basic terms Flashcards
Normal movement of gases into and out of the lungs?
ventilation
gas exchange between the blood and the cells-cellular level?
internal respiration
gas exchange between the lung and the blood stream?
external respiration
what does Pawo stand for?
pressure at the airway opening
what is the normal value for Pawo?
zero or atmospheric pressure (760mmHg or 1034cmH20)
What are three additional terms that can be used for Pawo?
- Paw - airway opening pressure
- Pm- mouth pressure
- Proximal airway pressure- mask pressure
what does Ppl or stand for?
intrapleural pressure
What is the pressure in the potential space between the parietal an visceral pleurae?
intrapleural pressure
What is the normal value for Ppl ( intrapleural pressure)?
- 5cmH20 at end of expiration
- 10cmH20at the end of inspiration
What does PA or Palv stand for?
intrapulmonary pressure
what is the normal values for intrapulmonary pressure during spontaneous breathing?
during inspiration -1 to -5cmH20
during expiration +1 or +5cmH20
what does the diaphragm do on inspiration?
descends and enlarges the thoracic cavity.
what does the diaphragm do on exhalation?
is passive and diaphragm returns to normal
Name the gas law that governs spontaneous ventilation?
Boyles law
What must be present in order to have gas flow?
must have a pressure gradient
what are the four basic pressure gradients?
- transairway pressure (PTA)
- transthoracic pressure (Pw or Ptt)
- transpulmonary pressure (PL or Ptp)
- transrespiratory pressure (Ptr)
What does PTA stand for?
transairway pressure
what does Pw or Ptt stand for?
transthoracic pressure
what does PL or Ptp stand for?
transpulmonary pressure
what does Ptr stand for?
transrespiratory pressure
the pressure difference between the airway opening and and the alveolus is known as?
Pta transairway pressure
Pta=Paw-Palv
the pressure difference between the alveolar space or lung and the bodys surface is known as?
Pw-transthoracic pressure
Pw=Palv-Pbs
what does Pbs stand for?
bodys surface pressure
the pressure difference between the alveolar space and the pleural space is known as?
PL - transpulmonary pressure
PL=Palv-Ppl
the pressure difference between the airway opening and the body surface is know as ?
PTR-transrespiratory pressure
Ptr=Pawo-Pbs
usually pressure at end expiration before next breath is know as ?
baseline or PEEP
normal values for baseline pressure is what?
zero or atmospheric pressure 760mmHg
The highest pressure recorded at the end of inspiration ?
Peak pressure or PIP
inspiratory pause. NO FLOW . elastic recoil of lung is still exerting a pressure . pressure taken after breath has been delivered but before exhalation is allowed to occur?
plateau pressure-breath hold
volume change per unit of pressure change is known as ?
compliance
reflects elastic recoil of lung (stiffness) and airway resistance to flow is know as ?
dynamic compliance
pressure is measured at static or no-flow conditions. eliminates airway resistance
static compliance
obstruction to air flow is know as?
resistance
C=Vt/Plateau-EEP is known as what equation?
static compliance
what is the normal values for compliance?
0.05 to 0.17 L/cmH20 or 50 to 170 mL/cmH20
what is the compliance values in intubated males?
40-50 mL/cmH20, up to 100mL/cmH20
what is the compliance values in intubated females?
35-45 mL/cmH20, up to 100mL/cmH20
PIP-Plateau/flow is known as what equation?
Raw or airway resistance
what is the normal airway resistance values
0.6 to 2.4 cmH20/L/sec
what is the airway resistance values for intubated patients?
approximately 6cmH20/L/sec or higher
what are a few conditions that would increase airway resistance?
COPD
Mechanical obstruction
infection
Emphysema
what are some reasons why it might be difficult to ventilate a patient?
lung stiffness
pneumonia
fibrosis
ARDS
for any value for R and C equals the time necessary for lungs to empty is know as what?
R x C
time constants
what is the value for one time constant?
63%
what is the value to 2 time constant?
86%
what is the value for 3 time constant?
95%
what is the value for 4 time constant?
98%
what is the value for 5 time constant?
100%
ventilator is the tank ventilator or “iron lung” individuals head is exposed to ambient pressure and thorax or entire body is encased in a airtight container is know as what?
negative pressure ventilation
ventilation occurs when a mechanical ventilator is used to move air into the patients lungs by way of an endotracheal tube is known as what?
positive pressure ventilation
ventilation uses above normal ventilating rates with below normal ventilating volumes is known as what?
High frequency ventilation
HFPPV stands for what?
High frequency positive pressure ventilation
HFJV stands for what?
High frequency Jet Ventilation
HFOV stands for what?
High frequency oscillatory ventilation
what is the breaths per min in HFPPV?
60-100
what is the breaths per min in HFJV?
100-600
What is the breaths per min in HFOV?
up to 4000 used for infants and adults with air leaks
incomplete expiration causes air trapping (hyperinflation) is known as what?
Auto (intrinsic) PEEP
a small amount of applied PEEP (3 to 5 cmH20) is used in most ventilated patients to prevent end-expiratory alveolar collapse is know as what?
Applied (extrinsic) PEEP
What does PEEP stand for?
Positive end expiratory pressure