Metabolic Profiles of Propofol and Fospropofol: Clinical and Forensic Interpretative Aspects

Total Intravenous Anesthesia with Propofol Reduces Discharge Times Compared with Inhaled General Anesthesia in Shoulder Arthroscopy: A Randomized Controlled Trial

BACKGROUND

Shoulder arthroscopy is commonly performed at ambulatory surgical centers (ASCs) with use of an interscalene block and inhaled general anesthesia (IGA). However, an alternative option known as total intravenous anesthesia with propofol (TIVA-P) has shown promising results in reducing recovery time for other surgeries. The objective of this study was to assess whether there is a clinically meaningful difference in post-anesthesia care unit phase-I (PACU-I) time following shoulder arthroscopy between patients receiving an interscalene block with IGA and those receiving an interscalene block with TIVA-P.

METHODS

Patients who underwent shoulder arthroscopy performed by a single surgeon at the ASC of our institution between 2020 and 2023 were enrolled. Enrollment was conducted in blocks, with up to 3 planned interim analyses. After 2 blocks, enrollment was halted because the study arms demonstrated a significant difference in the primary outcome measure, PACU-I time. A total of 96 patients were randomized into the TIVA-P and IGA groups; after patient withdrawals, the groups comprised 42 and 40 patients, respectively. Patients underwent shoulder arthroscopy with use of the anesthesia method corresponding to their assigned group. Pain, satisfaction, antiemetic use, perioperative interventions, surgical time, PACU-II time, postoperative care time, and total time until discharge were recorded and were analyzed with use of chi-square and Mann-Whitney U tests with a significance cutoff of 0.0167 to account for the interim analyses.

RESULTS

Across groups, 81.7% of patients were non-Hispanic White and 58.5% were male. Significant differences were observed between the TIVA-P and IGA groups with respect to median PACU-I time (0.0 minutes [interquartile range (IQR), 0.0 to 6.0 minutes] versus 25.5 minutes [IQR, 20.5 to 32.5 minutes]; p < 0.001) and median total time until discharge (135.5 minutes [IQR, 118.5 to 156.8 minutes] versus 148.5 minutes [IQR, 133.8 to 168.8 minutes]; p = 0.0104). The TIVA-P group had a 9.1% quicker discharge time, primarily as a result of bypassing PACU-I (66.7% of patients) and spending 25.5 fewer minutes there overall. The TIVA-P group also had a lower rate of antiemetic use than the IGA group (59.5% versus 92.5% of patients; p = 0.0013). No significant differences were detected between the TIVA-P and IGA groups in terms of median pain improvement (1.0 [IQR, 0.0 to 2.0] versus 1.0 [IQR, 0.0 to 2.0]; p = 0.6734), perioperative interventions (78.6% versus 77.5% of patients, p = 1.0000), or median patient satisfaction (4.0 [IQR, 4.0 to 4.0] versus 4.0 [IQR, 3.8 to 4.0]; p = 0.4148).

CONCLUSIONS

TIVA-P showed potential to improve both PACU-I time and the total time until discharge while reducing antiemetic use without impacting pain or satisfaction. TIVA-P thus warrants consideration by orthopaedic surgeons for use in shoulder arthroscopy performed at ASCs.

LEVEL OF EVIDENCE

Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

The Relationship between Pre-Anesthetic Analgesia and Nociception (ANI) and Propofol Injection Pain among Patients Receiving Remifentanil: A Prospective, Randomized, Controlled Study

Background and Objectives: The analgesia/nociception index (ANI) potentially monitors nociceptive status during anesthesia, but its link to preoperative pain sensitivity is unclear. We investigated the relationship between pre-anesthetic ANI scores and propofol injection pain (PIP) in patients receiving remifentanil. Materials and Methods: This study included 124 male patients aged 19-60 undergoing general anesthesia (ASA class I or II). Patients were randomized to group R (n = 62, remifentanil 4 ng/mL) or group C (n = 62, saline). The primary outcome was the association between PIP and ANI. Secondary outcomes included the incidence and severity of PIP or rocuronium-induced withdrawal movement (RIWM) and their association with ANI. Results: PIP and RIWM incidence and severity were lower in group R than in group C. A weak negative correlation between PIP and ANI at pre-induction (rpb = -0.21, p = 0.02, rpb = -0.37, p < 0.01) and a moderate negative correlation during propofol injection (rpb = -0.48, p = 0.02) were observed. A significant negative correlation was found between RIWM and ANI during rocuronium injection (τb = -0.61, p < 0.01). AUC, cut-off value, specificity, and sensitivity in ANI at pre-induction for predicting PIP were 0.67 (p = 0.02), 59, 76%, and 55%, respectively. AUC, cut-off value, specificity, and sensitivity in ANI during propofol injection for PIP were 0.77 (p < 0.01), 65, 81%, and 67%, respectively. Conclusions: ANI scores demonstrated significant differences between groups, suggesting potential predictive value for PIP despite the low pre-induction AUC value. This study highlights the potential of using ANI scores to predict and manage PIP in patients receiving remifentanil.

Effects of continuous intravenous infusion with propofol on intestinal metabolites in rats

Microbial metabolites play an important role in regulating intestinal homeostasis and immune responses. Propofol is a common anesthetic in clinic, but it is not clear whether it affects intestinal metabolites in rats. Tail vein puncture was performed after adaptive feeding for 1 month in eight 2-month-old rats and they were given continuous intravenous infusion of propofol for 3 h. The feces of rats were divided into different groups based on time periods, with before and after anesthesia with propofol on days 1, 3 and 7 labeled as groups P, A1, A3 and A7, respectively. The effect of continuous intravenous infusion with propofol on rat fecal metabolites was determined using the non-targeted metabolomics technique gas chromatography coupled with a time-of-flight mass spectrometer analysis. The types and contents of metabolites in rat feces were changed after continuous intravenous infusion with propofol, but the changes were not statistically significant. The contents of the metabolites 3-hydroxyphenylacetic acid and palmitic acid increased from day 3 to 7, and it was shown that the two metabolites were positively correlated at a statistically significant level. Linoleic acid decreased to its lowest level on day 3, and it returned to pre-anesthesia level on day 7. At the same time, linoleic acid metabolism was a metabolic pathway that was co-enriched 7 days after infusion with propofol. Spearman correlation analysis showed that there was significant correlation between some differential metabolites and differential microorganisms. It was observed that zymosterol 1, cytosin and elaidic acid were negatively correlated with Alloprevotella in the A3 vs. P group. In the A7 vs. P group, cortexolone 3 and coprostan-3-one were positively correlated with Faecalibacterium, whilst aconitic acid was negatively correlated with it. In conclusion, the present study revealed statistically insignificant effects of continuous intravenous propofol on the intestinal metabolites in rats.

Cytochrome P450 2B6 and UDP-Glucuronosyltransferase Enzyme-Mediated Clearance of Ciprofol (HSK3486) in Humans: The Role of Hepatic and Extrahepatic Metabolism

Ciprofol (HSK3486) is a novel intravenous agent for general anesthesia. In humans, HSK3486 mainly undergoes glucuronidation to form M4 [fraction of clearance (fCL): 62.6%], followed by the formation of monohydroxylated metabolites that further undergo glucuronidation and sulfation to produce M5-1, M5-2, M5-3, and M3 (summed fCL: 35.2%). However, the complete metabolic pathways of HSK3486 in humans remain unclear. In this study, by comparison with chemically synthesized reference standards, three monohydroxylated metabolites [M7-1, 4-hydroxylation with an unbound intrinsic clearance (CLint,u) of 2211 μl/min/mg; M7-2, ω-hydroxylation with a CLint,u of 600 μl/min/mg; and M7-3, (ω-1)-hydroxylation with a CLint,u of 78.4 μl/min/mg] were identified in human liver microsomes, and CYP2B6 primarily catalyzed their formation. In humans, M7-1 was shown to undergo glucuronidation at the 4-position and 1-position by multiple UDP-glucuronosyltransferases (UGTs) to produce M5-1 and M5-3, respectively, or was metabolized to M3 by cytosolic sulfotransferases. M7-2 was glucuronidated at the ω position by UGT1A9, 2B4, and 2B7 to form M5-2. UGT1A9 predominantly catalyzed the glucuronidation of HSK3486 (M4). The CLint,u values for M4 formation in human liver and kidney microsomes were 1028 and 3407 μl/min/mg, respectively. In vitro to in vivo extrapolation analysis suggested that renal glucuronidation contributed approximately 31.4% of the combined clearance. In addition to HSK3486 glucuronidation (M4), 4-hydroxylation (M7-1) was identified as another crucial oxidative metabolic pathway (fCL: 34.5%). Further attention should be paid to the impact of CYP2B6- and UGT1A9-mediated drug interactions and gene polymorphisms on the exposure and efficacy of HSK3486. SIGNIFICANCE STATEMENT: This research elucidates the major oxidative metabolic pathways of HSK3486 (the formation of three monohydroxylated metabolites: M7-1, M7-2, M7-3) as well as definitive structures and formation pathways of these monohydroxylated metabolites and their glucuronides or sulfate in humans. This research also identifies major metabolizing enzymes responsible for the glucuronidation (UGT1A9) and oxidation (CYP2B6) of HSK3486 and characterizes the mechanism of extrahepatic metabolism. The above information is helpful in guiding the safe use of HSK3486 in the clinic.

Is There a Need for a Dedicated Pharmacokinetic Trial for a Drug in Obese Populations? A Drug Prioritization Decision Tree Framework

Obesity is a growing global health concern associated with high comorbidity rates, leading to an increasing number of patients who are obese requiring medication. However, clinical trials often exclude or under-represent individuals who are obese, creating the need for a methodology to adjust labeling to ensure safe and effective dosing for all patients. To address this, we developed a 2-part decision tree framework to prioritize drugs for dedicated pharmacokinetic studies in obese subjects. Leveraging current drug knowledge and modeling techniques, the decision tree system predicts expected exposure changes and recommends labeling strategies, allowing stakeholders to prioritize resources toward the drugs most in need. In a case study evaluating 30 drugs from literature across different therapeutic areas, our first decision tree predicted the expected direction of exposure change accurately in 73% of cases. We conclude that this decision tree system offers a valuable tool to advance research in obesity pharmacology and personalize drug development for patients who are obese, ensuring safe and effective medication.

Bisphosphonates and osteonecrosis of the jaws: Clinical and forensic aspects

OBJECTIVE

This manuscript aims to provide a comprehensive review of the current knowledge in the pathophysiology, diagnosis, prevention, and other relevant clinical and forensic aspects of a potentially severe complication known as medication-related osteonecrosis of the jaw (MRONJ) while synthesizing state-of-the-art information on bisphosphonates and introducing a possible differential diagnosis.

DESIGN

An extensive search was conducted in PubMed (U.S. National Library of Medicine) without a time or language constraint, focusing on the epidemiology, pathophysiology, risk factors, site specificity, signs and symptoms, differential diagnosis, prevention, and forensic aspects of MRONJ. All types of original articles, reviews, case reports, short communications, opinion articles, guidelines, and letters to editors were considered to produce a complete review on this subject.

RESULTS

MRONJ prevention relies on a multidisciplinary approach and is critical since truly effective treatments are lacking. This therapeutic challenge is partly due to uncertainty regarding this condition's pathophysiology. Differential diagnosis of osteonecrosis of the jaws associated with krokodil abuse, one of the most dangerous and homemade psychoactive illicit substances, should be considered.

CONCLUSIONS

Further research into the etiology and site specificity of MRONJ is encouraged, aiming to develop novel treatment prospects. Indeed, comprehending this would allow for increased efficacy and therapeutic options while emphasizing the importance of prevention. In addition, we advocate for greater consensus among the various societies regarding MRONJ's treatment and management.

Predicting Regioselectivity of Cytosolic Sulfotransferase Metabolism for Drugs

Cytosolic sulfotransferases (SULTs) are a family of enzymes responsible for the sulfation of small endogenous and exogenous compounds. SULTs contribute to the conjugation phase of metabolism and share substrates with the uridine 5'-diphospho-glucuronosyltransferase (UGT) family of enzymes. UGTs are considered to be the most important enzymes in the conjugation phase, and SULTs are an auxiliary enzyme system to them. Understanding how the regioselectivity of SULTs differs from that of UGTs is essential from the perspective of developing novel drug candidates. We present a general ligand-based SULT model trained and tested using high-quality experimental regioselectivity data. The current study suggests that, unlike other metabolic enzymes in the modification and conjugation phases, the SULT regioselectivity is not strongly influenced by the activation energy of the rate-limiting step of the catalysis. Instead, the prominent role is played by the substrate binding site of SULT. Thus, the model is trained only on steric and orientation descriptors, which mimic the binding pocket of SULT. The resulting classification model, which predicts whether a site is metabolized, achieved a Cohen's kappa of 0.71.

Scale-free dynamics in the core-periphery topography and task alignment decline from conscious to unconscious states

Scale-free physiological processes are ubiquitous in the human organism. Resting-state functional MRI studies observed the loss of scale-free dynamics under anesthesia. In contrast, the modulation of scale-free dynamics during task-related activity remains an open question. We investigate scale-free dynamics in the cerebral cortex's unimodal periphery and transmodal core topography in rest and task states during three conscious levels (awake, sedation, and anesthesia) complemented by computational modelling (Stuart-Landau model). The empirical findings demonstrate that the loss of the brain's intrinsic scale-free dynamics in the core-periphery topography during anesthesia, where pink noise transforms into white noise, disrupts the brain's neuronal alignment with the task's temporal structure. The computational model shows that the stimuli's scale-free dynamics, namely pink noise distinguishes from brown and white noise, also modulate task-related activity. Together, we provide evidence for two mechanisms of consciousness, temporo-spatial nestedness and alignment, suggested by the Temporo-Spatial Theory of Consciousness (TTC).

A call for immediate climate action in anesthesiology: routine use of minimal or metabolic fresh gas flow reduces our ecological footprint

PURPOSE

Climate change is a global threat, and inhalational anesthetics contribute to global warming by altering the photophysical properties of the atmosphere. On a global perspective, there is a fundamental need to reduce perioperative morbidity and mortality and to provide safe anesthesia. Thus, inhalational anesthetics will remain a significant source of emissions in the foreseeable future. It is, therefore, necessary to develop and implement strategies to minimize the consumption of inhalational anesthetics to reduce the ecological footprint of inhalational anesthesia.

SOURCE

We have integrated recent findings concerning climate change, characteristics of established inhalational anesthetics, complex simulative calculations, and clinical expertise to propose a practical and safe strategy to practice ecologically responsible anesthesia using inhalational anesthetics.

PRINCIPAL FINDINGS

Comparing the global warming potential of inhalational anesthetics, desflurane is about 20 times more potent than sevoflurane and five times more potent than isoflurane. Balanced anesthesia using low or minimal fresh gas flow (≤ 1 L·min-1) during the wash-in period and metabolic fresh gas flow (0.35 L·min-1) during steady-state maintenance reduces CO2 emissions and costs by approximately 50%. Total intravenous anesthesia and locoregional anesthesia represent further options for lowering greenhouse gas emissions.

CONCLUSION

Responsible anesthetic management choices should prioritize patient safety and consider all available options. If inhalational anesthesia is chosen, the use of minimal or metabolic fresh gas flow reduces the consumption of inhalational anesthetics significantly. Nitrous oxide should be avoided entirely as it contributes to depletion of the ozone layer, and desflurane should only be used in justified exceptional cases.

One image is worth more than a thousand words: producing an atlas of medical signs for teaching clinical and forensic toxicology

Clinical and forensic toxicology are critically involved in the acquisition of basic skills to correctly suspect intoxication, collect biological and non-biological materials for toxicological analysis, comprehend the complexities inherent to laboratory activity, and understand the fundamentals of toxicokinetics and toxicodynamics that underlie the interpretation of results. This works presents a pedagogical innovation proposal for the teaching of clinical and forensic toxicology based on a compilation of more than 3 000 cases where the image was fulcra for suspicion. The experience in this article follows the model practiced in bachelors, masters, and PhD degrees, as well as in other continuing training courses, where we are teaching toxicology for more than 15 years. All these levels of education are considered fundamental to the sound development of this science. This approach aims also to offer strength to the intervention of the true toxicologist in all the toxicological phases, besides the classic analytical chemistry. Indeed, it is impossible to provide effective clinical and forensic toxicological interpretations without a proper and broad education, and not thinking exclusively in terms of laboratory techniques. In the future, it will be interesting to evaluate knowledge retention and to propose a database of videos of signs related to intoxications.

An intravenous anesthetic drug-propofol, influences the biological characteristics of malignant tumors and reshapes the tumor microenvironment: A narrative literature review

Malignant tumors are the second leading cause of death worldwide. This is a public health concern that negatively impacts human health and poses a threat to the safety of life. Although there are several treatment approaches for malignant tumors, surgical resection remains the primary and direct treatment for malignant solid tumors. Anesthesia is an integral part of the operation process. Different anesthesia techniques and drugs have different effects on the operation and the postoperative prognosis. Propofol is an intravenous anesthetic that is commonly used in surgery. A substantial number of studies have shown that propofol participates in the pathophysiological process related to malignant tumors and affects the occurrence and development of malignant tumors, including anti-tumor effect, pro-tumor effect, and regulation of drug resistance. Propofol can also reshape the tumor microenvironment, including anti-angiogenesis, regulation of immunity, reduction of inflammation and remodeling of the extracellular matrix. Furthermore, most clinical studies have also indicated that propofol may contribute to a better postoperative outcome in some malignant tumor surgeries. Therefore, the author reviewed the chemical properties, pharmacokinetics, clinical application and limitations, mechanism of influencing the biological characteristics of malignant tumors and reshaping the tumor microenvironment, studies of propofol in animal tumor models and its relationship with postoperative prognosis of propofol in combination with the relevant literature in recent years, to lay a foundation for further study on the correlation between propofol and malignant tumor and provide theoretical guidance for the selection of anesthetics in malignant tumor surgery.

Efficacy and Safety of the Remimazolam-Alfentanil Combination for Sedation During Gastroscopy: A Randomized, Double-blind, Single-center Controlled Trial

PURPOSE

Propofol infusion is a popular single drug of choice for sedation in the gastrointestinal endoscopy suite. Drug combinations are more beneficial than single-drug regimens in gastroscopy sedation. However, the cardiopulmonary complications of propofol sedation raise concern. Remimazolam is a novel, ultra-short-acting benzodiazepine sedative, and alfentanil is a weak opioid. During endoscopic procedures, remimazolam is an effective and safe sedative procedure. No synergistic effect has been reported when remimazolam was combined with alfentanil in gastroscopy sedation. Here, we evaluated the effective dose, sedative efficacy, and safety of the remimazolam-alfentanil combination in gastroscopy sedation and compared the results with those of the propofol-alfentanil combination.

METHODS

This study was conducted in two parts. In Part 1, Dixon's up-and-down method (sequential distribution) was adopted for determining the 95% effective dose (ED95) (95% CI) and 95% CI of remimazolam combined with 5 µg/kg alfentanil. In Part 2, after obtaining the predictive remimazolam ED95, 161 patients were randomized into the remimazolam group (remimazolam-alfentanil) and the propofol group (propofol-alfentanil). The effectiveness of the drug combinations was measured according to successful sedation parameters. Changes in vital signs and the appearance of adverse events were used to assess the safety of drug combinations. Evaluation of patient and physician satisfaction was included as quality indicators of treatment.

RESULTS

Baseline demographic and clinical characteristics were comparable between the 2 parts of the study. The ED95 of remimazolam in inhibiting a positive response to gastroscopy placement into the pharyngeal cavity was 0.33 mg/kg (95% CI, 0.289 to 1.023). The procedure success rate was 97.53% in the remimazolam group and 97.50% in the propofol group. The difference in the success rate of the procedure between the remimazolam and propofol groups was 0.03% (95% CI, -2.5 to 2.4). However, the incidence of injection pain, hypotension, respiratory depression, and dizziness was lower in the remimazolam group compared with the propofol group (P < 0.05). Furthermore, patients from the propofol group were more likely to be drowsy, and their work efficiency was reduced the day after leaving the hospital, whereas patients in the remimazolam group were less affected (P < 0.05).

IMPLICATIONS

The ED95 of remimazolam was 0.33 mg/kg when it was combined with alfentanil (5 µg/kg) for gastroscopy sedation. The sedation strategy of remimazolam-alfentanil has noninferior efficacy, fewer adverse effects, and a better postoperative recovery process than propofol-alfentanil for patients undergoing gastroscopy. Chinese Clinical Trials Registry identifier: ChiCTR2100051565.

Efficacy and safety of remimazolam besylate in bronchoscopy for adults: A multicenter, randomized, double-blind, positive-controlled clinical study

Background: With the development of fiberoptic bronchoscopy in the diagnosis and treatment of various pulmonary diseases, the anesthesia/sedation requirements are becoming more demanding, posing great challenges for patient safety while ensuring a smooth examination/surgery process. Remimazolam, a brand-new ultra-short-acting anesthetic, may compensate for the shortcomings of current anesthetic/sedation strategies in bronchoscopy.

Methods: This study was a prospective, multicenter, randomized, double-blind, parallel positive controlled phase 3 clinical trial. Subjects were randomized to receive 0.2 mg/kg remimazolam besylate or 2 mg/kg propofol during bronchoscopy to evaluate the efficacy and safety of remimazolam.

Results: A total of 154 subjects were successfully sedated in both the remimazolam group and the propofol group, with a success rate of 99.4% (95%CI of the adjusted difference −6.7 × 10%–6% to −5.1 × 10%–6%). The sedative effect of remimazolam was noninferior to that of propofol based on the prespecified noninferiority margin of −5%. Compared with the propofol group, the time of loss of consciousness in the remimazolam group (median 61 vs. 48s, p < 0.001), the time from the end of study drug administration to complete awakening (median 17.60 vs. 12.80 min, p < 0.001), the time from the end of bronchoscopy to complete awakening (median 11.00 vs. 7.00 min, p < 0.001), the time from the end of study drug administration to removal of monitoring (median 19.50 vs. 14.50 min, p < 0.001), and the time from the end of bronchoscopy to removal of monitoring (median 12.70 vs. 8.60 min, p < 0.001) were slightly longer. The incidence of Adverse Events in the remimazolam group and the propofol group (74.8% vs. 77.4%, p = 0.59) was not statistically significant, and none of them had Serious Adverse Events. The incidence of hypotension (13.5% vs. 29.7%, p < 0.001), hypotension requiring treatment (1.9% vs. 7.7%, p = 0.017), and injection pain (0.6% vs. 16.8%, p < 0.001) were significantly lower in the remimazolam group than in the propofol group.

Conclusion: Moderate sedation with 0.2 mg/kg remimazolam besylate is effective and safe during bronchoscopy. The incidence of hypotension and injection pain was less than with propofol, but the time to loss of consciousness and recovery were slightly longer.

Clinical Trial Registration:clinicaltrials.gov, ChiCTR2000039753

Raising Awareness on the Clinical and Forensic Aspects of Jellyfish Stings: A Worldwide Increasing Threat

Jellyfish are ubiquitous animals registering a high and increasing number of contacts with humans in coastal areas. These encounters result in a multitude of symptoms, ranging from mild erythema to death. This work aims to review the state-of-the-art regarding pathophysiology, diagnosis, treatment, and relevant clinical and forensic aspects of jellyfish stings. There are three major classes of jellyfish, causing various clinical scenarios. Most envenomations result in an erythematous lesion with morphological characteristics that may help identify the class of jellyfish responsible. In rare cases, the sting may result in delayed, persistent, or systemic symptoms. Lethal encounters have been described, but most of those cases happened in the Indo-Pacific region, where cubozoans, the deadliest jellyfish class, can be found. The diagnosis is mostly clinical but can be aided by dermoscopy, skin scrapings/sticky tape, confocal reflectance microscopy, immunological essays, among others. Treatment is currently based on preventing further envenomation, inactivating the venom, and alleviating local and systemic symptoms. However, the strategy used to achieve these effects remains under debate. Only one antivenom is currently used and covers merely one species (Chironex fleckeri). Other antivenoms have been produced experimentally but were not tested on human envenomation settings. The increased number of cases, especially due to climate changes, justifies further research in the study of clinical aspects of jellyfish envenoming.

Propofol enhances the sensitivity of glioblastoma cells to temozolomide by inhibiting macrophage activation in tumor microenvironment to down-regulate HIF-1α expression

Temozolomide (TMZ) is the first-line drug for the clinical treatment of glioblastoma (GBM), but drug resistance limits its treatment benefits. This study was intended to investigate whether propofol could restrict the resistance of GBM cells to TMZ and uncover the underlying mechanisms. Human GBM cell line U251 and TMZ-resistant U251/TMZ cell line were transplanted into mice to construct GBM and TMZ-resistant GBM xenograft tumors. Tumor growth in mice was monitored, and the tumor tissues were collected for biochemical analysis. THP-1 cell differentiated into M0 subtype macrophage using phorbol 12-myristate 13-acetate (PMA). The culture medium of M0 macrophage was collected for treating U251 cells with the presence or absence of propofol or propofol + DMOG (HIF-1α activator). Results showed that propofol significantly enhanced the inhibitory effect of TMZ on tumor growth, macrophage infiltration and inflammation in TMZ-resistant GBM xenograft tumors in vivo. Compared with GBM xenograft tumors, higher expression of HIF-1α, O6-methylguanine-DNA methyltransferase (MGMT), p-p65 and cyclooxygenase 2 (Cox2) was observed in TMZ-resistant GBM xenograft tumors, but propofol co-treatment markedly reduced the expression of these proteins. In in vitro experiments, culture medium from M0 macrophage promoted U251 cell survival, inflammation and expression of HIF-1α, MGMT, p65 and Cox2, whereas inhibited cell apoptosis. However, propofol suppressed the PMA-induced THP-1 M0 macrophage activation, and propofol-treated culture medium from M0 macrophage blocked all the effects of M0 medium on U251 cells. Additionally, DMOG reversed the effect of propofol-treated M0 medium on U251 cells. In conclusion, Propofol restricted TMZ resistance via inhibiting macrophage activation and down-regulating HIF-1α expression in GBM.

Methodological Developments for Metabolic NMR Spectroscopy from Cultured Cells to Tissue Extracts: Achievements, Progress and Pitfalls

This is a broad overview and critical review of a particular group of closely related ex vivo and in vitro metabolic NMR spectroscopic methods. The scope of interest comprises studies of cultured cells and excised tissue, either intact or after physicochemical extraction of metabolites. Our detailed discussion includes pitfalls that have led to erroneous statements in the published literature, some of which may cause serious problems in metabolic and biological interpretation of results. To cover a wide range of work from relevant research areas, we consider not only the most recent achievements in the field, but also techniques that proved to be valid and successful in the past, although they may not have generated a very significant number of papers more recently. Thus, this comparative review also aims at providing background information useful for judiciously choosing between the metabolic ex vivo/in vitro NMR methods presented. Finally, the methods of interest are discussed in the context of, and in relation to, other metabolic analysis protocols such as HR-MAS and cell perfusion NMR, as well as the mass spectrometry approach.

Propofol Protects Against Erastin-Induced Ferroptosis in HT-22 Cells

Propofol is a short-acting intravenous anesthetic that is widely used in clinical treatment. Previous articles have indicated that propofol is a therapeutic target for anti-apoptosis, anti-inflammation, anti-lipid peroxidation, and anti-reactive oxygen species (ROS). Moreover, cell ferroptosis is strongly correlated with cellular ROS, inflammatory responses, and lipid peroxidation. However, the mechanisms by which propofol attenuates neuronal injury by reducing ferroptosis remain unknown. Hence, we hypothesized that propofol could protect neurons by reducing ferroptosis. To test this hypothesis, HT-22 cells were treated with a specific ferroptosis activator (erastin) in the presence of propofol (50 μM). We found that propofol reduced erastin-induced high Fe²⁺ concentrations, lipid peroxides, and excess ROS. Western blotting results also suggested that propofol could rescue erastin-induced low expression of GXP4 and system Xc^-. Further experiments indicated that propofol attenuated p-ALOX5 expression at Ser663 independent of ERK. In addition, we built two transient transfection cell lines, ALOX5 OE and Ser663Ala-ALOX5 OE, to confirm the target of propofol. We found that the Ser663 point is the critical role of propofol in rescuing erastin-induced cell injury/lipid peroxidation. In conclusion, propofol may help attenuate ferroptosis, which may provide a new therapeutic method to treat neuronal injury or the brain inflammatory response.

Incidence and Risk Factors for Hypoxia in Deep Sedation of Propofol for Artificial Abortion Patients

Background

Respiratory depression is a life-threatening adverse effect of deep sedation. This study aimed to investigate the factors related to hypoxia caused by propofol during intravenous anesthesia.

Methods

Three hundred and eight patients who underwent painless artificial abortion in the outpatient department of Shanghai Tenth People’s Hospital between November 1, 2019 and June 30, 2020 were divided into two groups according to whether the patients experienced hypoxia (SpO₂ < 95%). Preoperative anxiety assessments, anesthesia process, and operation-related information of the two groups were analyzed. The univariate analysis results were further incorporated into logistic regression analysis for multivariate analysis to determine the independent risk factors affecting hypoxia.

Results

Univariate analysis revealed that body mass index (BMI) (21.80 ± 2.94 vs. 21.01 ± 2.39; P = 0.038, 95% confidence interval (CI) = [−1.54, −0.04]), propofol dose (15.83 ± 3.21 vs. 14.39 ± 3.01; P = 0.002, CI = [−2.34, −0.53]), menopausal days (49.64 ± 6.03 vs. 52.14 ± 5.73; P = 0.004, CI = [0.79, 4.21]), State Anxiety Inventory score (51.19 ± 7.55 vs. 44.49 ± 8.96; P < 0.001, CI = [−9.26, −4.15]), and Self-rating Anxiety Scale score (45.86 ± 9.48 vs. 42.45 ± 9.88; P = 0.021, CI = [−6.30, −0.53]) were statistically significant risk factors for hypoxia during the operation. Logistic regression analysis showed that propofol dosage, menopausal days, and State Anxiety Inventory score were independent risk factors for hypoxia.

Conclusion

Patient anxiety affects the incidence of hypoxia when undergoing deep intravenous anesthesia with propofol. We can further speculate that alleviating patient anxiety can reduce the incidence of hypoxia.

Clinical Trial Registration

[http://www.chictr.org.cn], identifier [ChiCTR2000032167].

A single nucleotide polymorphism-based formula to predict the risk of propofol TCI concentration being over 4 µg mL-1 at the time of loss of consciousness

We aim to develop a formula based on single nucleotide polymorphisms (SNPs) to predict whether the propofol target-controlled infusion (TCI) concentration would be over 4 μg mL^-1 at the time of loss of consciousness (LOC). We recruited 184 patients undergoing thyroid or breast surgeries with propofol anaesthesia. A total of 48 SNPs of CYP2B6, CYP2C9, UGT1A9, HNF4A, ABCB1, ABCC4, ABCG2, GABRA2, GABRA4, GABRB1, GABRB3, GABRG2, GABBR2, GAD1, SLC1A3, BDNF, and NRXN1, previously associated with propofol metabolic and pharmacology pathway, were genotyped. The formula was developed in the training cohort using the least absolute shrinkage and selection operator logistic regression model, and then validated in the testing cohort. The SNPs, GABBR2 rs1167768, GABBR2 rs1571927, NRXN1 rs601010, BDNF rs2049046, GABRA4 rs1512135, UGT1A9 rs11692021, GABBR2 rs2808536, HNF4A rs1884613, GABRB3 rs2017247, and CYP2B6 rs3181842 were selected to construct the SNP-based formula, which was used to calculate the risk score for over 4 μg mL^-1 TCI concentration of propofol at the time of LOC. Patients in the high-risk group were more likely to require a propofol concentration higher than 4 μg mL^-1 and presented a longer LOC latency. The SNP-based formula may significantly improve the safety and effectiveness of propofol-induced anaesthesia.

Clinical Importance of Potential Genetic Determinants Affecting Propofol Pharmacokinetics and Pharmacodynamics

Interindividual variability in response to drugs used in anesthesia has long been considered the rule, not the exception. It is important to mention that in anesthesiology, the variability in response to drugs is multifactorial, i.e., genetic and environmental factors interact with each other and thus affect the metabolism, efficacy, and side effects of drugs. Propofol (2,6-diisopropylphenol) is the most common intravenous anesthetic used in modern medicine. Individual differences in genetic factors [single nucleotide polymorphisms (SNPs)] in the genes encoding metabolic enzymes, molecular transporters, and molecular binding sites of propofol can be responsible for susceptibility to propofol effects. The objective of this review (through the analysis of published research) was to systematize the influence of gene polymorphisms on the pharmacokinetics and pharmacodynamics of propofol, to explain whether and to what extent the gene profile has an impact on variations observed in the clinical response to propofol, and to estimate the benefit of genotyping in anesthesiology. Despite the fact that there has been a considerable advance in this type of research in recent years, which has been largely limited to one or a group of genes, interindividual differences in propofol pharmacokinetics and pharmacodynamics may be best explained by the contribution of multiple pathways and need to be further investigated.

Genetic Susceptibility Toward Nausea and Vomiting in Surgical Patients

Postoperative nausea and vomiting (PONV) are frequently occurring adverse effects following surgical procedures. Despite predictive risk scores and a pallet of prophylactic antiemetic treatments, it is still estimated to affect around 30% of the patients, reducing their well-being and increasing the burden of post-operative care. The aim of the current study was to characterize selected genetic risk factors of PONV to improve the identification of at risk patients. We genotyped 601 patients followed during the first 24 h after surgery for PONV symptoms in the absence of any antiemetic prophylaxis. These patients were recruited in the frame of a randomized, placebo controlled clinical study aiming to test the efficacy of dexamethasone as a treatment of established PONV. We examined the impact of selected single nucleotide polymorphisms (SNPs) located around 13 different genes and the predicted activity of 6 liver drug metabolizing enzymes from the cytochromes P450 family (CYP) on the occurrence and recurrence of PONV. Our genetic study confirms the importance of genetic variations in the type 3B serotonin receptor in the occurrence of PONV. Our modelling shows that integration of rs3782025 genotype in preoperative risk assessments may help improve the targeting of antiemetic prophylaxis towards patients at risk of PONV.

Application of Dexmedetomidine combined with Propofol Intravenous Anesthesia in Laparoscopic Day Surgery in Pediatric Urology

Objectives

To evaluate the sedative and analgesic effects of dexmedetomidine combined with propofol intravenous anesthesia in laparoscopic day surgery in pediatric urology.

Methods

Eighty male children with cryptorchidism and hydrocele who underwent laparoscopic daytime surgery in our hospital from January 2019 to January 2021 were selected and randomly divided into two groups: the experimental group and the control group. Children in the experimental group ranged in age from 5.7 to 11.3, with an average of 8.52±2.17 years old, while those in the control group ranged in age from 5.3 to 12.0, with an average of 8.60±2.07 years old. There were 12 cases of cryptorchidism and 28 cases of hydrocele in the experimental group, and 14 cases of cryptorchidism and 26 cases of hydrocele in the control group. Children in the control group received conventional propofol intravenous combined anesthesia, while those in the experimental group were given dexmedetomidine (2-5 ug/kg) intranasally on the basis of conventional propofol intravenous anesthesia. The anesthetic effect, analgesic effect, serum levels of inflammatory cytokines before and after surgery and adverse drug reactions in the two groups were compared and analyzed.

Results

The awakening time, extubation time and retention time in the resuscitation room of the experimental group were shorter than those of the control group, with a statistically significant difference (P<0.05); The VAS pain scores of the experimental group were significantly lower than those of the control group at 15minutes, 12hour and 24hour after awakening, with a statistically significant difference (P<0.05). In addition, the levels of TNF-a, CRP, IL-6 and other inflammatory factors in the control group were significantly higher compared with those in the experimental group 24h after surgery, with a statistical significance (TNF-a, P=0.02; CRP, P=0.00; IL-6, P=0.03); The incidence of adverse drug reactions in the experimental group was 17.5%, while that in the control group was 12.5%, which was not statistically significant (P=0.53).

Conclusion

Dexmedetomidine combined with intravenous propofol anesthesia may be helpful to shorten the extubation time, the recovery time and the stay time in the anesthesia resuscative room, improve the analgesic effect, and may reduce the inflammatory response and the expression of serum inflammatory cytokines, with no significant increase in side effects.

Transforming liquid nicotine into a stable solid through crystallization with orotic acid

The volatile liquid active pharmaceutical ingredient, nicotine, is stabilized in the solid-state through crystallization with orotic acid. The structure, thermal properties and bonding environment are characterized and compared with previous examples.

[Propofol: use, toxicology and assay features]

The study objective is to review the literature on the use, pharmacological properties, toxicology, and assay methods for intravenous anesthetic propofol. The scope and forms of propofol use, its pharmacokinetics, biotransformation features, which occurs more than 90% in the liver, and side effects associated with propofol use for anesthesia, are addressed. Propofol infusion syndrome (also known as PrIS) and deaths from propofol overdose due to medical errors, abuse, suicide attempts, and homicide are reported. Propofol identification and assay methods based on high-performance liquid chromatography (HPLC), gas chromatography with mass spectrometry (GC-MS), and liquid chromatography (LC) are described. The features of the methods performance are outlined; biological materials (the study objects) are listed: mainly blood and plasma, as well as urine, bile, hair, etc. The relevance of a comprehensive forensic chemical study of propofol is indicated, though there are few forensic studies of propofol.

Bispectral Index Monitoring and Observer Rating Scale Correlate with Dreaming during Propofol Anesthesia for Gastrointestinal Endoscopies

Background and objectives: Dreaming is a commonly reported side effect of propofol anesthesia. Materials and Methods: We investigated the inci-dence and character of dreams in patients undergoing intravenous propofol anesthesia and cor-related it with an observer rating scale of facial expression on the seven-point scale from pain to smile. A total of 124 patients undergoing gastrointestinal endoscopy were recruited in the pro-spective observational study. Bispectral index (BIS), blood pressure (BP), and pulse were moni-tored. Upon emergence from anesthesia, the patient’s facial expression was rated numerically. Thereafter, patients were asked whether they had dreams and to rate their dreams as pleasant or unpleasant. The mean age of participants was 53; body mass index, 26.17; duration of procedure, 20 min; and average propofol dose, 265 mg. Results: Dreaming was reported by 43% of patients. Dreams were pleasant in all but one patient. There was a significant correlation of the observer’s rating of facial expression with dreaming (r = 0.260; p = 0.004). Dreamers had higher scores of observer rating of facial expression (1 (0–2) vs. 0.5 (0–1), p = 0.006). Conclusions: BIS values were lower in the dreamers vs. non-dreamers 2 min after the endoscopy started (48 (43–62) vs. 59 (45–71), p = 0.038). Both BIS and observer ratings correlate with dreaming in patients undergoing gastrointestinal endos-copy. Trial registration number: NCT04235894.

Effects of propofol on inflammatory response and activation of p38 MAPK signaling pathway in rats with ventilator-induced lung injury

Purpose:

To investigate the effects of propofol on inflammatory response and activation of p38 mitogen-activated protein kinase (MAPK) signaling pathway in rats with ventilator-associated lung injury (VALI).

Methods:

Thirty-six Sprague Dawley (SD) rats were divided into control, VALI and VALI+propofol groups. The VALI group received the mechanical ventilation for 2 h. The VALI+propofol group received the mechanical ventilation for 2 h, which was accompanied by intravenous injection of propofol with dose of 8 mg·kg^-1·h^-1. At the end, the mean arterial pressure (MAP) and blood gas indexes were measured, and the lung wet/dry mass ratio (W/D) and biochemical indexes of lung tissue and bronchoalveolar lavage fluid (BALF) were determined.

Results:

Compared with VALI group, in VALI+propofol group the blood pH, partial pressure of oxygen, partial pressure of carbon dioxide and MAP were increased, the lung W/D, lung tissue myeloperoxidase activity and total protein concentration, white blood cell count, and tumor necrosis factor α, interleukin 1β and interleukin 6 levels in BALF were decreased, and the p-p38 MAPK protein expression level and phosphorylated p38 MAPK (p-p38 MAPK)/p38 MAPK ratio were decreased.

Conclusions:

Propofol treatment may alleviate the VALI in rats by reducing the inflammatory response and inhibiting the activation of p38 MAPK signaling pathway.

The enhanced dissociation and associated surface structure of the anesthetic propofol at the water interface: vibrational sum frequency generation study

Propofol, the most administered drug for general anesthesia, affects the acid-base equilibrium at the interfacial region of arterial blood. Hence, the structure of propofol at the water interface under different pH conditions has been measured using the surface-selective vibrational sum frequency generation (VSFG) technique to understand the hydration as well as the dissociation of propofol at the water interface. Propofol remains in its neutral form at pH ≤ 5.8 in which the OH group of propofol forms a hydrogen bond with interfacial water molecules, where a few interfacial water molecules also interact with the π electron density of propofol. By contrast, propofol prefers to be in the deprotonated state at pH ≥ 7, due to which the surface of water becomes negatively charged and hence the interfacial water becomes oriented and the intensity of the OH stretch of water is enhanced. The pK_a of propofol at the water interface is ∼three units lower than in the bulk medium indicating that the dissociation of propofol is notably enhanced at the water interface. These VSFG studies suggest that, unlike the bulk, propofol prefers to be in the charged state at the water interface under physiological conditions, which may be important in understanding its diffusion and acid-base equilibrium in the interfacial arterial blood region.

Efficacy and Safety of Fospropofol Disodium for Injection in General Anesthesia Induction for Adult Patients: A Phase 3 Trial

Background: Fospropofol disodium for injection (Fospropofol_FD) is a prodrug that is metabolized into propofol to produce a general anesthesia effect when administered intravenously.

Objective: This study aimed to assess the efficacy and safety of Fospropofol_FD in comparison with propofol medium/long-chain fat emulsion injections (propofol-MCT/LCT) for general anesthesia induction in adult patients undergoing elective surgeries.

Setting: Nine academic medical centers in China.

Method: This multicenter, randomized, double-blind, double-simulated, controlled, and non-inferiority trial evaluated 540 eligible adult patients randomly assigned (2:1) to the intervention (20 mg/kg Fospropofol_FD) or control (2 mg/kg propofol-MCT/LCT) groups.

Main Outcome Measure: The primary efficacy endpoint was the success rate, defined as a Modified Observer’s Assessment of Alertness/Sedation Scale score of 1 within 5 min after study drug administration. The safety endpoints consisted of adverse events (AEs) related to consciousness, cognitive function, hemodynamic status, liver and kidney function, and blood tests.

Results: A total of 347 (96.3%) and 175 (97.2%) patients in the intervention and control groups, respectively, completed the study. The success rate for the primary outcome was 97.7% for both study drugs. The most frequent AEs in the intervention group were abnormal feeling (62.0%), blood pressure reduction (13.5%), and injection site pain (13.3%). No AEs related to consciousness and mental and cognitive functions or serious adverse events were reported.

Conclusion: Fospropofol_FD (20 mg/kg) is not inferior to propofol-MCT/LCT (2 mg/kg) in general anesthesia induction for American Society of Anesthesiologists (ASA) physical status I-II adult patients undergoing elective surgeries. It is safe and effective for clinical use under anesthesiologist monitoring.

Impact on Practice Statement: Fospropofol_FD can produce a general anesthesia effect and reduce the incidence of pain at the site of injection.

Effects of dexmedetomidine, propofol, sevoflurane and S-ketamine on the human metabolome: A randomised trial using nuclear magnetic resonance spectroscopy

BACKGROUND

Pharmacometabolomics uses large-scale data capturing methods to uncover drug-induced shifts in the metabolic profile. The specific effects of anaesthetics on the human metabolome are largely unknown.

OBJECTIVE

We aimed to discover whether exposure to routinely used anaesthetics have an acute effect on the human metabolic profile.

DESIGN

Randomised, open-label, controlled, parallel group, phase IV clinical drug trial.

SETTING

The study was conducted at Turku PET Centre, University of Turku, Finland, 2016 to 2017.

PARTICIPANTS

One hundred and sixty healthy male volunteers were recruited. The metabolomic data of 159 were evaluable.

INTERVENTIONS

Volunteers were randomised to receive a 1-h exposure to equipotent doses (EC50 for verbal command) of dexmedetomidine (1.5 ng ml-1; n = 40), propofol (1.7 μg ml-1; n = 40), sevoflurane (0.9% end-tidal; n = 39), S-ketamine (0.75 μg ml-1; n = 20) or placebo (n = 20).

MAIN OUTCOME MEASURES

Metabolite subgroups of apolipoproteins and lipoproteins, cholesterol, glycerides and phospholipids, fatty acids, glycolysis, amino acids, ketone bodies, creatinine and albumin and the inflammatory marker GlycA, were analysed with nuclear magnetic resonance spectroscopy from arterial blood samples collected at baseline, after anaesthetic administration and 70 min postanaesthesia.

RESULTS

All metabolite subgroups were affected. Statistically significant changes vs. placebo were observed in 11.0, 41.3, 0.65 and 3.9% of the 155 analytes in the dexmedetomidine, propofol, sevoflurane and S-ketamine groups, respectively. Dexmedetomidine increased glucose, decreased ketone bodies and affected lipoproteins and apolipoproteins. Propofol altered lipoproteins, fatty acids, glycerides and phospholipids and slightly increased inflammatory marker glycoprotein acetylation. Sevoflurane was relatively inert. S-ketamine increased glucose and lactate, whereas branched chain amino acids and tyrosine decreased.

CONCLUSION

A 1-h exposure to moderate doses of routinely used anaesthetics led to significant and characteristic alterations in the metabolic profile. Dexmedetomidine-induced alterations mirror α2-adrenoceptor agonism. Propofol emulsion altered the lipid profile. The inertness of sevoflurane might prove useful in vulnerable patients. S-ketamine induced amino acid alterations might be linked to its suggested antidepressive properties.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02624401. URL: https://clinicaltrials.gov/ct2/show/NCT02624401.

Potency of propofol for inducing loss of consciousness in end-stage kidney disease patients

It can be difficult for anesthesiologists to determine the optimal dose of propofol for end-stage kidney disease (ESKD) patients due to changes in drug disposition. The purpose of this study was to evaluate the potency of propofol for inducing loss of consciousness in ESKD patients. Patients with normal kidney function (Control group, n = 15), those with ESKD (ESKD group, n = 15), and those with ESKD undergoing cervical epidural anesthesia (ESKD-CEB group, n = 15) were administered propofol by target-controlled infusion (TCI) using the Schneider model. The effect-site concentration (Ce) of propofol started at 0.5 μg/ml and increased in increments of 0.5 μg/ml until the patient did not respond to verbal commands. The relationship between the probability (P) of loss of consciousness and the Ce of propofol was analyzed in each group using logistic regression. The Ce values of propofol at the time of loss of consciousness were 4.3 ± 0.9, 3.7 ± 0.9, and 3.3 ± 1.0 μg/ml for the Control, ESKD, and ESKD-CEB* groups, respectively (*significant difference vs. control, P < 0.05). The estimated Ce50 values for lost ability to respond to verbal command were 4.56, 3.75, and 3.21 μg/ml for the Control, ESKD, and ESKD-CEB groups, respectively. In conclusion, when inducing anesthesia in ESKD patients, we recommend using an initial dose similar to that of patients with normal kidney function, or rather starting with a lower dose.

Propofol misuse in Ireland - Two case reports and a review of the literature

Propofol is a rapidly acting sedative drug, which is usually administered intravenously. It is widely used in procedural sedation due to its rapid onset and easy reversibility. It has a good safety profile when used in combination with ventilation and monitoring. However, propofol can bring on feelings of euphoria, sexual disinhibition, tension relief and hallucinations, creating a potential for abuse. At an international level, recreational propofol use among medical staff is a growing, yet under reported problem. In order to highlight this issue in an Irish context, the case reports described are among the first recorded deaths in Ireland due to unmonitored self-administration of propofol. The difficulties facing forensic pathologists in detecting propofol and its metabolites in these cases are outlined. The potential for propofol abuse should influence healthcare facilities to make their staff aware of the risks associated with it. This in turn would promote vigilance and encourage those affected to seek treatment.

Drug detection in decomposed cadavers confirms testimonial evidence in a case of serial homicides

Toxicology investigation on human's buried dead bodies is a rare and challenging task in the forensic field. As requested by the Judicial Authority, this work aimed to verify testimonial evidence that emerged during a criminal investigation involving multiple murder cases. The statements indicated an improper medical administration of one or more alleged drugs (propofol, morphine, diazepam, and midazolam) which presumably caused the deaths. Since the supposed crimes took place several years before, the task of the present work was to obtain results to support the charges. The analyses involved 18 biological samples taken from four exhumed bodies, three of which were female and one male, each buried in a different date and mode. Each sample was treated with specific purification and extraction techniques (LLE - SPE) after the addition of the deuterated analogs of the searched analytes (propofol-d17, morphine-d3, diazepam-d5, midazolam-d4) as internal standards. Afterwards, the extracts were subjected to qualitative analysis by gas chromatography-mass spectrometry-Electron Impact (GC/MS - EI), both in full scan and SIM mode. Propofol, morphine, and diazepam were identified in the corpses. It supports testimonials that were administered just before the deaths occurred.

Serum and Erythrocyte Antioxidant Defense in Colorectal Cancer Patients during Early Postoperative Period: Potential Modifiers and Impact on Clinical Outcomes

A better understanding of antioxidant status, its modifiers, and its effect on clinical outcomes in patients undergoing colorectal cancer surgery is needed for effective antioxidant-based interventions. The objectives of this cohort study were: to determine baseline serum (total antioxidant capacity (TAC) and ferric reducing antioxidant power (FRAP); n = 72) and erythrocyte (superoxide dismutase (SOD) and glutathione peroxidase (GPx); n = 47) antioxidant capacity and time-course during the 72 h postoperative period, to identify potential modifiers, and to establish impact on clinical outcomes. Older patients with comorbidities had lower baseline FRAP. TAC was inversely and SOD directly correlated with inflammatory markers. Cancer pathology affected GPx (lower in advanced and more aggressive cancers) and SOD (higher in advanced cancers). Surgical intervention induced a transient increase in FRAP and TAC with greater FRAP elevation in older, obese patients with several comorbidities. SOD activity significantly increased while GPx non-significantly decreased between 8 and 24 h post-incision. Poorer health status was associated with an increase in SOD and a decrease in GPx at 72 h. Clinical manifestation of postoperative ileus was preceded by decreased TAC at 24 h and an increase in SOD between 8 and 24 h and anastomotic leak was manifested by diminished SOD at 72 h compared to activities at 8 and 24 h. The time-frame between 8 and 24 h post-incision might be the most critical regarding oxidant/antioxidant balance and therefore the best suited for antioxidant-based intervention.

Baclofen therapeutics, toxicity, and withdrawal: A narrative review

Baclofen is an effective therapeutic for the treatment of spasticity related to multiple sclerosis, spinal cord injuries, and other spinal cord pathologies. It has been increasingly used off-label for the management of several disorders, including musculoskeletal pain, gastroesophageal reflux disease, and alcohol use disorder. Baclofen therapy is associated with potential complications, including life-threatening toxicity and withdrawal syndrome. These disorders require prompt recognition and a high index of suspicion. While these complications can develop following administration of either oral or intrathecal baclofen, the risk is greater with the intrathecal route. The management of baclofen toxicity is largely supportive while baclofen withdrawal syndrome is most effectively treated with re-initiation or supplementation of baclofen dosing. Administration of other pharmacologic adjuncts may be required to effectively treat associated withdrawal symptoms. This narrative review provides an overview of the historical and emerging uses of baclofen, offers practical dosing recommendations for both oral and intrathecal routes of administration, and reviews the diagnosis and management of both baclofen toxicity and withdrawal.

Food allergy history and reaction to propofol administration in a large pediatric population

BACKGROUND

Anaphylaxis to propofol is rare; however, providers face a clinical quandary as medication warnings still exist regarding propofol administration to egg-, soy-, and peanut-allergic patients.

AIMS

The primary aim evaluated the rate of allergic reactions during propofol-containing anesthesia in patients listed allergic to egg, soy, or peanut compared with nonallergic patients who received propofol. The secondary aim evaluated the relationship between food allergy history and allergy testing data.

METHODS

A retrospective chart review conducted between May 2012 and October 2018 identified pediatric patients listed allergic to egg, soy, and/or peanut, who received propofol. Allergy testing and results are presented. Evidence of allergic reaction to propofol during anesthesia was evaluated, and compared with a large nonallergic cohort who received propofol.

RESULTS

Of the 232 392 anesthetics administered, 177 360 (76%) included propofol and 11308 (6%) involved a patient listed allergic to at least 1 index food. A large number of patients had no food allergy testing (n = 6153) or negative testing (n = 2198). Of the 3435 patients listed egg-allergic, 976 tested positive; 750 tested negative; and 1709 had no testing. Of the 2011 patients listed soy-allergic, 322 tested positive; 585 tested negative; and 1104 had no testing. Additionally, 5862 patients were listed peanut-allergic; 1659 tested positive; 863 tested negative and 3340 had no testing. One record of proven propofol anaphylaxis occurred; it was in a patient without a history of food allergies. There were 6 other cases of suspected allergy to propofol. One had a peanut and tree nut allergy and was lost to follow-up; one had no testing available, while 4 patients had positive propofol allergy testing and positive allergy tests to other medications. The rate of proven propofol anaphylaxis during anesthesia in the nonallergic cohort was 0.06/10 000, and the rate in egg- and soy-allergic patients was 0/5446. One patient with a listed peanut allergy had a possible reaction to propofol.

CONCLUSIONS

In the listed food-allergic cohort, the majority had no allergy testing or negative testing. We found no evidence of a relationship between food allergy history and perioperative propofol reaction. We suggest multiply allergic and atopic patients may have a similar likelihood of propofol reaction as with other medications.

HOTAIR/miR-17-5p Axis is Involved in the Propofol-Mediated Cardioprotection Against Ischemia/Reperfusion Injury

Background

Propofol (PPF) ameliorates ischemia/reperfusion (I/R) injury in multiple organs by reducing apoptosis and release of pro-inflammatory cytokines. This study aims to explore the mechanism of PPF in attenuating myocardial ischemia-reperfusion injury (MIRI).

Materials and Methods

Rat MIRI model was established, and PPF pre-treatment was performed 10 min before I/R. H9c2 cardiomyocytes treated with hypoxia/reoxygenation (H/R) were used to establish an in vitro model. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to evaluate HOTAIR and miR-17-5p expression levels. Flow cytometry was employed to detect the apoptosis of H9c2 cells. The interaction between HOTAIR and miR-17-5p was determined by bioinformatics analysis, luciferase reporter gene analysis, and RNA immunoprecipitation experiments. STAT3 and p-STAT3 expressions were detected by Western blot.

Results

PPF pre-treatment significantly reduced creatine kinase isoenzyme (CK-MB) and serum lactate dehydrogenase (LDH) levels in the serum of the rats with MIRI. PPF pre-treatment remarkably up-regulated HOTAIR expression and down-regulated miR-17-5p expression in both in vivo and in vitro models. HOTAIR adsorbed miR-17-5p to repress the expression of miR-17-5p. PPF pre-treatment markedly inhibited cardiomyocyte apoptosis induced by I/R or H/R. HOTAIR knockdown could partially reverse the protective effects of PPF on MIRI. HOTAIR could activate STAT3 signaling via repressing miR-17-5p expression.

Conclusion

PPF protects the MIRI by modulating the HOTAIR/miR-17-5p/STAT3 axis.

The effect of concentration, reconstitution solution and pH on the stability of a remifentanil hydrochloride and propofol admixture for simultaneous co-infusion

Background

There are scenarios where pre-mixing and infusing analgesic and anaesthetic agents as a single intravenous (IV) solution is highly desirable; however, it is important to ensure the agents are compatible when mixed. As such, the long-term stability of a remifentanil-propofol mixture, and means of improving this, were assessed across a range of remifentanil concentrations, diluents, and time points.

Methods

Remifentanil was reconstituted with ultrapure water, 0.9% saline, 20% saline, or 8.4% sodium bicarbonate solution (the latter two chosen for their pH characteristics, rather than their use in pharmaceutical reconstitution) and then mixed with propofol (1%) or further diluted with water to derive concentrations of 10–50 μg mL^− 1. Remifentanil and propofol concentrations were determined initially and then periodically for up to 24 h using high performance liquid chromatography (HPLC). Mass spectrometry (MS) was used to detect degradation products in solutions containing 30 μg mL^− 1 of remifentanil. Statistical analysis was performed using ANOVA and Student’s t-test, with a significance value of 0.05.

Results

Isolated remifentanil (pH < 4) and propofol (pH 7.35) did not degrade significantly when reconstituted with water or saline solution over 24 h, while remifentanil reconstituted with sodium bicarbonate degraded significantly (P < 0.001, pH 8.65). Mixing with propofol substantially increased the pH of the mixture and resulted in significant remifentanil degradation for all reconstitution solutions used, while propofol remained stable (pH 6.50). The amount of degradation product detected in samples containing isolated remifentanil and a mixture of the drugs was proportional to the remifentanil degradation observed.

Conclusions

Remifentanil stability is affected by both the reconstitution solution used and when mixed with propofol, with pH appearing to be a contributing factor to degradation. If the pH of the solution and concentration of remifentanil are correctly controlled, e.g. through the use of a more acidic diluent, an admixture of remifentanil and propofol may be useful clinically.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12871-020-01194-5.

Novel Approach for Characterizing Propofol Binding Affinities to Serum Albumins from Different Species

The interaction between the main carrier (serum albumin, SA) of endogenous and exogenous compounds in the bloodstream of different species (human, bovine, canine, rat, rabbit, and sheep) and a general anesthetic agent (propofol, PR) was investigated using an experimental technique (high-performance liquid chromatography) and computational methods (molecular docking, molecular dynamics, sequence, and phylogenetic analyses). The obtained results revealed the differences in the PR binding affinity to various homologous forms of this protein with reliable statistics (R ² = 0.9 and p-value < 0.005), correlating with the evolutionary relationships among SAs from different species. Additionally, the protein conformational changes (root-mean-square deviation ≈ 1.0 Å) and amino acid conservation of binding sites in protein domains were detected, contributing to the SA-PR binding modes. Overall, the outcomes from this study might provide a novel methodology to assess protein-ligand interactions and to gain some interesting insights into drug pharmacokinetics and pharmacodynamics to explain its variations among different species.

The Effect of Propofol on a Forced Swim Test in Mice at 24 Hours

Background

There are few rapidly acting treatments for acute suicidality or treatment-resistant depression. Propofol (2,6-diisopropylphenol) is an intravenous anesthetic agent used in outpatient settings. It is a gamma-aminobutyric acid type A agonist and has affinity at the N-methyl-D-aspartate receptor. Elevation in mood and sociality in humans has been observed following propofol-induced anesthesia. Other authors reported an open-label study of repeated dosing of propofol in treatment-resistant depression in which several patients experienced sustained improvement. Recently, we reported that in a rodent model of despair, a forced swim test, 45 minutes after administration of 50 mg/kg propofol, immobility time was significantly reduced.

Objective

The objective of the experiment was to determine whether the antidepressant-like effects of a single dose of propofol in mice are sustained for 24 hours.

Methods

The time spent immobile during a forced swim test 24 hours after intraperitoneal administration of a single dose of propofol 50 mg/kg or 0.9% saline was evaluated in 24 adult male mice (C57/BL6). Immobility time was quantified and evaluated with a custom video analysis software program.

Results

Propofol-treated mice were immobile for a mean (SEM) time of 115 (13) seconds, whereas saline-treated mice were immobile for a mean (SEM) time of 94 (14) seconds. A 2-tailed unpaired t test found no significant difference between the treatment groups (t = 1.07, df = 22; P = 0.30).

Conclusions

Twenty-four hours after intraperitoneal administration, the effect of propofol on immobility time was not statistically significantly different from vehicle. However, given our previous report of at least a short-term benefit of propofol on struggling time in the forced swim time and an encouraging pilot study in humans with treatment-resistant depression, further evaluation of propofol's antidepressant potential may be warranted.

Pharmacokinetic and Pharmacodynamic Aspects of Peyote and Mescaline: Clinical and Forensic Repercussions

BACKGROUND

Mescaline (3,4,5-trimethoxyphenethylamine), mainly found in the Peyote cactus (Lophophora williamsii), is one of the oldest known hallucinogenic agents that influence human and animal behavior, but its psychoactive mechanisms remain poorly understood.

OBJECTIVES

This article aims to fully review pharmacokinetics and pharmacodynamics of mescaline, focusing on the in vivo and in vitro metabolic profile of the drug and its implications for the variability of response.

METHODS

Mescaline pharmacokinetic and pharmacodynamic aspects were searched in books and in PubMed (U.S. National Library of Medicine) without a limiting period. Biological effects of other compounds found in peyote were also reviewed.

RESULTS

Although its illicit administration is less common, in comparison with cocaine and Cannabis, it has been extensively described in adolescents and young adults, and licit consumption often occurs in religious and therapeutic rituals practiced by the Native American Church. Its pharmacodynamic mechanisms of action are primarily attributed to the interaction with the serotonergic 5-HT2A-C receptors, and therefore clinical effects are similar to those elicited by other psychoactive substances, such as lysergic acid diethylamide (LSD) and psilocybin, which include euphoria, hallucinations, depersonalization and psychoses. Moreover, as a phenethylamine derivative, signs and symptoms are consistent with a sympathomimetic effect. Mescaline is mainly metabolized into trimethoxyphenylacetic acid by oxidative deamination but several minor metabolites with possible clinical and forensic repercussions have also been reported.

CONCLUSION

Most reports concerning mescaline were presented in a complete absence of exposure confirmation, since toxicological analysis is not widely available. Addiction and dependence are practically absent and it is clear that most intoxications appear to be mild and are unlikely to produce lifethreatening symptoms, which favors the contemporary interest in the therapeutic potential of the drugs of the class.

The effects of gasotransmitters inhibition on biochemical and haematological parameters and oxidative stress in propofol-anaesthetized Wistar male rats

This study aimed to investigate the effects of propofol through evaluating its interaction with nitric oxide (NO), hydrogen sulfide (H2S), and carbon monoxide (CO). Wistar male rats were divided in 4 groups: (1) bolus injection of propofol (1% 10 mg/mL, 100 mg/kg bw, i.p.); (2) Nω-nitro-l-arginine methyl ester (L-NAME; NO synthase inhibitor, 60 mg/kg bw, i.p.) + bolus injection of propofol (1% 10 mg/mL, 100 mg/kg bw, i.p.); (3) DL-propargylglycine (DL-PAG; H2S synthase inhibitor, 50 mg/kg bw, i.p.) + bolus injection of propofol (1% 10 mg/mL, 100 mg/kg bw, i.p.); (4) zinc protoporphyrin IX (ZnPPIX; CO synthase inhibitor, 50 μmol/kg bw, i.p.) + bolus injection of propofol (1% 10 mg/mL, 100 mg/kg bw, i.p.). Increased levels of albumins, low-density lipoproteins, alkaline phosphatase, amylase, high-sensitivity Troponin T, and fibrinogen were found in L-NAME + propofol group. Platelet crit, platelet count, total cholesterol, and high-density lipoproteins were elevated in ZnPPIX + propofol group. Hydrogen peroxide was increased in all groups treated with gasotransmitters inhibitors. Reduced glutathione was reduced in all groups, superoxide dismutase activity only in L-NAME + propofol. The effect of propofol on various biochemical, haematological, and oxidative stress markers may be at least in part mediated through interaction with 3 estimated gasotransmitters.