Respiratory System Flashcards
What is the definition of hypoxemia?
A PaO2 of less than 80 mmHg (decreased oxygen content in the blood)
Defined as: when metabolic demand EXCEEDS oxygen delivery
What constitutes severe hypoxemia?
A PaO2 of 60 mmHg or less (decreased oxygen content in the blood)
Defined as: when metabolic demand EXCEEDS oxygen delivery
The atmosphere is made up of what percentage of oxygen?
21%
The atmosphere is made up of what percentage of nitrogen?
78%
The volume of gas normally inspired with a given breath is known as what?
Tidal volume (Vt)
What is a patients appropriate tidal volume?
Between 10-20mL/kg (slightly less with a cat)
What does the following equation represent?
Ve = Vt x Vf
Minute volume (total ventilation) equals the patients tidal volume times their frequency (rate of breathing)
What diseases can be associated with dull or absent lung sounds?
Pleural space disease; severe lung consolidation of lung parenchyma, pleural effusion, pneumothorax
What are possible causes of increased breath sounds, wheezes or crackles?
Pulmonary parenchymal diseases: aspiration pneumonia, ALI, ARDS, fluid overload, congestive heart failure, and pulmonary thromboembolism.
Parenchyma is made up of alveoli, interstitial tissue and fibers and is involved in gas exchange.
Risks factors for the development of ALI or ARDS include:
SIRS, sepsis, infection, smoke inhalation, near drowning, severe trauma.
What percentage on an SpO2 constitutes hypoxemia?
An SpO2 of less than 95% or a partial pressure of oxygen (PaO2) of less than 80 mm Hg
Acute lung injury or ARDS can be identified using what formula?
PaO2 to FiO2 ratio (P/F ratio)
*controlled oxygen?
ALI may be suspected in patients with a PaO2 to FiO2 ratio of what?
< 300
ARDS may be suspected in patients with a PaO2 to FiO2 ratio of what?
< 200
How is a shock index calculated?
Heart rate divided by blood pressure
What shock index result can identify shock in both dogs and cats?
Shock index of > 1 in dogs and > 1.6 in cats.
What is the normal inspiration to expiration ratio?
1:2 meaning a patient exhales twice as long as it inhales in normal breathing