W1, Acid-Base Balance and ABGs

What is pH?

Measure of H+ ion concentration

What does increase in H+ concentration lead to?

Acidity

What does decrease in H+ concentration lead to?

Alkalinity

What is normal pH level in body?

7.35 to 7.45

What is normal PaCO2 level in body?

35 to 45

What is normal HCO3 level in body?

21 to 28

What are 3 mechanisms that regulate acid/base balance?

Buffer system, respiratory system, renal system

Why do acid/base imbalances occur?

They occur when compensatory mechanisms fail

What type of objective information do arterial blood gas (ABG) values give?

Acid/base status, underlying cause of imbalance, body’s ability to regulate pH, ABG analysis also shows PaO2 and O2 saturation

What are causes/risk factors of respiratory acidosis?

Respiratory depressant drugs, CNS trauma, respiratory muscle weakness, pulmonary disease like pneumonia or COPD, under ventilation while on ventilator

What is most common cause of respiratory acidosis?

Hypoventilation

How does body compensate in respiratory acidosis?

Kidneys retain increased amounts of HCO3 to increase pH

What are manifestations (11) of respiratory acidosis?

Hypoventilation, rapid and shallow respirations, increased BP and HR, dyspnea, headache, hyperkalemia, disorientation, increased CO2, muscle weakness, hypoxia, restlessness

What are diagnostics and assessments of respiratory acidosis?

ABGs, BMP (basic metabolic panel), EKG, drug screen, CBC (complete blood count)

What are nursing interventions (8) of respiratory acidosis?

Assess airway (monitor rate, depth, effort, SpO2, breath sounds), position patient to promote ventilation, administer bronchodilators and antibiotics if needed, perform postural drainage if necessary, supplemental O2 with caution, ventilator if needed, steroids, address cause

What are causes/risk factors of respiratory alkalosis?

Hyperventilation, pain, stress, anxiety, hypoxemia from acute pulmonary disorders

How does body compensate in respiratory alkalosis?

Kidneys will excrete increased amounts of HCO3 to decrease pH, but rarely occurs when is acute problem

What are manifestations (8) of respiratory alkalosis?

Seizures, deep and rapid respirations, hyperventilation, confusion, anxiety, hypokalemia, lightheadedness, tingling of extremities

What are diagnostics and assessments of respiratory alkalosis?

ABGs, BMP, EKG, CBC

What are nursing interventions (7) of respiratory alkalosis?

Treat underlying cause, assess respiratory status, administer pain meds as ordered, reduce anxiety, breathe into paper bag to conserve CO2 (only for a bit), consult respiratory therapist if needed, monitor ABGs, SpO2, and neurologic status

What are causes/risk factors of metabolic acidosis?

Diabetic ketoacidosis, lactic acidosis (aka septic shock), aspirin poison, alcoholism, renal failure, diarrhea, starvation, intestinal fistula

What is most common cause of metabolic acidosis?

Diabetic ketoacidosis

How does body compensate in metabolic acidosis?

Decreases CO2 in body to increase pH by increasing respirations, hyperkalemia may also occur as K+ shifts out of cells to put H+ (acid) in cells

What are manifestations (10) of metabolic acidosis?

Headache, CNS depression, confusion, fatigue, lethargy, hyperkalemia, EKG showing peaked T waves, dysrhythmias, hyperventilation, Kussmaul respirations

What are diagnostics and assessments of metabolic acidosis?

ABGs, BMP (showing increased K+), neuro assessment (LOC), EKG (related to hyperkalemia)

What are nursing interventions (7) for metabolic acidosis?

Assess ABCs, give HCO3, monitor K+, possible dialysis, monitor and give fluids/hydration, monitor safety related to neuro status (so implement fall precautions), identify and treat underlying cause

What are causes/risk factors of metabolic alkalosis?

Overdose on NaHCO3, blood products, or antacids, prolonged vomiting, NG drainage, hypokalemia (due to renal excretion or excessive diuretic use), fever

How does body compensate in metabolic alkalosis?

Lungs retain CO2 to decrease pH

What are manifestations (7) of metabolic alkalosis?

Decreased LOC, nausea and vomiting, decreased respirations, hypokalemia, EKG showing U wave, dysrhythmias, restlessness and lethargy

What are diagnostics and assessments of metabolic alkalosis?

ABGs, BMP (showing decreased K+), EKG (related to hypokalemia)

What are nursing interventions (5) for metabolic alkalosis?

Assess ABCs and neurologic status, correct dehydration, replace K+ if needed, give Diamox (carbonic anhydrase inhibitor to increase HCO3 excretion), identify underlying cause and treat it

Which type of IV fluids would be administered for respiratory acidosis, respiratory alkalosis, metabolic acidosis, or metabolic alkalosis?

Isotonic IV fluids (for most part)