This study, that evaluate the probable effect of N2O in increasing the incidence of nausea and vomiting after laparoscopy, sixty patients, class I or II of ASA physical status, undergoing diagnosed laparoscopy, were enrolled, and randomly divided in to two groups, each had 30 patients. After induction of general anesthesia, during the maintenance of anesthesia, N2O was not administered to group I of patients (control), and in group II (case), patients received N2O, in 50% concentration with O2. There was no significant difference in heart rate and blood pressure changes, oxygen saturation, and the use of any additional analgesic drug, between two groups (P>0.05). The incidence and intensity of nausea and vomiting in group 11, was higher than group I (p=0.0001), which it is significant. Duration of stay in the PACU was shorter in the patients of the group 11 (P<0.001) compared with the group I. With regard to the increased incidence of nausea and vomiting, we conclude that, it is better not to use N2O in general anesthesia for laparoscopic procedures.

Nitrous oxide is one of the most common inhalational anesthetics in current anesthesiological practice. This gas has many side effects. Hypoxia, particularly "diffusion hypoxia" and diffusion into air-containing cavities within the body are the side effects of N2O that cause significant morbidity and even death in the patients. N2O also inactivates synthesis of methionine. The hematological, neurological, immunological  and reproductive systems are affected by this unique property of N2O. Many anesthesiologists believe that the potential dangers of N2O are so great that it should no longer be used for routine clinical anesthesia. Because of the analgesic effect of fentanyl, a short acting synthetic opioid; it may be used instead of N2O . Our study was a clinical trial study and included 120 patients in two groups. In both the groups, induction of anesthesia was the same with thiopental sodium + fentanyl + pavlon and the trachea was intubated. Maintenance of anesthesia in group " N2O " was with oxygen + Halothane + N2O and in group “fentanyl” with oxygen + Halothane + fentanyl (o.5 mg/kg 1.2hr) .Blood pressure and pulse rate of patients were measured and recorded before, during, and after the anesthesia. The results were analyzed with K square, Z and t.tests. Blood pressure and pulse rate before, during and after anesthesia were the same in the two groups. These Hemodynamic measurements in the recovery room were not significantly different in the two groups. According to our finding it was concluded that: It is possible to use fentanyl [0.5 mcg/kg/1.2 hr], instead of N2O for the maintenance of anesthesia. With this dose, the hemodynamic conditions of the patients are stable during general anesthesia and recovery. More researches are needed to study the  efectivity of dosages lower than 0.5 mcg/kg/30 min.

Background and Objective: Climate change, such as the increase in hazardous N2O greenhouse gas, is always associated with various economic and developmental consequences. The environmental Kuznets curve indicates that the increase in greenhouse gases emissions until a country's development is directly related to that country's level of production and inversely related after development. The purpose of this study is to investigate the environmental Kuznets curve for N2O greenhouse gas emissions in Iran. Material and Methodology: The method of answering this problem is quantitative and through econometric analysis of time series data in the period 1960 to 2017 and the Auto Regressive Distributed Lag Model (ARDL) has been used to study and analyze variables. Findings: The results of the dynamic model show us that the area under cultivation has a negative effect and gross domestic product (GDP) and exports have a positive effect on N2O emissions. GDP2 also has a sign opposite to its root, and the inverse quadratic relation is established. As a result, the assumption of the Kuznets curve in Iran isn’ t rejected. Discussion and Conclusion: The maximum point of the chart for Iran in terms of GDP per capita will be around $7, 500. Therefore, if we go beyond this amount, N2O emissions will decrease. At present, the country's GDP per capita is about $6, 900 and we are on the upward trajectory of the Kuznets Curve. As a result, reducing N2O emissions will have a negative impact on Iran's growth. Thus, it isn’ t possible to implement some policies to reduce these greenhouse gas emissions without major consequences in various sectors of the economy.

Introduction: Spinal Anesthesia is a successful method for most surgical procedures on lower extremities and lower abdomen. Occasionally the duration of sensory blockade is shorter than the duration of the surgical procedures resulting in painful stress and discomfort. In one research, inhalation of N2O during spinal anesthesia provided analgesic effects and enhanced the level of sensory blockade. Our study evaluated the effects of N2O on the duration of sensory blockade in spinal anesthesia.Methods: In this double blind randomized controlled clinical trial, 80 adult patients who were candidates for lower extremity or lower abdominal surgery were randomly divided into two group received 500k N2O plus 50% O2 by inhalation and control group received 02 without N2O. Block level and the duration of T6 and T10 blockade were determined mean, systolic and diastolic blood pressures and heart rate recorded. Statistical analysis was performed by t-test.Results: The duration of sensory blockade above T6 and T10 levels in patients receiving N2O plus O2 was significantly superior to that in the control group (P<0.05). The mean changes in the heart rate and systolic, diastolic, and mean arterial blood pressures, were not significantly different between two groups. Discussion: Our results, show that N2O inhalation during spinal anesthesia enhances the duration of sensory block making this technique more piratical and appropriate. It also provided move homodynamic stability any adverse effects.

The purpose of this study is estimation of CH4, N2O and NO emission from agricultural lands, including citrus, wheat, date, sugarcane and rice in Khuzestan province, Iran. The actual concentration of each gas was determined by sampling from study sites. The DAYCENT model was used to simulate corresponding values of emission from each farm in selected sites. According to results, the highest and lowest annual amount of N2O emission were obtained in wheat and sugarcane farms of Shooshtar, 0.10 t.ha-1 and 0.002 t.ha-1, respectively. Similarly, the highest and lowest amounts of NO emission were observed in citrus orchards of Dezful and Shooshtar sugarcane fields, i.e. 0.152 and 0.004 t/ha, respectively. Average CH4 emission was highest for the paddy fields of Baghmalek and lowest in Abadan sugarcane farms with 1.369 and 0.12 t.ha-1.year-1, respectively. Considering the major contribution of agriculture in emission of greenhouse gasses, further studies in other regions of the country is recommended.

Chronic exposure to N20 environmental pollution may influence the health of personnel working in operating and recovery rooms. Human studies have indicated that chronic exposure to N20 may decrease mental performance, audiovisual ability, and manual dexterity and may also cause adverse reproductive effects like reduced fertility, spontaneous abortion and neurological, renal, and liver diseases. In this study, concentration of N20 in ambient air was monitored in 45 operating rooms and 12 recovery rooms at 12 hospitals. Ambient air was sampled automatically from three breathing sites in operating room (anesthetists, surgeons, operating room nurse) and one site in recovery room (recovery nurse) using a portable infrared spectrophotometer (N20 monitor 3010) with ppm mode. In addition, the effect of air ventilation system on the outcomes was measured. Statistical analysis of the data demonstrated that mean exposure of operating rooms was significantly lower in ventilated than unventilated rooms (P<0.05). Anesthetists showed higher mean exposure than other staff in all conditions, and operating room nurse showed lowest mean concentration. The breathing zone anesthetic concentration of N20 in 100% of sampling exceeded NIOSH recommended exposure limit (REL) for N20 (25ppm). Our data showed that exposure of recovery nurses to N20 was higher than REL of NIOSH but there was not any significant correlation between room air ventilation and the outcomes (P>0.05). In conclusion, proper use of air ventilation, anesthetic gases and scavenging system are necessary for having limited contamination with N20.

Climate change resulting from greenhouse gas emissions has endangered the life of humans. One of these atmospheric pollutants is N2O, which has a lifespan of 165 years and is roughly 310 times more efficient at trapping heat than CO2. Therefore, the aim of this study was to determine the amount of N2O production by domestic animals in Iran. The number of livestock in the last decade, was obtained from the Ministry of Jihad-e-Agriculture. Domestic animals were divided into five experimental treatments: the cows group, the small-ruminants group, the large-livestock’ s group, the industrial-poultry group and the other-poultry group. Then, using IPCC software (Tier 1), the amount of N2O emissions from domestic animal husbandry was obtained. Data wereanalyzedaccording to acompletely randomized design usingSAS software. The covariance among the considered years was estimated using repeated measurementsanalysis intimes. The amounts of N2O emissions in 2017 were 6. 34, 79. 87, 1. 26, 1452. 71, and 7. 15 million tons, respectively. Total emissions of this gas, feed intake and productions livestock’ s during the last decade were about 128. 13 Gg/Year, 605. 72 million tons and 118. 37 million tons, respectively. The covariance structure of emissions was unstructured and heterogeneous among the studied years. It seems that the industrial poultry section is the main producer of N2O gas. Therefore, special scientific attention should be made to optimize the poultry manure management.

Background and Objective: Today, laparoscopic surgeries, because of reducing postoperative complications, are increasingly developing. Intraperitoneal insufflations of CO2 and systemic absorption of it during laparoscopy results in hypercarbia. Using N2O during maintenance of anesthesia in these patients can enhance hypercarbia. This is because N2O increases the volume of pneumoperitoneum. This study was performed to determine the effect of N2O in enhancing hypercarbia during laparoscopy. Methods: Sixty Patients, with physical status I or II, undergoing outpatient diagnostic gynecologic laparoscopy according to ASA (American Society of Anesthesiology) scaling took part in this clinical and single blind trial, and were randomly divided in to two groups, each with 30 patients. In all patients, general anesthesia with end tracheal intubation was administered. The technique of anesthesia and ventilation were the same in all patients. Only, during the maintenance of anesthesia, N2O was not administered to group I (control) of patients, but in group II (case), patients received N2O, in 50% concentration in oxygen. The variables under study were evaluated and recorded at certain times and finally the data were analyzed using chi-square test, student t-test and EPI-5 software. Results: There was no significant difference between two groups in terms of demographic data, homodynamic variables (heart rate, mean arterial pressure, and electrocardiogram changes), oxygen saturation, and the use of any additional analgesic drug (instead of N2O in group I). Comparing the End tidal CO2 (Etco2) in two groups indicated that Etco2 increases in those patients who used N2O during maintenance of anesthesia (p=0.02). Conclusions: With regard to significant difference between two groups in the enhancement of intraoperative hypercarbia (although it was not associated with homodynamic changes in this study), it is better not to use N2O in general anesthesia for laparoscopic procedures.