Partial Handout for Online Portion - City University of ...websupport1.citytech.cuny.edu/Faculty/mfehrenbach/Handout.pdfsurgical pain relief via gas inhalation appeared at the very

Pain Control for the Dental Hygienists of the State of New York

Partial Handout for Online Portion History of Nitrous Oxide • Nitrous oxide was first identified around 1774 by the great English chemist, Unitarian

minister, author and all-around radical Joseph Priestley. Although Priestley suggested a potential medical use for the various gases with which he experimented, this potential was not tested until the late 1780s when English physician Thomas Beddoes began efforts to adapt gas inhalation for therapeutic uses. Beddoes' work eventually led to the founding of his Pneumatic Institution near Bristol, the hiring of a young Humphry Davy as research assistant and their experimental work over more than a year with Nitrous oxide. In the summer of 1800, Davy left us this tantalizing observation: "As Nitrous oxide in its extensive operation appears capable of destroying physical pain, it may probably be used with advantage during surgical operations in which no great effusion of blood takes place". Thus the concept of surgical pain relief via gas inhalation appeared at the very beginning of the nineteenth century. The medical community of the day met Davy's suggestion with stunning disinterest. At one such public demonstration in December 1844, in Hartford, Connecticut, dentist Horace Wells reconstructed Davy's observation about Nitrous oxide and began experiments with the gas on first himself and then his patients.

• In the following month he persuaded one of America's most famous surgeons, John Collins Warren, to let him demonstrate the gas in the operating theater of the Massachusetts General Hospital in Boston. When the patient cried out during the operation, Wells was hooted from the room by the medical faculty and students in attendance and the demonstration was widely perceived a failure. Almost two years later, in the same room, William Morton successfully demonstrated ether anesthesia for the same surgeon, and the battle over who "discovered" anesthesia began.

• Though Nitrous oxide had been in existence for years, it was used mainly for social entertainment. Wells is given the credit for becoming the first person to utilize the pain-relieving effects of Nitrous oxide in 1844 by having his own tooth extracted while under the influence of the "laughing gas". Throughout the year 1845, Wells used the gas in his dental practice, thus being given the credit by some as the founder of "modern anesthesia". After the effects of the gas had worn off, Wells exclaimed, "I did not feel so much as the prick of a pin. A new era in tooth-pulling has come!"

Copyright © 2007, Fehrenbach and Associates, Seattle, WA

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Online Material (continued): History of Local Anesthesia • Cocaine was widely used as a local anesthetic after Carl Koller (1857-1944) demonstrated its

effectiveness in 1884. Two months after Koller's discovery, an American surgeon, William Halsted (1852-1922), tried injecting the drug close to a nerve trunk to see if it would "block" the nerve conduction. Koller and other Europeans had only used cocaine anesthesia by topical application on mucous membranes. The first nerve blocked was the inferior alveolar (dental) nerve. Halsted experimented almost entirely on himself, blocking one nerve after another. Halsted became addicted to cocaine. He was made aware of the problem and made a valiant fight to break the addiction -- apparently with success.

• In 1901 Heinrich Braun discovered the vasoconstricting property of epinephrine and suggested its use with cocaine to prolong the anesthesia and slow the rate of absorption.

• Cocaine was a dangerous anesthetic and dentists had a difficult time getting profound anesthesia over a sufficiently long time without producing serious side effects. One approach to solving this problem was the invention of high-pressure syringes using snug-fitting needles inserted into either bone or dentin. A high degree of mechanical or chemical pressure was used to force the solution into a confined area of hard tissue. By the end of the 1800s, however, the addictive properties of cocaine had been recognized. Doctors, realizing they needed to develop substitutes for cocaine's active anesthetic ingredient, carefully studied the exact chemical structure of cocaine. Many of the first synthetic cocaine products that were developed were to irritating to be of any practical use.

• The first successful substitute was Ernest Fourneau (1872-1949) and his stovaine, discovered in 1904. Fourneau's product was soon followed, in 1905, by procaine, the discovery of German Scientist Alfred Einhorn. Einhorn gave his substance the trade name 'Novocaine', from the Latin novus ("new") plus cocaine. Introduced by Heinrich Braun (1862-1934) in 1905, novocaine soon showed that it had all the positive effects of cocaine with none of that drug's drawbacks. Guido Fisher popularized 'Novocaine', or procaine, in the United States. Injected by needle Novocaine immediately became popular as a local anesthetic for both medical and dental purposes. Other similar synthetic substitutes for cocaine were produced after novocaine.


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Online Material (continued): Blood Pressure Background: Patient Classification: ASA (ASA PHYSICAL STATUS CLASSIFICATION SYSTEM) • Adapted from the American Society of Anesthesiologists and Malamed, Medical Emergencies in the

Dental Office • Interpreted by Margaret J. Fehrenbach, RDH, MS, Dental Hygiene Educational Consultant ASA I Patients are considered to be normal and healthy. Patients are able to walk up one flight of stairs or two level city blocks without distress. Little or no anxiety. Little or no risk. This classification represents a "green flag" for treatment. The supervising DDS will not need to be made aware of the presence of this patient before treatment. ASA II Patients have mild to moderate systemic disease or are healthy ASA I patients who demonstrate a more extreme anxiety and fear toward dentistry. Patients are able to walk up one flight of stairs or two level city blocks, but will have to stop after completion of the exercise because of distress. Minimal risk during treatment. This classification represents a "yellow flag" for treatment. The supervising DDS will need to be made aware of the presence of this patient before treatment. Examples: well-controlled non-insulin dependent diabetes, epilepsy, asthma, and/or thyroid conditions; ASA I with a respiratory condition, pregnancy, and/or active allergies. ASA III Patients have severe systemic disease that limits activity, but is not incapacitating. Patients are able to walk up one flight of stairs or two level city blocks, but will have to stop enroute because of distress. If dental care is indicated, stress reduction protocol and other treatment modifications are indicated. This classification represents a "yellow flag" for treatment. The supervising DDS will need to be made aware of the presence of this patient and may want to examine patient and/or have medical consultation before treatment. Examples: angina pectoris, myocardial infarction or cerebrovascular accident history, insulin dependent diabetes, congestive heart failure, chronic obstructive pulmonary disease. ASA IV Patients have severe systemic disease that limits activity and is a constant threat to life. Patients are unable to walk up one flight of stairs or two level city block. Distress is present even at rest. Patients pose significant risk since patients in this category have a severe medical problem of greater importance to the patient than the planned dental treatment. Whenever possible, elective dental care should be postponed until such time as the patient's medical condition has improved to at least an ASA III classification. This classification represents a "red flag" - a warning flag indicating that the risk involved in treating the patient is too great to allow elective care to proceed. The supervising DDS will need to be consulted before proceeding with treatment. Examples: unstable angina pectoris, myocardial infarction or cerebrovascular accident within the last six months, uncontrolled high blood, severe congestive heart failure or chronic obstructive pulmonary disease, uncontrolled epilepsy, diabetes, or thyroid condition. ASA- E : Emergency operation of any variety (used to modify one of the above classifications, i.e., ASA III-E).


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Online Material (continued): Vital Signs, Standard Values: Review • Temperature • Pulse • Respiration • Blood Pressure Blood Pressure Devices For more than a century, the mercury gravity (blood pressure measurement device) has been

the gold standard for indirect measurement of blood pressure. However, in recent years modern, hi-tech devices have begun to replace the mercury

manometer. These include electronic instruments such as home pressure monitoring devices, or drugstore automated pressure-testing setups.

Non-mercury measuring devices are common in clinics and physician's offices--they have round faces attached to a cuff, which is inflated while the doctor listens to the pulse with a stethoscope. These new devices are portable and simple to use, making them ideal in certain situations, especially for home monitoring.

However, a crucial issue with the newer instruments is their reliability. In order to insure reliability, instruments must be calibrated--in the same way that a scale is "zeroed" before you step on it to check your weight. Unless the instrument is properly calibrated, the reading it gives cannot be accurate.

Justification for replacement of the mercury manometers has focused primarily on concerns over the safety of the mercury used in the devices. Nevertheless, modern mercury blood pressure measurement devices are available in models that prevent accidental spillage of mercury, which essentially eliminates the concern for this rare occurrence.

Blood Pressure Standards It is very important to have an accurate assessment of blood pressure as measurements

even a few points off can make a big difference. Recent studies article emphasize an important issue in measuring blood pressure. One needs to calibrate the electronic home devices periodically to the standard mercury meters.

This is usually easily done by bringing in the meter once or twice a year and making certain that both meters read the same. There is great variability in many of these monitors and it is not necessarily related to the cost of the meter. For physicians, it is important to use a mercury meter as the standard.

Discussion on Blood Pressure Standards However, the Mayo Clinic said investigators reached that conclusion after examining 283

aneroid devices, which are blood pressure monitors, or manometers, with moving parts rather than mercury. While the mercury manometer has been in use for more than 100 years and remains the standard by which others are judged, this study shows that well-maintained aneroid devices are an accurate and useful alternative.

With a regular calibration and maintenance program, hospitals and clinics can be confident that these devices do not compromise the quality of care for their patients. (Archives of Internal Medicine, American Medical Association, March 2001.)

The American Heart Association's Council for High Blood Pressure Research, cautions that the new electronic and non-mercury blood pressure devices are seldom calibrated regularly in hospital or office settings. (Hypertension: Journal of the American Heart Association, February 2001.)


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Blood Pressure Category

Systolic

Diastolic

Follow-Up Recommendations

Normal

<120

<80

----------------------

Prehypertension

120-139

80-89

May eval or refer

Stage 1 (Mild)

140-159

90-99

May eval or refer

Stage 2 (Moderate)

160-179

100-109

Eval or refer within 1 month

Stage 3 (Severe)

180-209

110-119

Eval or refer within 1 week

Stage 4 (Very Severe)

>210

>120

Eval or refer immediately

BP Readings Reviewed: Systolic/Diastolic Readings • Systole refers to the contraction of the heart and conventionally systolic arterial pressure is

the highest pressure developed in arteries during the ventricular contraction of the cardiac cycle.

• Diastole refers to a relaxed heart muscle and diastolic pressure has conventionally meant the lowest arterial pressure during a heart cycle.

Tips for BP: Be well trained and observant Blood pressure recording is a process that should be practiced and re-practiced. The reading that is taken is an important tool in diagnosing a patient. That’s why it is

considered one of the Vital Signs. When taking a blood pressure always be sure to concentrate on the task at hand. Good eyesight and hearing, as well as hand-eye-ear coordination is important.

Use actual numbers. Most people have a tendency to round off numbers; for example, 152 becomes 150; 166 may become 170. In blood pressure recording, a few millimeters may make the difference in a patient’s diagnosis. Always record the reading to the nearest 2mm Hg. Don’t be biased. Just because a patient (or yourself, in the case of home readings) is normally around 126/82 (for example), don’t prematurely assume the next reading will fall near that range. Record each reading based on your observations at that time.

Position the patient properly. For regular blood pressure recordings, the patient is seated with the midpoint of the upper arm at the level of the heart. When the arm is below the heart level, the reading will be too high. In fact, it has been reported that the reading can be as much as 8mm high when the patient’s arm is hanging at their side. However, some circumstances may require the patient to be in a different position. When lying down, position the patient’s arm at the side of the body, slightly raised; when the patient is standing, raise the patient’s arm and support at the heart level. Document the patient’s position when recording their measurement on their chart


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Have a calm manner and peaceful environment. Try to keep the patient relaxed and have everything ready (equipment, charts, pen, etc.) for the reading before the patient is seated. Since blood pressure levels are affected by emotions, physical activity, and the surroundings, minimize disturbances that may affect the reading. “White Coat Reading”

Check your equipment. Routinely inspect your blood pressure equipment - sphygmomanometer, cuffing system, bladders, tubes, valves, etc. - to make sure it is functioning properly. Check to see if the mercury level of your instrument is at zero. Check aneroid gauges over the entire range against a mercury sphygmomanometer. Repair, replace, and clean as necessary. Consider using a cuff that has an antimicrobial agent to help prevent bacterial growth and mildew. It has been reported that blood pressure cuffs can carry significant bacterial colonization and can actually be a source of transmission of infection.

Select the right size inflation system. Choose the appropriate size cuff based on the circumference of the patient’s bare upper arm. The bladder (inside the cuff) should encircle 80% of an adult’s arm and, for a child less than 13 years old, 100%. A cuff/bladder that is too narrow for the arm will result in a high blood pressure reading. This situation may lead to the overtreatment of hypertension; conversely, using a cuff too large may lead to the undertreatment of hypertension. Have a full range of cuff sizes available to accommodate your patient population.

Blood Pressure Devices and Calibration For more than a century, the mercury gravity (blood pressure measurement device) has been the gold standard for indirect measurement of blood pressure. However, in recent years modern, hi-tech devices have begun to replace the mercury manometer. These include electronic instruments such as home pressure monitoring devices, or drugstore automated pressure-testing setups or even aneroid devices. These new devices are portable and simple to use, making them ideal in certain situations, especially for home monitoring. However, a crucial issue with the newer instruments is their reliability. In order to insure reliability, instruments must be calibrated--in the same way that a scale is "zeroed" before you step on it to check your weight. Unless the instrument is properly calibrated, the reading it gives cannot be accurate. Justification for replacement of the mercury manometers has focused primarily on concerns over the safety of the mercury used in the devices. Nevertheless, modern mercury blood pressure measurement devices are available in models that prevent accidental spillage of mercury, which essentially eliminates the concern for this rare occurrence. It is very important to have an accurate assessment of blood pressure as measurements even a few points off can make a big difference. Recent studies article emphasize an important issue in measuring blood pressure. One needs to calibrate the electronic home devices periodically to the standard mercury meters. Bringing in the meter once or twice a year usually easily does this and making certain that both meters read the same. There is great variability in many of these monitors and it is not necessarily related to the cost of the meter. For physicians, it is important to use a mercury meter as the standard. However, the Mayo Clinic said investigators reached that conclusion after examining 283 aneroid devices, which are blood pressure monitors, or manometers, with moving parts rather than mercury. While the mercury manometer has been in use for more than 100 years and remains the standard by which others are judged, this study shows that well-maintained aneroid devices are an accurate and useful alternative. With a regular calibration and maintenance program, hospitals and clinics can be confident that these devices do not compromise the quality of care for their patients. (Archives of Internal Medicine, American Medical Association, March 2001). The American Heart Association's Council for High Blood Pressure Research, caution that the new electronic and non-mercury blood pressure devices are seldom calibrated regularly in hospital or office settings (Hypertension, American Heart Association, February 2001).


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For aneroid devices, the procedure requires adjusting calibration at several pressure points, while mercury devices are adjusted just at the zero point; the mercury column should be at zero when the cuff is deflated. Although simpler to calibrate, mercury sphygmos have inherent disadvantages that may contribute to inaccurate readings. However they are still considered the gold standard. Online Material (continued): Mercury BP Devices can have problems such as:

• It requires excellent technique to read the meniscus of a mercury column. Even if both types are in good working order, the aneroid dial is easier and requires less effort to read than a mercury column.

• Maintenance of mercury devices is cumbersome. For accuracy, the mercury tube must be perfectly perpendicular in its unit and perfectly vertical to the ground. The more off-vertical, the greater the inaccuracy.

• Each mercury sphygmomanometer has a vent or filter allowing outside air to be drawn in. Without frequent filter replacement, the mercury column experiences lag. "Lag" is a delay in the mercury response, which may result in an inaccurate reading. Once a year or so, the damping filters and kidskin diaphragm located in the top cap above the cartridge tube should be replaced.

• Oxidized mercury can make the column appear dirty, making it difficult to read the true mercury level. This should be swabbed away using alcohol applied to a pipe cleaner.

Some manufacturers routinely offer free lifetime calibration of the aneroid devices usually within ± 3 mmHg. If you do not have that, check the pamphlet with it and see if it has a calibrate feature with the manometer and comes with a calibration screwdriver. Now aneroid sphygs utilize mechanical gears and a mechanical linkage which can wear out or be knocked out of calibration. Aneroids are designed to provide a visual indication of accuracy. On some models they will require re-calibration if the indicator needle is outside the oval at the bottom of the dial. Unfortunately, when the needle is inside the oval, you can't be absolutely sure that the gauge is in calibration, unless it is a brand new unit from a reputable manufacturer (that's because gauges can be tampered with - some more easily than others). As such, it's a good idea to periodically test the gauge against a unit of known accuracy. How often you should perform these accuracy tests depends on many factors, but in general, once a year should be sufficient. Pick a physician's office that you have as patient or use as referral to use for calibration that has a mercury device. May want to drop off brochures from ADA or ADHA on PD and systemic disease with your office's stamp or label on them for patient reading in a nice holder with a label on it too. Good way for referral and education to more patients.


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Online Material (continued): Blood Pressure Cases to Consider ASA I (Normal BP to Prehypertension)

• Systolic pressure less than 140 and diastolic pressure less than 90. • Treat as usual.

ASA II (Stage I HBP: Mild)

• Systolic pressure between 140-159 and/or diastolic pressure between 90-99. As long as one of the numbers is in that category then that is the category you’re in.

• Repeat BP in 5 minutes. Why? Maybe the patient was running or walking fast. That can cause a rise in BP. Let them sit in the chair for about 5 minutes; the BP will come back down. You can treat them. There is no problem. Some examples of ASA II are 150/80 or 130/92.

ASA III (Stage 2 HBP: Moderate)

• Systolic pressure between 160-179 and/or diastolic pressure between 100-109. Repeat BP in 5 minutes.

• If the BP is still elevated after 5 minutes find out if the patient is ever told that they have high BP. Ask them if they are taking any medication and ARE they actually taking the medication?

ASA III (Stage 2 HBP: Moderate)

• The biggest problem with patients with high BP is that they forget, especially if they are taking it daily for life. So ask them do you have high BP medication and are you taking it?

• If they don't take the medication their BP will go up. If a patient is an ASA III and has HBP, after recording and re-recording the BP, if the BP is still up, contact your supervising dentist; you need to evaluate or refer to source of care within one month. This is where the stress reduction protocol becomes very important.

• Some examples of ASA III are 170/88 or 150/100. ASA IV (Stage 3 or 4 HBP: Severe to Very Severe)

• Systolic pressure 180 or greater than 210 and/or diastolic pressure 110 to greater than 120. No elective dental care.

• If you have a patient that you suspect is an ASA IV contact your supervising dentist and the patient’s physician, who can evaluate your patient for you; you need to evaluate or refer within one week to immediately (over 210/120). Knowing when to not treat a patient is very important.

• Some examples of ASA IV are 200/100 or 180/110.


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Online Material (continued): Blood Pressure Detection Using Aneroid Device

• Step 1 Position the patient's arm so the anticubital fold is level with the heart. Support the patient's arm with your arm or a table or patient chair.

• Step 2 Center the bladder of the cuff over the brachial artery approximately 2 cm above the anticubital fold. Be sure the index line falls between the size marks when you apply the cuff.

• Step 3 Position the patient's arm so it is slightly flexed at the elbow.

• Step 4 Palpate the radial pulse and inflate the cuff until the pulse disappears. This is a rough estimate of the systolic pressure.

• Step 5 Put the stethoscope ear pieces into your ears, with the ear pieces facing forward. Clip the dial on the top of the device so as to be easily seen. Place the stethoscope over the brachial artery.

• Step 6 Inflate the cuff to 30 mm Hg above the estimated systolic pressure.

• Step 7 Release the pressure slowly, no greater than 5 mm Hg per second.

• Step 8 The level at which you consistently hear beats is the systolic pressure.

• Step 9 Continue to lower the pressure until the sounds muffle and disappear. This is the diastolic pressure.

• Step 10 Record the blood pressure as systolic over diastolic ("120/80" for example).

Retake BP • If you want to repeat the measurement, wait 2 to 3 minutes before reinflating the

cuff. Using Digital Device

• Put the cuff around the arm. Turn the power on, and start the machine. • The cuff will inflate by itself with a push of a button on the automatic models. On the semiautomatic

models, the cuff is inflated by squeezing the rubber bulb. After the cuff is inflated, the automatic mechanism will slowly reduce the cuff pressure.

• Look at the display window to see your blood pressure reading. The machine will show your systolic and diastolic blood pressures on the screen. Write down your blood pressure, putting the systolic pressure before the diastolic pressure.

• Press the exhaust button to release all of the air from the cuff. • If you want to repeat the measurement, wait 2 to 3 minutes before reinflating cuff.


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Online Material (continued): Routine Lab Tests for HBP

• Routine lab tests are recommended before beginning treatment of high blood pressure to determine organ or tissue damage or other risk factors.

• These lab tests include urinalysis, blood cell count, blood chemistry (potassium, sodium, creatinine, fasting glucose, total cholesterol and HDL cholesterol), and an ECG (electrocardiogram). Additional tests may be recommended based on your condition.

Types of Blood Pressure Medications • Diuretics (best and main one given!!!)

• Beta blockers

• ACE inhibitors

• Angiotensin antagonists

• Calcium channel blockers (CCBs)

• Alpha blockers

• Alpha-beta blockers

• Nervous system inhibitors

• Vasodilators


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Issues for Women: Hormones • Three out of four women with high blood pressure know they have it. Yet fewer than one

in three are controlling their blood pressure. All women should take steps to control their blood pressure. All these involved hormones that can raise blood pressure: Pregnancy; Oral Contraceptives; Hormone Replacement Therapy.

• Pregnancy: However, some women develop high blood pressure while they are pregnant (often called gestational hypertension). The effects of high blood pressure range from mild to severe. High blood pressure can harm the mother's kidneys and other organs, and it can cause low birth weight and early delivery. In the most serious cases, the mother develops preeclampsia—or "toxemia of pregnancy"—which can threaten the lives of both the mother and the fetus.

• Oral Contraceptives: Women taking oral contraceptives experience a small but detectable increase in both systolic and diastolic blood pressure, usually in the normal range. To prevent a possible rise in blood pressure, women age 35 and older who smoke cigarettes are at even greater risk for heart disease and stroke and are encouraged to quit smoking. If they are unable to quit smoking, they should talk to their doctor about using other forms of contraception.

• Hormone Replacement Therapy: A recent study indicated that blood pressure does not increase significantly with hormone replacement therapy in most women with and without high blood pressure. However, a few women may experience a rise in blood pressure attributable to estrogen therapy. Therefore, it is recommended that all women treated with hormone replacement therapy have their blood pressure monitored more frequently after such therapy is started.

• Recommend that your patients take simple healthy lifestyle changes to prevent high blood pressure.

• Recommend that your patients take simple healthy lifestyle changes to prevent high blood pressure. These steps include: Maintaining a healthy weight; Being physically active; Following a healthy eating plan, that emphasizes fruits, vegetables, and low-fat dairy foods; Choosing and preparing foods with less salt and sodium; Drinking alcohol in moderation; Quitting tobacco use.

Children and HBP • Children, even very young babies, can have high blood pressure. The American Heart

Association recommends that all children have yearly blood pressure measurements. Early detection of high blood pressure will improve the health care of children. Some diseases - usually heart or kidney disease - can cause high blood pressure in children. This is called secondary hypertension. If the disease is successfully treated, blood pressure usually returns to normal. In addition, some medicines in children can cause high blood pressure, but when they're discontinued, blood pressure usually returns to normal.

• Complications of HBP- see figure


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Online Material (continued): ARMAMENTARIUM for Local Anesthesia Syringe Needles Cartridge Additional supplies Syringe assembly

Syringe Types Aspirating Self-aspirating

Parts Advantages and Disadvantages: see text Care: see text Other syringes: see text Aspirating: Most common Breech-loading, metallic,

cartridge-type Self-aspirating: see text

Parts Needle adapter Barrel Thumb ring Piston with harpoon

Syringe: Aspirating • With initial positive pressure on the thumb ring, the harpoon with piston penetrates the stopper at end of

cartridge. Keep the large window of the syringe orientated so that the cartridge is visible to check for aspiration of blood.

• With negative pressure on the thumb ring, the syringe aspirates. Blood will enter the needle lumen and become visible in the cartridge if the needle tip rests in a blood vessel: a positive aspiration. If only bubbles appear: a negative aspiration.

• With subsequent positive pressure on the thumb ring, the agent is forced into the needle lumen and into the tissues where the needle tip lies.

Needles Parts Gauge Length Care and handling of sharps: see text Scoop method for recapping needles

1. Slowly withdraw syringe from soft tissues protecting your patient and yourself! 2. Uncapped needle is then slid into the needle cap lying on the instrument tray or

table 3. After scooping, grab the plastic cap with other hand and push onto needle hub

Needle Care: Sharps Container OSHA recommends a Sharp’s Container in each room


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Parts Bevel at tip/point Shank or shaft Hub: plastic or metallic syringe adapter Syringe-penetrating end Needle cap or sheath

Gauge = diameter of the needle Smaller number the greater the diameter of the lumen thus 30 gauge has

smaller internal diameter than a 25 gauge. Recommends 27 for short and 25 for long if only two needle in practice. We will be using 27 short.

Use of smaller - diameter of the needle (higher gauge, like 30 gauge) on the supposition that they are less traumatic is unwarranted.

Best to use a larger diameter (lower gauge, like 25 or 27 gauge) to insure greater accuracy due to less deflection and aspiration is easier too!

Needles are very sharp but get dull fast. Change the tip after 3-4 injections, otherwise it will tear through the tissue. The patient won’t feel the tearing at the time of the injection, but after the anesthesia wears off, it will be very sore.

Length - Short: 1” (2.5 cm nor 25 mm, average 20 mm) Long 1 5/8” (4.0 cm or 40 mm, average 32 mm) Recommend short for all infiltration injections

Cartridge or carpule (patented name) Parts Contents: see text Care: see text

Parts Cylindrical glass tube Rubber Stopper or plunger Aluminum cap Diaphragm

Additional supplies: see text Cotton tip swab Long is recommended

and not short to help with anatomical considerations by mimicking the needle and syringe length Topical anesthetic

Syringe assembly (see presentation) Loading

1. Remove sterilized syringe from container 2. Retract piston by pulling back on the thumb ring 3. Insert cartridge, stopper end first 4. Engage harpoon, holding syringe as if injecting, pushing piston forward until harpoon is engaged in

the plunger or tap lightly on the thumb ring of syringe 5. Do not hit hard on the syringe to engage the harpoon since it is not necessary and there could be

damage to the cartridge by breaking the glass 6. Attach needle to syringe 7. Carefully remove cap from needle 8. Expel a few drops off face of bevel to check for harpoon engagement


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Unloading 1. Retract the piston 2. Pull cartridge away from the needle with thumb and forefinger until harpoon is disengaged from

plunger 3. Remove cartridge from syringe by inverting syringe, permitting the cartridge to fall free into ready

fingers 4. Discard the needle after unscrewing properly

Thumb Ring Engagement Be sure to have your thumb engaged high enough on the thumb ring of the syringe or you will

not be able to aspirate properly! So place the thumb high on the thumb ring before entering the tissue!

Developing Programs to Prevent Sharps Injuries from CDC: Latest Every dental office should develop and implement a program to prevent sharps injuries to dental personnel and patients. A staff person knowledgeable about or willing to be trained in injury prevention (i.e., a safety coordinator) should be assigned to:

• Promote safety awareness,

• Facilitate prompt reporting and post-exposure management of injuries,

• Identify unsafe work practices and devices,

• Coordinate the selection and evaluation of safer dental devices,

• Organize staff education and training,

• Complete the necessary reporting forms and documentation, and

• Monitor safety performance.

Ideally, these activities should be described in a written plan and mechanisms for staff feedback should be available. This feedback will assist the safety coordinator in reviewing the effectiveness of the plan and making the modifications needed. Needlestick Protocol from ADA (see references) OSHA Studies Sited (1997)

• Locations Where Percutaneous Injuries and Mucocutaneous Blood Exposures Occurred

• Items Most Frequently Causing Sharp-Object Injuries

• Health Care Workers Reporting Percutaneous and Mucocutaneous Blood Exposures, by Occupation

Risk of Needlestick: Discussion One of the most critical control components of health care worker protection against bloodborne pathogens must be the reduction of sharps-related incidents. The statistics cited below provide a picture of the seriousness of the problem. Hospital-based health care workers experience some 800,000 needlestick injuries each year in the United States (Jagger,1990). About 2% or approximately 16,000 of these are likely to be contaminated by HIV (American Hospital Association, 1992). Needlestick injuries account for up to 80% of all accidental exposures to blood. (Jagger, 1988).


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In well-documented studies, injuries from contaminated needles and other sharp devices used in the health care setting have been associated with transmission of bloodborne pathogens to health care workers. In fact, more than 20 pathogens have been transmitted through sharps or needlestick injuries (Chiarello, 1992). Of these, HIV, HBV and HCV pose the greatest risk to the health care worker (Ippolito et al., 1997). The risk of transmission of HBV and HCV through percutaneous injury is much higher than for HIV (CDC, 1991). Understanding the prevalence of these bloodborne diseases in the patient population gives a better picture of the risk health care workers face: A study of the Johns Hopkins Hospital emergency room determined the prevalence of the HCV, HBV and HIV in blood samples from 2523 patients. Of those patients: 18% were seropositive for HCV. 5% were seropositive for HBV 6% were seropositive for HIV (Kalen et al, 1997).

• OSHA Study Sited (1998) Health Care Workers with Documented and Possible occupationally Acquired AIDS/HIV Infection, by Occupation

Engineering Controls Intended to remove or isolate the hazard from the worker. Utilize appropriate sharps containers (puncture-resistant, labeled with a biohazard label or color-coded red, leak-proof on the sides and bottom) and ensure they are located as close to the work area as practical. Replace sharps containers at sufficiently frequent intervals (when filled to within 1-1.5 inches below the opening) to prevent overfilling. Place used sharps containers in the regulated waste container for disposal. Close or cover sharps containers when transporting from one place to another. Incorporate instruments and equipment and operatory layouts that remove or isolate percutaneous hazards. Reduce the risk of injury by changing the manner in which the task is performed. Recap anesthetic needles using one-handed scoop-technique or mechanical device to hold the needle sheath. Minimize uncontrolled movements of sharp instruments under force, such as scalers. Use instruments instead of fingers to retract tissues during suturing and anesthetic injections. Pass instruments with sharp ends pointing away from all persons. Announce passes. Reduce the risk of injury by changing the manner in which the task is performed. Maintain appropriate care in the handling and passage of syringes and other sharp instruments Use ultrasonic cleaner, washer/decontaminator, or other effective device to minimize handling during cleanup procedures Use utility gloves during instrument clean-up. Use mechanical devices to debride sharps. Two-handed debridement of sharps poses a potential risk for percutaneous injury. OSHA Summary of Position (1997) "Most preferable is the use of devices which offer an alternative to needles being used to perform the procedure. Examples of such devices include stopcocks (on-off switch), needle-protected systems or needleless systems, which can be used in place of open needles to connect intravenous lines. Other devices which are integral to the syringe, such as self-sheathing needles, allow both hands to remain behind the needle and require very little manipulation to isolate the needle safely." In addition, "While employers do not automatically have to institute the most sophisticated engineering controls (e.g., needleless IV connectors, self-sheathing needles), it is the employer's responsibility to evaluate the effectiveness of existing controls and to review the feasibility of instituting more advanced engineering controls." Sample Screening and Device Evaluation Forms: New Mandated by the Needlestick and Prevention Act, changes to OSHA’s bloodborne pathogen standard were published January 18, 2001, to take effect April 18, 2001. The revisions clarify the need for employers to select safer needle devices as they become available and to involve employees in identifying and choosing the devices. Prior to the act, only a few dental devices incorporated safety features (e.g., anesthetic syringe needles with sliding sheathes), and most dental healthcare personnel are uncertain about how to select and evaluate the safer devices now available on the market.


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Online Material (continued): Armamentarium for Nitrous Oxide TYPES OF NITROUS OXIDE MACHINES • There are several minor differences in N2O-O2 conscious or moderate sedation machines

manufactured today. • All are similar in that they provide a method of controlling the rate of flow of both the N2O

and O2 gases, mixing them together, flowing them into a reservoir bag and from there to a nasal "hood", mask, or full face mask.

• A decade ago, all nasal masks or hoods exhausted exhaled air and waste Nitrous oxide into the room through a "pop-off" valve.

• Realizing the potential hazards to chronic N2O exposure in the operatory, scavenging systems were designed into the nasal mask.

• Two types of machines that were available in dentistry. • The demand flow is an older model and is no longer used because it is highly inaccurate.

The dials control O2 and N2O and some % of each gas is delivered as the patient takes a breath. When the patient is not breathing, no gas is released.

• The continuous flow machines are used today, and they offer two advantages: accuracy within 2% and visualization of the gas flow. The gas is constantly being released so the disadvantage is that it uses more gas.

• Whether it is self-contained and portable or permanently fixed, all Nitrous oxide machines have flowmeters showing the rate of flow of the gas measured in liters per minute.

• It is also necessary to have pressure gauges which show the amount of pressure in the cylinders.

• Some have N2O Locks that prevents unauthorized use of Nitrous oxide, however, oxygen is still available even when the lock is engaged.

• All have a built-in oxygen failsafe system that prevents the O2 concentration from dropping below 30% and a failsafe system discontinues Nitrous oxide flow if the oxygen supply is interrupted.

• Maximum % given is only 70% Nitrous Oxide. Compressed Gas Cylinders • Continuous flow machines have both oxygen and Nitrous oxide compressed gas cylinders. • Oxygen is always on the right hand side of the machine. In North America, O2 is always

color-coded green and Nitrous oxide is always blue. Everything on the machine that carries O2 is also green while everything that carries Nitrous oxide is blue. Oxygen is always on the right hand side of the two tanks and on the machine.

• A full tank of oxygen is under 2000 pounds of pressure and contains only gas. The gauge on the oxygen tank can be used to determine how much gas remains in the tank. Nitrous oxide in the tank is under 750 pounds of pressure. The full Nitrous oxide cylinder contains ~3/4 liquefied Nitrous oxide, above which is Nitrous oxide gas. Regardless of the amount of Nitrous oxide left in the cylinder, the pressure is always 750 psi. As long as even 1 drop of Nitrous oxide remains in the cylinder, the gas pressure will always be 750 psi.

• Don’t use the gauge on the Nitrous oxide to judge how full the tank is. • The cylinders come in different sizes: • The large at 5 ft tall tank are centrally located in an office and pumped to the operatory and

would be G or H size while the smaller ones are E size, portable and ~ 3 ft tall. • Yokes keep the gas cylinders in position.


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Online Material (continued): Changing Gas Tank Cylinder • Monitor gas pressures at the beginning of each procedure to assure sufficient gas remains

in the tank to complete procedure. When empty, close the tank by slowly turning valve clockwise. Replace the tank with spare full cylinder.

• Identify the two in-use tanks by attaching "in-use" identification tags to them. When one of the in-use tanks is empty, close the tank by turning the valve slowly clockwise. Leave the empty tank in place. Move the "in-use" tag to the appropriate reserve tank, which now becomes the in-use tank. Replace the empty tank with a new tank, which then becomes the reserve tank. Open the valve located on the top of the in-use tank by slowly turning counter-clockwise. Note: Do not open the reserve tank until the in-use tank is empty. When changing gas tanks, make certain both same-gas cylinders (involved in the exchange) are closed. Always remember to switch the "in-use" tags over to the new tanks. Contact gas supplier to request new gas cylinders as needed.

Reducing Valves • Reducing valves decrease the pressure coming out of the tank to 50 psi, regardless of the

gas. Reducing valves are also known as regulators. If the high pressure cylinders are opened rapidly there will be a rapid increase in the temperature within the valve to ~ 2000°F.

• There are two parts to the system: high and low pressure. • The high pressure part of the system is from the tank to the reducing valve. • The reducing valve is the dividing point. • From the reducing valve into the patient is low pressure (includes the flowmeters, reservoir

bags, nasal hood). Flowmeters • The flowmeters measure the gas pressure coming through the line. After each gas passes

through the flowmeter the gases are mixed and the patient breathes this. The flowmeter is a calibrated, tapered glass or plastic tube that is read by estimating the middle of the silver ball on the gauge. The flowmeter is read in liters per minute (LPM or lpm) of gas in motion.

• The dentist or certified dental hygienist will turn the Flow Knob backward direction to increase flow rate and in a forward direction to decrease flow rate. This means that if you turn the Flow Knob in a clockwise direction to increase flow rate and in a counter-clockwise direction to decrease flow rate of oxygen. And you turn the Flow Knob in a counter-clockwise direction to increase flow rate and in a clockwise direction to decrease flow rate of nitrous oxide.

• One of the most common misconceptions is that the liter flow of the gases is equal to the percentage of gas being delivered. The percentage of gas being delivered is determined by dividing the liter flow per minute (LPM) of the gas by the total volume or minimum flow rate or tidal volume of both gases being delivered.

Definition: Tidal Volume (Minimum Flow Rate): Amount of air a person

needs for one respiration cycle. For the average adult it could be from 6-8 LPM, depending on the size and metabolic rate of the person. For most adults it is 6 and for large persons, athletes, and those with nasal obstruction may need a higher minimum flow rate of 7 or 8 LPM. For the average child it could be from 4-5 LPM, depending on the size and metabolic rate of the person.


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Online Material (continued): Rubber Tubing • The rubber tubing carries the gas to the nasal hood. Some of the gas coming out of the machine is

diverted to the reservoir bag which holds 3-5 liters. This allows the patient’s need for gas to be satisfied, even while they are taking an occasional deep breath. Can also be connected to the scavenging vacuum.

Masks

• There are three ways to deliver gas to the patient include:

• Full face mask (not used in dentistry but the most effective method)

• Nasal canula (rubber tube with 2 prongs in the nose often used in hospital and good for claustrophobic patients)

Nasal hood (used most often in dentistry). Scavenging Nasal Hood (Mask) • The scavenging nasal hood or nosepiece delivers fresh gases from the sedation unit and vents

exhaled gases away from the operator that may cause headaches or other problems. Two hoses come off each side of mask. Make sure that the hoses from the hood or mask are evenly placed on both sides of the patient head and tighten by adjusting the slip ring behind the headrest. To help this process, the patient holds the hood or mask in comfortable position as the hoses are adjusted, so that the hood is not tilted to one side. Do not make it too tight, allow some patient head movement.

• This can reduce the amount of Nitrous oxide exhaled by the patient and breathed by the dental staff from 900 ppm to 30 ppm; ideal is 50 ppm.

• The dentist or certified dental hygienist will always start the flow of O2 through the nosepiece before placing it on the patient’s face. If no gas is coming through the machine, an emergency air inlet valve will allow air in. If there is gas coming through the machine, this will be shut. Disposable Masks (ask patient to bring each time or store)

Reservoir Bag • Indicates a seal on the nasal hood or mask. Allows a determination of the adequacy of the

minimum flow rate or tidal volume of gas being delivered to the patient. • If it remains partially inflated or deflated and then changes with each breath, then the

minimum flow rate or tidal volume is adequate and the seal is tight. • If it remains partially inflated or deflated and then changes with each breath, then the

minimum flow rate is adequate and the seal is tight and patient complains of air blowing into their eyes each time they breathe, the hood or mask may have large leaks that may or may not be corrected by a 2x2 gauze square, adjusting the mask, or getting a smaller mask.

• If it remains deflated and the patient complains of not receiving enough air, then the minimum flow rate or tidal volume of gas is not adequate and the supervising dentist or certified dental hygienist needs to increase the minimum flow rate or tidal volume by ½ - 1 LPM.

• If it over inflates and the patient may complain about not being able to breathe against the rapid flow of air into the hood or mask, then the minimum flow rate or tidal volume is too great for the patient and needs to be reduced by ½ - 1 LPM by the supervising dentist or certified dental hygienist. Less common.

• Or the hoses leading from the sedation unit have become kinked (occluded) that may lead it to over inflate, then the supervising dentist or certified dental hygienist needs to abort the procedure and then possibly restart it if it can be corrected. More common.

• Squeezing the reservoir bag is not recommended in order to provide 100% O2 since it contaminates the operatory air. Just terminate the flow of N2O and continue the flow of O2.


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Online Material (continued): Oxygen Flush Valve and Button • Activated in order to fill the reservoir bag with O2 for patient’s first breaths (Push In to Turn

On). • Using the O2 flush button to remove mixture of gasses from bag in order to provide 100% O2

is not recommended since it contaminates operatory air. Just terminate the flow of N2O and continue the flow of O2.

Equipment Installation • The installation of N2O-O2 equipment requires the services of an expert. • It should not be attempted by a plumber unfamiliar with medical gas systems or anyone not

trained in the installation of anesthetic gases and equipment. • It should never be done as a "do it yourself project" by or for the dentist. • We are dealing with gases under considerable compression (2100 lbs PSI) and items or

material such as oil that will flash and burn at a surprisingly low temperature when in the presence of 100% oxygen.

• Never trust the installation of N2O-O2 conscious or moderate sedation equipment to anyone other than a reputable dental supply dealer experienced in the installation of N2O machines or one who regularly installs anesthetic machines.

• There are several companies manufacturing good N2O equipment today. When purchasing equipment, be certain that you are purchasing from a dealer capable of servicing the equipment after it is installed, and one that will respond appropriately.

“The installation of the gas storage must be in accordance with the National Fire Prevention Association Standards and inspected by the local fire department to assure compliance with NFPA.”

TYPES OF NITROUS OXIDE MACHINES (continued) • Nitrous oxide machines in general can be classified as being portable, if they are on wheels

and can go from room to room, or fixed and often installed into dental cabinets • Portable machines, either have the small N2O and O2 tanks attached to the machine itself,

or have tubing designed to plug into wall outlets in the various rooms or operatories where N2O is to be used (semi-portable).

• Semi Portable Nitrous Oxide Units • Nitrous Oxide Wall Mount and Quick Connect Hoses • "Enclosed" Portable Flowmeter System • Digital Portable Unit • Digital Wall Mounted Unit • Digital Portable Unit with Scavenger Control Valve


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Online Material (continued): Control of Nitrous Oxide in Dental Operatories Hazard • Dental workers are exposed to Nitrous Oxide (N2O) during administration of this anesthetic

gas to patients. • Exposures should be minimized to prevent short-term behavioral and long-term

reproductive health effects that can be produced by N2O. Dental Workers who should avoid exposure: • Women in first trimester of pregnancy • Infertile individuals using in vitro fertilization procedures • Individuals with neurological complaints • Immunocompromised individuals who are at risk from bone marrow suppression. Control • NIOSH research has shown controls including System Maintenance, Ventilation, and Work

Practices can effectively reduce N2O concentrations in dental operations to approximately 25 ppm during analgesia administration, the exposure limit recommended by NIOSH.

• Uncontrolled exposures to N2O have exceeded 1000 ppm. NIOSH • National Institute for Occupational Safety and Health (NIOSH) 1-800-35-NIOSH (1-800-356-4674) www.cdc.gov/niosh/nitoxide.html NIOSH Control of N2O at a pediatric dental operatory • Measurements of N2O concentrations were made on four occasions before and after

installation of different controls, using an infrared analyzer. • Air velocity and volumetric flow measurements also were taken, Video imaging was done in

some cases simultaneously with real-time N2O measurements to correlate work practices with exposure data.

• An infrared imaging system was used to identify sources of N2O. • Critical components of resulting recommendations for control include monitoring of N2O

concentrations; use of engineering controls, such as a scavenging mask, an effective dilution ventilation system, and auxiliary exhaust; good work practices; maintenance of the equipment; and worker education.

• Data presented strongly supports the hypothesis that better implementation of controls leads to reduction of N2O exposures. N2O concentrations were reduced by a factor of 61 from their initial levels.

• The current NIOSH recommended exposure limit of 25 ppm TWA during the time of N2O administration appears to be achievable.

Update on Nitrous Oxide Standards • In the March 1997 issue of the Journal of the American Dental Association (JADA), the

ADA Council on Scientific Affairs published recommendations for controlling Nitrous oxide exposure made by an expert panel sponsored by the ADA.

• Their recommendations were based largely on the work of NIOSH. They can be ordered either by calling NIOSH or via a form on their web page.

• The following action plan is a recommendation only and is based on guidelines published in the ADA Council on Scientific Affairs report and accompanying article.

• Obtain and review the JADA articles on Nitrous oxide. Order and review NIOSH publications

• Establish a written control plan developed specifically for each facility as described in JADA.


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Online Material (continued): Methods of Control Three methods of control are recommended: • SYSTEM MAINTENANCE • VENTILATION • WORK PRACTICES SYSTEM MAINTENANCE • Inspect and maintain the anesthetic delivery system to prevent N2O leaks in all hoses,

connections, fittings. • Use a non-oil-based soap worn solution to check for bubbles at high pressure connectors. • Repair all leaks immediately. • Contact the manufacturer for parts replacement. Ventilation • Scavenging System-- Use Scavenging. Exhaust ventilation of N2O from the patient's mask

should be maintained at an air flow rate of 45 LPM, measured by a calibrated flow device, and vented outdoors -- not into the room ventilation system.

• Room Ventilation-- Where possible, use 100% clean outdoor air for dental operatory ventilation. Supply and exhaust vents should be well separated to allow good mixing and prevent "short-circuiting.”

• ADA and NIOSH recommendations are for 10 or more air changes per hour. Additional Recommendations: • Improvement of circulation by opening window or using a nonrecycling air conditioning

system or airsweep fan • Minimizing conversation with patients and control of mouth breathing. • Supplemental Vacuum • In addition, NIOSH has recommended the use of supplemental vacuum devices vented

outside to remove additional air from the room. • However, to be effective their studies showed a need for 6" diameter capture ports and

substantial air flows producing in excess of 80 decibels of noise located near the patients’ ears.

• As a result, this may not be practical. To date no commercial systems are available. Continue to monitor commercial products and devices as they become available.

Work Practices • Select scavenging masks of proper sizes to fit patients. Use 2X2 gauze on bridge of nose

to prevent leaks. • Prudent use of N2O to appropriately sedate patients is encouraged. • Monitor the air concentration of N2O to insure Controls are effective in achieving low levels

during dental operations. Sampling Methods for N2O • NIOSH recommends air sampling for N2O be conducted periodically to: • measure worker exposures to N2O during anesthetic administration Personal Sampling,

and control N2O leaks in the delivery, scavenging and ventilation systems. • Sampling can be used to measure personal breathing zone exposures of dental workers,

and to detect leaks in the anesthetic delivery system, ineffective capture by the scavenging system, reentry in the room ventilation system, and circulation to other areas of the dental offices.

• Sampling utilizes mainly a portable Infrared Gas Analyzer (IGA). Nitrous Oxide Monitor Badge • NIOSH recommends Nitrous oxide monitoring at least four times per year. This is a passive

monitoring system. • OSHA requires Nitrous oxide levels to be maintained below 50 ppm in dental treatment areas. The

monitor provides accurate, affordable monitoring of Nitrous oxide levels. • Samples are thermally desorbed and analyzed by infra-red (IR) spectroscopy by the manufacturer.


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Online Material (continued): Nitrous Oxide Safety Record: N2O has an unparalleled 150-year safety record. Is It Safe for Dental Office Workers? • Positively. Practitioners have incorporated methods of scavenging or minimizing trace gas

to the point where health care workers have nothing to worry about. • Epidemiologic studies conclude there are increased general health problems and

reproductive difficulties among dental personnel chronically exposed to unscavenged Nitrous oxide.

• The mechanisms by which these toxic effects are produced are unclear, but ample evidence exists to warrant caution in the use of Nitrous oxide.

• Rowland et al. looked at the ability of female dental assistants to become pregnant, fucundability. He reevaluated the data taking into consideration whether they had been exposed to Nitrous oxide. The assistant were grouped into 5 groups, a control group that were exposed to no Nitrous oxide, two groups in offices that used scavenging to remove traces of Nitrous oxide depending on low, less than five hours per week or high usage, greater than five hours per week and two additional groups with no scavenging again grouped by high and low usage. Later he studied spontaneous abortions in similar groups.

• Only the group with no scavenging and high utilization had a statistically significant difference in facundability. Scavenging equipment appears to be important in protecting the reproductive health of women working with Nitrous oxide.

Potential for Abuse: What does Nitrous oxide look like for abuser? • Generally, inhalers buy Nitrous oxide packaged in small, steel, purple-silver canisters sold

as whipped cream chargers, commonly called, "whippets." • The only other equipment needed is a balloon and a "cracker." • Where can users find whippets? Generally, sale of Nitrous oxide for medical use is well

regulated by the Food and Drug Administration. • However, lesser grade Nitrous oxide which is generally used by huffers is readily available.

A box of whippets costs less that $10, and can be found at grocery convenience and hardware stores, as well as "head shops" or restaurant supply stores.

What are the short-term affects? • A person experiencing a Nitrous oxide high may have slurred speech; difficulty maintaining

his or her balance or walking; be slow to respond to questions; be immune to stimulus such as pain, loud noises and speech; and, lapse into unconsciousness.

• A person who is rendered unconscious by N2O is likely to stop breathing within seconds as a result of a depressed nervous system. If a person remains conscious and stops breathing the Nitrous oxide, recovery can occur within a few minutes.

Can death occur? • A person who remains unconscious and continues to inhale pure gas is likely to die. • Death also occurs when users, in their attempt to reach a higher state of euphoria, breathe

N2O in a confined space---in a small room, inside an automobile or by placing their head in a plastic bag. Long-term exposure (several minutes) is not necessary before death occurs.

What are effects of chronic N2O use? • Chronic abuse, though unusual, can occur. Such abuse may cause vitamin B12 deficiency. • When the level of B12 in the body is reduced, the red blood cell count is lowered, anemia

results and nerves degenerate. • Chronic users have described painful and/or numbing sensations, an unsteady walk or

appearing to be irritable. • Chronic abuse may also result in both depression of heart muscular functioning and in

cardiac disturbances.


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Online Material (continued): Can chronic users recover? • If death does not occur, the person who suffers from these symptoms may recover from all

of them. • The debilitating process is reversible, although some persons have experienced permanent

loss of balance. Potential for Abuse: What is being done to regulate the sale of Nitrous oxide? • Medical and dental industry use Nitrous oxide strictly regulated by the FDA. • Sale of whippet canisters is regulated in only a few states. Connecticut and Iowa, for

instance, are currently working to pass laws that would prohibit the sale of whippets to minors and fine businesses that sell the product.

• Most states, however, have no regulations regarding the sale of Nitrous oxide to minors.


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Partial Handout for Online Portion - City University of ...websupport1.citytech.cuny.edu/Faculty/mfehrenbach/Handout.pdfsurgical pain relief via gas inhalation appeared at the very