Chapter 10 Oxygen therapy Flashcards
Oxygen is a drug
given based on need and therapeutic benefit
Oxygen can cause harm
oxygen can actually cause harm at reperfusion situations at cellular level.
sometimes oxygen can send other toxins around the body as free radicals
Oxygen cylinders
- D
- E
- M
- G
- H
seamless steel or light weight alloy
liters of oxygen:
D= 350 LT
E= 625 LT
M= 3000 LT
G= 5300 LT
H= 6900 LT
Color code for oxygen
green or green and white
sometimes stainless steel, and aluminum
Oxygen cylinder saftey
cylinders should never be allowed to go below 200 psi
anything below this amount would not be able to push out O2 to a patient.
Pressure regulators
oxygen stored in a cylinder at 2000 psi is too much to deliver to a patient. so regulators must be used to bring the pressure down to a workable pressure (30-70 psi)
- on E size cylinders, regulators are secured to the valve assembly.
- E and larger size cylinders are used with a threaded portion on the regulators which can be used for high pressure air systems
hazards to oxygen therapy
end stage COPD patients switch the trigger for breaths from high carbon dioxide, to low oxygen become hazards to oxygen therapy.
as high amounts of O2 will prompt the body to stop breathing due to sufficient O2
Nonrebreather mask (NRB mask)
flow rate
12-15 liters per min
80-90 % O2 concentrate
nasal cannula
1-6 liters per min (no higher than 6)
24-44% O2 concentrate
high flow (above 6 liters) will cause harm to the nasal canal and dry out the nasal mucus membrane
partial rebreather mask
9-10 liters per min
40-60% O2 concentrate
used so patients can maintain a certain amount of carbon dioxide in their blood to promote breathing.
-this mask is not typically used in EMS but, is common with patients who use O2 at home.
venturi mask
up to a max of 15 liters mer min
24-60% O2 concentrate
mixes O2 with inhaled air. can be adjusted by using different tips allowing for different percentages
exact oxygen delivery
Tracheostomy mask
8-10 liters per min
varies and can be set by the patient
-designed to be placed over a stoma or tracheostomy
NRB
-non rebreather mask
EMTs best way to deliver high concentrations of oxygen to a breathing patient.
inflate bag first by covering air port in mask
perfect for patients with signs of hypoxia
facial injuries
blunt injuries to face frequently result in severe swelling or bleeding that could block or partially block the airway
frequent suctioning may be required, along with airway adjunct or endotracheal tube
Intubation
using the endotracheal tube to create an airway on a non responsive patient.
EMT may be requested to assist a paramedic in installing the tube.
-B.U.R.P (Bringing Up and to the Right Position)
a process of assisting medic by maneuvering the vocal cords into view for the paramedic
Proper placement of tube during intubation
medics use at least 2 methods to ensure proper placement.
- Auscultation of both lungs and the epigastrium (stethoscope to listen to both lungs with sound only coming from lungs not the epigastrium)
- capnometry (end-tidal C02 detector device)
wrong tube placement is fatal mistake if gone un noticed
intubation tube placement
average adult 22 cm mark will be at the teeth
intubation ventilation
ventilate about 10 breaths per minute, or every 6 seconds (press then count 5 seconds)
take note of any changes to ventilation pressure, a change in resistance could mean tube has fallen out of place, or something else is wrong.
intubation during defibrillation
remove the bag from the tube to avoid the unnecessary weight of the bag on the airway.
FROPVD
flow restricted oxygen powered ventilation device
- assisted ventilations at
- 10-12 per minute adult
- 20/min for child or infant
100% O2 and up to 40lit per min
inspiratory pressure release valve opens at approximately 60 cm of water pressure
prolonged exhalation
indicates a possible lower airway obstruction
prolonged inhalation
indicates a possible upper airway obstruction
Positive pressure ventilation
forcing oxygen into lungs when a patient has stopped breathing or has inadequate breathing
Decreasing cardiac output
- decreasing cardiac output/ dropping blood pressure
normally the heart uses negative pressure to help fill the chambers of the heart with blood.
when positive pressure is used to ventilate, it eliminates the negative pressure that assists in filling the heart with blood.
to mitigate damage, pressure must be just enough volume to raise the chest
dangers of PPV positive pressure ventilation
- decreases cardiac output / drops blood pressure
- gastric distention
- hyperventilation
gastric distention
filling the stomach with air/oxygen/pressure
(this causes vommiting, and restricted diaphragm movement
hyperventilation
-blowing off too much carbon dioxide can cause vasoconstriction (narrowing of blood vessels)
and limit blood flow to the brain
A.T.V
automatic transport ventilator
respiratory distress
unusual sounds during breathing
elevated breathing rate, but adequate volume
sometimes normal or pale due to vasoconstriction
sometimes agitated or anxious mental state
respiratory failure
unusual sounds during breathing, beware absent sounds
too fast or too slow, irregular breathing. inadequate minute volume
pale, blue, sometimes blotchy (mottled)
altered mental status
respiratory arrests
no breathing sounds at all
no breaths
pale or blue
typically unconscious or becoming unconscious
pressure regulators
- low pressure flowmeter
- pressure compensated
- constant flow selector valves are in general use in the field
pressure compensated flowmeter
this meter is gravity dependent and must be in an upright position to deliver accurate reading
-upright calibrated glass tube in which there is a ball float.
rises and falls according to the amount of gas passing through the tube.
meant to larger oxygen cylinders in the ambulance (M,G,H)
constant flow selector valve
this type of flowmeter is gaining in popularity.
-has no gauge, and allows for adjustment of flow in liters per minute
adjusts in stepped increments (2,4,6,8 ect…)
can operate in any position
be used with any cylinder
CAN BE USED WITH NASAL CANNULA OR NON REBREATHER MASK
high pressure flowmeters
used for oxygen powered devices
- thumper (CPR machine)
- CPAP & BiPAP devices
indications of high flow is threaded connection on oxygen regulator, or a thick green hose type tubing
humidifier
often used on COPD patients or children to make them more comfortable
-steril single use humidifiers are available and preferred
oxygen toxicity
lungs react unfavorably to over oxygenation and air sac can collapse
-extremely rare in the field
infant eye damage
oxygen over a long period of time can develop scar tissue on retina of eye
blind insertion devices
- King lt-d
- laryngeal mask airway (LMA)
to apply a blind insertion device, the head should be in a neutral position, not sniffing position
these blind insertion devices do not have masks
dead space
30% of tidal volume
