respiratory management Flashcards
define hypoxemia
abnormally low arterial oxygen tension (PaO2)
define hypoxia
insufficient oxygen in the tissues, and can be generalized or local.
what should be used to detect hypoxia
measurements should be used to accurately and efficiently detect hypoxia, including pulse oximetry and blood gas analysis.
What are the 5 mechanisms that can cause hypoxia
- hypoventilation (myesthenia gravis, overdose)
- V/Q mismatch (COPD, Asthma)
- Right to left shunt (AV malformations, intracardiac shunt)
- Diffusion abnormalities (pneumonia, pulm fibrosis)
- reduced oxygen inspired tension (mountain climbing/elevation)
what levels indicate the need for oxygen
PaO2 <60mmHg
SaO2 <90%
what is considered high flow oxygen supplementation
High-flow: (Venturi masks) maintain the selected FiO2 by using an oxygen flow rate that is higher than typical inspiratory flows or a reservoir bag
What is considered low flow oxygen supplementation
Low-flow: include oxygen delivery by nasal cannula (NC), simple mask, and reservoir mask (partial rebreather and non-rebreather). Low-flow systems do not deliver a constant inspired oxygen concentration since there is room air entrained into the NC or mask.
when do you use an oropharyngeal airway
in a deeply unresponsive patient who is unable to maintain his/her own airway
what are the 2 main causes of inadequate ventilation
- inadequate respiratory effort via intrinsic or extrinsic factors
- airway obstruction
how do you insert an oropharyngeal airway
start with the curve of the OPA inverted (directed cephalad) then rotate 180 degrees as its tip reaches posterior pharynx
how do you insert a nasopharyngeal airway
insert along the floor of the naris into the posterior pharynx behind the tongue. rotate tube slightly if resistance is encountered
Do patients tolerate NPA or OPAs better
NPA
what will happen if you insert an NPA that is too long
it might enter the esophagus and insufflate the stomach
what three things does adequate bag mask ventilation depend on
- patent airway
- adequate mask seal
- proper ventilation volume, rate and cadence
when ventilating a patient with a bag valve mask, what is the respiration rate that you should use
rate should not exceed 10-12 breaths per minute
squeeze steadily over 1 second.
In what cases are noninvasive ventilation preferred over intubation?
- COPD
- Acute CHF exacerbation
- asthma
- pneumonia (sometimes)
Is the presence/absence of a gag reflex a good way to assess airway patency?
NO!
20% of adults dont have a gag reflex
what is defined by the simultaneous administration of a sedative and paralytic agent to assist in endotracheal intubation usually via direct laryngoscopy
rapid sequence intubation
should you take a patients dentures out if youre going to attempt bag valve ventilation?
nooooo
what are the 5 indications for mechanical ventilation
- airway protection in a obtunded patient or patient with dynamic airway
- hypercapnic respiratory failure 2/2 decease in minute ventilation
- hypoxemic respiratory failure 2/2 failure of o2
- CV distress where mechanical ventilation can offload energy requirements of breathing
- expectant course (anticipated pt decline)
what are the four phases of a mechanical ventilation breath
- initiation by opening the inspiratory valve
- delivery where air flows from vent to pt
- termination by closure of inspiratory valve and cessation of airflow
- exhalation by opening of expiratory valve and air transfers from pt to vent
what are controlled mechanical ventilation breaths
triggered by the ventilator and have limit and cycle variables set by the ventilator operator.
what are assisted mechanical ventilation breaths
similar to controlled breaths, in that limit and cycle variables are set by the operator, but in contrast to controlled breaths are triggered by the patient.
what are spontaneous mechanical ventilation breaths
triggered and cycled by the patient.
what are the general criteria to evaluate an intubated patient for a spontaneous breathing trial?
