Nitrous oxide Test 3

Patient Preparation

Fasting is not necessary but it is recommended to avoid fried fatty foods Having the patient use the restroom before sedation should be considered. Children may be tempted to interrupt dental treatment with this request. This requires discontinuing the delivery of N2O and removing all associated items including rubber dam and necessitates starting the process over when the child returns. These steps can be disruptive and time-consuming. In addition, the relaxing effects of N2O/O2 sedation may trigger unintended, accidental voiding during treatment.

Inhalant categories

Inhalants are generalized to the categories of volatile solvents, nitrites, aerosols, and gases

Adjusting Levels Appropriately

* A great advantage of using N2O and O2 is the ability to adjust levels of sedation. Because of this important pharmacologic property, the onset of clinical effects is rapid. * when a potentially painful phase of treatment approaches, the amount of N2O gas delivered may be increased. Conversely, as the intensity of the treatment subsides, the amount of N2O gas provided can be decreased. * Remember that because of individual biovariability, patients will require different levels of N2O on different days and for different procedures. * Regarding titration within the technique of N2O/O2 sedation, it is critical that a patient's responses are closely monitored once signs and symptoms of sedation begin to appear so that time is given for doses to reach their peak effect.

Benefits of titration

*It is extremely desirable to provide only the amount of a drug necessary for the procedure being performed *It minimizes the chances of a severe, possibly life-threatening reaction should the patient be allergic to the drug. *allows for biologic variability. It is essential to treat each patient as an individual, taking into account the concept of individual biovariability. *Titration can be applied to other drugs as well. For example, staggering local anesthetic injections over time allows for biotransformation tailored to the procedure and the patient's unique physiologic response

Activating Nitrous Oxide and Oxygen Equipment

*Open Both the Oxygen and the Nitrous Oxide Cylinders *A bag barrier may be used to cover the unit; however, make sure the flowmeter can be easily read and knobs are easily accessible through the barrier *Ensure that the master switch on the flowmeter is in the "on" position *Activate the main portion of the scavenging system by turning on the suction or evacuation system to the appropriate level.

General Unit Preparation

*The N2O/O2 sedation armamentarium should include all equipment necessary to provide safe sedation experiences for the patient and a safe environment for the operator and all other exposed personnel. *A scavenging system will include an accurate flowmeter, scavenging masks, and a vacuum system able to eliminate gases at a rate of at least 45 liters per minute *Ensure vacuum and ventilation exhausts are vented to the outside; make sure they are not near fresh-air intake vents. *Assess the room and area ventilation *Confirm the absence of leaks at pressure connections on the unit. Bubbles will appear at leaking locations when a soap and water solution is used. *Inspect the conducting tubing and the reservoir bag and their connections for leaks. Reservoir bags can tear if pulled off by the bladder and not the collar. Sterilizing tubing and bags will decrease their life expectancy.

Fundamental Principles for Appropriate Administration

*The operator should be enthusiastic and confident that the experience will be positive. * Confidence is primarily preparation-reflected in the individual, who is informed and educated about N2O pharmacokinetics * Recognize that a patient in your care represents the best opportunity you have to express genuine care and concern *Informed consent must be obtained from each patient before each N2O/O2 administration. *The amount of N2O required by a patient on any given day or time varies. Do not adopt the fixed-dose philosophy; the amount of N2O required on the previous visit is not relevant for the current appointment *The procedure begins and ends with 100% pure O2 *The patient should never be left unattended. The effects of central nervous system depression may be quick and/or subtle; constant monitoring must be done by a professional trained in N2O/O2 sedation *Accurate documentation of all procedures must be maintained in the patient's file. *The patient should be placed in a comfortable position. *Maintain open communication with the patient. Sedated patients may not be able to accurately state their feelings *If N2O/O2 is to be given at a subsequent appointment, the patient should be advised to avoid eating a big meal that includes fatty, fried foods and minimize the amount of liquids before the appointment

Signs of Successful Nitrous sedation

*The patient is relaxed and comfortable *If asked, the patient acknowledges a reduced sense of fear and anxiety *The patient's mood may be categorized as happy, pleasant, satisfied, or even ambivalent *Relaxation may be expressed overtly or inadvertently through physical movements. Signs of relaxation may include shoulders dropping, legs uncrossing, and arms positioned looser on arm rests. *Patients usually take deeper respirations when they are relaxed. A deep sigh or large inhalation may signal the patient is relaxing. *As sedation begins, the activity of the patient's eyes will begin to slow. Eye movement will be reduced, and blink rate will be slower *As sedation continues, there will be a point, often, when the eyes may appear "glazed" or "glassy." *Patients who are appropriately sedated are content. There is more of a "flat" expression rather than one that is "alert." *There should be no signs of tension on the patient's face. *Patients will also smile easily *When appropriately sedated, patients are fully conscious and aware of their surroundings

Monitoring requirements are much different if N2O is used with another drug besides a local anesthetic or it is used in amounts greater than 50%. This definition of moderate sedation has a specific monitoring protocol

1. Continuous monitoring of heart rate, respiratory rate, blood pressure, O2 saturation, and expired carbon dioxide values should be completed. Ventilation is monitored by capnography (preferred), or pretracheal/precordial stethoscope. Blood pressure values are also recommended in 10- to 15-minute intervals. 2. Documentation is to be recorded in 10-minute intervals. 3. If any restraint device is used, a foot or hand should be kept exposed and airway patency is continuously assessed by maintaining appropriate head position.

Time-Weighted Average Dosimetry

1. It is also possible to determine the amount of N2O exposure of an individual over time. This method gives an estimate of the amount of exposure to a gas over a specified period.

Safety of Pediatric Patients

1.It is not advised to let the child fall asleep under N2O/O2 sedation 2.Ensure parental informed consent. Tahir reported a significant observation regarding parental consent. It was discovered that 40% of consent obtained was not valid, because the parents did not fully understand what they were consenting to even after a full explanation of the treatment and type of anesthesia their child was to undergo 3.Emergency situations involving children are often airway related.75,76 1. Ensure the adequacy of personnel training and cardiopulmonary resuscitation certification. 2. Ensure the availability of appropriate equipment such as positive-pressure ventilation and airway supportive devices. 3. Ensure vigilant monitoring. Never leave a patient alone. For legal reasons, the continuous presence of two team members with a patient in the operatory is strongly advised.

Appropriate Minimal Sedation

A desirable level of sedation for both patient and operator using N2O/O2 sedation can be achieved by the use of the titration-time technique plus careful monitoring of the patient's signs and symptoms.

Optimal point of sedation

A method of drug administration in which a substance is given in incremental doses until a specific desired clinical endpoint is reached.

Administration of Nitrous Oxide

A. Depending on the type of machine, there may be slight variations in the administration technique. B. The administration technique of titrating N2O is recognized as the standard of care. Slow titration of small doses of drug is important to prevent oversedation. C. There is no exact amount of N2O that is required to be delivered during the titration technique. D. Watch patient comfort level. Titrate to a level of sedation that is determined by patient comfort and relaxation. Watch closely for the signs and symptoms of ideal sedation E. Intraoperative monitoring includes vigilant observation of the patient's responses and reactions in addition to observation of the reservoir bag. F. While performing operative procedures ,the goal is to keep the patient relaxed and comfortable. G. When you terminate the N2O flow, continue delivering 100% O2 during the final minutes of the operative procedure. This begins your required postoperative oxygenation period of 5 minutes minimum. It is vital to pay close attention to this minimum time.

Postoperative Procedures

A. It is important to record information regarding the sedation procedure in the patient's file just as you would document delivering local anesthesia or performing an operative procedure B. Turn off the unit by use of the master switch on the flowmeter. C. Turn off gas cylinders on a portable unit immediately after use.

Adequate Recovery

A. Patients should be alert and oriented. B. Vital sign values should be stable and within acceptable limits. C. Use of scoring systems may assist in documentation of fitness for discharge. D. When, and only when, the patient feels normal, the breathing apparatus delivering 100% O2 can be removed and the patient can be allowed to breathe rE. E. Extend your appreciation of the patient's cooperation and trust. Reinforce the success of the appointment, and then dismiss the patient F. Documentation of adequate recovery must be maintained for each patient visit.

Patient Participation

A. Review the patient's health history and obtain informed consent. B. Measure the baseline vital signs C. Select the appropriate size and type of scavenging nasal hood for the patient. D. Begin O2 flow to the nasal hood or mask. E. Estimate the total liters flow per minute (L/min) according to the size and physical and physiologic condition of the patient. F. Push the O2 flush button until the reservoir bag is partially inflated to approximately two-thirds full G. Place the nasal hood or face mask on the patient H. Determine the appropriate minute volume needed for the patient by use of the flow of 100% O2.

Inhalant Abuse

All drugs that produce euphoria have the potential to be abused, whether they are injected, swallowed, or inhaled. However, not all drugs that can be abused through inhalation are defined as inhalants. The term inhalant applies to a group of volatile substances that have the ability to produce chemical vapors that can be inhaled with the intent of producing a psychoactive reaction

Hand-Held Monitoring Device

An innovative product on the market is a small, lightweight, portable N2O gas monitor that gives a continuous measure of N2O in the ambient air

Inappropriate Minimal Sedation

As N2O concentrations are increased, the signs and symptoms of comfort and relaxation may disappear. Some sensations may continue to be tolerable but become intense. Sometimes, changes in patient comfort occur rapidly, and a patient can suddenly become uncomfortable. In either case, the patient is no longer in a relaxed state

Recommendations and Preventive Measures for Minimizing Waste Nitrous Oxide Gas

Certain situations are more problematic for scavenging than others. 1. Patients who are intubated (e.g., tracheal tube) are in a closed-circuit system that affords opportunity for increased control over trace waste anesthetic gases. Sources of Leakage From the Patient 1. There are several ways that N2O can leak from the patient. Perhaps the most critical measure to control in this category is patient talking. Whenever patients talk, they are expelling N2O into the operator's breathing zone. Instruct patients to breathe through their nose and minimize talking.

Addictive Nature of Nitrous Oxide

Compared with other drugs, N2O abuse may be relatively low. However, it is now considered a substance of abuse Evidence exists that suggests N2O is involved with the endogenous opioid system directly at a receptor site and/or indirectly by activating opioid neurotransmitters. Compared with other drugs, N2O abuse has not risen to the level of a global public health concern; however, there are areas of the world where its abuse has risen significantly

Recordkeeping Procedures

Components of the Sedation Record • Patient's name and date • ASA Physical Classification Status Patient's Level of Pain and Anxiety • Indications for nitrous oxide (N2O)/oxygen (O2) use • Drugs or medications recently taken by patient • Assessment of oral intake • Preoperative, intraoperative (if using > 50% N2O), and postoperative vital sign values • Patient's minute volume • Peak percentage of N2O administered • Duration of drug administered • O2 saturation of hemoglobin (Spo2 when using > 50% N2O) • Assessment of recovery (i.e., postoperative oxygenation time in minutes, patient responses to subjective questions) • Adverse reactions and/or comments • Practitioner's signature or initials

Commonly inhaled substances

Computer duster, shoe polish Typewriter correction fluid, degreasers, dry cleaning agents Butane, gasoline, propane, lighter fluid Paint and paint thinner Rubber cement, model glue Hair spray, cooking spray, deodorant spray, nail polish remover Insect repellents Nitrous oxide

Sterilization and Disinfection

Consult the manufacturer's instructions for best results regarding the sterilization and disinfection of specific sedation equipment.

Environment- children

Create an inviting environment for children. Carefully choose soft, light colors for the walls; minimize clutter and ensure clean, fresh smells. Consider the temperature of the room, keeping it comfortable for kids as this may be different for adults

Legislation and Regulation Issues

Currently, there are few regulations governing the sale or purchase of N2O. Distributors are ethically obligated to confirm that their customers are purchasing the drug for appropriate use; however, there are no control measures to confirm this practice

Symptoms of too much sedation:

Detachment/disassociation from environment Dreaming, hallucinating, or fantasizing Out-of-body experiences Floating and/or flying Inability to move, communicate, or keep mouth open Humming or vibrating sounds that progressively worsen Patient may experience: Drowsiness Dizziness Diaphoresis Nausea Light-headedness Fixed eyes Uncomfortable body warmth Patient may progress to: Sluggish, delayed responses Slurred words or no verbal sense Agitated or combative behavior Vomiting Unconsciousness

Documentation

Documentation is mandatory for all pediatric sedation procedures just as it is for adults. Document the indication for use of N2O/O2 sedation, the dosage and flow rate, duration of the procedure, and postoperative oxygenation time. All patient responses/behaviors should be included in the notes, especially if there were any adverse reactions.

Sexual Phenomena Associated With Nitrous Oxide

Euphoric effects have been associated with N2O since it was first introduced. Some reports in the literature have indicated that hallucinations, visualizations, and auditory illusions have resulted from N2O abuse.71 There have also been situations in which aberrations of a sexual nature have been reported Obviously, the allegation of sexual impropriety can create uncomfortable situations. Use common sense when N2O is used; do not place yourself in potentially incriminating situations. Practice with a third party in the vicinity who is educated on the effects of N2O. Titrate to the appropriate endpoint of sedation to avoid high concentrations of N2O and oversedation symptoms

Infrared Spectrophotometry

Infrared (IR) spectrophotometry uses electromagnetic energy to detect levels of N2O in the atmosphere

History of Controversial Literature

In 1967, a scientist named Vaisman1 reported that both male and female anesthesiologists in Russia experienced reproductive problems at a significantly higher rate than the general population Also during the 1970s, Bruce and colleagues9 investigated the possibility of N2O affecting perceptual cognition and psychomotor skills of personnel exposed to varying concentrations of the gas In the United States, Cohen and colleagues2-4 published articles in the 1970s dealing with anesthetic health hazards. One 1980 published study5 surveyed more than 50,000 dentists and dental assistants who were exposed to trace anesthetics. The results suggested that long-term exposure to anesthetic gases could be associated with an increase in general health problems and reproductive difficulty

Principles of Recovery

In general, emergence (recovery) is a mirror image of induction. This mirror image includes patients returning to their original emotional state, as well as recovering from the pharmacologic action of the drug.

Concomitant Drug Use- children

It must be determined whether the intended treatment can be accomplished with N2O/O2 sedation or whether additional pharmacologic management is required. The addition of any other drug potentiates additional risk.

Best Practices

Monitor the Environment for Nitrous Oxide Concentrations Prevent leakage from the delivery system through proper maintenance and periodic inspection of the equipment. Control waste N2O with an appropriate evacuation system that includes securely fitting masks, sufficient evacuation flow rates (45 L/min), and properly vented pumps Assess the adequacy of room ventilation and air exchange for effectively removing waste N2O. Practice appropriate administration techniques. Institute an education program for members of the health care team that describes the hazards of N2O and defines the preventive measures for reducing or eliminating trace gas contamination

Monitoring Requirements

Monitoring requirements for minimal sedation (N2O alone and less than 50%) include observation and intermittent assessment of level of sedation. Watching the inhalation/exhalation via the reservoir bag, fogging nasal hood, or chest rise/fall will assess ventilation. Frequent verbal contact and continuous visual monitoring of the patient's behavior, color, plus signs and symptoms will verify consciousness.

Nitrous Oxide Abuse

N2O abusers tend to be somewhat older than those inhaling solvents and fuels. As when it was first introduced, N2O is popular today at college social activities, such as parties and concerts, and may be advertised in college papers or flyers.19 In some places, there is a greater proportional increase in the recreational use of N2O when compared with other drugs

Health Hazards Associated With Chronic Exposure to Nitrous Oxide

N2O has been shown to affect vitamin B12 metabolism. It oxidizes the cobalt ion in the vitamin B12 cofactor, rendering the enzyme methionine synthase inactive in folate metabolic pathways. Methionine synthase plays a vital role in the production of deoxyribonucleic acid. Megaloblastic hematopoiesis and leukopenia result after prolonged exposure to N2O. Neurologic side effects have been associated with chronic use of N2O. Several reports in the literature cite peripheral neuropathy in individuals who indicate habitual use of N2O

Specific Biologic Issues and Health Concerns

N2O oxidizes the cobalt(I) form of cobalamin (vitamin B12), which then prevents cobalamin from acting as a coenzyme for methionine synthase. Methionine synthase is vital for the synthesis of several materials and functions, most importantly of which is deoxyribonucleic acid (DNA) production and subsequent cellular reproduction. Inactivation of methionine synthase has been previously mentioned in Chapter 9, and will be mentioned again in subsequent chapters. Suppression of methionine synthase activity has been shown to occur in some humans within 1 to 2 hours following the administration of 70% N2O. Megaloblastic anemia, first described in the 1950s, was found in patients treated with N2O for tetanus.27 Leukopenia and reduced megaloblastic erythropoiesis resembling pernicious anemia ensued. Discussions continue regarding the toxicity of N2O and its effects on the body.28-35 It continues to seem that N2O is safe when administered in low therapeutic doses for short periods of time.

NO2 negative experiences

Occasionally, patients have had negative experiences with N2O/O2 sedation. In such cases, the operator most likely did not titrate properly; instead, the patient may have received an inappropriate amount of drug or doses were delivered too quickly.

Psychologic and Psychomotor Effects of Recovery

Operators need to be assured to the greatest extent possible that patients are adequately recovered from sedation, so they do not harm themselves or others on dismissal from practitioners' offices. To date, there are no references to cases in which patients who were dismissed after N2O/O2 sedation harmed or injured themselves or others because of incomplete recovery.

Technique for Assessing Adequate Recovery

Postoperative vital sign values are an objective measure of recovery Assessment of a patient's response to questioning is subjective, but, in most cases, valid

SOAPME

Preparation for Sedation Procedures S (suction)—size-appropriate suction catheters and a functioning suction apparatus (e.g., Yankauer-type suction) O (oxygen)—adequate O2 supply and functioning flowmeters/other devices to allow its delivery A (airway)—size-appropriate airway equipment (nasopharyngeal and oropharyngeal airways, laryngoscope blades [checked and functioning], endotracheal tubes, stylets, face mask, bag-valve-mask or equivalent device) P (pharmacy)—all the basic drugs needed to support life during an emergency, including antagonists as indicated M (monitors)—functioning pulse oximeter with size-appropriate oximeter probes and other monitors as appropriate for the procedure (e.g., noninvasive blood pressure, end-tidal carbon dioxide, electrocardiogram, stethoscope) E (equipment)—special equipment or drugs for a particular case (e.g., defibrillator)

Recovery Time

Recovery time has continued to be a subject of research studies through the years. A wide variety of recommendations exist regarding the number of minutes it takes for complete recovery after sedation with N2O. The important factor to remember is that each patient is different and recovery times may vary

General Guidelines

The AAP/AAPD considers children who fall in ASA classes 1 and 2 appropriate for all levels of sedation A responsible adult should accompany a child to and from an appointment and care should be taken to ensure adequate monitoring of those who need to travel in a car seat The guidelines state that the practitioner must have immediately available facilities, personnel, and equipment and must be able to manage all emergency and rescue situations Informed consent from the responsible accompanying adult must be obtained Risk of vomiting and aspiration should be considered before any type of sedation

Personnel- children

The attitude of the practitioner and staff is the single most important factor in the successful administration of N2O/O2 to pediatric patients

Goals of Sedation- pediactrics

The goals of sedation as listed in these guidelines include (1) guarding the patient's safety and welfare; (2) minimizing physical discomfort and pain; (3) controlling anxiety and maximizing amnestic potential; (4) modifing behavior and movement; and (5) returning the patient to a state where discharge is safe Selecting the lowest dose of drug, the fewest number of drugs, and the correct drug to meet the intended goal of accomplishing the procedure is recommended Knowledge of each drug's time of onset, peak response, and duration of action is important and emphasize what one must know if a previous dose has taken full effect before administering more drug(s). The guidelines recognize the importance of titration.

Health Evaluation

The health evaluation should include age and weight. Weight is usually a most important factor in the administration of proper medication dosages for patients, particularly children. However, weight is not a consideration for N2O/O2 administration. The evaluation should also include a history of allergies, medication or drugs taken, diseases and abnormalities, pregnancy status, prematurity, seizure disorders, prior hospitalizations, previous sedation experiences, relevant family history, and other relevant information related to anesthesia

Scavenging Trace Nitrous Oxide Gas

The term scavenging system traditionally referred to the mask and suction capabilities of the equipment but is currently a term used to identify several methods for the comprehensive removal of trace N2O.

Trust- children

The time it takes to establish trust between child and operator varies. Trust must also be obtained between parent and operator. Sometimes this may require more than one session.

Titration

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

Recovery

Toward the end of the procedure, or if behavior allows even sooner, turn N2O off and deliver 100% O2 for 3 to 5 minutes. Complete treatment, if necessary. Patient should demonstrate the ability to talk, sit up, and validate that he/she is feeling normal and without a headache, groggy, or any uncomfortable feeling. This postsedation level of consciousness should also parallel that of presedation.

Nitrous Oxide Pediatric Use in Various Disciplines

•Pediatric Dentistry •Emergency Medicine •Endoscopy •Medical Painful Procedures •Otologic Examination •Nonoperating Room

Piaget proposed a model for child development that addresses cognitive function

•Sensorimotor •Preoperational •Preoperational •Operational •Formal