Pulmonary Flashcards
What is a normal minute ventilation and how is it calculated? What does it mean if you increase your minute ventilation?
Normal 5-8L/minute
Tidal volume x RR
Increase work of breathing
What is the clinical indicator of ventilation? How do you know your patient is ventilating normally?
The PaCO2
What is the primary muscle of ventilation? What conditions affect this muscle?
Diaphragm
Deconditioning, hypoxemia, acidosis, hypophosphatemia
What is alveolar dead space? What condition increases it?
Alveolar dead space is pathologic and is the area of non-perfused alveoli
PE increases alveolar dead space- no blood flow past the alveoli in the area of the pulmonary circulation
What is pulmonary perfusion? What conditions affect perfusion?
It’s a movement of blood through the pulmonary capillaries.
PE, low cardiac output- any decrease in blood flow past the alveoli will affect the ventilation/perfusion ratio and gas exchange.
What is a normal Ventilation/ Perfusion (VQ) ratio?
4L ventilation/min/ 5L perfusion/min
Ideal lung unit =0.8
A patient is experiencing a large right lung PNA. What side should the patient lay on to prevent hypoxia?
“You want the GOOD lung down”
Turn pt to left side
What is V/Q mismatch? What causes it and how do you treat a V/Q mistmatch?
Is when there is excessive blood flow in relation to ventilation OR ventilation with decreased perfusion
Causes: ARDS( shunting), PNA,mucus plugging
Treatment: give O2 and identify and treat the underlying cause
With shunting even providing 100%FiO2 will not correct the hypoxemia
What are the effects of PEEP?
- prevents expiratory pressure from returning to zero by keeping the expiratory pressure positive
- decreases surface tension of thr alveoli (preventing atelectasis)
- increases alveolar recruitment
- increases driving pressure- extending the time of gas transfer, allows for a decrease in FiO2
What is the PaO2? What is the normal?
Arterial oxygen. Normal 80 - 100mmHg on RA.
Less than 80 = hypoxemia
What is the SaO2, normal and relevance?
Saturation of arterial oxygen
95- 99% on RA
Direct relationship with PaO2: amount of hemoglobin combined with O2
What is an SvO2, normal, relevance?
Mixed venous o2 saturation
60-75%
Most sensitive indicator of oxygenation at the cellular level
What is CaO2, normal and relevance?
Oxygen content
15-20ml/100 ml blood
Severe anemia may result in hypoxia
What is DO2, normal, relevance?
Oxygen delivery
900 to 1,100 ml/min
Pump problem ❤ will decrease the DO2
What is the alveolar arterial gradient (A-a)?
<10mmHg
Calculates the difference between the alveolar oxygen and the arterial oxygen. Indicates whether the gas transfer is normal and if not how bad the VQ mismatch or shunt is
According the oxyhemoglobin dissociation curve, what clinical conditions shift the curve to the left?
“Left is aLkaLosis, coLd, Low Bad for patients; SaO2 is high but the O2 is stuck to the Hgb”
Alkalosis
Low PaCO2
Hypothermia
Low 2,3 DPG