Resp Insufficiency Flashcards
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
what do you need to do if you want to increase the amount of support of ventilation?
Increase IPAP or decrease EPAP
The amount inspiratory support is the difference between IPAP and EPAP
What is a normal inspiratory support?
10 cm H2O
IPAP 15 - EPAP 5 = 10cm H2O
What has the ability to influence gas exchange most directly
EPAP. By creating the same outcome as PEEP in CPAP.
it decreases alveolar collapse and improves alveolar surface area and increases FRC (thinning of alveolar-cap mem) = decreased V/Q mismatch and improves diffusion and improves gas exchange
What does IPAP most influence?
Ventilation or PaCO2
If you want to decrease PaCO2 then you increase IPAP
What does EPAP most influence?
Oxygenation and Gas exchange (like PEEP) PaO2
If you want to increase PaO2 then you increase EPAP
explain how BiPAP will support PTs ventilation
IPAP 15
EPAP 5
FiO2 0.7
back up breaths 6/min
- BiPAP will take breaths if PT doesnt after 10 sec by delivering gas until IPAP reaches 15
- when PT initiates a breath, the BiPAP machine recognises the inspire effort and delivers a high flow of gas until IPAP 15 is reached (this will give him a boost of 10cm H2O)
- this will decrease WOB (esp begin inhale) and support him achieving adequate Vt to improve vent
- EPAP of 5 cm will thin out the alveoli-cap mem, improving lung compliance and decrease WOB
- effects of IPAP and EPAP will decrease WOB and O2 demand
explain how BiPAP will support PTs gas exchange
IPAP 15
EPAP 5
FiO2 0.7
back up breaths 6/min
- EPAP set to 5 will enhance alveolar recruitment and minimize alveolar collapse = decrease V/Q mismatching
- Also thins out alveolar-cap membrane = supports diffusion and gas exchange = improve O2 supply
- FiO2 of 0.7 = increases the driving pressure a the alv-cap membrane = increase diffusion and improve O2 supply
- The improvement in vent will bring more O2 to alveoli = enhance gas exchange and improve O2 supply
Why did the Dr want to give Pt a bolus before putting him on BiPAP?
- BC the pressure causes positive intrathoracic pressure throughout the resp cycle and particularly during inspiration = + intrathoracic pressure will inhibit venous return = decreased preload!!!
- if preload drops too low it cannot support contractility
to improve ventilation with a CO2 of 50 on a BiPAP machine, one could adjust the…?
Increase the IPAP
To improve oxygenation, PaO2 while on BiPAP one could….?
increase the EPAP OR FiO2 but not past 50%
when breathing spontaneous on inspire we create a______ pressure in our lungs
negative
While on BiPAP if you need to improve the oxygenation/PaO2 by increasing the EPAP, what can you negatively impact?
Vt and CO2
If you increase EPAP without increasing IPAP, you decrease ventilation which will increase PaCO2***
pH 7.34 PaCO2 38 PaO2 60 HCO3 24 SaO2 88%
What do you need. CPAP or BiPAP?
CPAP bc PaCO2 is normal (not a ventilation issue)
need to improve oxygenation and gas exchange
pH 7.22 PaCO2 50 PaO2 59 HCO3 24 SaO2 88
CPAP or BiPAP?
BiPAP bc it a ventilation, oxygenation and gas exchange issue.
pH 7.37 PaO2 55 PaCO2 42 HCO3 24 SaO2 85% FiO2 60% IPAP 15 EPAP 5
What do you want to adjust on the BiPAP machine?
Increase EPAP. Not increase FiO2 because it is already over 50%
pH 7.33 PaO2 79 PaCO2 48 HCO3 24 SaO2 94%
What do you adjust?
Increase the IPAP bc now it is a ventilation problem
Nursing care for PTs with NIV
- assess
- monitor PT response to determine effectiveness, VS, resp status
- monitor and manage potential complications
- reassure PT. they often feel claustrophobic : explain, reassure, coach breathing
- straps firm 1-2 fingers between mask and face
- -> small air leaks are acceptable but not toward the eyes
- RT will prob start low and increase IPAP/EPAP to desirable level/PT tolerance, until Vt is achieved. Set alarms
- check ABG in one hr after start BiPAP
- SaO2 > 90% suggested/reasonable goal
- If SaO2< 90% then increase FiO2 or EPAP (but increasing EPAP might mean that you increase IPAP so you dont decrease Vt)
- monitor status esp preload. + pressure vent increases intrathoracic pressure = decreased venous return to heart and decreases preload
- when you decrease PEEP/EPAP or DC the + pressure vent, a PTs hemodynamic status needs to be considered as their preload might increase
complications with NIV
- not fitting, air leaks, skin urcers
- airflow complications, dryness, gastric insufflation (risk increases with higher IPAP)
weaning
can take several hrs to days
you notice changes to a PTs RR and Vt while on BiPAP but SpO2 has not changed what do you do?
- ABC!
- what is causing the change? pain, anxiety, increased secretion or decreased lung compliance (pneumonia)
- Increased RR and decreased Vt = resp distress
- Auscultate lungs
- CXR?
- ABG to see PaCO2
what do you do if the PT gets restless with the BiPAP mask?
- determine the cause of discomfort… hypoxemia (SpO2??), fever, pain, anxiety, need to ee…
- If hypoxemia is low then call RT/MRP, complete ABG to confirm PaO2 and SaO2
- check face mask
- coach breathing
How do you know when things/breathing has improved?
Ventilation
- access muscles not used, RR down, Vt adequate (500cc normal), less crackles, no wheeze
- less crackles = improved compliance
- no wheeze = improved resistance
- improved WOB
How do you know when things/breathing has improved?
Gas exchange
- less crackles = improved V/Q matching and diffusion
- PaO2 and SaO2 improving
How do you know when things/breathing has improved?
CO
- Lower HR, decreased WOB and improved SaO2
- BP and CVP ok
what is the gold standard measurement for ventilation
what is it affected by?
PaCO2
- lung compliance, airway resistance, resp muscle function, Vt,….
What is the gold standard measurement for gas exchange?
What is it affected by?
PaO2
- Diffusion and V/Q mismatch
3 main classifications of pneumonia
- site of acquisition
- casual agent
- Severity
Site of acquisition 4
- Community Acquired Pneumonia (CAP)
< 48hrs
- thin watery sputum
- gram + - Hospital Acquired Pneumonia (HAP)
> 48hrs
- thick green sputum
- gram - - Vent acquired Pneumonia (VAP)
- > 48hrs - Health care acquired pneumonia (HCAP)
- long term care
Typical vs atypical pneumonia
Typical- bacterial strep
xray- consolidation lobar/bronchial
Atypical- virus, fungi, protozoa
XRAY- patchy infiltrates multiple foci
pH 7.47
PaCO2 33
Pa 58
HCO3 23 SaO2 88%
analyze this and what do you do
Resp alkalosis with mod hypoxemia.
Dont fix the alkalosis. this is not the problem. Fix the hypoxemia. the alkalosis is the effects of the hypoxemia (compensation)
how do you support pneumonia vent and gas exchange?
- O2 therapy
Optimize gas exchange:
- positioning
- secretion removal (DBand C, hydration) diffusion and V/Q matching
Ventilation:
- inhalers
- nutrition and hydration (improve resp muscle function and secretion clearance)
which is the most common to increase, IPAP or EPAP?
IPAP first bc of the effect EPAP has on gas exchange
IF Pt has an increase in CO2 you ?
Increase IPAP
NIPPV stands for?
Non Invasive Positive Pressure Ventilation
what do you do if your PaO2 - 168?
Turn down FiO2 or turn down EPAP
what is mixed acidosis?
when you see resp asidosis, higher PACO2 55, but you also have HCO3 opposite- high 30
when do you have anaerobic lactic acidosis
when you have a low O2 supply. HCO3 is low (metabolic)
what happens of you increase EPAP but dont increase IPAP?
the pressure support will likely not be high enough and the PTs PaCO2 will increase
pH 7.34 PaCO2 46 PaO2 80 HCO3 22 SaO2 93
On BiPAP. what do you do?
Increase IPAP only because you want to increase
