Mechanical Ventilation Flashcards
Examples of thoracic abnormalities that affect spontaneous ventilation (5)
- Open chest
- pneumothorax, -
- pleural effusion
- external pressure on the chest
- obesity
_____: Total volume of new air entering the alveoli each minute
alveolar minute ventilation (Va)
In pressure controlled ventilation, the _________ delivered to the patient will depend upon the respiratory compliance
tidal volume
___________, also known as Intermittent Positive Pressure Ventilation, is a system where the patient is unable to initiate a breath and the operator sets the tidal volume and respiratory rate
controlled ventilation
Factors affecting spontaneous ventilation (4)
- CNS depresssion
- thoracic abnormalities
- increased intraabdominal pressure
- hypoventilation
Re-expanding a lung can result in ________ or __________
- reperfusion injury
- acute respiratory distress syndrome
In controlled ventilation, ideally PIP should be < ____ cm H2O to avoid barotrauma and TV should be < ____ mL/kg to avoid volutrauma
- <20 cm H2O
- <20 mL/kg
_____________ is to reduce the work of breathing for a patient who is able to initiate the breath
assisted ventilation
_________: manual positive pressure ventilation system used exclusively in large animals
demand valve (too easy to overinflate lungs in small animals)
PEEP reduces ______ and can have a profound cardiovascular impact on hypovolemic patients
venous return
_____: Volume of air inspired or expired with each normal breath
tidal volume (TV)
______Energy required by respiratory muscles to produce an inspiration
Work of breathing
increased intraabdominal pressure causes decreased alveolar ventilation due to _______
reduced compliance
What is the purpose of positive end expiratory pressure?
to avoid collapse of the poorly ventilated alveoli
normal airway pressure is ____-____ cm H2O
10-20 cm H2O
3 causes of atelectasis
- compression atelectasis
- absorption atelectasis
- decreased surfactant
3 manual positive pressure ventilation systems
- ET tube with reservoir bag
- Ambu bag
- Demand valve
Examples of CNS depression that affect spontaneous ventilation (4)
- general anesthesia
- sedatives
- opiods
- CNS disease
4 measurements of ventilation which can be adjusted to maintain normocapnia
- TV
- PIP
- RR
- I:E
How is atelectasis treated?
recruiting manuvers (artificial sigh) followed by PEEP
Amount of air entering the alveoli equals ____ minus ________
- TV
- anatomical
dead space volume
5 potential causes of patient asynchrony
- light anesthetic plan
- nociception
- hypercapnia
- hypoxemia
- hyperthermia
3 potential consequences of atelectasis
- v/q mismatch
- hypoxemia
- risk of post-operative pulmonary infection.
________: measure of the lung’s ability to stretch and expand, is the change in volume for any given applied pressure
Compliance
the airway pressure in volume controlled ventilation will depend on the _______
compliance of the respiratory system
2 modalities of controlled ventilation
- volume controlled
- pressure controlled
High expiratory CO2 indicates ___________
hypoventilation
Potential physiological consequences of PEEP (4)
- High and sustained intrathoracic pressure can cause decreased venous return resulting in hypotension,
- risk of barotrauma
- risk of pneumothorax
- diaphragmatic hernia
Mandatory situations requiring ventilatory support (6)
- Open chest surgery
- Use of neuromuscular
blocker agents - Respiratory arrest
- Lung disease where normoxemia is not maintained by
supplementing O2 - Hypercapnia
- Patients that cannot tolerate
increases in CO2 (i.e: brain
tumors)
______________ occurs when the timing of the ventilator cycle is not simultaneous with the timing of the patient’s respiratory cycle
Patient-Ventilator Asynchrony
4 causes of hypoxia
- hypoventilation
- diffusion limitation
- shunt
- ventilation-perfusion inequality
_________: Total amount of new air moved into the respiratory passages each minute
minute ventilation (Vm)
2 categories of Positive Pressure Ventilation Systems
- manual
- mechanical
PEEP is usually kept at ___-____ cm H2O
5-10 cm H2O
During _________ positive pressure is generated in the breathing system producing movement of air into the alveoli.
positive pressure ventilation
low expiratory CO2 indicates __________
hyperventilation
6 situations where ventilatory support is highly recommended
these groups of animals are prone to severe hypoventilation, therefore ventilatory support can become mandatory
- low lung/chest compliance
- obese
- GDV
- pregnant
- horses
- laparoscopic surgery
Examples of increased abdominal pressure that affect spontaneous ventilation (6)
- Pregnancy
- GDV
- abdominal fluids
- large abdominal masses
- pneumoperitoneum
- obesity
_________: collapse or closure of a lung resulting in reduced or absent gas exchange.
atelectasis
Energy is required by the lungs in order to overcome 3 things
- to expand the lungs against elastic forces
- to overcome the viscosity of the
lung and chest wall structures - to overcome airway resistance
CNS depression causes decreased alveolar ventilation due to __________
reduced central drive
