PHRM 825: Acid-Base Balance - Respiratory Disorders Flashcards
What is respiratory acidosis characterized by?
- Low pH (<7.35)
- Hypercapnia (>45 mmHg)
- Compensatory increase in HCO3- concentration
What is hypercapnia?
Excessive carbon dioxide in the bloodstream
What does respiratory acidosis almost always result from?
A failure of excretion versus overproduction
What can cause respiratory acidosis?
- Airway obstruction
- Reduced stimulus for respiration from the CNS
- Failure of heart or lungs
- Neuromuscular defects affecting nerves or skeletal muscles required for ventilation
- Mechanical ventilation
What can cause airway obstruction that leads to respiratory acidosis?
- Asthma
- Foreign body
- Aspiration
What can cause reduced stimulus for respiration from the CNS that leads to respiratory acidosis?
- Drug overdose
- Sleep apnea
- CNS infection
- Trauma
What can cause failure of heart or lungs that leads to respiratory acidosis?
- PE
- Cardiac arrest
What does PE stand for?
Pulmonary embolism
What can cause neuromuscular defects affecting nerves or skeletal muscles required for ventilation that leads to respiratory acidosis?
- ALS
- Guillain-Barre
What are symptoms of respiratory acidosis in the respiratory system?
- Dyspnea
- SOB
What are symptoms of respiratory acidosis in the CNS?
- HA
- Drowsiness
- Confusion
- Coma
- Seizures
What are symptoms of respiratory acidosis in the cardiovascular system?
- Tachycardia
- Arrhythmias
- Hypotension
What are treatment options for respiratory acidosis?
- Correct the underlying cause
- Mechanical ventilation or oxygen
- Avoid rapid correction to prevent alkalemia
- Bicarb (rare instances only)
When should you use bicarb to treat respiratory acidosis?
With acute acidosis if pH <7.15 where patient is at greater risk for arrhythmias
Why should you be cautious when giving COPD patients oxygen?
Their drive to breathe is hypoxemia and not hypercapnia (they breathe when there is a lack of oxygen and not when there is excess CO2)
