Maintenance Of General Anesthesia Research Articles

Effect of Remimazolam on Induction and Maintenance of General Anesthesia in Kidney Transplant Patients

Effect of Remimazolam on Induction and Maintenance of General Anesthesia in Kidney Transplant Patients

Long-term Survival after Volatile or Propofol General Anesthesia for Bladder Cancer Surgery: A Retrospective National Registry Cohort Study.

Prospective interventional trials and retrospective observational analyses provide conflicting evidence regarding the relationship between propofol versus inhaled volatile general anesthesia and long-term survival after cancer surgery. Specifically, bladder cancer surgery lacks prospective clinical trial evidence. Data on bladder cancer surgery performed under general anesthesia between 2014 and 2021 from the National Quality Registry for Urinary Tract and Bladder Cancer and the Swedish Perioperative Registry were record-linked. Overall survival was compared between patients receiving propofol or inhaled volatile for anesthesia maintenance. The minimum clinically important difference was defined as a 5-percentage point difference in 5-yr survival. Of 7,571 subjects, 4,519 (59.7%) received an inhaled volatile anesthetic, and 3,052 (40.3%) received propofol for general anesthesia maintenance. The two groups were quite similar in most respects but differed in American Society of Anesthesiologists Physical Status and tumor stage. Propensity score matching was used to address treatment bias. Survival did not differ during follow-up (median, 45 months [interquartile range, 33 to 62 months]) in the full unmatched cohort nor after 1:1 propensity score matching (3,052 matched pairs). The Kaplan-Meier adjusted 5-yr survival rates in the matched cohort were 898 of 3,052, 67.5% (65.6 to 69.3%) for propofol and 852 of 3,052, 68.5% (66.7 to 70.4%) for inhaled volatile general anesthesia, respectively (hazard ratio, 1.05 [95% CI, 0.96 to 1.15]; P = 0.332). A sensitivity analysis restricted to 1,766 propensity score-matched pairs of patients who received only one general anesthetic during the study period did not demonstrate a difference in survival; Kaplan-Meier adjusted 5-yr survival rates were 521 of 1,766, 67.1% (64.7 to 69.7%) and 482 of 1,766, 68.9% (66.5 to 71.4%) for propofol and inhaled volatile general anesthesia, respectively (hazard ratio, 1.09 [95% CI, 0.97 to 1.23]; P = 0.139). Among patients undergoing bladder cancer surgery under general anesthesia, there was no statistically significant difference in long-term overall survival associated with the choice of propofol or an inhaled volatile maintenance.

Effect of ultrasound-guided stellate ganglion block on lung protection for patients undergoing one-lung ventilation.

To explore the potential effect of ultrasound-guided stellate ganglion block (SGB) on lung protection for patients undergoing one-lung ventilation (OLV). A total of 123 patients undergoing elective one-lung ventilation surgery were selected as research subjects in this prospective study. These patients were randomly divided into the SGB group, control group and blank group on average. Stellate ganglion block was carried out in the SGB and control groups. Patients in the SGB group were injected with 6 ml mixture of 0.25% ropivacaine hydrochloride and 1% lidocaine hydrochloride, while those in the control group were injected with 6 mL of 0.9% saline. Punctures weren't performed for patients in the blank group. The same induction and maintenance of general anesthesia was adopted for all three groups. Hemodynamics, respiratory parameters and arterial blood gas analysis were recorded after entering the operation room (T0), pre-OLV (T1), 30 min after OLV (T2), 60 min after OLV (T3), at the end of surgery (T4), and 30 min after extubation (T5). Oxygenation index (OI), pulmonary shunt fraction (Qs/Qt) and pH value were compared at different time points. Intravenous serum was collected at T0, T3 and T5 for the detection of surfactant proteins A (SP-A), superoxide dismutase (SOD), malondialdehyde (MDA), interleukin-6 (IL-6) and interleukin-10 (IL-10) levels, respectively. The complications related to SGB after surgery and the postoperative pulmonary complications within 72 h were recorded. At T1, T2, and T3, MAP level in SGB group was lower than that in blank and control groups (P<0.05). At T2, and T3, SGB group had lower hear rate (HR), peak airway pressure (Ppeak) and tidal volume (TV) than blank and control groups (all P<0.05). From T2 to T5, SGB group had higher OI but lower Qs/Qt than blank and control groups (both P<0.05). At T3 and T5, SGB group had lower SP-A, IL-6, and MDA levels but higher IL-10 and SOD levels than blank and control groups (all P<0.05). There was one case of hypoxemia in the blank group within 72 h after surgery. Ultrasound-guided SGB has lung-protective effects on patients undergoing OLV, which significantly improves patients' OI, reduces intrapulmonary shunts, declines ventilator-induced lung damage, and inhibits inflammatory response as well as oxidative stress (China Clinical Trial Registry, registration number ChiCTR2000033385, https://www.chictr.org.cn).

Anaesthesia and brain development: a review of propofol-induced neurotoxicity in pediatric populations.

With the advancement of medical technology, there are increasing opportunities for new-borns, infants, and pregnant women to be exposed to general anaesthesia. Propofol is commonly used for the induction of anaesthesia, maintenance of general intravenous anaesthesia and sedation of intensive-care children. Many previous studies have found that propofol has organ-protective effects, but growing evidence suggests that propofol interferes with brain development, affecting learning and cognitive function. The purpose of this review is to summarize the latest progress in understanding the neurotoxicity of propofol. Evidence from case studies and clinical studies suggests that propofol has neurotoxicity on the developing brain. We classify the findings on propofol-induced neurotoxicity based on its damage mechanism. We end by summarizing the current protective strategies against propofol neurotoxicity. Fully understanding the neurotoxic mechanisms of propofol can help us use it at a reasonable dosage, reduce its side effects, and increase patient safety.

Clinical Application and Research Progress of Remimazolam for Pediatric Patients.

Remimazolam is a novel ultrashort-acting benzodiazepine that allosterically modulates γ-aminobutyric acid type A (GABAA) receptors to exert sedative effects. Remimazolam has the properties of controllable sedation, rapid onset, and a short duration of action, along with minor depression of circulation and respiration. Remimazolam has been approved for clinical use since 2020 in Japan, and it has been applied for procedural sedation, general anesthesia induction and maintenance, and sedation in ICU patients, and has been proven to be safe and effective. Currently, no consensus has been reached on the clinical application of remimazolam in pediatric patients. This review introduces the clinical research progress and limitations of remimazolam in recent years, aiming to supply scientific guidance and a theoretical reference for the application of remimazolam in pediatric anaesthesia.

A randomised controlled trial comparing quality of recovery between desflurane and isoflurane inhalation anaesthesia in patients undergoing ophthalmological surgery at a tertiary hospital in South Africa (DIQoR trial)

BackgroundThe patient's experience of their postoperative recovery is an important perioperative outcome, with the 15-item quality of recovery scale (QoR-15) recommended as a standardised outcomes measure. Desflurane has a faster emergence from anaesthesia compared with other volatile anaesthetics, but it is uncertain whether this translates to better subjective quality of recovery. The hypothesis for this study is that patients receiving desflurane for maintenance of anaesthesia would have better postoperative quality of recovery than patients receiving isoflurane. MethodsMale and female adult patients undergoing ophthalmological surgery under general anaesthesia were randomly allocated to receive desflurane or isoflurane for maintenance of anaesthesia. The primary outcome was to compare postoperative QoR-15 scores. Secondary outcomes included comparing preoperative QoR-15 scores, volatile agent consumption, and time spent in the recovery room. ResultsData from 164 patients were analysed (80 desflurane, 84 isoflurane). Median (Q1, Q3) postoperative QoR-15 scores were not significantly different (desflurane: 145 [141, 148], isoflurane: 144 [139, 147], 95% confidence interval 0–3, P=0.176, minimal clinically important difference=8). Median (Q1, Q3) volatile agent consumption was 15.4 (12.5, 19.3) ml hr−1 in the desflurane group, and 7.4 (5.9, 9.7) ml hr−1 in the isoflurane group. Median (Q1, Q3) time spent in the recovery room was significantly shorter in the desflurane group (desflurane: 18 [13, 23]; isoflurane: 25 [19, 32], 95% confidence interval −10 to 5, P<0.001). ConclusionsThis study found no difference in quality of recovery between patients who received desflurane or isoflurane for maintenance of general anaesthesia during ophthalmological surgery. A shorter time in the recovery room was not associated with improved QoR-15 scores. Clinical trial registrationNCT04188314.

Remimazolam attenuates myocardial ischemia-reperfusion injury by inhibiting the NF-ĸB pathway of macrophage inflammation

BackgroundInflammation is a major contributing factor in myocardial ischemia/reperfusion (I/R) injury, and targeting macrophage inflammation is an effective strategy for myocardial I/R therapy. Though remimazolam is approved for sedation, induction, and the maintenance of general anesthesia in cardiac surgery, its effect on cardiac function during the perioperative period has not been reported. Therefore, this research aimed to explore the impact of remimazolam on inflammation during myocardial ischemia/reperfusion (I/R) injury. MethodsAn in vivo myocardial I/R mice model and an in vitro macrophage inflammation model were used to confirm remimazolam's cardiac protective effect. In vivo, we used echocardiography, hematoxylin and eosin (HE), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining to determine remimazolam's therapeutic effects on myocardial I/R injury and inflammation. In vitro, we employed enzyme-linked immunosorbent assay (ELISA), Western blot, Real-time Quantitative PCR (qPCR), flow cytometry, and immunofluorescence staining to assess inflammatory responses, especially remimazolam's effects on macrophage polarization after I/R. Furthermore, molecular docking was used to identify its potential binding targets on the inflammatory pathway to explore the mechanism of remimazolam. ResultsRemimazolam exhibited significant anti-myocardial I/R injury activity by inhibiting macrophage-mediated inflammation to reduce myocardial infarction, enhancing cardiac function. In addition, macrophage depletion counteracted improved cardiac function by remimazolam treatment. Mechanistically, the activated NF-ĸB signaling pathway and phosphorylation of p50 and p65 were repressed for anti-inflammatory effect. Consistently, two binding sites on p50 and p65 were identified by molecular docking to affect their phosphorylation of the Ser, Arg, Asp, and His residues, thus regulating NF-κB pathway activity. ConclusionOur results unveil the therapeutic potential of remimazolam against myocardial I/R injury by inhibiting macrophages polarizing into the M1 type, alleviating inflammation.

Comparison of Remimazolam and Propofol for Intubated General Anesthesia for Oral and Maxillofacial Surgery

Objective Remimazolam is a new, ultra-short-acting benzodiazepine that can be used for induction and maintenance of general anesthesia. We compared the hemodynamic stability and depth of anesthesia during general anesthesia using remimazolam or propofol along with remifentanil for oral and maxillofacial surgery. Methods A total of 95 patients were divided into remimazolam and propofol groups and then subdivided into bispectral index (BIS) and patient state index (PSI) groups. Blood pressure, heart rate, and BIS/PSI values were compared at fixed time points perioperatively. Time to loss of consciousness and total opioid doses were also compared across groups. Other items that were compared included intraoperative arousal and postoperative nausea and vomiting. Results Propofol produced more significant hemodynamic depression than remimazolam, although both groups were stable. BIS/PSI values were similar in both groups. Time to loss of consciousness was significantly shorter in the remimazolam group. Total opioid dosing was higher in the remimazolam group, and there were no differences regarding other postoperative complications. Conclusion The perioperative hemodynamics with remimazolam were more stable that with propofol, especially during induction. Therefore, remimazolam may be a safe alternative to propofol for providing TIVA general anesthetics.

Strong opioids-induced cardiac, neurologic, and respiratory disorders: a real-world study from 2004 to 2023 based on FAERS.

Opioids are mainly used as adjuncts to the induction and maintenance of general anesthesia, postoperative analgesia, and treating moderate to severe cancer pain and chronic pain. However, the hazards of these drugs to various organ organs still need to be further explored. This study used the US FDA Adverse Event Reporting System (FAERS) database to determine whether commonly receiving opioids was higher than the baseline risk for all other medications. FAERS was asked about adverse events (AEs) for the opioids "morphine," "fentanyl," "oxycodone," "hydromorphone," "sufentanil," and "remifentanil" from the first quarter of 2004 (2004Q1) through the second quarter of 2023 (2023Q2). Disproportionality signaling analysis was performed by calculating reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and Empirical Bayesian Geometric Mean (EBGM). AEs with system organ classes (SOCs) of "cardiac disease," "neurologic disease," and "respiratory, thoracic, and mediastinal disease" were then screened. The statistical analysis included 12,819,518 reports in the FAERS database from 2004Q1 to 2023Q2, of which 236,619 AEs were reported as "primary suspect" for the six drugs mentioned above, which were selected as "cardiac disorders," "nervous system disorders," and "respiratory, thoracic and mediastinal disorders." Some AEs identified in this study are consistent with the drug labeling, such as bradycardia, respiratory depression, and somnolence. In addition, some unexpected and significant acute adverse drug reactions (ADRs), such as toxic leukoencephalopathy and coma, may occur. This study identified potential new and unexpected ADRs for opioids, providing valuable evidence for safety studies of opioids.

Evaluation of the Galenic stability of a Propofol Emulsion after the Expiration date

Objective: Propofol is an intravenous lipid emulsion indicated for the induction and maintenance of general anesthesia or sedation. Like all emulsions, propofol is thermodynamically unstable. The objective of this study was to evaluate the post expiration stability of a batch of propofol. Methods: The parameters studied to evaluate the stability of the drug were: visual appearance, ph, droplet diameter and zeta potential.For this purpose we had 20 ampoules of Propofol Fresenius with an expiration date of May 2021. The measurements started directly 1 month after the expiration of the batch and lasted 6 months. Results: Visual examination showed no abnormalities suggestive of instability. The pH varied between 6.95 and 7.15 until it decreased to a value of 5.58 at the 6th month after expiration. The diameter of the droplets ranged from 109.52nm to 125.15nm with a maximum of 169.5nm. Conclusion: The results obtained suggest a good galenic stability up to 3 months after expiry and may allow a use beyond the limit of use in case of complete stability study.

Population pharmacokinetic/pharmacodynamic modeling and exposure-response analysis of ciprofol in the induction and maintenance of general anesthesia in patients undergoing elective surgery: A prospective dose optimization study

AimThis study aimed to establish a population pharmacokinetic and pharmacodynamic (PK-PD) model to explore the optimal maintenance dose and appropriate starting time of maintenance dose after induction of ciprofol and investigate the efficacy and safety of ciprofol for general anesthesia induction and maintenance in patients undergoing elective surgery. MethodA total of 334 subjects with 3092 concentration measurements from nine clinical trials and 115 subjects with 5640 bispectral index (BIS) measurements from two clinical trials were used in the population PK-PD analysis. Exposure-response relationships for both efficacy endpoints (duration of anesthesia successful induction, time to recovery from anesthesia, time to respiratory recovery, and time from discontinuation to the 1st/3rd consecutive Aldrete score ≥ 9) and safety variables (hypotension, bradycardia, and injection site pain) were evaluated based on the data gathered from 115 subjects in two clinical trials. ResultCiprofol pharmacokinetics (PK) were adequately described by a three-compartment model with first-order elimination from the central compartment and redistribution from the deep and shallow peripheral compartments. An inhibitory sigmoidal Emax model best described the relationship between ciprofol effect-site concentrations and BIS measurements. Body weight, age, sex, blood sampling site, and study type (short-term infusion vs long-term infusion) were identified as statistically significant covariates on the PK of ciprofol. No covariates were found to have a significant effect on the pharmacodynamic (PD) parameters. The PK-PD simulation results showed that the optimal maintenance dose was 0.8 mg/kg/h and the appropriate time to start the maintenance dose was 4–5 mins after the induction dose of ciprofol. Within the exposure range of this study, no meaningful correlations between ciprofol exposures and efficacy or safety endpoints were observed. ConclusionA population PK-PD model was successfully developed to describe the ciprofol PK and BIS changes. Efficacy was consistent across the exposure range with a well-tolerated safety profile indicating no maintenance dose adjustment is required for patients undergoing elective surgery.

Topical sevoflurane: a galenic experience

Sevoflurane is a volatile liquid from the family of ether-derived halogenated hydrocarbons that is approved for the induction and maintenance of inhalational general anesthesia in the hospital setting. This review describes the pioneering experience of a Spanish Pain Unit in the home treatment of complicated painful wounds using topical sevoflurane instillations according to a protocol approved for off-label use. Aspects of safety and efficacy, both analgesic, antimicrobial and pro-healing are addressed, and some future lines of research are discussed in terms of new formulations for topical use. After more than seven years of use of the protocol, an experience of over 70,000 applications of topical sevoflurane has been gained. In general terms, the analgesic effect appears quickly, is highly intense and persists for several hours. As a result, patients can reduce their consumption of systemic analgesics and benefit from an improvement in their quality of life. In addition, there are signs that suggest sevoflurane also possesses antimicrobial and pro-healing properties. Regarding safety, pruritus at the level of the periulcerous skin is the most frequently reported adverse effect, although it is usually transient and well-tolerated, and no systemic toxicity has been reported. Overall, the risk-benefit balance of the drug has so far been very favorable. To avoid manipulation of this volatile liquid, we have developed a new formulation of sevoflurane in gel form, which has made it possible to successfully apply sevoflurane in the context of painful pathologies where the skin remains intact. Furthermore, these types of new formulations, including sevoflurane microspheres, which we have also developed, could improve the efficacy and safety of topical sevoflurane while reducing the occupational exposure of healthcare staff. This means that the development of new formulations is a field with a very promising future.

Perioperative Care and Outcomes of Patients with Brain Tumors Undergoing Elective Craniotomy: Experience from an Ethiopian Tertiary-Care Hospital

To describe patients, perioperative care, and outcomes undergoing supratentorial and infratentorial craniotomy for brain tumor resection in a tertiary-care hospital in Ethiopia. A retrospective cohort study of patients consecutively admitted between January 1, 2021, and December 31, 2021, was performed. We characterized patients, perioperative care, and outcomes. The final sample comprised 153 patients; 144 (94%) 18 years and over, females (n= 48, 55%) with primarily American Society of Anesthesiologists physical class II (n=97 (63.4%) who underwent supratentorial (n= 114, 75%), or infratentorial (n=39, 25%) tumor resection. Patients were routinely admitted (95%) to floor/wards before craniotomy; Inhaled anesthetic (isoflurane 88%/halothane 12%) was used for maintenance of general anesthesia, 3) Propofol (n=93, 61%; n=72), mannitol (n=73, 48%, n=54l), and cerebrospinal fluid drain (n=28, 18%, were used facilitate intraoperative brain relaxation, while the use of hyperventilation was rate (n=1). The average estimated blood loss was 1040+727 ml; 37 (24%) patients received tranexamic acid, and 57 (37%) received a blood transfusion. Factors associated with extubation were a) infratentorial tumor location: relative risk RR 0.45 (95% CI 0.29-0.69), preoperative hydrocephalus: RR 0.51, (95% CI 0.34-0.79), shorter total anesthesia duration: 277.8+8.8 vs. 426.77+13.1 minutes, p < 0.0001, lower estimated blood loss: 897+68 ml vs. 1361.7+100 ml, p=0.0002, and CSF drainage to facilitate brain relaxation: RR 0.52, 95% CI 0.32-0.84). Approximately one in ten patients experienced postoperative obstructive hydrocephalus, surgical site infections, or pneumonia. These findings suggest that certain factors may impact patient outcomes following craniotomy for tumor resection. By identifying these factors, healthcare providers may be better equipped to develop individualized treatment plans and improve patient outcomes. Additionally, the study highlights the importance of postoperative monitoring and management to prevent complications.

The effect of COVID-19 pandemic on perioperative factors: data from the Swedish Perioperative Register

BackgroundThe COVID-19 pandemic has affected healthcare organizations in many areas. The aim of this study was to describe surgical interventions, anesthesia, and postoperative outcomes in adult patients during the first wave and 1 year into the COVID-19 pandemic in Sweden, and to compare these outcomes with outcomes during the same period the year before the pandemic.MethodsData were collected from the Swedish PeriOperative Register, and included 417, 233 perioperative registration of patients ≥ 18 years old between period 1 (March–June 2019), period 2 (March–June 2020), and period 3 (March–June 2021).ResultsCompared with pre-pandemic (period 1), the number of surgical interventions decreased by 28% in the first wave (period 2); 1 year into the pandemic (period 3), the number of interventions was still 7.5% lower than pre-pandemic. The largest drops between periods 1 and 2 were noted in the specialties of ear, nose, and larynx surgery, – 55.6%; teeth, jaws, mouth, and pharynx surgery, – 45.0%; endocrine system surgery, – 38.8%. The number of acute surgeries remained stable during all three periods. Volatiles were more frequently used for the maintenance of general anesthesia in period 2 than in either period 1 or 3 (p < 0.001). Minor differences were noted throughout the periods in postoperative nausea and vomiting as well as postoperative pain.ConclusionsThe COVID-19 pandemic has had an impact on perioperative care in Sweden. During the first wave of the pandemic, the number of surgical interventions decreased, but the number of acute surgeries remained stable compared with pre-pandemic numbers. Perioperative organizations have had and will continue to have challenges handling the increased number of patients needing perioperative care.

A prospective randomized study examining the impact of intravenous versus inhalational anesthesia on postoperative cognitive decline and delirium

The present prospective randomized study was designed to investigate whether the development of Post Operative Cognitive Decline (POCD) is related to anesthesia type in older adults. All patients were screened for delirium and mental status, received baseline neuropsychological assessment, and evaluation of activities of daily living (ADLs). Follow-up assessments were performed at 3-6 months and 12-18 months. Patients were randomized to receive either inhalation anesthesia (ISO) with isoflurane or total intravenous anesthesia (TIVA) with propofol for maintenance anesthesia. ISO (n = 99) and TIVA (n = 100) groups were similar in demographics, preoperative cognition, and incidence of post-operative delirium. Groups did not differ in terms of mean change in memory or executive function from baseline to follow-up. Pre-surgical cognitive function is the only variable predictive of the development of POCD. Anesthetic type was not predictive of POCD. However, ADLs were predictive of post-operative delirium development. Overall, this pilot study represents a prospective, randomized study demonstrating that when examining ISO versus TIVA for maintenance of general anesthesia, there is no significant difference in cognition between anesthetic types. There is also no difference in the occurrence of postoperative delirium. Postoperative cognitive decline was best predicted by lower baseline cognition and functional status.

Changes in external respiratory during cesarean section in dogs under various methods of general anesthesia

The aim of this study was to investigate the effect of popular non-inhaled and inhaled general anesthetics on the respiratory function of dogs during operative delivery. Experimental studies have been performed on pregnant bitches that have been subjected to caesarean section. The selection of animals was carried out according to pre-selected criteria, the age of the animals participating in the experiment was from 2 to 6 years, the average body weight was 22 ± 4.6 kg. Animals were divided into 3 groups. Dogs in the first group received intravenous anesthetic propofol at a dose of 4-6 mg/kg for induction and maintenance of general anesthesia. he dogs of the second group used an inhaled halogen-containing anesthetic isoflurane 0.5–2.0 vol% for the administration and maintenance of anesthesia. For the induction and maintenance of general anesthesia in animals of the third group, a more modern inhalation anesthetic sevoflurane 1.0–2.0 vol% was used. Each group included 20 animals. Analyzing the results obtained on the study of the functions of external respiration of dogs during caesarean section under general anesthesia, it can be argued that the most significant changes in the studied parameters occurred at the initial stages of anesthesia with propofol, which are associated with an increase in the concentration of this anesthetic in the blood and a more pronounced depression of the respiratory center compared to with inhalation anesthetics.

Changes in the gas composition and acid-base state of blood during cesarean section in dogs with various methods of general anesthesia

The purpose of the studies was to compare and evaluate the effect of different anesthesia protocols for operative delivery in dogs. The studies were performed on 60 pregnant females of different breeds aged 2 to 6 years, with an average weight of 22 ±4.6 kg. Animals were divided into three groups, 20 in each. Animals of the first group for the introduction and maintenance of general anesthesia used Propofol at a dose of 4-6 mg/kg. Animals of the second and third groups were introduced into anesthesia using inhalation anesthetics through a mask, then tracheal intubation was performed and general anesthesia was maintained by an anesthetic-respiratory apparatus. In the second group, Isoflurane 0.5 - 2.0 vol% was used as the main anesthetic; in the third group, Sevoflurane 1.0 - 2.0 vol%. Sevoflurane had the least impact, minimally deviating the studied parameters from the original data. The greatest changes were always observed when administered to anesthesia, manifesting as moderate and severe hypoxemia and hypercapnia. Analyzing the data obtained, we concluded that the use of inhalation anesthetics isoflurane and, in particular, sevoflurane, during caesarean section is preferable due to their less pronounced effect on gas composition and acid-base blood composition.

Pharmacodynamic mechanism-based interaction model for the haemodynamic effects of remifentanil and propofol in healthy volunteers

BackgroundPropofol and remifentanil are frequently combined for the induction and maintenance of general anaesthesia. Both propofol and remifentanil cause vasodilation and potentially reduce arterial BP. We aimed to develop a mechanism-based model that characterises the haemodynamic interactions between remifentanil and propofol. MethodsData from two clinical trials in healthy volunteers were analysed using remifentanil-alone, propofol-alone, and combination groups. We evaluated remifentanil effects on haemodynamics using a previously developed mechanism-based haemodynamic model of propofol. The interaction between propofol and remifentanil was explored using the principles of the general pharmacodynamic interaction (GPDI) model. ResultsRemifentanil alone increased the dissipation rate of total peripheral resistance by 50% at 3.0 ng ml−1. Additionally, the dissipation rates of HR and stroke volume were attenuated by 4.8% and 4.9% per 1 ng ml−1 increase in remifentanil concentration, respectively. The maximal effect of propofol alone in decreasing the production rate of total peripheral resistance was 78%, which decreased to 32% when combined with remifentanil 4 ng ml−1. The effects of remifentanil on HR and stroke volume were attenuated by propofol with maximum decreases of 11.9% and 21.2%, respectively. Goodness-of-fit plots and prediction-corrected visual predictive check plots showed good predictive performance of the models. ConclusionsThe structure of the previous mechanism-based haemodynamic model for propofol was able to describe the effects of remifentanil alone on haemodynamic variables. The GPDI model provided a good framework for characterising the pharmacodynamic interaction between remifentanil and propofol on haemodynamic properties. Clinical trial registrationNCT02043938; NCT03143972.

Frequency and characteristics of patients with bispectral index values of 60 or higher during the induction and maintenance of general anesthesia with remimazolam

In Korea, the approved anesthetic regimen of remimazolam starts with 6 mg/kg/h or 12 mg/kg/h until loss of consciousness, followed by maintenance at 1–2 mg/kg/h. Some patients receiving remimazolam for general anesthesia experience occasional difficulty maintaining bispectral index (BIS) value ˂ 60. This retrospective study aimed to analyze the data from patients undergoing elective surgery under remimazolam based-general anesthesia to determine the frequency and physical characteristics of patients with BIS values ˂ 60. The criterion was established for patients with a poorly maintained BIS value < 60. The frequency and physical characteristics of patients who satisfied this criterion were investigated through their medical records. The modified Brice interview was conducted within 24 h after surgery. Among the 1500 patients included in the analysis, 61 (4.1%) met the criteria for BIS ˂ 60. Based on the modified Brice interview, none of the patients with poorly maintained BIS ˂ 60 complained of intraoperative awareness based on the modified Brice interview or exhibit specific physical characteristics. These patients accounted for less than 5% of the total population studied. Notably, physical characteristics alone are insufficient to predict such patients before surgery.

Comparison of hemodynamic alterations and post-operative profile of sevoflurane and propofol during laparoscopic cholecystectomies

Background: Modern laparoscopic surgeries with insufflation of gas into peritoneal cavity are gold standard treatment for cholelithiasis. Propofol, a GABA receptor positive allosteric modulator and Sevoflurane, an inhalational anesthetic are used for maintenance of general anesthesia. In laparoscopy, significant hemodynamic changes occur. Searching in field of anesthesia is going on for anesthetic agent for better recovery. Aims and Objectives: Objective of the study is to compare sevoflurane with propofol for intraoperative hemodynamic changes and post-operative recovery profile of patient’s undergone laparoscopic cholecystectomies under general anesthesia. Secondary objective is to compare post-operative complications. Materials and Methods: A prospective, randomized, single-blinded, and comparative study done after permission from the institutional ethical committee and informed consent from patients. Total 84 patients of 20–50 years age of either sex were scheduled for laparoscopic cholecystectomy, divided in two equal groups – Group P, induced with propofol and anesthesia was maintained with propofol (100–120 μg/kg/min), nitrous oxide and oxygen and Group S induced with propofol and anesthesia was maintained using sevoflurane (1–2%), nitrous oxide, and oxygen. Results: We found that time for eye opening was 9±1.21 min in Group P and 8±1.34 min in Group S. Time for following verbal command was 10±1.20 min in Group P and 9±1.32 min in Group S. Time for speaking name by patient was 11±1.20 min in Group P and 10±1.34 min in Group S. Difference between two groups regarding eye opening, following verbal command, and time to speak own name are highly significant with P&lt;0.001 which proves that eye opening, following verbal command and time for speaking name by patient were significantly shorter in sevoflurane group. Time to achieve modified aldrete score &gt;8 was 14±1.30 min in Group P and 13±1.37 min in Group S. Difference between two groups is also highly significant with P&lt;0.001 which proves that time to achieve modified aldrete score&gt;8 were significantly shorter in sevoflurane group. Conclusion: From our study, maintenance of general anesthesia with sevoflurane is associated with faster recovery from anesthesia.