Midterm study guide: Pulmonary Flashcards
FiO2
measure of how much oxygen we breathe in compared to the other gases in the air.
*ex: if you breathe in air with an FiO2 of 0.21, it means that about 21% of what you’re breathing is oxygen.
*Room air is 21%.
*Max is 100%.
*We start getting more concerned when FIO2 is 60% or higher
*You can extubate on 40% fiO2 because it could be very small volumes we were doing → get them off vent and on NC
PEEP: Positive End Expiratory Pressure.
(when to be concerned and why? PEEP for obese pts?)
*How much air or pressure is in the lungs just after a breath out. Like a diastolic reading for BP, but for the lungs’ pressure at rest.
*Normally lowest is a 5 cause we have to make up for the pressure the vocal cords would keep in the lungs if the pt didn’t have an ETT blocking it.
*Concerning is 10 or above
*Too high? = decreased cardiac output cause there is more physical pressure on the heart.
*PEEP and vasopressors can be increased together
*Increased PEEP could be good if patient has a higher BMI
Respirations
(can indicate…, what is hypervent? What if tidal vol is too low?
*Can indicate pain
*Patient can still initiate breaths so looking and taking RR’s can be important
*Hyperventilation = blowing off too much CO2
*If trauma happens and you lower your tidal volume… you then have to increase the respirations in order to get the same amount of air in and out of the lungs per minute
Oxygenation vs Ventilation
*ventilation: CO2 (inhalation and exhalation)
*Oxygenation: O2 (getting o2 to the tissue level)
Tidal volume:
Vol of air normally displaced between inhalation and exhalation (how big of a breath you’re taking)
PIP: Peak Inspiratory Pressure
(what + goal PIP)
the max volume/amount of pressure in your lungs when you take a breath in
*goal PIP: <40 cm H2O
Plateau pressure
(what is it? what does it measure? what is the goal?)
*pressure at the end of inspiration inside your lungs measured after a brief pause in the delivery of air during mechanical ventilation
*measures the compliance of the airway
*goal <30 cm H2)
Ventilation: who is initiating the breath?
(control, support, SIMV)
*control: vent is initiating the breath
*support: pt is initiating the breath
*SIMV: mix of both
Ventilators: Volume
Volume is the constant and pressure varies
*vent adjusts the pressure to ensure the flow
*increase the TV and the required pressure increases
Volume Control: pros and cons
Pro: ensures adequate ventilation
Con: risk of barotrauma (happens when there is a fast change in pressure)
Pressure control: pros and cons
pro: decreased risk of barotrauma
con: server hypercapnia (too much CO2) can occur
ARDS: def
your lungs become inflamed and filled with fluid, making it difficult for oxygen to get into your bloodstream.
ARDS: etiology
(2)
non-cardiogenic PE and disruption of the alveolar-capillary membrane.
ARDS: factors that precipitate it/lead to it (15 possible, name 5)
*aspiration (30-40% of cases)
*near drowning
*Toxic inhalation
*Pulmonary contusion
*Pneumonia
*Oxygen toxicity
*Transthoracic radiation
*Sepsis
*Non-thoracic trauma
*Hypertransfusion
*Cardiopulmonary bypass
*Severe pancreatitis
*Embolism-air, fat, amniotic fluid
*DIC
*Shock states
Standardized criteria used to dx ARDS: (4)
(when does it start? 3 criteria)
*Acute onset (w/in 1 week of known clinical insult or new or worsening respiratory symptoms)
*Bilateral infiltrates on CXR (complete white-out)
*Pulmonary edema (not explained by HF or fluid volume overload)
*Ratio of PaO2 to FiO2 is ≤ 200 mmHg regardless of PEEP level (60/0.25 = 240 or 60/0.80 = 75)
Patho ARDS (4)
injury/infamm -> increased permeability -> difficult gas exchange -> breathing difficulty
ARDS Medical and Nursing Management: 3
- optimize o2 and ventilations
- provide comfort and emotional support
- maintaining surveillance
ARDS Medical and Nursing Management: optimize o2
(oxygen 3 + 1 other)
- oxygen:
*Goal is to maintain o2 sats (90% using lowest o2 level, preferably < FiO2 of 0.050)
*pts will be intubated and ventilated by this time
*may use ECMO when conventional therapy failing - PEEP (usually high PEEP)
Positive reasons to use high PEEP for ARDS pts (4)
*opens collapsed alveoli
*stabilizes flooded alveoli
*decreases intrapulmonary shunting
* increases compliance
Negative reasons to use high PEEP for ARDS pts (2)
*Decreases CO
*Barotrauma - gas escaping into the surrounding spaces d/t alveoli rupture
ARDS Medical and Nursing Management: optimizing ventilation -> “who will be initiating breaths”
Ventilator so the lungs can rest
ARDS Medical and Nursing Management: optimizing ventilation -> “Is volume or pressure control better for this pt?”
*Volume so less likely to have problems
*Pressure less risk of barotrauma
ARDS Medical and Nursing Management: optimizing ventilation -> “is ventilation or oxygenation the problem?”
both
ARDS Medical and Nursing Management: optimizing ventilation -> “how do we fix it?”
Prone position
ARDS Medical and Nursing Management: tissue perfusion (4)
- Keep adequate CO and Hgb levels
- Manipulate HR, preload, and contractility to keep wedge 5-8
- Use fluid restrictions and diuretics to minimize fluid leakage
- Use vasoactive and inotropic meds to keep CO up
ARDS Medical and Nursing Management: the other P’s (4)
- Positioning
- Prone
- Preventing desaturation
- Promoting secretion clearance