Nitrous Delivery Systems Flashcards
what are the four main divisions of nitrous delivery systems?
- demand flow units
- continuous flow units (what we use in dentistry)
- portable
- central (more complex)
what is the biggest source of contamination for Nitrous?
talking
what do regulators do?
- reduce pressure from 750-2200 psi to a safe 45-55 psi
- only used with central systems
- uses grease (cannot use petroleum based products w O2 lines bc it creates explosive mixture)
what color is used for Nitrous and what color is used for O2?
- Nitrous = blue (not fluted)
- Oxygen = green (fluted)
what are some of the advancements in flowmeters?
- digital
- increments of 0.1L
- built in alarms for O2 depletion
- emergency air intake valve
what are 3 available inhalation units?
- accutron - NO2 lock
- porter - automatic vaccum
- matrix
Nitrous oxide/oxygen when used in combination with sedative agents may produce?
- anxyiolysis
- consious sedation
- deep sedation / general anesthesia
how many people should be there to administer the Nitrous ?
- at least one additional person should be present in addition to the dentist
- this may be the chair-side dental assistant
when must an in-line oxygen analyzer be used?
if nitrous oxide and oxygen delivery equipment is capable of delivering less than 25% oxygen.
*the equipment must have an appropriate scavenging system
what must occur during administration?
-direct clinical observation of pt (do not leave the room)
what should be observed at all times while using nitrous/
- color of mucosa, skin, or blood should be continually evealuated
- oxygen saturation must be evaluated by pulse oximetry
- must observe chest excursions
- should auscultate breath sounds or monitor end-tidal CO2
what must happen during recovery and discharge?
- oxgyen and suction equipment must be immediately available in the recovery area and/or operatory
- must dertermine and document that oxygenation, ventilation, and circulation are stable prior to discharge
- must provide explanation and documentation of postoperative instructions to the patient
- dentist must determine that pt has met discharge criteria prior to leaving the office
what receptors is required by Nitrous for its action in caenorhabditis elegans
N-methyl-aspartate
what will prevent uptake of nitrous?
- nasal obstruction
- sinus problems
- mouth breathing
*may not be adequate for extremely anxious pt
what occurs in the pretreatment visit?
- explain technique
- consider trial administration
- preoperative instructions
what are the reoperative instructions to give your pt using nitrous?
- take preop meds if extremely anxious
- avoid heavy meals 4 hrs prior to treatment
- escort requirement if indicated
how do you monitor the pt during the procedure?
- preoperative vital signs
- verbal communication and periodic vitals
how should you prepare the equipment for use?
- open cylinders slowly
- inspect unit for cleanliness and leakage
how should you prep the pt before the nitrous?
- suggest restroom
- review med hx and record vitals
- baseline Trieger test
what are the 4 basic principles of administration?
- always 100% O2 pre-op before placing hood
- always 100% O2 post-op for 3-5 minutes
- titrate N2O to optimal effect
- always have 2nd adult present
what is the technique for administering N2O?
- position patient supine
- place unit behind patient’s head
- start O2 flow 5-8 liters/minute
- place and secure nasal hood
- observe reservoir bag
- begin to titrate N2O
what are the two techniques for titration of N2O?
- constant liter flow (recommended)
- constant O2 flow
*initial 20% N2O (approx 1L of 6L total)
what is the technique for constant liter flow?
- establish liter flow rate with 100% O2
- inc N2O to 1L/min, while dec O2 by 1L/min
- titrate by inc N2O by 0.5L/min and dec O2 by 0.5L/min
what are the adv to constant liter flow?
- smaller volume of gas
- less cost
- dec trace gases
what are the disadv to constant liter flow?
-easier to oversedate (with fixed increments)
what is the technique for constant O2 flow?
- establish O2 flow
- inc N2O by 1L/min (O2 constant)
- titrate by inc N2O at 1L/min
what are the adv of constant O2 flow?
- easy
- large volumes (breathing adequacy)
what are the disadv to constant O2 flow?
- more costly
- more trace gases
what is the ideal sedation with N2O?
-70% of pts at 30-40% N2O
- 12% required less than 30%N2O
- 18% required more than 40%N2O
what are the signs of oversedation?
- mouth closing
- mouth breathing
- nausea/ discomfort
- inappropriate responses
- dreaming
- uncooperative
- crying or laughing
- lack of muscular coordination
what three things do you do before discharging the patient?
- question the pt
- vitals
- motor coordination test (Triger test)
how common is excessive perspiration?
- 2-3% incidence
- peripheral vasodilation
- treatment is to dec N2O
when should you consider syncope?
- if pallor, dec BP, and inc HR
* give 100% O2
what is the most common cause of nausea?
- oversedation (more than 50%)
* also caused by long procedures, anxious pts, inherent tendency, full stomach
what is the tx for nausea?
dec N2O
what are the complications with vomitting?
- potentially serious, aspiration pneumonia, obstruction
- pediatric more often than adult
- early recognition of nausea is key to prevention
what is the management for vomitting?
- 100% O2
- remove dental instruments and rubber dam
- turn head to the side
- emesis basin (high volume suction)
- replace nasal hood (100% O2)
is shivering common?
not common but if it does happen it would be at the end of a procedure
*tx with reassurance and a blanket
where are the sources of contamination with the normal gas flow?
- exhaling valve
- nasal hood
where are the sources of contamination with the patient
- talking
- laughing
- mouth breathing
where are the sources of contamination with the equipment?
-defective valves and fittings
where are the sources of contamination with the air conditioning?
recirculation
what are the four factors affecting trace gas concentrations
- frequency of use
- operatory size
- operatory ventilation
- open v closed operatory
what are the different ways to detect trace N2O?
- inspection of rubber goods
- soapy water test
- professional service company
- infared analyzer
what is the ADA recommended concetration of N2O?
50 ppm
*within 6 inches of a dentist’s nose
what is the ppm for scavenging hoods?
31ppm +/- 4.8ppm
what things concerning N2O does the ADA recomend?
- scavenging nasal hood
- venting of suction outside
- minimize patient talking
- test equipment for leaks
- air monitoring program (50ppm or less)
what have animal studies shown as far as nitrous chronic exposure?
damage to brain cells and bone marrow suppression
what are human reports of the chronic exposure to nitrous?
- peripheral neuropathy
- long/term high dose abuse (greatest risk)
who does the sexual phenomena of nitrous affect more?
females
- always have an assistant present
- avoid concentrations greater than 50%
what are the legal considerations with nitrous?
- never leave a pt unattended
- get signed parent consent for children
- monitor vitals
- document vitals, %N2O, administration times, 3-5 min of 100% O2, and trieger test
what is the N2O cylinder properties?
- gas AND liquid
- blue
- 750 psi
- 1590 L
what is the O2 cylinder properties?
- gas ONLY
- green
- 2000 psi
- 625 L
