Abbreviations
Name these abbreviations:
C, R, Raw, Pm, Paw, and Pawo
Compliance, resistance, airway resistance, pressure at the mouth (same as Pawo), airway pressure (usually upper airway), and pressure at the airway opening (mouth pressure or mask)
Define pressure gradient, respiration, ventilation:
Pressure Gradient- air moving from high to low pressure
Respiration- the movement of gas molecules across a membrane
Ventilation- movement of air into and out of lungs
Define:
Intrapleural pressure, alveolar pressure, and static compliance
pressure in the space between the visceral and parietal pleura, changes as the intrapleural pressure changes, and Used to describe the elastic forces that oppose inflation Change in volume that occurs when pressure is applied to the system.
Transrespiratory pressure is made up of two components:
Transthoracic pressure and transairway pressure
Ptr = Ptt + Pta
(Pawo - Pbs) = (Palv - Pbs) + (Paw - Palv)
A.) 1 mm kg = ___ cm h20
B.) 1 kPa = ___ mm hg
C.) 1 Torr = ___ mm hg
D.) 1 atm = 760 mm hg = ___ cm H2O
A.) 1.36
B.) 7.5
C.) 1
D.) 1034
Name these abbreviations:
Pbs, Palv, Ppl, CST, and Cdym
Pressure at the body surface, alveolar pressure (also PA), intrapleural pressure, static pressure, and dynamic compliance.
Define:
normal mechanics, external respiration, and internal respiration
normal mechanics- spontaneous breathing (breathing on your own) and passive exhalation
external respiration- Involved the diffusion of oxygen and carbon dioxide between the alveoli and the pulmonary capillaries.
Internal respiration- Occurs at the cellular level and involves the exchange of oxygen and carbon dioxide between the systemic capillaries and the cells of the body
Define:
airway resistance, flow, manometer, and bronchopleural fistula.
The measurement of the frictional forces that must be overcome during breathing, gas flow measured during inspiration, instrument for measuring pressure, pressure gauge, and Abnormal connection between bronchus and pleural space.
Alveolar pressure normals for inspiration and expiration:
normal during inspiration -1
normal during exhalation +1
Normal compliance in spontaneous breathing patterns:
Normal compliance in intubated pt:
Spontaneous- 0.05 to 0.17 l/cm h2o or 50 to 170 ml/cm h20
Intubated-
Males: 40 to 50 ml/cm h20, up to 100 ml/cm h2o
Females: 35 to 45 ml/cm h2o, up to 100 ml/cm h2o
Name these abbreviation:
PaO2, PaCO2, Pes, and pl or ptp
Arterial oxygen pressure, arterial carbon dioxide pressure, esophageal pressure, and trans pulmonary pressure.
Name the 4 pressure gradients and what they measure
Transairway pressure (PTA) airway pressure- alveolar pressure
Transthoracic pressure (PW) alveolar pressure- body surface Pressure
transpulmonary pressure (PL) AKA transalveolar pressure alveolar pressure- pleural pressure
transrespiratory pressure (PTR) Airway opening pressure- body surface pressure
The product of Compliance and Resistance is called a
Time constant
Name diseases that reduce compliance and increase compliance:
Three types of mechanical vent
Reduces- kyphoscoliosis and ARDS
Increases- emphysema
Negative pressure ventilation, positive pressure ventilation, and high frequency ventilation.
Name the intrapleural pressure (Ppl) end exhalation and end inspiration in cm h20:
normal at end exhalation is -5 cm h20
normal at end inspiration is 2-5 cm h20
Name these abbreviations:
paw or Ptt, pta, and ptr
trans thoracic pressure, trans airway pressure, and trans respiratory pressure.
Define :
Peak pressure (peak airway pressure), plateau pressure, compliance, and elastance
peak pressure (peak airway pressure)- the highest pressure achieved during inspiration on positive pressure ventilation (PIP)
Plateau pressure- a pressure measurement taken during positive pressure ventilation after a breath has been delivered to the patient and before exhalation has begun
compliance- the ease with which a structure distends
elastance- the ease with which a structure returns to normal form after being stretched
Negative pressure ventilation, critical opening pressure, homogenous, heterogeneous, ascites, and Baseline Pressure.
Ventilation of the lungs by expanding the rib cage so as to "pull" air into the lungs, The pressure required to open a collapsed lung unit, of same kind, composed of unlike parts, Accumulation in the peritoneal cavity, and The point from which we measure airway pressures Can be zero (atmospheric)
airway resistance is increased when there is an artificial airway. Why?
the inserted tube is narrower than the natural airway and passes the humidifying and warming upper airway structures
The resistance to airflow through the conductive airways depends on:
HINT there are 4 things
gas viscosity, the gas density, the length and diameter of the tube, and the flow rate of the gas through the tube as defined by Poiseuille’s Law.
BONUS DOUBLE POINT SURPRISE!!
Three types of high frequency ventilation
High frequency jet ventilation (HFJV), High frequency oscillatory ventilation, and high frequency percussive ventilation
Define (in detail):
FRC (functional residual capacity), PEEP, Extrinsic PEEP, and auto-PEEP.
FRC- the volume of a gas remaining in the lungs at the end of a normal exhalation
PEEP- pressure above atmospheric, applied to the airway during exhalation, that increases the functional residual capacity.
extrinsic PEEP- positive and expiratory pressyre applied by the operator
auto-PEEP- inadvertent PEEP that is not set by the operator but results in a buildup of positive Pressure in the lungs at the end of exhalation.
peak pressure (peak airway pressure)- the highest pressure achieved during inspiration on positive pressure ventilation (PIP)
Plateau pressure- a pressure measurement taken during positive pressure ventilation after a breath has been delivered to the patient and before exhalation has begun
compliance- the ease with which a structure distends
elastance- the ease with which a structure returns to normal form after being stretched
positive pressure ventilation (PPV):
high frequency ventilation:
When a mechanical vent is used to deliver air into the pt's lungs by either endotracheal tube or positive pressure mask.
Uses rates of 60-100 breaths per minute. Uses above-normal ventilating rates with below-normal ventilating volumes.
Three types of high frequency ventilation:
High frequency jet ventilation (HFJV), High frequency oscillatory ventilation, and high frequency percussive ventilation
explain time consult:
One time constant = what % of volume inhailed
two time constant=
three time constant =
four time constant =
what is it after five?
The time constant always equals the length of time (in seconds) required for the lungs to inflate or deflate to a certain amount (percentage) of their volume.
1 time constant = 63% of volume inhailed
2 = 86%
3 = 95%
4 = 98%
time constant over 5 means 100% FIO2