Resp Insufficiency Flashcards
(63 cards)
Gram +
-
+ bacteria wall turn blue
Other: can see size and shape of walls, arrangements (chains), presents or lack of structures
who should use a low flow system
Someone who can take adequate breath and rate/depth are normal
> than RA but not sufficient to fill lungs entirely bc concentration of O2 is diluted
actual FiO2 (fraction of inspired O2) is inconsistent
use humidification if >
4 L (24-44%)
switch to mask if >
6L (60%)
Masks should be min 5L to prevent rebreathing CO2
low-flow reservoir system
partial or non-rebreather
Partial- when some PTs exhaled CO2 is inhaled during next
bag fills with O2 each inspiration so each breath contains higher FiO2
Keep bag 1/3-1/2 filled on inspiration and keep snug
High flow
3-4x higher that PT inspiration rate.
desirable if O2 concentration must be held constant (COPD)
what is a venturi mask?
uses nozzle to accelerate O2 flow and mix with RA at precise ratio (24-50%)
S and S of O2 toxicity
(IF FiO2 > 50% for > 12 hours)
dyspnea, paraesthesia in extremities, signs pulm edema
If FiO2 required at 100%, PT would be at risk for atelectasis = the normal nitrogen that we breath, keeps the alveoli open. With 100% O2 there would be no nitrogen and the alveoli would collapse
COPD drive to breath
lack of O2
1L NP =
6L NP =
Face mask 5= 7-8=
Mask with reservoir 6= 9=
1L = 24% 6L = 44%
Mask 5 = 50% 7-8 = 60%
With reservoir 6 = 60% 9 = 90%
what are the 2 non-invasive ventilation systems
- CPAP - continuous positive airway pressure
2. BiPAP - Bilevel positive airway pressure
when and why would you use NIV
- support both the PTs vent and gas exchange
- use as bridge therapy from mechanical vent
- best for PTs who can cooperate and protect their own airway
- and for those who have not developed severe acid/base or gas exchange issues
- preserves PT swallow, speech, and cough.
Criteria that indicate need for NIV include:
- mod-severe dyspnea
- tachypnea (>24/min if hypercapnic, > 30/min if hypoxic)
- use of accessory muscles
- paradoxical breathing (dysfunctional)
- ABG changes
- pH < 7.35
- PaCO2 >45
- PaO2/FiO2 ratio < 200
what is a normal PaO2/FiO2 ratio and how do you calculate it?
Normal >350
PaO2 of 80 mmHg divided by FiO2 0.21 (RA) = 380.95
criteria to exclude for NIV:
- respiratory arrest
- CAP/HAP
-hypoxic resp failure
RI and RF - bridge from mechanical vent
- medically unstable (hypotensive, uncontrolled cardiac ischemia, dysrhythmias, uncontrolled GI bleed…)
- unable to protect own airway, risk aspiration, excessive secretions, agitated/combative, facial trauma, burns, recent upper GI bleed, airway sx, cant fit mask
CPAP/BiPAP machines deliver…
- Mixed gas. can be controlled
- Both use + pressure
- Ventilator can be set to be used as CPAP or BIPAP.
- PT data can be kept (RR, Vt, minute vol…)
- has alarm parameters (pressure alarms, volume alarms, RR alarms, FiO2 alarms…)
- there are a variety of interfaces avail (nasal pillows, oronasal or full face, nose/mouth, total face, mouth piece with lip seals…)
NIV machines control settings:
- how the breath is started
- how quickly the air/O2 is delivered to the PT (flow meter)
- How inspiration is ended (how does delivery stop– > when PTs inspiratory effort has decreased? Predetermined air pressure has been reached? Or certain volume has been delivered
- the degree to which a PT can exhale a breath (preventing full exhale can be beneficial)
Inhalation creates…. ? and is …..?
Exhalation….?
- Inhalation creates negative thoracic pressure that sucks air into the lungs. It is active
- Exhalation creates positive pressure and is passive.
CPAP
- ** use when there is only an oxygenation issue**
PT breathes spontaneous - the pressure while breathing is maintained as continuous and is always positive throughout inhale and exhale
- back and fourth between 3-5 cm H2O
- PEEP CPAP applied pressure at the end of expire (positive end expiratory pressure). This prevents PT from exhaling fully, which rises the baseline pressure for the whole resp cycle.
- PEEP is created with valve in tubing
- keeps intrapulm pressure above zero
- increases FRC NOT Vt!!!!
- CPAP pushes fluids down and out, thinning layer of fluid and allowing for better diffusion of O2 = improving shunt keeping alveoli open ***
Explain CPAP for O2 supply and demand***
CPAP PEEP/continuous pressure, keeps the alveoli open = increasing FRC = also thinning lung walls = increasing surface area avail for gas exchange and decreasing V/Q mismatch = improving gas exchange and ventilation and decreasing WOB
thin walls also helps lung compliance = increasing WOB
BiPAP pressure settings
supports:
Inspiration and expiration
Spontaneous breathing- can set rate. Will breathe if PT doesnt (6/min or one in 10 sec)
IPAP
Inspiratory positive pressure- machine delivers high flow O2 and air untill preset pressure level is reached and maintained throughout inspiratory phase
- usually set to 10-16 cm H2O
- this boost in early inspiration decreases in PT inspiratory effort, gas flow will stop, inspire will end, and PT breaths out
** reduces WOB and increases Vt = supports Ventilation ***
EPAP
Expiratory positive airway pressure- usually same as peep (3-5 cm H2O)
- Pt will breath out until preset EPAP is reached - preventing them from completely emptying their alveoli
** maintains alveoli open and decreases A-C membrane thickness and increases surface area = increases diffusion = supports oxygenation **
BiPAP helps ventilation by:
Inspiration boost from IPAP
- decreases WOB at the beginning - saves energy for remainder of inspire
- gas that is delivered to create the preset IPAP actually provides some Vt for the PT
these 2 things support PT in achieving effective Vt and improve ventilation
