Exam 4 Flashcards
What are hazards of O2 therapy?
- Oxygen toxicity
- Depression of ventilation
- Retinopathy of prematurity
- Absorption atelectasis
- Fire hazards
What are the symptoms of oxygen toxicity?
- Maintain FiO2 below 50-60% if possible
- substernal chest pain, coughing, restlessness
- decreased diffusion
- decreased lung surfactant / consolidation
What are the symptoms of depression of ventilation?
- confused, lethargic, decreased respiratory rate, decreased chest expansion
what are the symptoms of Retinopathy of prematurity?
PaO2 is the issue!
- PaO2 = 40-60%
what is Absorption atelectasis?
Greater risk with FiO2> 50%,
- High O2 depletes Nitrogen from the lungs and reduces the production of surfactant this then causes atelectasis
- Post-op pts.
- Central nervous system dysfunction pts.
- Retained secretion pts.
KNOW THE MATH
KNOW THE TABLE FOR PAO2 AND FiO2
what is co-oximetry?
Arterial blood gases
- Measures the O2 carrying state in the blood (SaO2)
- uses wave lengths or light to measure
What is the troubleshooting with pulse oximetry?
- Motion
- Low perfusion
- Ambient light
- Electromagnetic Interference (MRI)
- Nail polish
- Dark skin pigmentation
- edema
- Anemia
- CO2 poisoning
What are oxygen analyzers?
- measure inspired O2 concentrations
- most exam answers are calibration
what is the difference between fuel cell and clark analyzers?
Fuel cell
- battery powered
requires exposure to 100% air
Clark
- powered by fuel cells
- If unable to calibrate, change the fuel cell.
what are the home delivery systems and their indications?
- Cylinders - for patients who use small volumes of gas
- Liquid - patients who require high flow rates of oxygen
- Concentrators - oxygen use
what is a transtracheal catheter?
- long term use
- Delivers and FiO2 of 22 -35%
- surgically placed in trach
what is the resevoir cannula?
It requires less O2 to achieve the same effect
what are the classifications for hypoxemia on room air (21%)?
- Normal – 80 to 100
- Mild – 60 to 79
- Moderate – 40 to 59
- Severe - <40
what are the classifications for supplemental O2?
- Corrected – 80 to 100
- Under corrected - <80
- Overcorrected - >100
what is carboxyhemoglobin?
- The binding of CO prevents O2 from binding to hemoglobin.
- it’s reversible
- Pulse oximetry assumes that the patient has normal hemoglobin, PaO2, and SpO2 relationship (should be subtracted from SPO2)
where are the sensor cites for pulse oximetry?
Finger, forehead (temporal), toe, foot (pedal), nose, wrist, hand
what should we chart during pulse oximetry?
- Date, time, actual reading
- Patient’s position, activity level, location of monitoring
- FiO2, delivery device
- Probe type and placement
- Patient’s clinical appearance
what do you do when you get an incorrect reading on an oxygen analyzer?
Always recalibrate first before taking a second reading
how do you get accurate results during oxygen analyzation?
- Expose sensor to two gases - 100% and 21%
- Expose to 100% and adjust to that reading (per Egans)
- Expose to room air
- Use only if calibrated
What are oxygen analyzing results effected by?
- Water
- Positive pressure
- High altitude – Most effected by altitude changes
- Torn membrane
- Lack of electrolyte gel
what is the troubleshooting with oxygen analyzers?
Clark - change batteries
Galvanic fuel cell - replace fuel cell
what should a prescription for home oxygen include?
- Flowrate in L/min, concentration of device or both
- Frequency of use in hours/day
- Mode of delivery
- Duration of need (up 12 months)- revaluated after 12 months
what are the advantages and disadvantages of cylinder delivery devices?
advantage - prevents waste and can be stored easily
disadvantage - more costly, big and bulky
what are the advantages and disadvantages of liquid oxygen delivery devices?
advantage - high flow system, has portable units,
disadvantage - professional refills, not good to store (evaporates), potential spills, frostbite and evacuation for 20 mins.
what are the advantages and disadvantages of cencentrators?
Advantage - cheaper, uses room air, Generally go up to 5L but some have capability of 10L
Disadvantage - Runs on electricity, has limited portability, On higher flows O2 concentrations can fall to 85-93%, Less pure than tanks
how do you calculate the duration of the liquid O2 system?
liquid weight X 860/flow
what is the maintenance for a concentrator/
- if molecular sieves aren’t working: analyze FiO2, check circuit breaker/fuse
- Patients must check and change filters weekly
- Outlet needs to be grounded
- Backup system (tank or liquid) must be available in case of power failure – notify electric company
what does an O2 conserving device do?
– uses flow sensor and valve to synchronize gas delivery with beginning of inspiration
what are the advantages and disadvantages of Transtracheal catheter?
Advantages
- Upper airway acts as reservoir
- Portable O2 use / time extended
- Increased mobility
- Increased comfort and self image
Disadvantages
- High cost
- Mucus plugging
- Lost tract
- Patient selection, education, follow up
- Infection
- Bleeding
what are the advantages and disadvantages of Reservoir cannula?
Advantages:
- Low O2 use
- Less discomfort due to decreased flow
- Increased mobility
Disadvantages:
- Replace every 3 wks due to membrane wear
- No humidification
- Unattractive and cumbersome
- Must exhale thru nose to reset membrane
- Pendant is heavy and can irritate ears/face
what are the indications for pulse oximetry?
- surgery
- Lung disease
- Heart disease
- Sleep apnea
- Oxygen therapy
- SOB
what happens to the SpO2 when smoke is inhaled?
the SpO2 level (oxygen saturation in the blood) decreases
what are some oxygen in home safety rules?
- store away from heat source
- always position upright
- have backup device
- do not wear wool
- do not use oil based products
- do not use flammable products near oxygen
how do we avoid complications of O2 therapy?
Monitor SpO2/ABG
what are the normal values of O2?
- PaO2 80-100mmHg (COPD 50-65mmHg)
- PaCO2 35-45 mmHg
- SaO2 95-100%
- SpO2 94-100%
- Clinically keep SpO2 > 92%
What is the estimation for saturation?
PaO2 is 30 less than SaO2
- ex. PaO2 = 40mmHg then SaO2 = 70%
ALWAYS TREAT PATIENTS, NOT MEASUREMENTS
- always collect ABGs
- do NOT use to measure hyperoxia
- +/- for final readings
what is the response time?
- varies by manufacturer
- vary from 10-60 seconds
How do we assure an accurate reading on pulse oximetry?
- ALWAYS compare HR on oximeter to patient’s actual HR
- Most accurate: Compare SpO2 and PaO2
what are the different types of oximetry?
- Hemoximetry (Co-oximetry)
- Pulse Oximetry
- Venous Oximetry
- Tissue Oximetry
