Protective Lung ventilation and Driving Pressures Flashcards
What is the goal of lung protective strategies in mechanical ventilation?
To minimize ventilator-induced lung injury (VILI) and protect the lungs from barotrauma, volutrauma, atelectrauma, and biotrauma.
What tidal volume is recommended in lung protective strategies?
Tidal volume of 6 ml/kg of predicted body weight (PBW).
Why is tidal volume calculated using predicted body weight (PBW)?
PBW reflects lung size and capacity more accurately than actual body weight.
What is the recommended plateau pressure (Pplat) to prevent barotrauma?
Plateau pressure (Pplat) ≤ 30 cmH₂O.
What does plateau pressure (Pplat) represent in mechanical ventilation?
Plateau pressure reflects the pressure needed to inflate the lungs at the end of inspiration.
What is the purpose of applying PEEP in lung protective strategies?
PEEP prevents alveolar collapse at the end of expiration and reduces atelectrauma.
What is atelectrauma in the context of mechanical ventilation?
Atelectrauma occurs when alveoli repeatedly collapse and reopen, causing mechanical injury.
What is permissive hypercapnia, and why is it used in lung protective ventilation?
Permissive hypercapnia allows slightly elevated PaCO₂ to reduce tidal volume and lung stress.
What are the recommended SpO₂ targets to avoid oxygen toxicity in lung protective ventilation?
SpO₂ targets of 88-95% to avoid oxygen toxicity and maintain adequate oxygenation.
What is the principle of open lung ventilation?
Open lung ventilation focuses on recruiting collapsed alveoli and keeping them open throughout the respiratory cycle.
How is optimal PEEP determined in open lung ventilation?
Optimal PEEP is determined through incremental PEEP titration or oxygenation and compliance monitoring.
What is a recruitment maneuver in mechanical ventilation?
A recruitment maneuver involves applying high pressures to reopen collapsed alveoli.
What pressures are typically applied during a recruitment maneuver?
Typically, pressures of 35-40 cmH₂O are applied during a recruitment maneuver.
Why is it important to avoid disconnections from the ventilator in open lung ventilation?
Disconnections can cause lung de-recruitment and alveolar collapse, which must be avoided.
How does open lung ventilation combine PEEP and tidal volume to protect the lungs?
Open lung ventilation combines low tidal volumes (6 ml/kg) with adequate PEEP to maintain alveolar recruitment.
What is the formula for calculating driving pressure?
Driving Pressure = Plateau Pressure (Pplat) - PEEP.
What does driving pressure represent in mechanical ventilation?
Driving pressure reflects the pressure needed to expand the alveoli during tidal volume delivery.
What is the recommended driving pressure to improve outcomes in ARDS patients?
Driving pressure ≤ 15 cmH₂O is associated with better outcomes in ARDS patients.
What does a high driving pressure indicate in mechanical ventilation?
High driving pressure indicates over-distension or poor compliance of the lungs.
How can driving pressure be reduced during mechanical ventilation?
Driving pressure can be reduced by titrating PEEP, reducing tidal volume, and improving alveolar recruitment.
What are the key components of lung protective ventilation?
Low tidal volume, limiting plateau pressure, adequate PEEP, and permissive hypercapnia.
Why is it important to monitor plateau pressure and driving pressure in ARDS patients?
Monitoring ensures lung stress is minimized and ventilator-induced lung injury is prevented.
How does titrating PEEP help optimize open lung ventilation?
Titrating PEEP optimizes alveolar recruitment, improves oxygenation, and reduces atelectrauma.
What is the role of compliance in assessing ventilatory stress on the lungs?
Compliance measures how easily the lungs expand; reduced compliance indicates higher lung stress.
What are the main goals of mechanical ventilation in ARDS management?
The main goals are to optimize oxygenation, reduce lung stress, and minimize ventilator-induced lung injury.
What is driving pressure in mechanical ventilation, and how is it calculated?
Driving pressure is the pressure required to inflate the lungs during a tidal breath. It is calculated as: Driving Pressure = Plateau Pressure (Pplat) - PEEP.
What does an elevated driving pressure indicate?
An elevated driving pressure indicates increased lung stress and poor compliance, which can lead to ventilator-induced lung injury (VILI).
How does driving pressure behave in patients with obstructive lung disease?
In obstructive lung disease, driving pressure can be moderately elevated due to increased airway resistance and air trapping.
What are examples of obstructive lung diseases where driving pressure is affected?
Examples include COPD, asthma, and bronchiectasis.
Why is driving pressure often higher in obstructive lung disease?
Driving pressure is higher because air trapping and airflow obstruction increase lung volumes and resistance, requiring more pressure to deliver tidal volumes.
How does driving pressure behave in patients with restrictive lung disease?
In restrictive lung disease, driving pressure is often markedly elevated due to poor lung compliance.
What are examples of restrictive lung diseases where driving pressure is affected?
Examples include ARDS, pulmonary fibrosis, obesity hypoventilation, and pleural effusions.
Why is driving pressure often elevated in restrictive lung disease?
Driving pressure is elevated because the lungs are stiff and non-compliant, requiring more pressure to deliver the same tidal volume.
What role does lung compliance play in determining driving pressure?
Lung compliance measures how easily the lungs expand. Poor compliance increases the driving pressure for a given tidal volume.
How can reducing tidal volume help in minimizing driving pressure?
Reducing tidal volume lowers the amount of pressure required to expand the lungs, minimizing driving pressure and lung stress.
What is the relationship between driving pressure and patient outcomes in ARDS?
Lower driving pressures (≤ 15 cmH₂O) are associated with better survival in ARDS patients, as they reduce the risk of over-distension and ventilator-induced lung injury.
What is considered a normal driving pressure in mechanical ventilation?
Normal driving pressure is ≤ 15 cmH₂O.
What does a driving pressure greater than 15 cmH₂O indicate?
A driving pressure > 15 cmH₂O indicates increased lung stress and poor compliance, associated with worse outcomes.
What happens to driving pressure in a recruitable lung?
In a recruitable lung, driving pressure can decrease with optimal PEEP, as alveolar recruitment improves compliance.
What happens to driving pressure in a non-recruitable lung?
In a non-recruitable lung, driving pressure remains elevated despite increasing PEEP, as compliance does not improve.
How does PEEP adjustment affect driving pressure in recruitable lungs?
In recruitable lungs, increasing PEEP can recruit collapsed alveoli, improving compliance and reducing driving pressure.
How does PEEP adjustment affect driving pressure in non-recruitable lungs?
In non-recruitable lungs, increasing PEEP may over-distend already open alveoli, worsening compliance and increasing driving pressure.
