Inhalational Anesthetic Agents Research Articles

Factors associated with postoperative nausea and vomiting after laparoscopic cholecystectomy at the National Referral Hospital, Bhutan: a cross-sectional study

IntroductionPostoperative nausea and vomiting (PONV) are common distressing symptoms experienced after laparoscopic cholecystectomy. We report the rate, and the factors associated with postoperative nausea and vomiting, the patterns of prophylactic antiemetic prescription, and the anesthetic techniques used among patients who underwent laparoscopic cholecystectomy at the Jigme Dorji Wangchuck (JDW) National Referral Hospital, Bhutan.MethodsA cross-sectional study was conducted at the JDW National Referral Hospital, from January to December 2018. All the patients who underwent laparoscopic cholecystectomy under general anesthesia were included in the study. The demographic variables, premedication, induction agents, muscle relaxants, inhalational agents for maintenance, opioid and adjuvant analgesics, the reversal agents used, and the occurrence of PONV within 24 h were recorded. Data were analyzed using SPSS (version 23). Continuous variables were compared using a t-test or Mann-Whitney test, categorical variables were tested using chi-square or Fisher’s exact tests. Binary logistic regression analysis was performed to determine the factors associated with postoperative nausea and vomiting.Results190 patients underwent laparoscopic cholecystectomy under general anesthesia. The rate of PONV after laparoscopic cholecystectomy was 31.1% (59/190). Over half (53.7%, 102/190) of the study population were within 21–40 years of age, over 80% (157/190) were female, and 2/3rd were overweight and obese. The most frequently used premedication was ranitidine (39%, 34/87) and metoclopramide (31%, 27/87). More than half (57.4%, 109/190) of the patients received morphine as an opioid analgesic before induction. Sodium thiopentone was a commonly used induction agent (65.8%, 125/190). Succinylcholine and atracurium were mostly preferred muscle relaxants. Isoflurane and air were the most used inhalational anesthetic agents for the maintenance of anesthesia. Ondansetron was the most preferred anti-emetics during the intraoperative period. Previous history of motion sickness (OR 5.8, 95%CI 2.9–11.2, p < 0.001), and use of sodium thiopental (OR 4.1, 95%CI 1.9–9.1, p < 0.001) were independent risk factors for PONV. The use of antiemetics (OR 0.1, 95%CI 0.0-0.4, p = 0.002), propofol (OR 0.2, 95%CI 0.1–0.5, p < 0.001), adjuvant analgesic paracetamol (OR 0.4, 95%CI 0.2–0.8, p = 0.026), and adequate hydration with IV fluids (OR 0.9, 95%CI 0.9-1.0, p = 0.042) were preventive factors for PONV.ConclusionThe rate of PONV after laparoscopic cholecystectomy was high. History of motion sickness and use of sodium thiopental for induction were independent risk factors of PONV. The use of multimodal prophylactic antiemetics was robust and superior to monotherapy in preventing PONV. This finding re-emphasizes the need for risk stratification and appropriate use of antiemetics and anesthetic agents to prevent PONV.

Potential perioperative cardiovascular outcomes in cannabis/cannabinoid users. A call for caution.

Cannabis is one of the most widely used psychoactive substances. Its components act through several pathways, producing a myriad of side effects, of which cardiovascular events are the most life-threatening. However, only a limited number of studies address cannabis's perioperative impact on patients during noncardiac surgery. Studies were identified by searching the PubMed, Medline, EMBASE, and Google Scholar databases using relevant keyword combinations pertinent to the topic. Current evidence shows that cannabis use may cause several cardiovascular events, including abnormalities in cardiac rhythm, myocardial infarction, heart failure, and cerebrovascular events. Additionally, cannabis interacts with anticoagulants and antiplatelet agents, decreasing their efficacy. Finally, the interplay of cannabis with inhalational and intravenous anesthetic agents may lead to adverse perioperative cardiovascular outcomes. The use of cannabis can trigger cardiovascular events that may depend on factors such as the duration of consumption, the route of administration of the drug, and the dose consumed, which places these patients at risk of drug-drug interactions with anesthetic agents. However, large prospective randomized clinical trials are needed to further elucidate gaps in the body of knowledge regarding which patient population has a greater risk of perioperative complications after cannabis consumption.

Total intravenous anaesthesia with propofol and remifentanil is associated with reduction in operative time in surgery for glioblastoma when compared with inhalational anaesthesia with sevoflurane

BackgroundTotal intravenous anaesthesia (TIVA) is emerging as a preferred neuroanaesthetic agent compared with inhalational anaesthetic (IA) agents. We asked if TIVA with propofol and remifentanil was associated with shorter operative times compared to IA using sevoflurane in brain tumour surgery under GA. MethodsWe performed a retrospective analysis of all patients undergoing surgery for glioblastoma (GBM). We assessed choice of GA agent (TIVA or IA) with total time patient was under GA (anaesthetic time), operative time and time taken to recover fully from GA (recovery time). ResultsOver a two year period 263 patients underwent surgery under GA for their GBM including 188 craniotomy operations, 63 burr hole biopsy procedures and 12 open biopsy procedures. Of these, 79 operations took place under TIVA and 184 operations under IA.TIVA was associated with significantly reduced mean operative time including time taken to wake up in theatre (104 min with TIVA, 129 min with IA; p = 0.02). TIVA was also associated with trends toward shorter mean recovery time (118 min, versus 135 min with IA; p = 0.08) and shorter mean anaesthetic time (163 min, versus 181 min with IA; p = 0.07). There was no difference between TIVA and IA groups as regards duration of inpatient stay, readmission rates, complications or survival. ConclusionsTIVA with propofol and remifentanil may reduce anaesthetic, operative and recovery times in patients undergoing surgery for their GBM. These findings may be attributable to favourable effects on intracranial pressure and cerebral perfusion, as well as rapid recovery from GA. In addition to clinical advantages, there may be financial and logistical benefits.

Inhalational volatile anaesthetic agents: the atmospheric scientists' viewpoint.

All sectors of society must reduce their carbon footprint to mitigate climate change, and the healthcare community is no exception. This narrative review focuses on the environmental concerns associated with the emissions of volatile anaesthetic agents, some of which are potent greenhouse gases. This review provides an understanding of the global warming potential metric, as well as the concepts of atmospheric lifetime and radiative efficiency. The state of knowledge of the environmental impact and possible climate forcing of emitted volatile anaesthetic agents are reviewed. Additionally, the review discusses how climate metrics can guide mitigation strategies to reduce emissions and suggests present and future options for mitigating the climate impact.

Anaesthetic subspecialties and sustainable healthcare: anarrative review.

The principles of environmentally sustainable healthcare as applied to anaesthesia and peri-operative care are well documented. Associated recommendations focus on generic principles that can be applied to all areas of practice. These include reducing the use of inhalational anaesthetic agents and carbon dioxide equivalent emissions of modern peri-operative care. However, four areas of practice have specific patient, surgical and anaesthetic factors that present barriers to the implementation of some of these principles, namely: neuroanaesthesia; obstetric; paediatric; and cardiac anaesthesia. This narrative review describes these factors and synthesises the available evidence to highlight areas of sustainable practice clinicians can address today, as well as posing several unanswered questions for the future. In neuroanaesthesia, improvements can be made by undertaking awake surgery, moving towards more reusables and embracing telemedicine in quaternary services. Obstetric anaesthesia continues to present questions regarding how services can move away from nitrous oxide use or limit its release to the environment. The focus for paediatric anaesthesia is addressing the barriers to total intravenous and regional anaesthesia. For cardiac anaesthesia, a significant emphasis is determining how to focus the substantial resources required on those who will benefit from cardiac interventions, rather than universal implementation. Whilst the landscape of evidence-based sustainable practice is evolving, there remains an urgent need for further original evidence in healthcare sustainability targeting these four clinical areas.

Stability study and development of the validated infrared spectrometric method for quantitative analysis of sevoflurane compared with the gas chromatographic method.

Sevoflurane, also called fluoromethyl ether, is an inhalation anesthetic agent used to initiate and maintain general anesthesia for adults and pediatric patients during surgical procedures. Several analytical methods have previously been applied to follow the properties and quality of sevoflurane, including mass spectrometry and gas chromatography methods. These methods are practically tedious and need sophisticated apparatus. In the present work, an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometric method was used for the quantitative determination of sevoflurane which is characterized as a fast, accurate, and available technique for most pharmaceutical laboratories, besides the gas chromatographic method which is the most suitable for the detection of impurities. Sevoflurane is a liquid and it is applied directly on the glass top of the ATR-FTIR either as a concentrated solution or diluted with hexane as a diluent, which did not interfere with sample determination within the specified wavelength range of the IR spectrum, particularly the wavelength of the ethereal group at 1200 cm-1. This method can be applied to the identification test and quantitative assay of sevoflurane since it is validated for the precision, accuracy, reproducibility, and specificity in the analysis of sevoflurane as a pharmaceutical product. However, still, there is a need for a gas chromatographic method to detect the impurities and degradation products during the stability study of sevoflurane.

Incidence of and risk factors for poor recovery quality in dogs recovering from general anaesthesia—a prospective case control study

ObjectiveTo investigate the incidence of and identify risk factors associated with poor quality of recovery in dogs recovering from general anaesthesia. Study designCase controlled study. MethodsAll dogs undergoing general anaesthesia at the University of Liverpool Small Animal Teaching Hospital between January 2020 and January 2021 were eligible for recruitment. Signalment, anaesthetic case management and a recovery score were recorded. Univariable and multivariable logistic and ordinal logistic regression analysis were used to identify factors which impact incidence of poor quality of recovery. ResultsA total of 247 dogs undergoing general anaesthesia were included. Overall, 72 [29.1%; 95% confidence interval (CI) 23.8%–35.1%] dogs experienced a poor quality recovery. Of these, 40 (55.5%) required sedation to manage behaviours associated with poor recovery. Multivariable logistic regression revealed American Society of Anesthesiologists (ASA) physical status classification of III or higher was associated with a decreased incidence of poor quality recovery [odds ratio (OR) = 0.34, 95% CI 0.12–0.93, p = 0.037] and the use of multiple inhalational anaesthetics during one procedure was associated with an increased incidence of poor quality of recovery (OR = 42.5, 95% CI 3.0–598.3, p = 0.005). Conclusions and clinical relevancePoor quality recovery is common in dogs recovering from general anaesthesia and sedation is often required for resolution. It is more likely to occur in healthy veterinary patients (ASA I and II). The use of multiple inhalational anaesthetic agents during one procedure should be discouraged as this may increase the likelihood of poor quality of recovery.

Use of molecular simulation for evaluating adsorption equilibrium of inhalation anaesthetic agents on metal–organic frameworks

AbstractMetal–organic frameworks (MOFs) were studied as alternatives to zeolites and activated carbon for adsorptive removal of wasted inhalation anaesthetic agents (IAA). Monte Carlo simulation was used to predict equilibrium adsorption isotherms of IAA on selected MOFs. Rather than generic forcefields (FFs), the all‐atom FF parameters published by Arcario were used for IAA modelling. Continuous fractional component Monte Carlo (CFCMC) proved crucial for speedy simulation of large molecules. We found that allocating 70% probability to the CFlambdaSwap move gave optimum fits between simulation and experiment. The simulations provided us with an insight into the adsorption mechanisms of IAA in these structures. Heats of adsorption, Brauner‐Emmet‐Teller (BET) surface area, and total pore volume were deduced to be the crucial parameters for low, medium, and high range of relative pressures in the isotherm. Therefore, the chromium atoms in MIL‐101‐Cr are better adsorbers of IAA than MIL‐100‐Al at lower pressures despite the similarities in terms of the type of linkers and topology. Our simulation results corroborated the earlier published studies on the self‐association behaviour of sevoflurane molecules based on the experimental isotherms reported for MOF‐177‐Zn. Finally, the high polarity of IAA is thought to explain good low‐pressure simulation/experiment data agreement for the MOFs possessing coordinatively unsaturated sites (CUS) despite using generic DREIDING FF for the framework atoms. Our in‐house parsing code helped realize that the grand‐canonical Monte‐Carlo simulation speed is not the same for all pressure points but decreases for higher pressure points. This can be explained by increased density of the adsorbates making successful trial moves less probable.

Propofol versus Desflurane in Moyamoya Disease Patients-A Pilot Study.

Objectives The choice of inhalational or intravenous anesthetic agents is debatable in neurosurgical patients. Desflurane, a cerebral vasodilator, may be advantageous in ischemic cerebral pathologies. Hence, we planned to compare desflurane and propofol in patients with moyamoya disease (MMD) with the objective of comparing neurological outcomes. Materials and Methods This prospective pilot trial was initiated after institutional ethics committee approval. Patients with MMD undergoing revascularization surgery were randomized into two groups receiving either desflurane or propofol intraoperatively. Neurological outcomes were assessed using a modified Rankin score (mRS) at discharge and an extended Glasgow outcome score (GOS-E) at 1 month. Intraoperative parameters, including hemodynamic parameters, end-tidal carbon dioxide, entropy, intraoperative brain relaxation scores (BRS), and rescue measures for brain relaxation, were compared. Statistical Analysis The normality of quantitative data was checked using Kolmogorov-Smirnov tests of normality. Normally distributed data were compared using unpaired t -tests, skewed data using Mann-Whitney U tests, and categorical variables using chi-squared tests. Results A total of 17 patients were randomized, 10 in the desflurane and 7 in the propofol group. mRS (1.3 ± 0.6 and 1.14 ± 0.4, p = 0.450) and GOS-E (6.7 ± 0.6 and 6.85 ± 0.5, p = 0.45) were comparable between desflurane and propofol groups, respectively. BRS was significantly higher in the desflurane group (3.6 ± 0.5) compared to the propofol group (2.1 ± 0.3, p = 0.001), with a significant number of patients requiring rescue measures in the desflurane group (70%, p < 0.001). Other outcome parameters were comparable ( p > 0.05). Conclusion We conclude that postoperative neurological outcomes were comparable with using either an anesthetic agent, desflurane, or propofol in MMD patients undergoing revascularization surgery. Maintenance of anesthesia with propofol had significantly superior surgical field conditions.

Potential Risk of Choline Alfoscerate on Isoflurane-Induced Toxicity in Primary Human Astrocytes.

Isoflurane, a widely used common inhalational anesthetic agent, can induce brain toxicity. The challenge lies in protecting neurologically compromised patients from neurotoxic anesthetics. Choline alfoscerate (L-α-Glycerophosphorylcholine, α-GPC) is recognized for its neuroprotective properties against oxidative stress and inflammation, but its optimal therapeutic window and indications are still under investigation. This study explores the impact of α-GPC on human astrocytes, the most abundant cells in the brain that protect against oxidative stress, under isoflurane exposure. This study was designed to examine changes in factors related to isoflurane-induced toxicity following α-GPC administration. Primary human astrocytes were pretreated with varying doses of α-GPC (ranging from 0.1 to 10.0 μM) for 24 hours prior to 2.5% isoflurane exposure. In vitro analysis of cell morphology, water-soluble tetrazolium salt-1 assay, quantitative real-time polymerase chain reaction, proteome profiler array, and transcriptome sequencing were conducted. A significant morphological damage to human astrocytes was observed in the group that had been pretreated with 10.0 mM of α-GPC and exposed to 2.5% isoflurane. A decrease in cell viability was identified in the group pretreated with 10.0 μM of α-GPC and exposed to 2.5% isoflurane compared to the group exposed only to 2.5% isoflurane. Quantitative real-time polymerase chain reaction revealed that mRNA expression of heme-oxygenase 1 and hypoxia-inducible factor-1α, which were reduced by isoflurane, was further suppressed by 10.0 μM α-GPC pretreatment. The proteome profiler array demonstrated that α-GPC pretreatment influenced a variety of factors associated with apoptosis induced by oxidative stress. Additionally, transcriptome sequencing identified pathways significantly related to changes in isoflurane-induced toxicity caused by α-GPC pretreatment. The findings suggest that α-GPC pretreatment could potentially enhance the vulnerability of primary human astrocytes to isoflurane-induced toxicity by diminishing the expression of antioxidant factors, potentially leading to amplified cell damage.

Intraoperative Anesthetic Management of Bilateral Intraventricular Hemorrhage Secondary to Anterior Communicating Artery Aneurysm Rupture in Hypertensive Patient

Introduction: Primary (IVH) is non traumatic intracerebral hemorrhage confined to the ventricular system which is relatively infrequent, but is more commonly caused by hypertensive (52%) hemorrhagic stroke, followed by trauma (15%), intraventricular arteriovenous malformation (7.5%), coagulopathy (7.5%), diabetic vasculopathy (7.5%), anterior communicating artery aneurysms (3%), and undetectable cause. Clipping of ruptured anterior communicating artery with hypertension possess anesthetic challenges in managing intra-operatively, and when it comes for an ideal neuroprotective agent, barbiturates induced anesthesia was planned. Case Report: A 70 years old male came to our hospital with history of sudden loss of consciousness and a known case of systemic hypertension for 3 years and was on irregular medications, intubated in emergency medicine department in view of low GCS which was difficult intubation. CT brain Angiogram was done and diagnosed as ruptured Anterior Communicating Artery Aneurysm and underwent Aneurysmal clipping of anterior communicating artery aneurysm under general anesthesia. Emergency medications were kept ready. Intensive neuro monitoring, invasive blood pressure monitoring and to decrease the intraoperative intracranial pressure, to preserve autoregulation of cerebral blood flow, barbiturates induced anesthesia were planned (thiopentone as an induction agent and maintained with inhalational anesthetic agent). Patient was shifted to ICU for observation and extubated on next day uneventfully. Conclusion: We present a successful anesthetic management of hypertensive patient with ruptured anterior communicating artery who underwent clipping of aneurysm. A detailed pre-anesthetic evaluation and proper planning is utmost important to encounter the risk of ischemic injury to brain while clipping of ruptured aneurysmal vessel.

Perioperative considerations of pyruvate dehydrogenase complex deficiency: a case report of two consecutive anesthesia.

Pyruvate dehydrogenase complex (PDHC) deficiency is a rare mitochondrial disorder caused by a genetic mutation affecting the activity of the PDHC enzyme, which plays a major role in the tricarboxylic cycle. Few cases of surgery or anesthesia have been reported. Moreover, there is no recommended anesthetic method. A 24-month-old child with a PDHC deficiency presented to the emergency room with respiratory failure, mental decline, systemic cyanosis, and lactic acidosis. During hospitalization period, the patient presented with pneumothorax, pneumoperitoneum, and multiple air pockets in the heart. Two surgeries were performed under general anesthesia using an inhalational anesthetic agent. The patient was discharged with home ventilation. Anesthesiologists should be wary of multiple factors when administering anesthesia to patients with PDHC deficiency, including airway abnormalities, acid-base imbalance, intraoperative fluid management, selection of appropriate anesthetics, and monitoring of lactic acid levels.

Comparative Study on Postoperative Recovery Profiles of Desflurane and Sevoflurane Using I-GEL in Elective Ambulatory Surgeries

Introduction: In providing general anesthesia for ambulatory surgery, the goal is to achieve optimal surgical conditions while ensuring a rapid early recovery without side effects. Desflurane and sevoflurane are proven as effective ambulatory inhalational anesthetic agents. The aim of this research is to investigate and compared the hemodynamic stability, postoperative outcome and airway responses in elective ambulatory surgeries in patients receiving anesthesia with desflurane or sevoflurane using I-Gel supraglottic airway.Methods: A prospective, observational study was conducted involving 60 patients of age 18 – 50 years undergoing ambulatory surgeries under general anesthesia, randomly allocated into 2 equal groups receiving desflurane (Group D) or sevoflurane (Group S) for maintenance of anesthesia with suitable size I-Gel. Patients were monitored for hemodynamic parameters and postoperative recovery profile using fast track criteria (FTC) score at different time intervals. Pearson’s Chi Square test and Mann- Whitney U test were used for statistical analysis.Results: The mean time taken for postoperative recovery characteristics were significantly lower in Group D than Group S (p&lt;0.001).The FTC score was significantly higher (p&lt;0.001) in Group D than Group S at all-time intervals for 30 minutes. The requirement of additional analgesics was 46.7% in Group D and 60% in Group S (p&gt;0.301) and that of antiemetic was 30% in Group D and 26.67% in Group S (p&gt;0.774).Conclusions: Desflurane showed superior postoperative recovery characteristics and better FTC score without any increase in adverse airway events than sevoflurane.

Effects of Alfaxalone on the Induction and Maintenance of Total Intravenous Anesthesia in Gentoo Penguins (Pygoscelis papua).

Systemic anesthesia in penguins is often achieved using inhalation anesthetic agents alone, and information on injectable drugs for systemic anesthesia is limited. General anesthesia with a minimal effect on circulatory dynamics is necessary to perform noninvasive examinations and treatments in animals, including penguins. In this study, alfaxalone (ALFX), an injectable anesthetic agent, was examined to establish the optimal anesthetic method for gentoo penguins (Pygoscelis papua). Alfaxalone was administered intravenously through the metatarsal vein, and anesthesia was maintained by a constant rate infusion (CRI). A biological monitor was used to record numerous clinical indices, and the anesthetic depth was evaluated every 5 minutes during anesthesia; the CRI was adjusted until the optimal anesthetic depth was obtained. Anesthesia depth was assessed, and the CRI rate was adjusted. The CRI was stopped, and the time until recovery was recorded. Blood samples were collected to analyze plasma concentrations of ALFX. The mean total dose of ALFX required for anesthetic induction was 9 ± 1.9 mg/kg, the intubation time was 126 ± 21 seconds, and the maintenance infusion rate of ALFX was 0.3 ± 0.08 mg/kg/min. The time from discontinuation of anesthesia to extubation was 42 ± 23 minutes, and the time to recovery was 90 ± 33 minutes. Significant changes in the heart rate and blood pressure were not observed during the anesthetic events. The plasma concentration of ALFX under stable anesthesia was 6734 ± 4386 ng/mL (range, 3315-14 326 ng/mL). Although anesthesia using ALFX tended to result in a prolonged time to recovery in gentoo penguins, rapid induction of anesthesia and stable hemodynamics during anesthetic maintenance were achieved. Therefore, ALFX may be considered a suitable anesthetic method for noninvasive examinations and treatments in penguins.

Reducing the environmental impact of mask inductions in children: A quality improvement report.

Inhalational anesthetic agents are potent greenhouse gases with global warming potential that far exceed that of carbon dioxide. Traditionally, pediatric inhalation inductions are achieved with a volatile anesthetic delivered to the patient in oxygen and nitrous oxide at high fresh gas flows. While contemporary volatile anesthetics and anesthesia machines allow for a more environmentally conscious induction, practice has not changed. We aimed to reduce the environmental impact of our inhalation inductions by decreasing the use of nitrous oxide and fresh gas flows. Through a series of four plan-do-study-act cycles, the improvement team used content experts to demonstrate the environmental impact of the current inductions and to provide practical ways to reduce this, by focusing on nitrous oxide use and fresh gas flows, with visual reminders introduced at point of delivery. The primary measures were the percentage of inhalation inductions that used nitrous oxide and the maximum fresh gas flows/kg during the induction period. Statistical process control charts were used to measure improvement over time. 33 285 inhalation inductions were included over a 20-month period. nitrous oxide use decreased from 80% to <20% and maximum fresh gas flows/kg decreased from a rate of 0.53 L/min/kg to 0.38 L/min/kg, an overall reduction of 28%. Reduction in fresh gas flows was greatest in the lightest weight groups. Induction times and behaviors remained unchanged over the duration of this project. Our quality improvement group decreased the environmental impact of inhalation inductions and created cultural change within our department to sustain change and foster the pursuit of future environmental efforts.

Trigeminal Somatosensory Evoked Potentials During Neurosurgical Procedures Using Electrical Stimulation of the Lips Under General Anesthesia.

Background Intraoperative neurophysiology monitoring is rapidly evolving with the advent of newer modalities. Long latency sensory evoked potentials from the trigeminal nerve distribution have rarely been demonstrated during neurosurgical procedures. Trigeminal sensory evoked potential (TSEP) can be used to prevent nerve injury during surgical procedures, such as those for trigeminal neuralgia and tumors involving the trigeminal nerve and pathway. Methodology We attempted to record TSEP from 12 subjects who underwent various neurosurgical procedures with low doses of inhalational anesthetic agents. We stimulated the upper and lower lip and recorded from C6 and Fz locations. We used 14-17 mA current stimuli with a pulse width of 50-150 microseconds and a stimulation rate of2.1 Hz. Results We could obtain a clear, reproducible TSEP response in two out of 12 subjects. We observed a TSEP waveform with negative peaks at 13 and 27 milliseconds and a positive wave at around 19 milliseconds. Conclusions The TSEP produced by the electrical stimulation of the upper and lower lip can be detected from the scalp C5, C6, and Fz area even during neurosurgical procedures, even if inhalational anesthesia was used at induction, but only in a small proportion of cases. It appeared to reflect the activity of trigeminal cortical response. Avoiding the notch filter and turning off the inhalational agents are essential for a good response.

Inhalational anaesthetics: an assessment of agent delivery and capture.

Inhalational anaesthetics: an assessment of agent delivery and capture.

Diagnostic Accuracy of Tympanometry for Diagnosis of Fluid the Middle Ears of Children with Otitis Media with Effusion staking Myringotomy as Gold Standard

Objective: To determine the diagnostic accuracy of tympanometry for diagnosing fluid in the middle ears of children with Otitis Media with Effusion taking myringotomy as a gold standard.&#x0D; Study Design: Cross-sectional study&#x0D; Place and Duration of Study: Department of ENT &amp; Head and Neck Surgery, Combined Military Hospital, Peshawar Pakistan, from Oct 2018 to Sep 2020.&#x0D; Methodology: A total of 201 patients who underwent tympanometry followed by myringotomy of aged between 3 to 12 years of either gender were included. All patients underwent tympanometry. After that, myringotomy was carried out through a radial incision in the anteroinferior quadrant using a general inhalational anaesthetic agent. The operative findings at myringotomy were recorded. The presence of fluid on intraoperative findings using myringotomy was considered positive for the presence of fluid in the middle ears of children.&#x0D; Results: The age range of the patients was from 3-12 years, with a mean age of 7.35±2.41 years. Of these 207 patients,133(64.18%) were males, and 74(35.82%) were females. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of tympanometry for diagnosis of fluid in the middle ears of children with Otitis Media with Effusion taking myringotomy as the gold standard was 85.7%, 86.3%, 89.4%, 81.7% and 85.9% respectively.&#x0D; Conclusion: This study concluded that the diagnostic accuracy of tympanometry for the diagnosis of fluid in the middle ears of children with Otitis Media with Effusion is quite high.

Clinical Effects and Adverse Events Associated With Desflurane Use in Adult Patients Undergoing Supratentorial Craniotomy: A Systematic Review.

Desflurane is an inhalational anesthetic agent with an appealing recovery profile. The present systematic review investigates the clinical effects and adverse events associated with desflurane use during supratentorial craniotomy for brain tumor resection in adults in comparison with other inhalational and intravenous anesthetic agents. A literature search was conducted across the MEDLINE, Library of Congress and LISTA (EBSCO) databases from January 2001 to January 2021. Twelve studies published between 2003 and 2020 were included in this systematic review. Desflurane was compared with either isoflurane, sevoflurane, or propofol for anesthesia maintenance. Brain relaxation scores showed no statistically significant difference between desflurane and the other anesthetic agents. Recovery timepoints, such as time to recovery, time to eye opening, time to extubation, time to follow commands, and time to reach a modified Aldrete score ≥9 were significantly shorter with desflurane in the majority of studies. Systemic hemodynamic variables (mean arterial pressure and heart rate) and cerebral hemodynamics (intracranial pressure and cerebrospinal fluid pressure) were comparable between desflurane and other anesthetic agents in each study. The results of this systematic review demonstrate that desflurane is associated with few adverse events when used for anesthesia maintenance in adult patients undergoing supratentorial brain tumor surgery. Large, prospective, comprehensive studies, utilizing standardized parameter evaluation could provide higher levels of evidence to support these findings.

Euthanasia of Neonatal Rats and Mice using Carbon Monoxide.

Minimization of potential pain and distress of rodents undergoing euthanasia is a touchstone of veterinary clinical medicine. Evaluation of this issue in postweanling rodents has supported revisions to the AVMA (American Veterinary Medical Association) Guidelines on Euthanasia in 2020. However, relatively little information is available on humane aspects of anesthesia and euthanasia in neonatal mice and rats. These neonates are not reliably euthanized by exposure to commonly used inhalant anesthetic agents due to their physiologic adaptations to hypercapnic environments. Therefore, options such as prolonged inhalant anesthetic gas exposure, decapitation, or use of injectable anesthetics are recommended for neonates. All of these recommended methods have operational implications, ranging from reported job dissatisfaction by animal care staff to rigorous reporting requirements associated with the use of controlled substances. This lack of a euthanasia method that does not entail operational issues hampers the ability of veterinary professionals to provide appropriate guidance to scientists working with neonates. This study was designed to assess the effectiveness of carbon monoxide (CO) as an alternative euthanasia agent for mouse and rat pups on postnatal days (PND) 0 to 12. The study demonstrates that CO may be a potential alternative for preweanling mice and rats at PND6 or older but is not appropriate for neonates at PND5 or younger.