Nitrous oxide-Test

Analgesic Properties (Pain Control)

-Raises the patient's pain threshold when given before intraoral injections

-Used when other drugs are contraindicated (allergy)

-Has the ability to manage both pain and fear

Anxiolytic Properties (Sedative Effects)

-Assist patients in handling their fear or anxiety by producing sedation or a sense of well-being.

-Patients become calm, relaxed, and able to tolerate the situation better

•Amnestic Properties

Patients often cannot recall their pain or anxiety or its duration

Passage of time tends to become unclear or compressed

•Onset of Action

Rapid onset - begin in less that 30 seconds, with peak usually occurring in less than 5 minutes

Titration

•The process of administrating a drug incrementally to a specific level or endpoint.

Titration is a safety feature - minimizes unintentional overdose

Combining Nitrous Oxide and Oxygen Sedation With Other Methods

•N2O/O2 is enhanced with the spoken word. Soothing, calm, encouraging words and actions help with relaxing effects.

•Distraction Techniques

•Audioanalgesia - Addition of music

•Oral Medication - Such as diazepam etc.

•N2O/O2 and local anesthesia - Local anesthesia and N2O/O2 combined offer a superior pain and anxiety management

Dinitrogen monoxide (N2O)

•a stable, linear compound. It is slightly sweet-smelling, colorless gas.

Nitrous Oxide

•a gas at room temperature. Becomes a liquid when compressed into a cylinder but returns to a gas through the process of vaporization when the tank is opened.

•The US Department of Transportation classifies N2O as nonflammable; however, it supports combustion. (Pg. 31)

•Joseph Priestly was credited with discovering O2.

•Preparation

Primarily prepared by evaporation of liquid air or by heating

potassium chloride using manganese dioxide as a catalyst

Nitrogen and other elements evaporate, leaving liquid O2

Also produced by plants during photosynthesis

•Characteristics

At gaseous state is odorless, colorless and tasteless

Supports combustion but alone is not flammable

•Users of Nitrous Oxide

85% to 90% of N2O produced by major manufacturing companies is used in health care

Of this 80%-85% is used by hospitals during general anesthesia

Dentistry uses up to 10% of the N2O in ambulatory clinics

Food industry uses 5% to 8% of the N2O manufactured. It acts as a propellant for dairy products, such as whipped cream

N2O is used in the agent that inflates an automobile air bag

Used in the manufacture of computer chips

N2O has also been used in hybrid rocket engine

The FDA regulates the N2O industry.

They have established manufacturing practices and quality system requirements for companies that produce and package gases.

The US Department of Transportation

•oversees the packaging and transport of the gas. Considered hazardous material because of the pressurization.

The CGA and the Gases and Welding Distributors Association

•have recommended guidelines for N2O sales and security. Identify measures to minimize theft and promote safe use.

The National Fire Protection Association

sets parameters for levels of health care facilities to minimize the hazards of fire and explosion.

Cylinders are imprinted with critical information

•such as origin and age of the cylinder, inspection compliance, etc.

•The size of the cylinder has a direct relationship with the economy of its use. Large cylinders are more cost-effective for high-frequency users. Different sizes are available

A full N2O cylinder contains

•approximately 95% liquid and 5% vapor. Liquid N2O in the tank is vaporized by the ambient air.

A full cylinder will measure

•750 psi on the pressure gauge.

•Because the liquid is vaporized as the gas is used, this reading is not proportional to the actual amount of gas available in the cylinder.

•Therefore, the gauge will not show a pressure decrease until the tank contains approximately 20% N2O.

•O2 is found as a gas in a cylinder. When full it will indicate approximately

2000 psi

•The pressure gauge for O2 will accurately

•indicate the amount of gas present in the cylinder.

Fail-safe mechanism was developed in the

mid-1970's. This prevented the delivery of 100% N2O and ensured that no less than 21% O2 would ever be delivered to the patient. Today that percentage is 30.

Central gas supply is an option for practices who prefer N2O/O2 sedation availably in several operatories as a

"built-in" system.

a)Is preferred when; there is a high frequency of use, cost-savings, convince, and space-saving features

b)Most conveniently and effectively used when it is incorporated as part of the operatory design.

The hub of a central gas supply system

is its manifold

This is a device that connects several large cylinders of gas together and ensure the constant availability of gas to each operatory through copper lines within the walls.

a) A manifold will transfer the gas supply from one tank to another when one is out.

For gases to be dispensed safely, there must be a means for reducing the amount of pressure in the cylinder.

•Regulators and pressure-reducing valves serve this purpose. Regulators are commonly found on or near the cylinders of central supply delivery systems. Pressure is further decreased within the flowmeter.

Alarm systems will alert if the pressure of the gas falls

below 40 psi or becomes greater the 60 psi.

Pressure relief valves exhaust

any gas with a pressure greater that 75 psi.

Large cylinders are used in central supply systems. Another safety feature is located within the thread valves that open the cylinders. Threaded stems are

•designed to fit into specific cylinders, thus preventing the cylinders from being filled with the wrong gas. Cylinders must be secured to the wall, usually with chains around each cylinder.

All gas from the manifold travels through

precleaned, degreased copper tubing and pressure tested for 24 hours

•A portable as delivery system is often used when N2O/O2 sedation is not used frequently. This unit has smaller tanks which can be moved to different locations

The yoke stand of the portable machine is

•the backbone and supporting structure on which the equipment rests. Stands typically hold four tanks.

Metal pins, specifically arranged, protrude from the yoke onto which the cylinder is fitted.

•This precise mechanism is designed to prevent the incorrect cylinder attachment to the yoke also know as pin index safety system

Regulators are also on the portable system.

•Gas is reduced through hosing connected to the back of the flowmeter, which is the portion of the unit with parts such as switches and knobs. These hoses are often color-coded and are purposely vary in size and threaded-end connections to prevent incorrect gas flow.

flow meter

•highly calibrated device that sits on top of the yoke assembly and is mounted to an arm or on the wall or is located within a cabinet. Gas flows from the cylinder through the flowmeter. The flowmeter indicates the amount of gas being delivered to the patient.

•One of the most important safety features is the flowmeter's fail-safe mechanism. A valve opens to allow N2O flow only when there is for of O2 to the system. Any time the O2 flow is less than 30%, N2O stops flowing. This prevents the potential delivery of 100% N2O and is standard on all sedation units made today.

flow meter purposes

•Its primary purpose is to provide a source of additional gas should the need.

•Provides a mechanism for monitoring the patient's respiration.

•In an emergency it can provide positive-pressure O2 to the patient. The bag is gently squeezed to empty its contents; the action is like that of a manual-resuscitator bag.

conduction tubing

Gas is delivered through tubing or hose stemming from the unit and attaching to the breathing apparatus.

Care should be taken to prevent kinking in the hose. If this happens the patient may alert the operator of difficulty breathing. This will cause the reservoir bag to overfill.

Tubing diameters vary, with most tubing narrowing near the attachment of the breathing apparatus.

Breathing Apparatus (Nasal Hood or Face Mask)

Gas may be delivered to the patient through a nasal hood or a full-face mask. All mask currently made are latex free.

The nasal hood is most used with today's sedation equipment. The nasal hood is designed to fit snugly over the patient's nose so that gas does not leak out from the sides. Several sizes are available.

Hoods are also available in a variety of scents.

The most current models of nasal hoods are designed for single-patient use. Regarded as disposable because they are not sterilizable.

Reusable versions of the hoods are also available but must be sterilized between patients.

All nasal hoods must have scavenging capabilities. Scavenging hoods are designed to provide fresh gas to the patient through one-two hoses, while an additional one-two hose evacuates gas being exhaled by the patient via a vacuum system that exhausts the gases out of the building.

•Systems in the US are designed to deliver a minimum of 30% O2 at all times. The equipment is designed to deliver no more than 70% N2O at any time.

•An index pin safety system is designed to prevent accidental attachment of the N2O to an O2 portal

The diameter index safety system (DISS),

the hoses from the cylinder to the unit are unable to be attached to the wrong stem.

Near the unit's reservoir bag is an emergency air inlet

•This provides an additional source of air for the patient

The Oxygen Flush Button/Knob found on the flowmeter

•will dispense 100% oxygen at a high flow rate into the reservoir bag.

Cardiovascular System-N2O

1.does not negatively affect the any significant physiologic changes.

a. Blood flow to major organs is not significantly affected.

b. Has a positive effect in myocardial infraction by providing supplemental O2

c. Blood pressure effects may be dose related. In most cases blood pressure was not affected. Research has shown that blood pressure readings have been lowered as a result of relaxation.

d. Heart rate may decrease as anxiety is lowered.

Respiratory System

2.System-Because the route of administration is inhalation, airway must be open. If the patient is unable to breath through the nose, insufficient amounts of N2O2 will enter the respiratory system.

a.Any type of common infection-such as a cold, cough, sinus infection, bronchitis, or allergy-related symptoms (upper respiratory infections)-may occlude the nasal passage such that adequate air exchange will be incomplete.

b.Patients susceptible to hypoxia because of airway resistance, such as emphysema and chronic bronchitis should receive medical consultation.

c. Not contraindicated for asthma patients. Has a positive influence because anxiety can trigger an asthmatic episode.

d. Patients with severe chronic respiratory diseases should receive medical consultation before undergoing any type of sedation, such as COPD.

e. It is recommended that medical consultation be obtained before the use of N2O in any patient with cystic fibrosis(CF).

Pneumothorax condition may be complicated with N2O2 and should be avoided

central nervous system

like other anesthetics, can depress the central nervous system; however, the exact mechanism is unknown.

a. N2O2 sedation is contraindicated for patients having undergone recent pneumoencephalography or patients who are abusers of N2O.

Hematopoietic System

4.interferes of the vitamin B12-dependent enzyme methionine synthase

a. N2O2 sedations should be avoided, or medical consultation is advised for patients with pernicious anemia or other B12 deficiency.

Endocrine system

currently, no conditions of this system indicate medical consultation or postponement of treatment.

hepatic system

N2O is not metabolized in the liver, nor does it affect the liver in the presence of liver impairment.

a. No conditions involving the hepatic system indicate medical consultation or postponement of treatment.

Gastrointestinal system

the bowl exemplifies a nonrigid air space in which expansion occurs.

a. Sedation should be postponed for patients with a significant bowel obstruction.

Genitourinary System

8.does not pose any negative effect.

a.No condition involving the genitourinary system indicate medical consultation or postponement of treatment

Reproductive system

Most pharmacologic agents cross the placental barrier; N2O is no exception

a. N2O/O2 sedation is contraindicated for pregnant patients in the first trimester and medical consultation is advised at any other time during a pregnancy.

Neuromuscular System

N2O/O2 has no effect on patients with neuromuscular conditions.

a. Currently, no condition involving the neuromuscular system indicate medical consultation or postponement of treatment.

cancer

N2O/O2 - N2O/O2 has been used in the final stages of life as an adjunct for pain and anxiety management.

a. Should be avoided or postponed for patients receiving bleomycin sulfate therapy

Allergies

For more than 160 years there have been no known reported allergies to N2O.

a. Persons sensitive to latex may experience contact dermatitis form the nasal hood made from rubber products. Products are latex-free.

Cognitive disorders

For patients with a mental deficiency, such as Down syndrome, it is necessary to determine the ability of the individual to understand the sedation procedure.

a. If a patient can understand what to expect, then it would be appropriate to administer.

b. If the level of understanding is not present, then it should not be used.

The same rational is used for patients with Alzheimer disease and autism.

•Dental procedures may be completed with stage 1 hypertension (140-159) systolic and (90-99)diastolic