Ventilation Flashcards
Tidal Volume
normal volume of air displaced between normal inhalation and exhalation when extra effort is not applied 500ml
Vital Capacity
the max amount of air a person can expel from the lungs after a max inhalation
IRV + TV + ERV
Inspiratory Reserve Volume
the max volume that can be inhaled from the end inspiratory level
Expiratory Reserve volume
the max amount of air that can be exhaled from the end expiratory position
Inspiratory capacity
the sum of IRV and Vt
Total Lung Capacity
the volume of air in the lungs at max inflation
VC + RV
sum of all volumes
Functional Residual Capacity
the volume in the lungs at the end-expiratory position
what is left over after a normal unforced exhale
Residual Volume
the volume that cannot be expelled or measured
Anatomical Dead Airspace
the volume of the conducting airways from the nose or mouth down to the terminal bronchioles
anatomic dead space fills with inspired air at the end of each inspiration, but this air is exhaled unchanged
Advantage of mechanical ventilation
keeps air going in and out improve oxygenation decreased work of breathing improve V/Q mismatch decrease fatigue
Disadvantages of mechanical ventilation
facial and nasal pressure injury and sores
gastric distension
dry mucous membranes and thick secretions
aspiration of gastric contents
complications of both noninvasice and invasive ventilation
hypotension related to positive intrathoracic pressure
INPV
intermittent negative pressure ventilation
tank ventilator
IPPV
intermittent positive pressure ventilation
air is delivered into a person’s lungs under pressure in short bursts, to stimulate intake of breath
CMV
controlled mechanical ventilation
continuous mandatory ventilation
SIMV
synchronized intermittent mandatory ventilation
breathes as per patient need
MMV
mandatory minute ventilation
select minute ventilation for the pt and monitors pts ability to generate this volume
PEEP
positive end expiratory pressure
pressure in the lungs above atmospheric pressure that exists at the end of expiration
CPAP
continuous positive airway pressure
applies mild air pressure on a continuous basis to keep airways open in a pt
NIPPV
non-invasive intermittent positive pressure ventilation
delivered through non invasive interface rather than an invasice interface
BiPAP
biphasic positive airway pressure ventilation
the pressure gradient alters during the phases of inspiration and expiration
how does capnography work
detection of CO2 gases
amount of light absorbed is proportional to the percentage of CO2 in the expired gas
Peak flow
measures the peak exp flow of a person
used to determine the severity of a persons airway disease in respect to narrowness or degree of obstruction within the airways
V/Q mismatch
occurs with altered lung physiology or ventilation/perfusion dysfunction resulting in ineffective gas exchange
V/Q mismatch leads to:
shunting - reduced ventilation
dead-space ventilation - reduced perfusion
silent unit - combination
left-right shunt
areas of no or low ventilation
perfusion is adequate
deadspace
area of no or low perfusion
blood flow through alevolar capillaries in some segments reduced
ventilation is adequate
Resp failure type 1
shunt
hypoxia due to an inability to maintain gas exchange
V/Q mismatch
caused by: problems with conducting airways, alveoli, pulmonary vessels
Resp failure type 2
mechanical or neurologic
cardiac failure
increasing pCO2 decreasing pH and pO2
caused by problems with resp centre, spinal cord lesion, motor neuron disease, musculoskeletal, upper airway, diaphragmatic splinting
