Nitrous Oxide versus Medical Air Using in General Anaesthesia During Laparoscopic Cholecystectomy: A Comparative Study.

This study was designed to observe the haemodynamic changes, recovery status and cost effectiveness during anaesthesia in laparoscopic cholecystectomy with medical air in comparison to anaesthesia with nitrous oxide associated with maintain of adequate analgesia and was conducted in the department of Analgesia and Intensive Care Medicine, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2017 to June 2017. Nitrous oxide is popularly using as an analgesic in current balanced general anesthesia in addition carrier agent for anesthetic. Intraoperative pain intensity depends on many variables including, type of surgery, surgical stimulation and surgical incision. It is difficult to measure intraoperative pain properly under general anesthesia therefore anesthetist depends on the surrogate marker of inadequate analgesia like raised heart rate, blood pressure, sweating and lacrimation. However, unfortunately, these parameters may changes in same direction with light plane of anesthesia, hypercarbia and ongoing procedural status of the patient.

Implementation of an Evidence-Based Practice Change to Offer Nitrous Oxide During Labor.

OBJECTIVE: The aim of this evidence-based practice change was to implement use of nitrous oxide as a pain management option during labor and to examine women's satisfaction with that option. DESIGN: Evidence-based practice change guided by the model for evidence-based practice change. SETTING: Labor and delivery unit in a tertiary medical center in the southwestern United States. PARTICIPANTS: Laboring women who met eligibility criteria were offered the option of nitrous oxide during a 2-month period. MEASUREMENTS: Process indicators to measure compliance with the practice change among staff, uptake of nitrous oxide among women, and women's satisfaction with the choice to use nitrous oxide. RESULTS: Nitrous oxide was offered to 26% (n = 55) of eligible women. Most of the 55 women who used nitrous oxide during the implementation period reported satisfaction with it and indicated that they would consider nitrous oxide for a future labor. CONCLUSION: Our experience implementing a practice change to offer nitrous oxide to laboring women indicated that use of nitrous oxide was feasible in this setting and that women were receptive to this option, were satisfied with its use, and would use nitrous oxide for a future labor.

The Spatial-Temporal Characteristics and Influential Factors of NOx Emissions in China: A Spatial Econometric Analysis.

While the progress of China’s industrialization and urbanization has made great strides, atmospheric pollution has become the norm, with a wide range of influence and difficult governance. While many previous works on NOx pollution have been developed from the perspectives of natural science and technology, few studies have been conducted from social-economic points of view, and regional differences have not been given adequate attention in driving force models. This paper adopts China’s provincial panel data from 2006 to 2015, an extended STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model, and spatial econometric models to investigate the socio-economic influential factors and spatial-temporal patterns of NOx emissions. According to the spatial correlation analysis results, the provincial NOx emission changes not only affected the provinces themselves, but also neighboring regions. Spatial econometric analysis shows that the spatial effect largely contributes to NOx emissions. The other explanatory variables all have positive impacts on NOx emissions, except for the vehicular indicator (which did not pass the significance test). As shown through the estimated consequences of direct and indirect effects, the indicators have significant positive effects on their own areas, and exacerbate NOx pollution. In terms of indirect effects, only three factors passed the significant test. An increase in gross domestic product (GDP) and energy consumption will exacerbate adjacent NOx pollution. Finally, a series of socio-economic measures and regional cooperation policies should be applied to improve the current air environment in China.

Use and perception of nitrous oxide sedation by French dentists in private practice: a national survey.

AIM: The aim of this national survey was to record the use of nitrous oxide and the perceptions of French dental practitioners to this form of sedation. The use of nitrous oxide sedation (NOS) has been authorised in private dental practice in France since December 2009 but, to date, no study implementing both quantitative and qualitative methods has explored such use. METHODS: The data were collected using a Google Forms questionnaire. A mixed methodology was used for data analysis: a quantitative approach to explore the use of conscious sedation and a qualitative thematic approach (using Nvivo software) to determine the practitioner's perception of it. RESULTS: Responses were collected from 225 practitioners (19% of the target population of 1185). Most of the responders were trained in NOS use in private dental clinics. Seventy-three percent of those who trained privately actually used NOS, compared to 53% of those trained at university (p-value = 0.0052). Above all, NOS was used for children requiring restorative dentistry. The average price of the sedation was 50 Euros and it lasted, on average, for 37 min. The qualitative and thematic analysis revealed the financial and technical difficulties of implementing NOS in private practice. However, it also showed the benefits and pleasure associated with NOS use. CONCLUSION: This statistical survey of French dental practitioners offers an insight of the current state of the use of conscious sedation with nitrous oxide in private general dental practice in France. It also includes the first report of dental practitioners' perceptions of NOS use and may lead to a better understanding of the reasons why sedation is sometimes not used in private practice.

Cost-effectiveness analysis of farmers' rice straw management practices considering CH4 and N2O emissions.

This study assessed the environmental consequences of burning and other rice straw management practices in terms of non-CO2 greenhouse gas (GHG) emissions, and evaluated the cost-effectiveness of selected rice straw management alternatives. On a per-hectare basis and considering a time horizon of five years, incorporating stubble more than 30 days before crop establishment, and incorporating composted rice straw in the field yielded the lowest cumulative CH4 and N2O emissions. Considering the associated costs and secondary benefits, the most cost-effective option for farmers is to incorporate stubble and straw in the soil more than 30 days before crop establishment. Rapid straw composting and incorporation of rice straw compost entails much higher additional cost but it also significantly mitigates GHG emission, hence it is the next most cost-effective option. Incorporating rice stubble and straw less than a month before crop establishment and removing rice straw for use as animal feed, on the other hand, appear to result in a net increase in ton CO2-eq given the assumed time horizon. The results underscore the impacts on the environment of small changes in straw management practices entailing minimal costs. Cost-effectiveness analysis considering rice straw for power generation and bio ethanol production is recommended. Further study on water management and tillage practice as mitigation options is recommended for a broader perspective useful for farmers, policy-makers, and other rice stakeholders.

[Impact of the decrease of nitrous oxide use on the consumption of halogenated agents]. / Impact de la diminution d'utilisation du protoxyde d'azote sur la consommation d'agents halogénés.

OBJECTIVE: Nitrous oxide (N2O) toxicity and its impact on pollution lead to restrict its use. A decrease of N2O consumption should increase the hypnotic inhaled consumption. This monocentric study estimated consumptions and costs of halogenated agents (HA) and N2O over 5 years when the N2O consumption was reduced. STUDY DESIGN: Retrospective from a computerized database. PATIENTS: Between 2006 and 2010, 34,097 procedures were studied after two meetings exposing the risks of the N2O. METHODS: At the end of anesthesia, consumptions of hypnotic agents (millilitres transmitted by the injectors and the blender) were archived in the database. The annual consumption of agents was obtained by adding the individual consumptions, then divided by the annual number of cases. The costs were given by the hospital pharmacy from invoices. RESULTS: N2O consumption per anesthesia constantly decreased during the study, from 75.1L by act to 22.7L. The sum of the annual consumptions of N2O and air did not change suggesting that total fresh gas flow remained stable. Between 2006 and 2010, the sevoflurane consumption by act increased by 25%, from 16.5 to 20.6mL, and desflurane consumption by 37%, from 46.1 to 63.1mL by patient. The costs of the administration of hypnotic agents remained stable. CONCLUSION: N2O consumption decrease had an impact on the consumption of HA. The cost reduction of the N2O was counterbalanced by the increase of halogenated vapor cost. The profit of the ecological impact of the reduction in N2O use could be quantified.

A cost-benefit analysis of the ENIGMA trial.

BACKGROUND: The ENIGMA trial was a prospective, randomized, multicenter study that evaluated the clinical consequences of including N2O in general anesthesia. Patients who were given a N2O-free anesthetic when undergoing major surgery for which the expected hospital stay was at least 3 days had lower rates of some postoperative complications. This suggests that, despite a higher consumption of potent inhalational agent, there could be a financial benefit when N2O is avoided in such settings. METHODS: A retrospective cost analysis of the 2,050 patients recruited to the ENIGMA trial was performed. We measured costs from the perspective of an implementing hospital. Direct health care costs include the costs for maintaining anesthesia, daily medications, hospitalization, and complications. The primary outcome was the net financial savings from avoiding N2O in major noncardiac surgery. Comparisons between groups were analyzed using Student t test and bootstrap methods. Sensitivity analyses were also performed. RESULTS: Rates of some serious complications were higher in the N2O group. Total costs in the N2O group were $16,203 and in the N2O-free group $13,837, mean difference of $2,366 (95% CI: 841-3,891); P = 0.002. All sensitivity analyses retained a significant difference in favor of the N2O-free group (all P ≤ 0.005). CONCLUSIONS: Despite N2O reducing the consumption of more expensive potent inhalational agent, there were marked additional costs associated with its use in adult patients undergoing major surgery because of an increased rate of complications. There is no cogent argument to continue using N2O on the basis that it is an inexpensive drug.

Farm, land, and soil nitrogen budgets for agriculture in Europe calculated with CAPRI.

We calculated farm, land, and soil N-budgets for countries in Europe and the EU27 as a whole using the agro-economic model CAPRI. For EU27, N-surplus is 55 kg N ha(-1) yr(-1) in a soil budget and 65 kg N(2)O-N ha(-1) yr(-1) and 67 kg N ha(-1) yr(-1) in land and farm budgets, respectively. NUE is 31% for the farm budget, 60% for the land budget and 63% for the soil budget. NS values are mainly related to the excretion (farm budget) and application (soil and land budget) of manure per hectare of total agricultural land. On the other hand, NUE is best explained by the specialization of the agricultural system toward animal production (farm NUE) or the share of imported feedstuff (soil NUE). Total N input, intensive farming, and the specialization to animal production are found to be the main drivers for a high NS and low NUE.

[Desflurane and isoflurane in minimal-flow anesthesia. Consumption and costs with forced fresh gas reduction]. / Desfluran und Isofluran bei Niedrigflussnarkosen. Verbrauch und Kosten bei forcierter Frischgasreduktion.

BACKGROUND: In the present investigation we compared the consumption of desflurane (DES) and isoflurane (ISO) using a standardized minimal-flow protocol with a forced reduction of the fresh gas flow (FGF). METHODS: 54 adult women were examined. After induction of anaesthesia a forced reduction of the FGF was started: 5 min 0.5 l/min O(2) + 1 l/min N(2)O, 10 min 0.5 l/min O(2) + 0.5 l/min N(2)O; finally 0.3 l/min O(2) + 0.2 l/min N(2)O up to the end of surgery. The consumption of DES/ISO was determined with a precision balance. RESULTS: In the DES group the uptake was around 0.3 vol-%, i.e. less than 8% of the target 2/3 MAC value was taken up. For ISO the uptake was around 0.25 vol-%, i.e. the uptake was approximately 30% of the target 2/3-MAC value. The DES consumption was after 60 min 17.0+/-1.1 g, 120 min--27.3+/-1.8 g and 180 min--36.5+/-1.7 g. ISO consumption was significantly lower: 7.6+/-0.8 g, 12.4+/-1.7 g and 15.5+/-1.6 g. The use of DES yielded higher costs, i.e. 2.28 EUR for 60 min, 3.63 EUR for 120 min and 4.97 EUR for 180 min. The consumption of the inhaled anaesthetics can be calculated as: DES (g)=4.84+0.184 x duration (min) (R(2)=0.981), ISO (g)=2.049+0.0826 x duration (R(2)=0.979). The costs are: DES (EUR)=0.85+0.0323 x duration (min); ISO (EUR)=0.19+0.0077 x duration (min). CONCLUSION: With a forced reduction of the FGF the DES consumption is still higher.

[Propofol for paediatric patients in ear, nose and throat surgery. Practicability, quality and cost-effectiveness of different anaesthesia procedures for adenoidectomy in infants]. / Propofoleinsatz für Hals-Nasen-Ohren-Eingriffe im Kindesalter. Praktikabilität, Qualität und Kosteneffektivität verschiedener Narkoseverfahren zur Adenotomie bei Kindern.

BACKGROUND: The aim of this study was an improvement in patient comfort, reduction of anaesthesia costs and room contamination by the use of propofol for adenoidectomy. METHODS: A total of 103 infants (aged 1-5 years) undergoing elective adenoidectomy were randomized for anaesthesia with sevoflurane-nitrous oxide/oxygen (group 1), sevoflurane-air/alfentanil (group 2), alfentanil-propofol under induction with sevoflurane (group 3) or alfentanil-propofol (group 4). RESULTS: Using propofol, postoperative agitation and emesis were significantly less and the anaesthesia costs as well as the need for analgesics was reduced compared to inhalative anaesthesia. CONCLUSIONS: The use of propofol for preschool children undergoing ear, nose and throat (ENT) surgery seems to be advantageous because of less postoperative agitation, emesis and costs.

Efficacy and costs of 3 anesthetic regimens in the prevention of postoperative nausea and vomiting.

STUDY OBJECTIVE: The aim of the study was to compare the antiemetic efficacy and costs associated with 3 different anesthesia regimens used in gynecologic laparoscopy. DESIGN: This was a randomized, controlled study. SETTING: The study was conducted at a university hospital. PATIENTS: We studied 150 ASA physical status I or II patients, undergoing elective gynecologic laparoscopy with general anesthesia. INTERVENTION: Patients were allocated into the following 3 groups: group P-preoperative placebo tablet, propofol induction, propofol-air/O2 maintenance; group I + O-preoperative 8-mg ondansetron tablet, thiopental induction, isoflurane-N2O maintenance; group I (control)-preoperative placebo tablet, thiopental induction, isoflurane-N2O maintenance. MEASUREMENTS: The frequency of postoperative nausea and vomiting (PONV), number needed to treat to prevent PONV, and the costs of the anesthetic drugs to prevent PONV in one additional patient were evaluated. MAIN RESULTS: The frequency of PONV within the 24-hour study period was lowest in group I + O (P, 38%; I + O, 33%; and I, 59%; P < 0.05 I + O vs I). The number needed to treat was 5 in group P and 4 in group I + O, compared with group I. The median costs of anesthetic drugs to prevent PONV in one additional patient were $65 in group P and dollar 68 in group I + O, compared with group I. CONCLUSIONS: We conclude that in gynecologic laparoscopy, propofol-air/O2 anesthesia alone, and isoflurane-N2O anesthesia combined with an oral 8-mg dose of ondansetron had similar efficacy and costs to prevent PONV. Isoflurane-N2O anesthesia without ondansetron was less expensive, but was also less efficacious.

Willingness to pay for dental fear treatment. Is supplying dental fear treatment socially beneficial?

The aim of this paper is to discuss the social desirability of supplying dental fear treatment in addition to dental treatment using the results from a treatment programme for patients with severe dental fear. The programme consisted of three different dental fear treatments: Cognitive therapy, applied relaxation and nitrous oxide sedation, in addition to dental treatment. To evaluate the effects of uncertainty on the patients' benefits from the programme, we elicited their willingness to pay, both before and after receiving treatment, since we expected patients to be uncertain about the outcome of the dental fear treatment. We found that the social desirability of the treatment was very sensitive to uncertainty. While only 24% of the patients were willing to pay the actual cost of the treatment before attending, 71% were willing to pay afterwards. This implies that many patients who would benefit from the treatment ex post are not willing to pay the cost of the treatment ex ante, and will thus not receive any treatment unless it is subsidized.

[Nitrous oxide. Sense or nonsense for today's anaesthesia]. / Lachgas. Sinn oder Unsinn für die heutige Narkoseführung.

Nitrous oxide has been used in addition to other volatile anaesthetics to provide general anaesthesia and short time sedation for more than 150 years. However, the exact mechanisms of action remain unclear. For decades nitrous oxide was considered to be the ideal anaesthetic because of his favourable physical properties and low cardiovascular side effects. However, the known side effects of nitrous oxide as well as the implementation of new anaesthetic agents and short acting opiates led to more and more criticism about the administration of this gas. Nitrous oxide is still frequently used for mask induction primarily in paediatric anaesthesia and gynaecology. However, recent studies have shown that omitting nitrous oxide can also be a risk factor because of an increased susceptibility to intraoperative awareness. Careful consideration of the illustrated contraindications and side effects as well as the available alternatives, shows that nitrous oxide is still an option in general anaesthesia.

Sevoflurane-N2O versus propofol/isoflurane-N2O during elective surgery using the laryngeal mask airway in adults.

STUDY OBJECTIVES: To compare a sevoflurane-nitrous oxide (N2O) general anesthetic technique with a standard technique of propofol for induction, and isoflurane-N2O for maintenance. DESIGN: Prospective, randomized study. SETTING: University-affiliated tertiary-care hospital. PATIENTS: 62 adults undergoing elective surgery using the laryngeal mask airway (LMA). INTERVENTIONS: Patients received either the standard technique of propofol for induction and isoflurane-N2O for maintenance (controls) or sevoflurane-N2O for both induction and maintenance of general anesthesia. MEASUREMENTS: Induction and emergence times, heart rate, blood pressure, oxygen saturation, and end-tidal carbon dioxide were recorded. MAIN RESULTS: Time to loss of consciousness was faster after propofol (mean +/- SEM: 51 +/- 3 sec) than after sevoflurane-N2O (85 +/- 10 sec; p < 0.05). Ready for surgery times, were however, similar between groups (10 +/- 1 vs. 11 +/- 1 min, respectively). All patients in the control group had apnea after LMA insertion compared with 4 patients in the sevoflurane-N2O group (p < 0.05). Heart rate was lower 5 and 10 minutes after LMA insertion in the sevoflurane-N2O group (69 +/- 3 and 66 +/- 3 bpm) versus the control group (81 +/- 3 bpm and 74 +/- 3 bpm, p < 0.05). After cessation of anesthetic gases, there were no differences in time to LMA removal, eye opening, or exiting the operating room (OR) between the control group (7, 8, and 10 min) and sevoflurane-N2O groups (7, 8, and 12 min, respectively). The majority of patients in both groups (92% to 97%) rated their anesthetic experience as excellent or good. CONCLUSIONS: Sevoflurane-N2O and propofol provided comparable conditions for LMA insertion. Sevoflurane-N2O was not associated with a faster return of consciousness or faster time to exit the OR compared with isoflurane-N2O.