiting

• high pH

• HCO3- excess or loss of H+

metabolic alkalosis causes

• vomiting

• gastric suction (NG tube draining stomach secretions)

• antacids

• excessive use of bicarbonate

metabolic alkalosis manifestations

• dizziness, confusion

• irritability

• tingling of digits

• decrease in RR

• tachycardia from low K+

• increase in anxiety, seizures

metabolic alkalosis intervention

• reverse underlying disorder

• IV solutions + electrolyte replacements

• observe for hypokalemia

• acetazolamide - med promotes renal excretion of bicarb (contains diuretic)

respiratory acidosis

H2CO3 - excess (carbonic acid)

respiratory acidosis causes

• cardiac/respiratory arrest

• COPD

• over-sedation (too much narcotics/sleeping pill) = decrease in RR

respiratory acidosis manifestatsion

• mental changes → hypoxia

• headache

• restlessness, muscle weakness, hyperreflexia

• dizziness

• coma

• decrease in BP

• hyperkalemia

respiratory acidosis interventions

• improve ventilation - CO2 needs to come out!

  • bronchodilators

  • mechanical ventilation

  • hydration

• administer bicarbonate = questionable, since this is NOT a bicarb issue

respiratory alkalosis

H2CO3 - deficit (carbonic acid)

respiratory alkalosis causes

• hyperventilation

• aftermath of severe exercise

• anxiety - panic attack

• nervousness

• fever

• pain thyrotoxicosis

• pulmonary disease

• high altitudes

respiratory alkalosis manifestations

• “hyperventilation syndrome”

• palpitations

• lightheadedness

• sweating

• dry mouth

• nausea/vomit

• epigastric pain

respiratory alkalosis interventions

• eliminate cause

• control breathing, slow deep breathing

• providing emotional support - anxiety!!

• breath into closed system - breathing into bag

compensation

the response to an imbalance in an attempt to normalize the pH

• if respiratory problem, kidneys work to compensate

• if renal problem, lungs work to compensate

uncompensated

• pH is abnormal

• either PaCO2 OR HCO3 is abnormal

some levels could be normal!

partially compensated

• pH is abnormal

• BOTH PaCO2 and HCO3 are abnormal

all abnormal!

completely compensated

• pH is normal

• both PaCO2 and HCO3 are abnormal