L21: Respiratory Failure Flashcards
What is respiratory failure
The inability of the lung to meet the metabolic demands of the body. Failure of tissue oxygenation or carbon dioxide homeostasis
Clinically how is respiratory failure defined
Pao2 less than 8kpa
Or
Pac02 greater than 6.5kpa
What are the 3 elements that cause respiratory failure
Alveolar hyperventilation (mechanical)
Circulation failure
Alveolar tissue problem
What can a mechanical failure be due to
Central problem
Peripheral problem
Lung structure problem
What are the types of respiratory failure
Type 1
Type 2
What is type 1 respiratory failure
Pa02 less than 8kpa with normal/low paco2 this leads to normal/high ph
What is the problem in type 1 respiratory failure
Oxygen exchange occurring at the alveolar and pulmonary circulation
Is there a problem with mechanical ventilation in type 1 respiratory failure
No
What does a type 1 respiratory failure lead to
V/Q mismatch and shunt
What is type 2 respiratory failure
Hypoxic and Paco2 greater than 6.5kpa
What are the underlying causes of respiratory failure
Sepsis Pneumonia Pulmonary embolus COPD exacerbation Cardiogenic pulmonary edema
What are the symptoms of sepsis
Fever
Chills
What are the symptoms of pneumonia
Cough
Sputum production
Chest pain
What are the symptoms of pulmonary embolus
Sudden onset of shortness of breath
Chest pain
What are the symptoms of COPD exacerbation
Heave smoking
Cough
Sputum
What does hypotension (low blood pressure) suggest
Sepsis
Pulmonary embolus
What does hypertension (high blood pressure) suggest
Poor effusion : cardiogenic pulmonary edema
What does wheezing suggest
Airway obstruction
How do we diagnose for respiratory failure
Arterial blood gas Blood Cardiac markers Microbiology Chest x-ray ECG Echocardiogram Pulmonary function test CTPA Ct scan
What causes a patient with respiratory failure to die
Hypoxia
What is the primary objective to reverse respiratory failure
Reverse and prevent hypoxia
After correcting the hypoxia in respiratory failure what is secondary objective to treat
Control paco2 and respiratory acidosis
If a patient has rising paco2 what is required
Support to blow out co2
How do we treat hypoxia
secure airway
Give supplemental oxygen
Treat underlying condition
Why is oxygen therapy used
Prevent tissue hypoxia and maintain normal oxygen
What is the most basic equipment to provide oxygen
Nasal cannula
What is nasal cannula
Tubes with two small prongs inserted into the nose
After nasal cannula what is used to supply oxygen
Simple face mask
What is the disadvantages of simple face masks
Rebreathing carbon dioxide
What is a non rebreather mask
A face mask attached to a bag
What does the bag in a non rebreather mask allow
Act as a reservoir for oxygen and allow more oxygen to be inspired at each breath
What are Venturi masks
Different sized adapters deliver different oxygen
When simple measures of proving oxygen failure what do we need to provide a patient
Mechanical ventilation
What does mechanical ventilation provide
The effort to breath
What are the 2 ways mechanical ventilation be carried out
Non invasive with a mask
Invasive with endobronchial tube attached to a machine
What is mechanical ventilation good to treat
Hypoxia
Hypercapnia
What is hypercapnia
High carbon dioxide
What does mechanical ventilation allow to rest
Respiratory muscles
When is mechanical ventilation used
Cardiac arrest Tachypnoae Acute respiratory acidosis Cardiogenic shock Brain injury
What pressure does mechanical ventilation provide
Positive pressure
Does invasive mechanical ventilation completely take over breathing
Yes
Why do we not want patients to reach negative pressure
The alveoli will collapse all the way down
Why is positive end expiratory pressure (PEEP) used in ventilation
Keeps the alveolus open and prevent them from collapsing
Improve gas exchange
Treat hypoxia
Treat pulmonary edema
