Anesthetic Agents Research Articles

Preoperative echocardiography and anesthetic drugs as predictors of post-induction hypotension during general anesthesia: a prospective observational study

Post-induction hypotension (PIH) during general anesthesia is a serious concern due to its high incidence and association with adverse postoperative outcomes and prognosis. We prospectively enrolled consecutive 1,603 patients scheduled for non-cardiac and cardiac surgery under general anesthesia. The primary outcome was defined as the lowest mean blood pressure from induction of general anesthesia to the start of surgery: post-induction blood pressure (PIB). Multivariable regression analysis was used to investigate the relationships between PIB and preoperative echocardiographic measurements, types and doses of anesthetic agents, and preoperative comorbidities and oral medication. Left ventricle regional wall motion abnormality (RWMA) and lower estimated glomerular filtration rate significantly associated lower PIB. Factors significantly associated with higher PIB were high BMI, beta blockers, high pre-induction mean blood pressure, and starting induction in the afternoon. Sevoflurane and prophylactic norepinephrine use were associated with higher PIB as anesthetic interventions. Significant interactions were found between sevoflurane and RWMA (P for interaction: 0.01). This is the first study to demonstrate the feasibility of intervening in the selection of anesthetic agents based on echocardiographic findings and to recommend the use of sevoflurane and prophylactic norepinephrine for the prevention of PIH, especially in patients with RWMA.

Remimazolam Reduces Vasopressor Use Post-Induction and During Maintenance of General Anesthesia in Patients Undergoing Laparoscopic Gynecology: A Propensity Score-Matched Analysis.

Objectives: Laparoscopic gynecological surgeries are commonly performed under general anesthesia and can induce cardiovascular depression and hypotension, requiring vasopressor support. Remimazolam, a novel ultra-short-acting benzodiazepine, is used to treat minimal cardiovascular depression. This study compared the hemodynamic effects of remimazolam and sevoflurane anesthesia in patients undergoing laparoscopic gynecological surgery. Methods: A retrospective analysis was conducted on 474 patients who underwent laparoscopic gynecological surgery at Korea University Anam Hospital between September 2021 and December 2022. The patients were categorized into two groups based on the anesthetic agent used: remimazolam or sevoflurane. Hemodynamic parameters, vasopressor use, and intraoperative variables were compared between anesthetic agents. Propensity score matching was applied to account for potential confounders, and logistic regression was utilized to assess the relationship between anesthesia type and outcomes. Results: Remimazolam anesthesia was linked to a significantly lower incidence of vasopressor use compared to sevoflurane-based anesthesia (3.7% vs. 19.5%, p < 0.0001). The odds of requiring vasopressor support were significantly lower during the post-induction and maintenance phases in the remimazolam group. Furthermore, hemodynamic stability, particularly systolic and mean arterial pressures, was better maintained with remimazolam than sevoflurane. Conclusions: Remimazolam provides superior hemodynamic stability and reduces the need for vasopressor support during laparoscopic gynecological surgery compared with sevoflurane.

Anesthetics in pathological cerebrovascular conditions.

The increasing prevalence of pathological cerebrovascular conditions, including stroke, hypertensive encephalopathy, and chronic disorders, underscores the importance of anesthetic considerations for affected patients. Preserving cerebral oxygenation and blood flow during anesthesia is paramount to prevent neurological deterioration. Furthermore, protecting vulnerable neurons from damage is crucial for optimal outcomes. Recent research suggests that anesthetic agents may provide a potentially therapeutic approach for managing pathological cerebrovascular conditions. Anesthetics target neural mechanisms underlying cerebrovascular dysfunction, thereby modulating neuroinflammation, protecting neurons against ischemic injury, and improving cerebral hemodynamics. However, optimal strategies regarding mechanisms, dosage, and indications remain uncertain. This review aims to clarify the physiological effects, mechanisms of action, and reported neuroprotective benefits of anesthetics in patients with various pathological cerebrovascular conditions. Investigating anesthetic effects in cerebrovascular disease holds promise for developing novel therapeutic strategies.

Therapeutic Applications of Xenon (Literature Review).

Introduction: Xenon is a noble gas with unique properties that make it an attractive anesthetic agent. In addition to its anesthetic and analgesic effects, xenon has demonstrated organ-protective properties in preclinical studies, suggesting potential therapeutic applications beyond anesthesia. This review aims to systematically evaluate the available clinical evidence on the therapeutic use of xenon, focusing on its effects on various organ systems. Methods: A comprehensive literature search was conducted in medical databases including PubMed, Google Scholar, Cochrane Library, and eLIBRARY.RU. Original clinical studies evaluating the therapeutic use of xenon were included and analyzed. Results: The review identified several areas of potential therapeutic application for xenon: 1. Neuroprotection: Xenon has shown promise in reducing neurological injury and improving outcomes in patients with conditions such as cardiac arrest, traumatic brain injury, and neonatal hypoxic-ischemic encephalopathy. However, the clinical evidence remains limited, and larger randomized controlled trials are ongoing to further evaluate its efficacy. 2. Cardioprotection: Xenon has been found to attenuate myocardial injury and improve cardiac function in patients undergoing cardiac surgery or experiencing cardiac arrest, potentially through its anti-inflammatory and anti-apoptotic effects. 3. Addiction treatment: Inhalation of xenon has been investigated for its potential to alleviate withdrawal symptoms and cravings in patients with opioid and alcohol dependence, with some studies suggesting beneficial effects on cognitive function and mood. 4. Psychiatric applications: Preliminary evidence suggests that xenon may have anxiolytic and antidepressant properties, with potential applications in the treatment of panic disorder and other mood disorders. Conclusion: The available clinical data indicate that xenon may have therapeutic potential beyond its use as an anesthetic agent. However, further well-designed, large-scale studies are needed to establish the efficacy and safety of xenon in various clinical settings and to elucidate the underlying mechanisms of its organ-protective and psychoactive effects.

Ketamine and Major Ketamine Metabolites Function as Allosteric Modulators of Opioid Receptors.

Ketamine is a glutamate receptor antagonist that was developed over 50 years ago as an anesthetic agent. At subanesthetic doses, ketamine and some metabolites are analgesics and fast-acting antidepressants, presumably through targets other than glutamate receptors. We tested ketamine and its metabolites for activity as allosteric modulators of opioid receptors expressed as recombinant receptors in heterologous systems and with native receptors in rodent brain; signaling was examined by measuring GTP binding, β-arrestin recruitment, MAPK activation, and neurotransmitter release. Although micromolar concentrations of ketamine alone had weak agonist activity at μ opioid receptors, the combination of submicromolar concentrations of ketamine with endogenous opioid peptides produced robust synergistic responses with statistically significant increases in efficacies. All three opioid receptors (μ, δ, and κ) showed synergism with submicromolar concentrations of ketamine and either methionine-enkephalin (Met-enk), leucine-enkephalin (Leu-enk), and/or dynorphin A17 (Dyn A17), albeit the extent of synergy was variable between receptors and peptides. S-ketamine exhibited higher modulatory effects compared with R-ketamine or racemic ketamine, with ∼100% increase in efficacy. Importantly, the ketamine metabolite 6-hydroxynorketamine showed robust allosteric modulatory activity at μ opioid receptors; this metabolite is known to have analgesic and antidepressant activity but does not bind to glutamate receptors. Ketamine enhanced potency and efficacy of Met-enkephalin signaling both in mouse midbrain membranes and in rat ventral tegmental area neurons as determined by electrophysiology recordings in brain slices. Taken together, these findings support the hypothesis that some of the therapeutic effects of ketamine and its metabolites are mediated by directly engaging the endogenous opioid system. SIGNIFICANCE STATEMENT: This study found that ketamine and its major biologically active metabolites function as potent allosteric modulators of μ, δ, and κ opioid receptors, with submicromolar concentrations of these compounds synergizing with endogenous opioid peptides, such as enkephalin and dynorphin. This allosteric activity may contribute to ketamine's therapeutic effectiveness for treating acute and chronic pain and as a fast-acting antidepressant drug.

Comparison of discussion-based and simulation-based learning methods using the Gas Man® on knowledge of the uptake and distribution of inhalation anesthetics of anesthesia resident: A randomized controlled trial

Abstract Background and Aims: Inhalation anesthetics is basic knowledge that must be mastered by an anesthesiologist. Lack of competencies can result in higher morbidity and mortality in anesthesiology practice. Various learning methods were developed to improve understanding and retention. With the advancement of technology, the utilization of screen-based simulation (SBS) using applications is common, such as the Gas Man® application, to help students understand physiology, pathophysiology, and kinetic inhalation anesthetic agents. The primary objective of this study was to compare the knowledge improvement of anesthesia residents between the simulation-based and discussion-based learning methods on the uptake and distribution of anesthetic inhalation. The secondary objective was to compare the satisfaction levels of participants in both learning methods. Material and Methods: This study is a randomized controlled trial involving anesthesiology and intensive care residents from the Faculty of Medicine, Universitas Indonesia (FKUI) 2022–2023. The participants were randomized into two groups (simulation and discussion groups). A senior attending anesthesiologist led the discussion. The participants answered a pretest, followed by a 1-hour lecture about inhalation gas. Lastly, participants answered a posttest and filled in the satisfaction survey. Statistical analyses used the Mann–Whitney test to compare the two groups. The Wilcoxon test was used to compare the knowledge improvement between the two groups. Results: Thirty-eight residents underwent simulation-based (n = 19) and discussion-based (n = 19) learning methods. The simulation group demonstrated a median (interquartile range) posttest score of 80 (76.67–83.33) compared with the discussion group with a score of 50 (40–66.67) (P value &lt;0.05). More than half of the participants in both groups answered “satisfied.” Conclusion: The simulation-based learning method using the Gas Man® application performed better than the discussion-based learning method on increasing knowledge of the uptake and distribution of inhalation anesthetics in anesthesia residents. Key Message: Simulation-based learning method may improve understanding and retention. This study supported the conclusion that the simulation-based learning method with Gas Man is better than the discussion-based learning method for improving knowledge of the uptake and distribution of inhalation anesthetics.

Adiponectin deficiency is a critical factor contributing to cognitive dysfunction in obese mice after sevoflurane exposure

BackgroundThe number of major operations performed in obese patients is expected to increase given the growing prevalence of obesity. Obesity is a risk factor for a range of postoperative complications including perioperative neurocognitive disorders. However, the mechanisms underlying this vulnerability are not well defined. We hypothesize that obese subjects are more vulnerable to general anaesthesia induced neurotoxicity due to reduced levels of adiponectin. This hypothesis was tested using a murine surgical model in obese and adiponectin knockout mice exposed to the volatile anaesthetic agent sevoflurane.MethodsObese mice were bred by subjecting C57BL/6 mice to a high fat diet. Cognitive function, neuroinflammatory responses and neuronal degeneration were assessed in both obese and lean mice following exposure to 2 h of sevoflurane to confirm sevoflurane-induced neurotoxicity. Thereafter, to confirm the role of adiponectin deficiency in, adiponectin knockout mice were established and exposed to the sevoflurane. Finally, the neuroprotective effects of adiponectin receptor agonist (AdipoRon) were examined.ResultsSevoflurane triggered significant cognitive dysfunction, neuroinflammatory responses and neuronal degeneration in the obese mice while no significant impact was observed in the lean mice. Similar cognitive dysfunction and neuronal degeneration were also observed in the adiponectin knockout mice after sevoflurane exposure. Administration of AdipoRon partially prevented the deleterious effects of sevoflurane in both obese and adiponectin knockout mice.ConclusionsOur findings demonstrate that obese mice are more susceptible to sevoflurane-induced neurotoxicity and cognitive impairment in which adiponectin deficiency is one of the underlying mechanisms. Treatment with adiponectin receptor agonist ameliorates this vulnerability. These findings may have therapeutic implications in reducing the incidence of anaesthesia related neurotoxicity in obese subjects.

A new herbal anesthetic agent for common carp (Cyprinus carpio) sedation and anesthesia: nutmeg (Myristica fragrans) essential oil.

In aquaculture, interest in natural essential oils is increasing alongside synthetic anesthetic agents. In this context, the anesthetic efficacy of nutmeg essential oil, which had not been previously tested, was investigated in common carp (Cyprinus carpio). The study, conducted using three different concentrations (800 μL/L "LC", 1,200 μL/L "MC", and 1,400 μL/L "HC"), found that induction times were <3 min for MC and HC, while LC had a longer induction time, exceeding acceptable levels. Within the first 4 h, white blood cells, red blood cells, hemoglobin, and hematocrit levels increased to >5 103/μL, >1 106/μL, >6 g/dL, and >12%, respectively. However, they returned to control levels after 8 h. Histological signs were more severe with higher concentrations, and necrosis was only observed in the HC group. Alkaline comet assay results showed DNA migration only in the HC group. According to the PROMETHEE multi-criteria decision-making model, the LC concentration is suitable for sedation, while the MC concentration should be used for deep anesthesia. The current study demonstrates that nutmeg essential oil can be used as an alternative to commercial synthetic anesthetic agents.

A systematic review on the use of sevoflurane in the management of status asthmaticus in adults

BackgroundTo conduct a systematic review looking into the use of sevoflurane in the management of status asthmaticus (SA) in adults.MethodsWe performed a systematic search on PubMed, EMBASE, and The Cochrane Library – CENTRAL through 23rd August 2023, restricting to studies reported in English. We included studies reporting use of sevoflurane in asthmatics beyond its use as an anaesthetic agent in surgeries i.e. in the emergency department (ED) and critical care setting, and focused on patient’s clinical parameters, ventilation pressures and weaning of invasive ventilation.ResultsA total of 13 publications fulfilled the inclusion criteria, comprising of 18 cases. All publications were of case reports/ series and conference abstracts, and no randomised trials were available. Most patients required intubation despite best medical management before sevoflurane administration, and high airway pressures and respiratory acidosis were apparent. There was significant heterogeneity regarding severity of asthma, treatment instituted, and the delivery, duration and concentration of sevoflurane administered. Many of the studies also did not quantify the changes in parameters pre- and post-sevoflurane. Sixteen patients experienced improvements in clinical status with sevoflurane administration—one required escalation to extracorporeal membrane oxygenation (ECMO), and another did not survive.ConclusionThe systematic review suggests sevoflurane can be a valuable treatment option in SA. As these cases are rare and heterogenous, further prospective case series are needed to support this.

Improvement of Statistical Models by Considering Correlations among Parameters: Local Anesthetic Agent Simulator for Pharmacological Education

Improvement of Statistical Models by Considering Correlations among Parameters: Local Anesthetic Agent Simulator for Pharmacological Education

Pioneer of epidemiology and anesthesiology – John Snow (1813–1858)

IntroductionJohn Snow, a British physician of the 19th century, played a pivotal role in challenging prevailing medical beliefs during his time. His groundbreaking studies on the cholera epidemic led to the rejection of the miasma theory and the establishment of the link between contaminated water and the spread of the disease.AimThis study aims to explore the contributions of John Snow to the fields of anaesthesiology and epidemiology, focusing on his significant findings and methodologies.Material and methodsThis study utilizes a literature review approach to examine John Snow's contributions to anaesthesiology and epidemiology. Searches were conducted in databases using relevant keywords, focusing on peer-reviewed articles and authoritative sources. The data was qualitatively synthesized to extract key insights into Snow's methodologies and findings, aiming to provide a brief overview of his impact on medical science.Results and discussion:John Snow (1813-1858) is celebrated as a pioneer in epidemiology and anaesthesiology. He identified contaminated water as the source of the 1854 cholera outbreak in London, establishing the basis for modern epidemiology. Snow's innovative mapping of cholera cases was crucial in controlling the epidemic. He also advanced anaesthetic techniques, notably using chloroform on Queen Victoria during childbirth, improving the safety of anaesthesia. His work remains influential in both fields.Conclusions:John Snow's pioneering work significantly impacted the development of anaesthesiology and epidemiology. His insights into cholera transmission and anaesthetic agents, along with his seminal publication On Chloroform and Other Anaesthetic, continue to inspire advancements in medical science. Snow's legacy underscores the importance of evidence-based medicine and the pursuit of knowledge in addressing public health challenges.

Recent Advancement of Novel Drug Delivery Systems for Topical Anaesthesia Formulations

Abstract: In recent years, there have been exciting developments in improving how we deliver anaesthesia through the skin. Nanotechnology is a key player, using tiny particles to encapsulate and transport anaesthetic agents, ensuring a controlled and steady release. This helps overcome challenges like inconsistent absorption and short-lasting effects seen with traditional methods. Transdermal patches are gaining attention too; they release drugs slowly and steadily, eliminating the need for frequent reapplication while maintaining a constant drug level at the application site. Smart polymers are bringing innovation by responding to specific triggers, enabling on-demand drug release. This allows for personalized anaesthesia based on individual patient needs. In recent years, there have been exciting developments in improving how we deliver anaesthesia through the skin. Nanotechnology is a key player, using tiny particles to encapsulate and transport anaesthesia agents, ensuring a controlled and steady release. This helps overcome challenges like inconsistent absorption and other short-lasting effects seen with traditional methods. Microemulsion systems, made of water, oil, surfactants, and co-surfactants, are another promising approach. They enhance drug solubility and availability, providing a stable environment for including anaesthesia agents. Transdermal patches are gaining attention too; they release drugs slowly and steadily, eliminating the need for frequent reapplication and maintaining a constant drug level at the application site. Smart polymers are bringing innovation by responding to specific triggers, enabling on-demand drug release. This allows for personalized anaesthesia based on individual patient needs. Together, these advancements mark a significant shift towards more effective, patient-friendly, and personalized topical anaesthesia delivery systems.

Intravenous lidocaine infusion therapy and intraoperative neurophysiological monitoring in adolescents undergoing idiopathic scoliosis correction: A retrospective study.

Posterior spinal instrumentation and fusion is an established surgical procedure for the correction of adolescent idiopathic scoliosis. Intraoperative neurophysiological monitoring is standard practice for this procedure. Anesthetic agents can have different, but significant, effects on neurophysiological monitoring outcomes. To determine if intravenous lidocaine infusion therapy has an impact on the intraoperative neurophysiological monitoring during posterior spinal instrumentation and fusion for adolescent idiopathic scoliosis. Following ethical approval, we conducted a retrospective review of charts and the archived intraoperative neurophysiological data of adolescents undergoing posterior spinal instrumentation and fusion for adolescent idiopathic scoliosis. Intraoperative neurophysiological monitoring data included the amplitude of motor evoked potentials and the amplitude and latency of somatosensory evoked potentials. A cohort who received intraoperative lidocaine infusion were compared to those who did not. Eighty-one patients were included in this analysis, who had surgery between February 4, 2016 and April 22, 2021: 39 had intraoperative intravenous lidocaine infusion and 42 did not. Based on hourly snapshot data, there was no evidence that lidocaine infusion had a detrimental effect on the measured change from baseline for MEP amplitudes in either lower (mean difference 41.9; 95% confidence interval -304.5 to 388.3; p = .182) or upper limbs (MD -279.0; 95% CI -562.5 to 4.4; p = .054). There was also no evidence of any effect on the measured change from baseline for SSEP amplitudes in either lower (MD 16.4; 95% CI -17.7 to 50.5; p = .345) or upper limbs (MD -2.4; 95% CI -14.5 to 9.8; p = .701). Finally, there was no evidence of a difference in time to first reportable neurophysiological event (hazard ratio 1.13; 95% CI 0.61 to 2.09; p = .680). Data from these two cohorts provide preliminary evidence that intravenous lidocaine infusion has no negative impact on intraoperative neurophysiological monitoring during PSIF for adolescent idiopathic scoliosis.

Comparative Evaluation of Minimal and Metabolic Flow Anaesthesia Using Desflurane

Objective: The aim of this study is the comparative evaluation of minimal and metabolic flow anaesthesia with regard to hemodynamic stability, trends of anaesthesia gases, problems during maintenance, time to recovery and the consumption of anaesthetic agent. Methods: A randomised controlled prospective study was conducted on 60 patients of ASA grades I and II between 20 and 60 years of age undergoing routine surgeries under general anaesthesia using the Dräger Primus workstation. Patients were randomly allocated to Group 1 (minimal flow) and Group 2 (metabolic flow). Anaesthesia consumption was calculated manually using Dion’s method and the Dräger Primus machine also using the Dräger algorithm. Results: The two groups were found comparable with regard to the above-mentioned objectives. No statistically significant difference was observed between the two groups. Conclusion: Metabolic flow anaesthesia is safe and feasible on a day-to-day basis with the judicious use of advanced anaesthesia workstations and newer lower solubility halogenated agents.

8281 Continuous Low-Dose Etomidate Infusion For The Management Of Severe Hypercortisolism In Metastatic Adrenocortical Carcinoma

Abstract Disclosure: A. Jamil: None. N. Mohammad: None. S. Narayana: None. Background: Adrenocortical carcinoma (ACC) is a rare endocrine malignancy of the adrenal glands with a poor prognosis that often presents with excess hormone secretion. Approximately, 45% of cases present with hypercortisolism.1 A key component of management is achieving control of hypercortisolism. Though there are multiple enteral therapies that can inhibit cortisol production, few treatment options are available for use in critically ill patients who are not surgical candidates and cannot take oral medications. Though primarily known as a short-acting intravenous anesthetic agent used for sedation, etomidate also inhibits 11-β-hydroxylase, a key enzyme involved in corticosteroid biosynthesis.2 Clinical Case: A 28-year-old woman with metastatic adrenocortical carcinoma with associated hypercortisolism was initially admitted for anemia and thrombocytopenia, with an initial cortisol on admission of 29.3 μg/dl (normal range: 2.3-19.4 ug/dl). Due to her large tumor burden with metastasis to the liver and invasion into the inferior vena cava, she was deemed a poor surgical candidate with a poor overall prognosis. Her hospital course was complicated by acute hypoxemic respiratory failure requiring intubation, and thus her enteral steroidogenesis inhibitors (mitotane, ketoconazole, and metyrapone) were discontinued as none were administrable via nasogastric tube. Consequently, her hypercortisolism worsened rapidly with a cortisol level of 351.3 μg/dl , prompting initiation of continuous low-dose etomidate infusion, which resulted in significant improvements in her cortisol levels. After eight days of etomidate treatment, her cortisol levels reached a goal value of 25.0 μg/dl. However, she then suffered an ischemic cerebrovascular event and multiorgan failure, and was subsequently transitioned to hospice care. Conclusion: Low-dose etomidate infusion is an effective therapeutic agent for hypercortisolism in patients with ACC that are unable to take oral medications.

What anesthesiologists need to know about Antidepressants and other Psychotropic Drugs

Psychotropic medications are widely prescribed and are a mainstay treatment for various mental health disorders. A significant portion of patients undergoing surgery or various procedures take these medications. With the rising prevalence of mental health conditions, anesthesiologists increasingly find themselves encountering patients who depend on these medications, making the understanding of potential interactions with anesthetic agents crucial during the perioperative period. Appreciating the adverse-effect profiles and familiarity with the clinically relevant drug interactions that may occur in the perioperative setting are imperative to ensure the best possible outcome in delivering patient care. This review focuses on various classes of psychotropic agents, including antidepressants, antipsychotics, mood stabilizers, and anxiolytics. It covers the pharmacodynamics and pharmacokinetics of these medication classes and their interactions with agents commonly used in anesthesia.

Impact of general anesthesia type on chronic postsurgical pain following video-assisted thoracoscopic surgery for lung cancer: a retrospective propensity-matched cohort study.

Anesthetic agents are potential modifiable factors that can mitigate chronic postsurgical pain (CPSP) development. This study aimed to investigate the association between propofol-based total intravenous anesthesia (TIVA) and the occurrence of CPSP following video-assisted thoracoscopic surgery (VATS) for lung cancer resection. This single-center retrospective cohort study included adult patients with lung cancer who underwent elective VATS between January 2018 and December 2022. Patients were divided based on the maintenance anesthetic used (propofol vs. sevoflurane). The primary outcome was the presence of CPSP, defined as any level of surgical site pain recorded within 3-6 months postoperatively. The authors investigated the association between anesthetic agents and CPSP using propensity score matching with stabilized inverse probability of treatment weighting (sIPTW) to adjust for confounders. Additionally, multivariable logistic regression was used to further adjust for intraoperative opioid use that sIPTW could not account for. The robustness of these associations was evaluated using the E-value. Of the 833 patients analyzed, 461 received propofol and 372 sevoflurane. The overall incidence of CPSP was 43.3%. After sIPTW, the use of TIVA was significantly associated with a lower incidence of CPSP (odds ratio [OR]: 0.75, 95% confidence interval [CI]: 0.57-0.99, P = 0.041), and remained significant after adjusting for intraoperative remifentanil equivalent dose (OR: 0.73, 95% CI: 0.55-0.96, P = 0.026). The E-values were 1.08 and 1.17, respectively. Propofol-based TIVA is associated with reduced CPSP occurrence in VATS for lung cancer. Further prospective studies are needed to confirm the results.

Comparing the effects of three local anaesthetic agents on cardiac conduction system - A randomised study.

This study aimed to compare the effects of three local anaesthetic (LA) agents, namely bupivacaine, levobupivacaine, and ropivacaine, on the cardiac conduction system as assessed by corrected QT (QTc) and P wave dispersion (PWD) intervals in lower limb orthopaedic surgeries and to find the most suitable LA agent that can be used for a long duration. The study included 75 patients with American Society of Anesthesiologists physical status I and II of either gender in the age group of 18-65 years undergoing elective lower limb orthopaedic surgeries under epidural anaesthesia. These were allocated to groups B (bupivacaine), L (levobupivacaine), and R (ropivacaine). We observed blood pressure, heart rate, respiratory rate, PWD, and QTc intervals from baseline value through Holter monitoring, pain assessment by visual analogue scale, and demand and total volume of LA consumed by patient-controlled analgesia devices. The repeated measures of ANOVA were carried out to find the effect of time and time-to-group interaction among the groups across the periods. On intergroup comparison of QTc and PWD, no significant difference among groups was observed, but on intragroup analysis, a statistically significant increase in QTc and PWD from baseline was observed for each of groups B, L, and R at all time intervals. However, the mean increase in QTc and PWD recorded for Group B was higher than in groups L and R. Bupivacaine has the maximal tendency to prolong QTc and PWD. All three agents showed comparable haemodynamic effects and time to onset of sensory and motor blockade.

Propofol-induced transient arginine vasopressin deficiency.

We describe and characterise the case of a 26-year-old female undergoing surgery for a right-sided sinonasal alveolar rhabdomyosarcoma who developed profound, transient arginine vasopressin deficiency (AVP-D, formerly central diabetes insipidus (DI)) associated with anaesthesia. In this case report, we characterise the development of AVP-D with serial copeptin and paired urine and serum osmolality measurements. Based on the anaesthetic agent's profile and the literature, we attribute this presentation to propofol exposure. We present a description of the literature on anaesthesia-associated DI as well as poignant learning points. Exposure to anaesthetic agents is a rare cause of self-limited but sudden and profound arginine vasopressin deficiency (AVP-D) or arginine vasopressin resistance (AVP-R). Sevoflurane has been associated with AVP-R and propofol with AVP-D, although the responsible agent may be difficult to identify. Differentiation of AVP-R and AVP-D can be made based on copeptin concentration, where available, or clinical response to desmopressin. Whilst the patient is anaesthetised, intravenous fluid replacement should be targeted to match urine output until the patient is able to drink to thirst. This should be clearly communicated to staff and the patient. Rapid resolution of AVP-R/AVP-D when the causative agent is discontinued has been reported with both propofol and sevoflurane. As such, switching the agent used to maintain anaesthesia may terminate increased urine output in a clinically meaningful timeframe.

Ketamine plus midazolam compared to midazolam infusion for the management of refractory status epilepticus

BackgroundData for the use of ketamine (Ket) in treatment of refractory and super-refractory status epilepticus (RSE, SRSE) is lacking despite its widespread growing use. We examined the efficacy of ketamine plus midazolam (MDZ) infusions for treating RSE versus midazolam alone. We hypothesized that ketamine initiation would result in earlier seizure termination. MethodsData was obtained from electronic health records (EHR) of adult patients who received intravenous anesthetic agents for RSE in our neurointensive care unit. Two cohorts were identified. The MDZ cohort received midazolam as the only intravenous anesthetic agent for RSE. The Ket+MDZ cohort received midazolam infusion followed by ketamine infusion. The primary outcomes were time from midazolam infusion start to SE end in both cohorts, and time from ketamine infusion start (Ket Start) to SE end in the Ket+MDZ cohort versus midazolam infusion start (MDZ start) to SE end in the MDZ cohort. Results73 patients were included (MDZ cohort n=17, Ket + MDZ cohort n=56). Cohorts did not differ significantly in age, sex, race, RSE etiology, or GCS on admission. Mean APACHE II score was higher in the Ket +MDZ cohort (26 ± 7.32SD) versus the MDZ cohort (22 ± 5.89SD)(P=.015). In survival analyses, cohorts did not differ significantly in time from midazolam start to SE end (HR=0.965, 95% CI=0.556-1.673, P=.899; median [IQR]: MDZ: 25hours [4.5-58]; Ket+MDZ: 21.5hours [IQR 13.5-49]). Time from Ket start (Ket+MDZ group) versus time from MDZ start (MDZ group) to SE end was significantly shorter in the Ket+MDZ cohort (HR=1.895, 95% CI=1.083-3.314, P=.025). The pattern of results was similar when including APACHE II and MDZ maximum dosage as covariates. ConclusionTime to SE end was significantly shorter after addition of ketamine infusion to midazolam infusion, versus after initiation of midazolam infusion monotherapy. Patients with higher disease severity favored Ket+MDZ. Randomized controlled trials are warranted in determining optimal anesthetics in RSE and SRSE.