Rcp 100 exam 2 Flashcards
oxygen
Hyperoxia
-2-3 ata and up to 7 ata
- vasoconstriction and small decrease in CO
- can reduce edema and tissue swelling in burns, cerebral edema, and crush injuries while maintaining oxygenation
- can aid in neovascularization (formation of new capillary beds) for tissue repair
late hypoxemia
- low pH
-high PaCO2
-low Pao2
-hypoventilating due to decreased respiratory drive
early hypoxemia
-high pH
-low PaCO2
-low PaO2
-hyperventilating due to decreased oxygen
oxygen-induced hypoventilation
-seen in COPD pts with CO2 retention
-can suppress hypoxic drive
-CO2 increase
-target PaO2 is 60 (Spo2 90%)
absorption atelectasis
-alveolar collapse (shunt) due to a decrease in body nitrogen because of too much oxygen (oxygen replaces nitrogen and causes atelectasis)
effects of oxygen toxicity
-vasoconstriction
-decreased CO
-decreased perfusion to the body
-thickened a-c membrane (shunt)
oxygen toxicity
-overproduction of oxygen free radicals
-caused by too much oxygen over an extended length of time
-PaO2 greater than 150
pulmonary dead space
-normal alveolar ventilation, poor blood perfusion
- anatomical and alveolar
shunt
-normal blood perfusion, poor alveolar ventilation
-anatomical and capillary
shunt causes
pneumonia, pulmonary edema, tissue trauma, atelectasis, mucus plugging
pulmonary dead space causes
cardiovascular shock, emphysema
v/q ratio
-ventilation to perfusion ratio
- normal is 0.8 mL (4mL/5mL)
alveolar ventilation (va)
VA=(VT-VD) x F
causes of hypoxemia
-hypoventilation (high PaCO2)
-diffusion block (thickening of alveolar-capillary membrane)
-V/Q mismatch
Pb
760 mm Hg at sea level
PH2O
47
PaCO2
from ABG
A-aDO2
-difference between alveolar and arterial oxygen
-A-aDO2=PAO2-PaO2
-normal is 2-10 torr
-low is good
-high is bad
cylinder safety
-oxygen is a fire hazard
-keep liquids away from oxygen
-labeled
-valve is fully closed
-never drop cylinders
-secure cylinders
-use dollies when lifting
Thorpe tubes
-pressured uncompensated: some ventilators and anesthesia machines
-pressured compensated: prevents change in downstream resistance, back pressure, most of them are these
Piss
pin-index safety system
Diss
diameter index safety system
Tiss
thread index safety system
Department of Transportation
responsible for construction standards
National Fire Protection Agency
sets standards for storing medical gases
Food and Drug Administration
determines purity standards and labeling
Compressed Gas Association
sets safety standards by making recommendations
High flow nasal cannula
-loss of muscle tone
-#cause of sleep apnea
-obstruction caused by tongue
-loss of consciousness
-central nervous system depression
-drugs
advantages of LVN
-controlled FiO2
-humidification
-optional heat (heater donut)
indications for LVN
-trach patient (not ventilated)
-trach mask
-t-piece
-oxyhood (for babies)
-face tent
Large volume nebulizers (lvn)
-bland aerosol setup
-wet set
-trach setup
magic box
-air:o2 ratio
-entrainment devices(venturi mask, lvn, jet nebulizer)
patient inspiratory demand (flow)
=Ve x 3
(Ve=Vtxf)
device total flow
=(air:O2) x flow rate
venturi mask-Bernouli’s principle
-the amount of air entrained varies directly with the size of the port and velocity of O2 at the jet
-velocity of a substance- gas moving through a tube at a constant flow is indirectly to the diameter of the tube. (the smaller the tube, the faster the velocity)
venturi mask
-air-entrainment mask
-flow varies; should provide output flow more than 60 lpm
-O2 range: 24-50 %
-best for pts in unstable condition who need precise low FiO2
- the higher the FiO2 the lower the total flow
Calculating FiO2
FiO2= 21 or 20 + (4 x liter flow)
high flow devices
deliver more total flow than a patient’s inspiratory demand
nasal cannula
-up to 6 lpm
-variable oxygen stability
-for pts in stable condition who need low FiO2
-easy to use, disposable, low cost
-O2 range: 22-40%
-low flow
non-rebreather mask
-minimum of 10 lpm (always flush)\
-O2 range: 60-80%
-best for emergencies; short term therapy requiring high FiO2
-low flow
low flow devices
deliver less than the total flow than a patient’s inspiratory demand
alveolar gas equation (PAO2)
-PAO2=(Patm-PH2O) x FiO2 - (PaCO2/RQ)
or
-PAO2=(Patm-PH2O) x FiO2 - (PaCO2x1.25)
-Patm or Pb is 760
-PH2O is 47
PAO2
partial pressure of alveolar pressure
room air
21% oxygen
high flow devices
-venturi mask
-high flow nasal cannula
-cpap
-bipap
-ventilator
low flow devices
-nasal cannula
-simple mask
-partial rebreather mask
-non rebreather mask
-face tent
examples of ischemic/circulatory hypoxia
-shock
-coronary artery disease
-peripheral vascular disease
-heart attack
ischemic/circulatory hypoxia
-low blood flow
-low CO
-low preload
-low contractility
-increased afterload
histotoxic hypoxia (cellular hypoxia)
-dysoxia: inadequate tissue oxygenated
-normal PaO2 and hemoglobin
-inability of mitochondria to metabolize O2
-severe acidema (low pH)
-severe alkalemia (high pH)
examples of histotoxic hypoxia
-cyanide poisoning
-carbon monoxide (CO) poisoning
Cardiac output
-CO
-heart rate x stoke volumee
examples of anemic hypoxia
-carbon monoxide (CO) poisoning
-trauma (bleeding)
-malnutrition
-iron deficiency
-B12 deficiency bone marrow problems
anemic hypoxia
-normal PaO2
-reduced Hb to carry oxygen to tissues
-blood loss (and therefore oxygen loss)
-reduced blood content of arterial blood (CaO2)
-CaO2=(hb x 1.34)(SaO2/100)+(PaO2x0.003)
4 points of partial pressure
-atmosphere
-airway
-alveoli
-artery
hypoxic hypoxia
-low arterial PO2 (PaO2)
-low atmospheric O2
-inadequate alveolar ventilation
-insufficient O2 diffusion through capillaries
-less hemoglobin (Hb) is converted to oxy-hemoglobin
-low A-aDO2
causes of hypoxic hypoxia
-high altitude
-fluid in lungs (pulmonary edema)
-airway obstruction
-lung disease (COPD, pulmonary fibrosis,etc)
4 types of hypoxia
-anemic
-hypoxic
-ischemic/circulatory
-histotoxic/tissue
hypoxia
cellular deficiency of oxygen
oxygen indications
-hypoxia (4 types)
-tachypnea (fast breathing)
-cyanosis (blue, low O2)
-disorientation(confused)
-cardiac arrhythmias
-tachycardia (fast heartbeat)
-labored breathing (increased wob)
-pre-surgery
-anemia
-carbon monoxide poisoning
-high altitude
