Mechanical Vent Flashcards
(57 cards)
4 Main Types of conditions which would lead to mechanical ventilation
- Depressed respiratory drive
- Excessive ventilatory workload (increased work of breathing)
- Failure of ventilatory pump (respiratory muscle failure)
- Impending respiratory failure
What might cause a depressed respiratory drive
- Drug overdose
- Acute SCI
- Head trauma
- Sleep disorders
What might cause an excessive ventilatory workload
- Airflow obstruction - COPD
- Dead space ventilation - PE
- Congenital heart disease - Pulmonary artery hypertension
- Decreased lung compliance - ARDS, Pneumonia
What might lead to failure of ventilatory pump
Chest trauma
What are the two type of Clinical signs of impending respiratory failure
- Decreased PaO2
2. Decreased PaO2 and increased PaCO2
Features of decreased PaO2
- Agitation
- Cyanosis
- Decreased SpO2
- Air hunger
- Tachycardia
Features of decreased PaO2 and PaCO2
- Agitation
- Cyanosis
- Decreased SpO2
- Air hunger
- Tachycardia
- Decreased LOC
- Confusion
- Rapid shallow breathing
2 types of mechanical ventilation?
- Positive pressure ventilation - pushing air into lungs
- Negative pressure ventilation - putting them in cavity with sub-atmospheric pressure surround lungs in turn allowing chest wall to expand and air to flow into lungs
Is positive pressure or negative pressure ventilation closer to normal lung physiology
Negative pressure
Is positive pressure or negative pressure ventilation the most common for of mechanical ventilation
positive pressure
Two methods for positive pressure ventilation
- Invasive positive pressure ventilation
- non-invasive positive pressure ventilation
What are the pulmonary effects of mechanical ventilation that need monitoring
- Increased V/Q and dead space/tidal volume ratio
- Air trapping
- Barotrauma leading to multisystem failure
- Pneumothorax and subcutaneous emphysema
- Increased work of breathing
- Respiratory distress (narrow ETT tube, discomfort)
What are the Hemodynamic effects of mechanical ventilation that need monitoring
- Decreased venous return
- Decreased cardiac output (caused by decreased venous return)
- Decreased BP (due to decreased CO)
- Decreased renal perfusion (as a result of decreased BP)
In MV air flows in which way
Path of least resistance
What is the pump for the venous system (i.e heart is pump for arterial system)
The lungs!! they pull the blood back up to heart
Does prophylactic manual chest physio decrease the incidence of ventilatory associated pneumonia
no
Ventilator associated pneumonia is a pneumonia which starts after ____ hours of ventilation
> 48hours
What are some extra precautions taken when on a ventilator
- Head of bed elevation
- oral hygiene
- DVT and peptic ulcer prophylaxis (prevention)
- Daily sedation vacation
- Reduced frequency of changing vent circuit
Contraindications + precautions of non-invasive ventilation
- Facial trauma
- Obstruction to upper airway
- Hemodynamic instability & multi organ failure
- Decreased LOC
- Undrained pneumothorax
- High risk of aspiration & vomiting
Do you want to put a patient with COPD on a ventilator
No - it is very hard to get them off
Patient interfaces for non-invasive MV
- Face mask
- Nasal mask
- Nasaal Cannula
- Full face mask
Patient interfaces for invasive MV
- Oral endotracheal tube
- Nasal endotracheal tube
- Tracheostomy
When do you most often see a nasal endotracheal tube
in neonatal population or if there was an oral surgery
How do you decide type of patient interface?
For NIV: Patient comfort is biggest player. Most often start with oronasal mask
For IPPV: Most adults intubated with a cuffed oral endotracheal tube.
