nitrous oxide pt. 2

what is the percentage of adults that have dental anxiety?

~ 50% to 80%

T/F: pain receptors (nociceptors) are first to receive a stimuli

TRUE

what is psychogenic pain?

pain that does not happen directly because of an injury or illness

what signs of fear would you expect to see?

• white-knuckle syndrome

• increased heart rate

• increased BP

• increased respiration

what is safe to use to manage fear?

diazepam (valium)

• peak effect in ~ one hour

T/F: pain is always physiological and not psychological

FALSE

manufacturing and delivery of nitrous is regulated by…

the FDA

what size tanks are most common?

E size tanks

in the united states, what colors are N2O and O2 tanks?

N2O = blue

O2 = green

under NO circumstances, what substances should NEVER come in contact with gas or gas delivery equipment?

grease, oil, or any other organic substance

how should cylinders be stored?

vertically and chained to a wall or secured in carts as a means of storage

should nitrous be readily accessible?

no

a full N2O cylinder contains approximately __% liquid and __% vapor

95 ; 5

a full cylinder of N2O will read ____ psi at 70 degrees

750

why is the reading on the gauge not proportional to the actual amount of gas in a N2O cylinder?

it is due to the vaporization of the liquid

when the O2 cylinder is full, what is the psi?

2000

what sedation-specific information should be included in the medical history?

• medical problems including OSA

• airway concerns

• respiratory conditions

• previous sedation experience

• current medications

• psychotropic drug use

ASA I

A normal healthy patient (non-smoker, no or minimal alcohol use)

ASA II

A patient with mild systemic disease (current smoker, pregnancy, well-controlled DM/HTN, mild lung disease)

ASA III

A patient with severe systemic disease (poorly controlled DM or HTN, COPD, ESRD, alcohol dependence/abuse, implanted pacemaker, history > 3 months of an MI, TIA, CVA, CAD/stents)

ASA IV

A patient with severe systemic disease that is a constant threat to life (< 3 months MI, CVA, TIA, CAD/stents, ESRD w/o regular dialysis)

T/F: vital signs should be taken only before nitrous administration

FALSE. vitals should be taken before and after to provide a baseline

must know BP!

dairy should be avoided for a minimum of how many hours before nitrous? (to prevent vomiting)

6 hours

informed consent includes what?

• purpose of the procedure

• how it will be accomplished

• what to expect

• risks and benefits

• alternative options must be offered

• have the opportunity to ask questions

• recommended to have a designated form for nitrous administration

T/F: the patient should never be left alone during nitrous administration

TRUE

level of consciousness should be monitored through what?

questioning

ventilation should be monitored through what?

observation or auscultation

• reservoir bag

• frequency and depth of respiration

can pulse oximetry uncover early hypoxemia?

yes

T/F: cyanosis is an early sign of respiratory distress

FALSE. it is a late sign

what should the sedation record include?

• the reason why N2O was administered

• the peak percentage of N2O

• the minute volume

• the duration of the procedure

• the amount of post-op oxygen time

T/F: personnel who use nitrous and/or LA must be certified in BLS that includes CPR, AED use and management of airway obstruction

TRUE

According to the ASA Physical Status Classification System, a 52-year-old patient with hypertension being controlled by daily medication would be classified as a

A. ASA I (1)

B. ASA II (2)

C. ASA III (3)

D. ASA IV (4)

B. ASA II (2)

what is titration?

a method of administering a drug in incremental amounts until a desired endpoint is reached

The concept of individual biovariability when administering drugs is based on the premise that

A. all people will react to a drug regardless of the dose.

B. individuals are likely to require the same amount of a drug when prescribed at different times.

C. individuals may not react similarly to the same drug on different days.

D. the majority of people react the same way to the same drug.

C. individuals may not react similarly to the same drug on different days.

what should be inspected before using a nitrous unit?

check all equipment for leaks, tears, or damage in the tubing and reservoir bag

what should be done if the tubing and reservoir bag are not attached?

connect the tubing and reservoir bag before use

how are the nitrous oxide and oxygen cylinders activated?

open both cylinders by turning the knob counterclockwise with a wrench

what must be checked on the flowmeter before administration?

ensure the master switch is in the ON position

how is the scavenging system activated?

turn on suction to the appropriate level (at least 45 L/min)

how should the scavenging system sound?

suction should be barely audible

what can happen if scavenging suction is too strong?

it may compromise the flow of gases

why is it better to start with slightly more oxygen flow initially?

to avoid a suffocating feeling

how full should the reservoir bag be before placing the nasal hood?

about 2/3 full

how is the reservoir bag inflated initially?

press the O2 flush button until the bag is 2/3 full

what should the patient be told regarding the nasal hood?

adjust it at any time to maintain a snug but comfortable fit

how can gas leakage around the nasal hood be minimized?

place gauze around the periphery of the hood

what may hissing from the nasal hood indicate?

gas flow is too high

what does a bulging reservoir bag indicate, and what should you do?

too much gas is being delivered

• decrease oxygen flow until the bag is about 2/3 full

what does a collapsing reservoir bag indicate, and what should you do?

the patient is breathing in all the gas being delivered

• increase flow and reinflate the bag using the O2 flush button

once the appropriate liters per minute are established, what happens to the flow rate?

it remains constant for the duration of the procedure

what amount of nitrous oxide should be administered initially?

1-1.5 L/min

how should nitrous oxide be increased during titration?

in increments of 0.5-1 L/min

how long should you wait between nitrous increments?

at least 60 seconds

why should you wait between nitrous increments?

to allow the peak effect of the previous dose to occur before adding more

when should post-operative oxygenation begin?

near the end of the procedure

how long should 100% oxygen be administered after nitrous?

minimum of 5 minutes

what should be done if the patient does not feel well after 5 minutes of oxygen?

continue 100% oxygen until recovery is complete

what position should the patient be in during recovery?

slightly upright with the nasal hood in place

what blood pressure difference is considered acceptable after recovery?

within 10 mm Hg of pre-op values

what pulse difference is considered acceptable after recovery?

within 10 beats/min of pre-op

what respiration difference is considered acceptable after recovery?

within 5 breaths/min of pre-op

what should be turned off immediately after use on a portable unit?

gas cylinders

when are central gas systems usually turned off?

at the end of the day

when should the lines be bled on a portable unit?

at the end of the day

what is the purpose of the fail-safe system?

prevent administration of 100% nitrous oxide

why can't the oxygen flowmeter usually go below 2–3 L/min?

to ensure oxygen is always being delivered and prevent 100% nitrous administration

An acceptable amount of nitrous oxide to begin the titration technique for an adult requiring 7L/min would be _____ on a machine with floating balls in glass tubes.

A. 1 to 1.5 L

B. 2 to 2.5 L

C. 3 to 3.5 L

A. 1 to 1.5 L

The purpose of the O2 flush button is to

A. Fill the reservoir bag, when necessary

B. Flush the patient with O2 at the end of the procedure

C. Monitor the patient’s respiration

D. Substitute for CPR in an emergency situation

A. Fill the reservoir bag, when necessary

why is nitrous exposure a concern during pregnancy?

it may impair fetal development

A major source of trace N2O that contaminates the ambient air in a dental office is from

A. Cracked reservoir bags.

B. Improperly soldered central piping.

C. Leaking valve stems on the cylinder.

D. The patient talking.

D. The patient talking

What is the occupational exposure limit in the United States per NIOSH?

A. 25 ppm

B. 45 ppm

C. 50 ppm

D. 100 ppm

A. 25 ppm

who are the biggest abusers of N2O?

dental professionals

what can happen as a result of chronic exposure to nitrous?

peripheral neuropathy

• tingling, numbness in the extremities

• weakness and incoordination

• lack of strength and dexterity in the hands

• slowed gait

• electric shock feeling on flexion of the neck

what precautions should be taken during nitrous sedation?

• have a third party nearby

• titrate to the appropriate level of sedation

• avoid oversedation

Symptoms of neuropathy commonly seen in persons who chronically abuse N2O include the following except one. Which one is this exception?

A. Impaired psychomotor function and dexterity

B. Insomnia, acute sensitivity, hyperactivity

C. Tingling and/or paresthesia in extremities

D. Unsteady gait, clumsiness

B. Insomnia, acute sensitivity, hyperactivity

what information must be included in informed consent?

• patient identification

• proposed treatment and alternatives

• cost

• risks/adverse outcomes

• opportunity to ask questions

nonmaleficence?

do no harm

beneficence?

provide care that benefits the patient

autonomy?

the patient’s right to make informed healthcare decisions

veracity?

truthfulness