Test 2 Ch.1 Flashcards
The movement of air into an out of the lungs
ventilation
involves the exchange of oxygen and carbon dioxide between an organism and its environment
Respirations
Contraction of the muscles of inspiration, which causes expansion of the thorax. what kind of breath is this?
Spontaneous breath
Accessory muscles of inspiration (4)
- Scalene
- Sternoclediomastoids
- Pectoralis
- Trapezius
Accessory muscles of expiration (6)
- rectus abdominus
- external oblique
- internal oblique
- transverse abdominal
- Serratus ( anterior and posterior)
- Latissimus dorsi
_______ ________ is pressure is when your breathing in
Negative pressure
________ ____________ is on the vent and pushing positive pressure into the lungs
postive pressure
From air to flow through a tube or airway what must exist?
pressure gradient
pressure at one end of the tube must be higher than pressure at the other end of the tube
pressure gradient
What changes as a result of gas flow into and out of the airways
Lung volumes
This is caused by changes in the pressure gradient between the airway opening and the alveoli
Lung volume change
Concentration of the inspiratory muscle
Inspiration
Alveolar pressure becomes less than the pressure at the airway opening and gas flow into the lungs
Inspiration
Relaxation of the inspiratory muscles causes in a decrease in the thoracic volume
Expiration
Intrapulmonary pressure or lung pressure
Alveolar pressure (PA or Palv)
Highest pressure at the end of inspiration
peak pressure
If peak pressure is high then what needs to be done?
Suctioning b/c of secretions
is also called PIP or peak airway pressure
peak pressure
PIP can increase if
a pt is fighting the vent while awake
An airway pressure measurement is called the
plateau pressure
measured after a breath has been delivered to the pt and before exhalation begins
plateau pressure
__________ is prevented by the vent for a brief moment _____ to ______ seconds
Exhalation; 0.5 to 1.5 s
To obtain the measurement the ventilator operator normally selects a control marked
“inspiratory hold” or “inspiratory pause”
The relative ease w/ which the structure distends
Compliance (c)
Normal compliance in spontaneous breathing pts
0.05 to 0.17 L mL/cmH2O
Normal compliance in intubated pts
Males :40 to 50 up to 100
Females: 35 to 45 up to 100
The tendency of a structure to return to its original form after being stretched or acted on by an outside force
Elastance (e)
Elastance is the
opposite of compliance
In the clinical setting compliance measurements are used to describe
the elastane forces that oppose lung inflation
-30 for plateau pressure is
normal
The compliance by the respiratory system is determined by
measuring the change (🔺) of volume (v) that occurs when pressure (P) is applied to the system
C=
🔺V/🔺P
For pts receiving MV, compliance measurements are made during
static conditions
The tidal volume used in this calculation is to determine by measuring the pt’s exhaled volume near the pt connected
static compliance (cs)
What are the 2 cs equation
- cs=(exhaled tidal volume /plateau pressure -EEP)
- cs =Vt/ (Pplat- EEP)
EEP is the en expiratory pressure, which some clinicians call the
baseline pressure ; it is the baseline from which pt breathes
Normal resistance values for unintubaned pts
0.6 to 2.4 cm H2O (L/s) at 0.5 L/s flow
Normal resistance values for intubated pt
Approximately 6 cm H20 or higher (airway resistance increase as ETT size decreases)
Attempts to mimic the function of the respiratory muscles to allow breathing through the normal physiological mechanism
Negative pressure ventilation (NPV)
With this device, the pt’s head and neck are exposed to ambient pressure while the thorax and the rest of the body are enclosed in an airtight container that is subjected to negative pressure
Iron Lung
Mechanical ventilator is used to deliver air into the pt’s lungs by way of an ETT or positive pressure mask
Positive pressure ventilation (ppv)
Uses above normal ventilating rates with below- normal ventilating volumes
high frequency ventilation
3 types of high frequency ventilation strategies
- high frequency positive pressure ventilation (HFPPV)
- high- frequency jet ventilation (HFJV)
- high- frequency oscillatory ventilation (HFOV)
Uses respiratory rates of about 60 to 100 breaths/ min
high frequency positive pressure ventilation (HFPPV)
Uses rates between 100 and 400 to 600 breaths/ min
high- frequency jet ventilation (HFJV)
uses rates into the thousands up to 4000 breaths/ min
high- frequency oscillatory ventilation (HFOV)
____ can be trapped in the lungs during MV if not enough time is allowed for exhalation
air
The most effective way to prevent air trapping complication is to monitor the
pressure in the ventilator circuit and the end of exhalation
If no extrinsic PEEP is added and the baseline is greater than zero
air trapping or auto-PEEP is present
Airway pressure are measured relative to a
baseline value
If baseline is zero it indicates that
no additional pressure is applied at the airway opening during expiration and before inspiration
If the baseline is higher than zero the ventilator operator selects a….. AND IS CALLED
higher pressure to be present at the end of end of exhalation; positive end- expiratory pressure (PEEP)
When PEEP is set the ventilator prevents the pt from
exhaling to zero (atmospheric pressure)
PEEP increases the volume of gas remaining in the lungs at the
end of a normal exhalation
PEEP applied by the operator is called
extrinsic PEEP
The air that is accentually trapped in the lungs
Auto-PEEP (intrinsic PEEP)
Usually occurs when a pt does not have enough time to exhale completely before the ventilator delivers another breath
Intrinsic PEEP
Physiologically everyone has a PEEP of
5
1mm HG =
136 cm H20
The pressure difference between the alveolus (Palv) and the body surface is called
Transthoracic pressure
Define elastance
Ability of a structure to return to its natural shape after stretching
What is the formula used for compliance?
C=🔺V/🔺P
Another term for airway pressure
Airway opening pressure
Intraalveolar pressure (in relation to atmospheric pressure) at the end of inspiration during a normal quiet breath is
0 cm h20
Which of the following Associated with Increase in airway resistance
Decreasing the flow rate of gas into the airway
Which of the following statements is true regarding negative pressure ventilation (npv)
Thes ventilators mimc normal breathing mechanics
PEEP is best defined
Positive pressure at the end of exhalation on a mechanical ventilator
Which of the following statements is true regarding plateau pressure
Plateau pressure is used as a measure of alveolar pressure
One time constant should allow approximately what percentage of a lung unit to fill
63%
