Physiology of Respiratory Failure Flashcards
What are the reasons we would intubate?
To bypass an obstruction, to protect the airway, to assist in removal of secretions, and to provide mechanical ventilation,
How do we categorize failure?
Ventilatory failure and Respiratory failure?
What is the difference between ventilatory failure and respiratory failure?
Ventilatory failure is the failure to move air while respiratory failure is the failure to exchange gas
What are some reasons for apnea?
Sedation or analgesic use, coma, loss of cerebral perfusion, central injury
Why should we intervene early in ventilatory failure?
The recovery is quicker and patient outcome is better if ventilation is initiated early
What is the major difference in blood chemistry between ventilatory failure and respiratory failure?
Ventilatory failure is too much CO2 in the blood and Respiratory failure is too little O2
What is the major problem associated with ventilatory failure?
The patient is unable to appropriately clear CO2 (why it is called hypercarbic ventilatory failure)
What are some causes of ventilatory failure?
Muscle function is inadequate for the imposed load, there is excessive ventilatory load, or there is inadequate or absent drive to breath
How is phosphate related to ventilatory failure?
Low phosphate levels are linked to diaphragmatic insufficiency
What are some reasons for increased CO2 production?
Infection, fever, shock, trauma; metabolic conditions such as lactic acidosis, renal failure, diabetic ketoacidosis, pharmacological
Why does infection increase CO2 production?
White blood cells are huge consumers of oxygen
What are the five main reasons for respiratory failure?
- Right to left shunt
- V/Q mismatch
- Inadequate FiO2
- Alveolar hypoventilation
- Diffusion defects
What are some reasons for shunting?
Atelectasis, consolidation, and airway obstruction. Anything that causes blood to move through the pulmonary system without being adequately exposed to oxygen.
What is a normal amount of anatomic deadspace?
About 2.2 ml/kg
Why is lack of FRC an issue?
There is not enough surface area between the alveolus and capillary for oxygen to diffuse across
