Environmental monitoring of nitrous oxide during dental anaesthesia

The environmental impact of nitrous oxide inhalation sedation appointments and equipment used in dentistry

PURPOSE

This paper reports a life cycle impact assessment (LCIA) to calculate the environmental footprint of a dental appointment using N2O, comparing single-use equipment with reusable equipment. Nitrous oxide (N2O) is used successfully in dentistry to provide sedation and pain relief to anxious patients, most commonly in children. However, N2O is a powerful climate pollutant 298 times more damaging than carbon dioxide over a 100-year estimate.

METHODS

The functional unit chosen for this LCIA was 30 min delivery of N2O to oxygen in a 50:50 ratio at 6 L per minute flow rate as inhalation sedation to one patient. Two types of equipment were compared to deliver the anaesthetic gas: reusable and disposable items.

RESULTS

The use of disposable equipment for N2O sedation produces a significantly larger environmental impact across nearly all of the environmental impact scores, but the overall global warming potential is comparable for both types of equipment due to the vast environmental pollution from N2O itself.

CONCLUSION

N2O sedation is a reliable treatment adjunct but contributes to climate change. Single-use equipment has a further deleterious effect on the environment, though this is small compared to the overall impact of N2O. Dental priorities should be to deliver safe and effective care to patients that protects staff, minimises waste and mitigates impact on the environment alongside promoting research into alternatives.

Nitrous oxide abuse direct measurement for diagnosis and follow-up: update on kinetics and impact on metabolic pathways

Recreational use of nitrous oxide (N2O) has become a major health issue worldwide, with a high number of clinical events, especially in neurology and cardiology. It is essential to be able to detect and monitor N2O abuse to provide effective care and follow-up to these patients. Current recommendations for detecting N2O in cases of recreational misuse and consumption markers are lacking. We aimed to update current knowledge through a review of the literature on N2O measurement and kinetics. We reviewed the outcomes of experiments, whether in preclinical models (in vitro or in vivo), or in humans, with the aim to identify biomarkers of intoxication as well as biomarkers of clinical severity, for laboratory use. Because N2O is eliminated 5 min after inhalation, measuring it in exhaled air is of no value. Many studies have found that urine and blood matrices concentrations are connected to ambient concentrations, but there is no similar data for direct exposure. There have been no studies on N2O measurement in direct consumers. Currently, patients actively abusing N2O are monitored using effect biomarkers (biomarkers related to the effects of N2O on metabolism), such as vitamin B12, homocysteine and methylmalonic acid.

Safe use of chemicals and risk communication among dentists and dental students in Greece

Use of chemicals, most often classified for intrinsic hazards, is rather common among dentists. To date, no data have been recorded in the European Union (EU) on dentists' awareness regarding the safe use of chemicals. In the EU regulatory framework, two Regulations with wide applications, namely Regulations (EC) 1907/2006 (REACH) and 1272/2008 (CLP), have been introduced to protect human health and the environment and clearly communicate hazards posed by chemicals to workers and consumers. The aim of this study was to assess the extent of comprehension of hazard communication of chemicals among Greek dentists. For this, a closed-ended, anonymous and validated questionnaire was initially distributed to a total of 300 Greek dentists, both professionals and university students, over a period of 4 months. The collected data from 240 final responders were subjected to statistical analysis (frequencies, percentages, chi-square (χ²) and significance (p < 0.05)). The vast majority (90%) of the interviewed dentists are not aware of the CLP. Main sources of information regarding chemical hazard and safe use was the supplier through direct communication (90%), while some dentists also consulted the product labels (39%) and the material safety data sheets (54%). Regarding hazard communication, the perceived information from the pictograms is confusing to the vast majority of the dentists (86%), especially for systemic hazards (carcinogenicity and/or reproductive toxicity). In addition, 88% of the professional dentists have not noticed any changes in the labelling of chemical products, which also shows the low input of labels to hazard communication. On the other hand, 90% of the responders always utilize personal protective equipment (PPE), although it is not clear whether this PPE is adequate. In conclusion, rising awareness campaigns are needed, in collaboration with universities and dental care professional associations, to inform dentists about the safe use of chemicals not only to ensure protection of their own health but also to contribute to environmental sustainability.

Nitrous oxide occupational exposure in conscious sedation procedures in dental ambulatories: a pilot retrospective observational study in an Italian pediatric hospital

BACKGROUND

Nitrous oxide has a proven clinical efficacy in conscious sedation. At certain environmental concentrations it may pose a health risk to chronically exposed healthcare workers. The present pilot study aims at evaluating the exposure to nitrous oxide of dental ambulatory personnel of a pediatric hospital.

METHODS

A descriptive study design was conducted in two phases: a bibliographic analysis on the environmental safety policies and a gas concentration analysis in the dental ambulatories of a pediatric hospital, detected every 6 months from December 2013 to February 2017 according to law provisions. The surveys were carried out using for gas analysis a photoacoustic spectrometer Innova-B&K "Multi-gas monitor model 1312" and Innova-B&K "Multi-sampler model 1309". The biological analysis and monitoring have been carried out on staff urine.

RESULTS

The analyses were performed during 11 dental outpatient sessions on pediatric patients. All the patients were submitted to the same dental procedures, conservative care and dental extractions. The pediatric patients were 47 (23 males, 24 females; age range 3-17 years; mean age 6,63, SD ± 2,69) for a mean of 4,27 (SD ± 1,49) per session., The mean environmental concentration of nitrous oxide during the sessions was 24.7 ppm (SD ±16,16). A correlation was found between urinary nitrous oxide concentration of dentists (Pearson's correlation 0.786; p = 0.007) and dental assistants urines (Pearson's correlation 0.918; p < 0.001) and environmental concentrations of nitrous oxide. Weak negative correlations were found between age and sex of patients and environmental concentrations of nitrous oxide. The mean values of the biological monitoring data referring to all the outpatient sessions are lower than the reference values foreseen in accordance to the regulations in force on nitrous oxide concentration.

CONCLUSIONS

The mean environmental concentration values recorded in our study are below the limit of 50 ppm considered as a reference point, a value lower than those reported in other similar surveys. The results of the present study provide a contribution to the need to implement technical standards, criteria and system requirements for the dental ambulatories, to date not yet completely defined, and cannot be assimilated to the ones established for the surgical rooms.

Past, present, and future of nitrous oxide

INTRODUCTION

For a drug that has been omnipresent for nearly 200 years, nitrous oxide's (N2O) future seems less certain than its illustrious past. Environmental concerns are coming to the fore and may yet outweigh important clinical benefits.

SOURCES OF DATA

After determining the scope of the review, the authors used PubMed with select phrases encompassing the words in the scope. Both preclinical and clinical reports were considered.

AREAS OF AGREEMENT

The analgesic and anaesthetic advantages of N2O remain despite a plethora of newer agents.

AREAS OF CONTROVERSY

N2O greenhouse gas effect and its inhibition of key enzymes involved in protein and DNA synthesis have provided further fuel for those intent on eliminating its further clinical use.

GROWING POINTS

The use of N2O for treatment-resistant depression has gained traction.

AREAS TIMELY FOR DEVELOPING RESEARCH

Comparative studies for N2O role in combatting the prescription opioid analgesic epidemic may well provide further clinical impetus.

Occupational hazards to dental staff

Dental professionals are predisposed to a number of occupational hazards. These include exposure to infections (including Human Immunodeficiency Virus and viral hepatitis); percutaneous exposure incidents, dental materials, radiation, and noise; musculoskeletal disorders; psychological problems and dermatitis; respiratory disorders; and eye insults. Percutaneous exposure incidents remain a main concern, as exposure to serious infectious agents is a virtual risk. Minimizing percutaneous exposure incidents and their consequences should continue to be considered, including sound infection control practices, continuing education, and hepatitis B vaccination. Basically, for any infection control strategies, dentists should be aware of individual protective measures and appropriate sterilization or other high-level disinfection utilities. Strained posture at work disturbs the musculoskeletal alignment and leads to stooped spine. The stooped posture also involved certain groups of muscles and joints. This may lead to diseases of the musculoskeletal system. Continuous educating and appropriate intervention studies are needed to reduce the complication of these hazards. So, it is important for dentists to remain constantly up-to-date about measures on how to deal with newer strategies and dental materials, and implicates the need for special medical care for this professional group.

Regulatory compliance in the dental office

Dentists in the private sector, as well as their academic counterparts, must comply with a variety of federal, state, and local regulations. The scope of this regulation ranges from specifying who may engage in the practice of dentistry to the disposition of extracted teeth. In this review, some requirements imposed by various regulatory agencies are described. Because of the importance of state and local oversight, each clinician must determine what state and local requirements exist for them. A number of states have enacted various regulations that are more stringent than the federal versions. It is necessary, therefore, to seek appropriate local counsel regarding applicable statutes and regulations.

A randomised, controlled, crossover trial of oral midazolam and nitrous oxide for paediatric dental sedation

A randomised, controlled, crossover trial was designed to assess the safety and effectiveness of oral midazolam sedation for orthodontic extractions. Forty-six ASA physical status I children aged 10-16 years were recruited. Each child required two treatment sessions. Sedation with either oral midazolam 0.5 mg.kg-1 or nitrous oxide in oxygen was used at the first visit, the alternative being used at the second visit. Blood pressure, heart rate, arterial oxygen saturation, and sedation and behavioural scores were recorded every 5 min. Anxiety levels and postoperative satisfaction were also recorded. Blood pressure, heart rate and arterial oxygen saturation in both groups were similar and within acceptable clinical limits. The median [range] lowest arterial oxygen saturation levels for subjects in the midazolam and nitrous oxide groups were 95 [90-100]% and 98 [93-100]%, respectively. The median [range] time to the maximum level of sedation in the midazolam group was 20 [5-65] min compared with 5 [5-10] min in the nitrous oxide group (p < 0.001). The median [range] duration of treatment was similar in both groups (midazolam group: 10 [5-30] min, nitrous oxide group: 10 [5-25] min). Seventy-four per cent of subjects were prepared to have oral midazolam sedation again, 54% preferring it. Oral midazolam appears to be a safe and acceptable form of sedation for 10-16-year-old paediatric dental patients.

Seminars on controversial issues. A review of the pharmacological approach to the management of dental anxiety in children

This paper aims to review the existing literature on the pharmacology of a number of sedative drugs used in the management of dental anxiety in the conscious child patient. Pharmacological agents may be used as a complement to behavioural techniques to assist in the management of anxiety in some paediatric dental patients. Their use may also be especially indicated in children with disabilities. These agents are usually sedative in action and do not, in themselves, eliminate anxiety but merely enhance patient acceptance by reducing arousal and modifying anticipation of danger. The agents used are varied and diverse and include nitrous oxide, benzodiazepines and narcotics. Nitrous oxide has proved to be of particular value but carries a degree of risk for the operating staff. Amongst the benzodiazepines, Midazolam has been used more frequently in recent years. It may be given by a variety of routes, including intra-nasally. Dentists who employ sedative agents and techniques should be familiar with the pharmacology of the agents selected, be cognisant of the risks and benefits of the technique employed and be able to manage any adverse events that may arise through their use.

A study of the effectiveness of oral midazolam sedation for orthodontic extraction of permanent teeth in children: a prospective, randomised, controlled, crossover trial

OBJECTIVES

To assess the safety, effectiveness and acceptability of o:ral midazolam sedation for orthodontic extraction of permanent teeth in children.

DESIGN

A prospective, randomised, controlled, crossover trial.

METHODS

A total of 26 children aged 10-16 (ASA I), referred for orthodontic extraction of premolar or canine teeth under sedation, were included in the study. Each child required two treatment sessions for the extraction of equivalent teeth on opposite sides of the mouth. Each subject was sedated with either ora midazolam (0.5 mg/kg) or nitrous oxide and oxygen (30%/70%) at the first visit and the alternative form at the second visit. At each visit two teeth were extracted, one upper and one lower. Heart rate, arterial oxygen saturation, respiration rate, sedation and behavioural scores were recorded every five minutes. Overall behaviour, patient acceptance and patient satisfaction were recorded at the end of treatment.

RESULTS

Of the 26 children included in the study there were 12 males and 14 females. The mean age was 12.5 years. The mean heart rate and respiratory rate for both groups were similar and within acceptable clinical limits. The lowest mean arterial oxygen saturation levels for nitrous oxide and midazolam sedation were 97.7% and 95.0% respectively. Although midazolam caused greater oxygen desaturation, the range (91%-100%) was within safe limits for conscious sedation. The mean level of sedation was greater in the midazolam group compared with the nitrous oxide group and all but one case completed treatment. A total of 23 patients (88%) said they would be prepared to have ora midazolam sedation again and 17 (65%) actually preferred oral midazolam to nitrous oxide sedation.

CONCLUSION

Oral midazolam (0.5mg/kg) appears to be a safe and acceptable form of sedation for 10-16 year old paediatric dental patients.