Mechanical ventilation Flashcards
What is mechanical ventilation?
A method of assisted breathing where a machine (ventilator) helps patients inhale and exhale, used when the patient is unable to breathe adequately on their own.
what are the common Indications for Mechanical Ventilation
Respiratory failure, severe hypoxemia, hypercapnia, airway protection after surgery, and acute lung injury (ALI) or acute respiratory distress syndrome (ARDS).
What are the two main types of mechanical ventilation?
Invasive ventilation (via endotracheal or tracheostomy tube) and non-invasive ventilation (via masks, like CPAP or BiPAP).
What is Volume Control Ventilation (VCV)?
A mode where the ventilator delivers a preset volume of air with each breath, regardless of the pressure required to deliver that volume.
What is Pressure Control Ventilation (PCV)?
A mode where the ventilator delivers air until a preset pressure is reached, with the volume varying depending on the patient’s lung compliance.
What does SIMV stand for and how does it work?
Synchronized Intermittent Mandatory Ventilation; the ventilator synchronizes mandatory breaths with the patient’s spontaneous breathing, allowing spontaneous breaths between controlled breaths.
What is PEEP and why is it used in mechanical ventilation?
Positive End-Expiratory Pressure is a mode used to keep alveoli open at the end of expiration, improving oxygenation and preventing atelectasis
What is FiO2 in mechanical ventilation?
The fraction of oxygen in the air delivered to the patient; typically set between 21% (room air) and 100% in critical settings.
What is tidal volume in mechanical ventilation?
The amount of air delivered to the lungs with each breath, typically set at 6-8 mL/kg of ideal body weight to avoid barotrauma.
What are some complications of mechanical ventilation?
Ventilator-associated pneumonia (VAP), barotrauma (lung injury from high pressure), oxygen toxicity, and ventilator-induced lung injury (VILI).
What is the weaning process in mechanical ventilation?
The gradual reduction of ventilator support to allow the patient to resume spontaneous breathing.
What is oxygen toxicity?
A condition caused by prolonged exposure to high concentrations of oxygen (FiO2 > 50%), leading to cellular and tissue damage, primarily affecting the lungs and central nervous system.
What are the two main types of oxygen toxicity?
Pulmonary oxygen toxicity and central nervous system (CNS) oxygen toxicity.
What are the signs and symptoms of pulmonary oxygen toxicity?
Cough, chest pain, difficulty breathing (dyspnea), and decreased lung compliance, which can lead to acute respiratory distress syndrome (ARDS) in severe cases.
What are the symptoms of CNS oxygen toxicity?
Nausea, visual disturbances, twitching, dizziness, and seizures. It is most often associated with hyperbaric oxygen therapy or deep-sea diving.
What causes tissue damage in oxygen toxicity?
Overproduction of reactive oxygen species (ROS), which overwhelm the body’s antioxidant defenses, leading to oxidative stress, inflammation, and cellular damage.
How does oxygen toxicity affect the lungs?
High oxygen concentrations can damage the alveoli, leading to inflammation, alveolar collapse (atelectasis), and fibrosis, impairing gas exchange and lung function.
What are the risk factors for developing oxygen toxicity
Prolonged exposure to high FiO2 (>50%), hyperbaric oxygen therapy, mechanical ventilation with high oxygen levels, and underlying lung disease
What FiO2 level is considered safe to avoid oxygen toxicity?
FiO2 levels below 50% are generally considered safe for prolonged use, though the exact threshold can vary depending on the patient’s condition and duration of exposure.
How can oxygen toxicity be prevented?
By using the lowest FiO2 necessary to maintain adequate oxygen saturation (SpO2), closely monitoring oxygen therapy, and minimizing exposure to high concentrations of oxygen
Why is CNS oxygen toxicity a concern in hyperbaric oxygen therapy?
The increased pressure in hyperbaric oxygen therapy increases the partial pressure of oxygen, raising the risk of CNS toxicity, especially seizures.
What is the treatment for oxygen toxicity?
Reducing FiO2 to the lowest effective level, supportive care for symptoms, and using antioxidant therapy in some cases to counteract oxidative damage.
