Manifestaciones clínicas post supresión de sedoanalgesia en pacientes adultos de una terapia intensiva / Clinical manifestations after suppression of sedoanalgesia in adult patients in intensive care

Introducción: en la unidad de cuidados intensivos (UCI), las personas asistidas con patologías relevantes se encuentran bajo sedación, una vez que estas se encuentran bajo los principios de supresión de la sedación, es importante identificar cuáles son las manifestaciones que presentan, propias de las sedaciones. Objetivo: describir las manifestaciones clínicas del síndrome de supresión de la sedoanalgesia presentes en pacientes asistidos en un Hospital Público de la Ciudad de Corrientes de enero a diciembre del 2022. Metodología: estudio cuantitativo, descriptivo, transversal y observacional. La muestra incluyó pacientes adultos de UCI. El cálculo del tamaño muestral se realizó a través del método probabilístico aleatorio simple resultando de éste una muestra de 100 historias clínicas. Para la recolección de datos se utilizó la observación y como instrumento un formulario semiestructurado, de carácter anónimo. Cada formulario contenía datos específicos donde se categorizan las variables en estudio como ser edad, sexo, comorbilidades, tiempo de sedoanalgesia, tipo de sedación, sedoanalgesia utilizada, agitación, confusión, alucinación, diaforesis, taquicardia. Resultados: en cuanto a la edad se obtuvo un promedio de 49 años, el sexo predominante fue el masculino con 52%, en cuanto a las comorbilidades más frecuentes, el 20% presentó Insuficiencia Respiratoria Aguda y el 16% Insuficiencia renal. El motivo de ingreso a UCI en mayor medida con el 33% fue por dificultad respiratoria y Post Quirúrgicos complicados 32%. Los fármacos de mayor elección fueron midazolam 94%, seguido del fentanilo 80%. En cuanto al tiempo de sedación de los pacientes, se encontró una media de 1265 horas. Las manifestaciones clínicas que se observaron en la muestra en mayor medida corresponden a taquicardia 70%, agitación 52%, un 37% confusión e hipertensión y un 24% alucinación. Conclusión: las manifestaciones que se presentaron con mayor frecuencia fueron taquicardia, agitación, confusión, hipertensión y con menor frecuencia alucinación[AU]

Introduction: in the intensive care unit (ICU), people treated with relevant pathologies are under sedation. Once they are under the principles of sedation suppression, it is important to identify the manifestations they present, typical of sedations. Objective: To describe the clinical manifestations of sedation suppression syndrome present in patients treated at a Public Hospital in the City of Corrientes from January to December 2022. Methodology: quantitative, descriptive, cross-sectional and observational study. The sample included adult ICU patients. The calculation of the sample size was carried out through the simple random probabilistic method, resulting in a sample of 100 medical records. Manifestaciones clínicas post supresión de sedoanalgesia en pacientes adultos de una terapia intensiva. Observation was used to collect data and a semi-structured, anonymous form was used as an instrument. Each form contained specific data where the variables under study were categorized, such as age, sex, comorbidities, sedation time, type of sedation, sedation used, agitation, confusion, hallucination, diaphoresis, tachycardia. Results: regarding age, an average of 49 years was obtained, the predominant sex was male with 52%, regarding the most frequent comorbidities, 20% presented Acute Respiratory Failure and 16% Renal failure. The reason for admission to the ICU to a greater extent with 33% was due to respiratory difficulty and complicated Post-Surgeries 32%. The drugs of greatest choice were midazolam 94%, followed by fentanyl 80%. Regarding the sedation time of the patients, an average of 1265 hours was found. The clinical manifestations that were observed in the sample to a greater extent correspond to tachycardia 70%, agitation 52%, confusion and hypertension 37% and hallucination 24%. Conclusion: the manifestations that occurred most frequently were tachycardia, agitation, confusion, hypertension and, less frequently, hallucination[AU]

Introdução: na unidade de terapia intensiva (UTI), as pessoas tratadas com patologias relevantes estão sob sedação. Uma vez sob os princípios da supressão da sedação, é importante identificar as manifestações que apresentam, típicas das sedações. Objetivo: Descrever as manifestações clínicas da síndrome de supressão da sedação presentes em pacientes atendidos em um Hospital Público da Cidade de Corrientes no período de janeiro a dezembro de 2022. Metodologia: estudo quantitativo, descritivo, transversal e observacional. A amostra incluiu pacientes adultos internados em UTI. O cálculo do tamanho amostral foi realizado pelo método probabilístico aleatório simples, resultando em uma amostra de 100 prontuários. A observação foi utilizada para a coleta de dados e um formulário semiestruturado e anônimo foi utilizado como instrumento. Cada formulário continha dados específicos onde foram categorizadas as variáveis em estudo, como idade, sexo, comorbidades, tempo de sedação, tipo de sedação, sedação utilizada, agitação, confusão, alucinação, sudorese, taquicardia. Resultados: em relação à idade obteve-se uma média de 49 anos, o sexo predominante foi o masculino com 52%, quanto às comorbidades mais frequentes, 20% apresentavam Insuficiência Respiratória Aguda e 16% Insuficiência Renal. O motivo de internação na UTI em maior proporção com 33% foi por dificuldade respiratória e pós-cirúrgicos complicados 32%. Os medicamentos de maior escolha foram midazolam 94%, seguido de fentanil 80%. Quanto ao tempo de sedação dos pacientes, foi encontrada uma média de 1265 horas. As manifestações clínicas mais observadas na amostra correspondem a taquicardia 70%, agitação 52%, confusão e hipertensão 37% e alucinação 24%. Conclusão: as manifestações que ocorreram com maior frequência foram taquicardia, agitação, confusão, hipertensão e, menos frequentemente, alucinação[AU]

Effects of dexmedetomidine, fentanyl and magnesium sulfate added to ropivacaine on sensory and motor blocks in lower abdominal surgery: a randomized clinical trial.

This study aimed to compare the effects of intrathecal dexmedetomidine, fentanyl and magnesium sulfate added to ropivacaine on the onset and duration of sensory and motor blocks in lower abdominal surgery. This double-blind randomized clinical trial included 90 patients scheduled for lower abdominal surgery at Vali-Asr Hospital in Arak, Iran. The enrolled patients were randomly divided into three equal groups and then underwent spinal anesthesia. The first group received 10 µg of dexmedetomidine, the second group received 50 µg of fentanyl, and the third group received 200 mg of 20% magnesium sulfate intrathecally in addition to 15 mg of 0.5% ropivacaine. In the dexmedetomidine group, the mean arterial blood pressure was lower than the other two groups (P = 0.001). Moreover, the time to onset of sensory block (P = 0.001) and the mean duration of sensory block (P = 0.001) were shorter and longer, respectively, in the dexmedetomidine group than in the other two groups. In the dexmedetomidine group, the mean time to onset of motor block (P = 0.001) and the mean duration of motor block (P = 0.001) were lower and higher than in the other two groups, respectively. There was no significant difference in visual analog scale score, heart rate, administered opioid, and drug side effects among the three groups. Dexmedetomidine caused early sensory and motor blocks while prolonging the duration of sensory and motor blocks compared with the other two groups. In addition, dexmedetomidine reduced mean arterial blood pressure in patients. Based on the findings of this study, it is recommended that dexmedetomidine can be used in order to enhance the quality of sensory and motor block in patients.

Opioid-sparing effect of erector spinae plane block and intravenous dexmedetomidine for obese patients with obstructive sleep apnea: A randomized controlled trial.

OBJECTIVE: This study assessed the impact of erector spinae plane block (ESPB) and intravenous (IV) dexmedetomidine in reduction of perioperative opioid consumption following bariatric surgery and their impact on post-operative recovery, analgesia, and pulmonary functions. DESIGN: A randomized controlled trial. SETTING: Tanta University Hospitals, Tanta, Gharboa, Egypt. PATIENTS: Forty obese patients with obstructive sleep apnea syndrome (OSAS), aged 20-55 years, and eligible for bariatric surgery were included. INTERVENTIONS: Patients randomized into group I (received general anesthesia [GA] with opioid, sham ESPB, and IV normal saline) or group II (received GA [without opioid], ESPB [at T7 level] using 20 mL bupivacaine 0.25 percent and bolus IV dexmedetomidine 1 µg/kg and then 0.25 µg/kg/h). MAIN OUTCOME MEASURES: Fentanyl consumption (primary outcome), sevoflurane consumption, recovery time, Visual Analog Scale (VAS), and pulmonary functions (secondary outcomes) were recorded. RESULTS: Perioperative fentanyl (intraoperative, post-operative, and total) consumption and sevoflurane consumption were substantially lower in group II compared to group I (p = 0.010, <0.001, <0.001, and <0.001, respectively). Moreover, recovery time was shorter in group II (p < 0.001). At 2, 4, 8, and 24 hours after surgery, group I patients had VAS values considerably higher. Relative to preoperative values, pulmonary function did not significantly alter after surgery. Oxygen desaturation was significantly lower in group II (p = 0.001). CONCLUSIONS: The ESPB with IV dexmedetomidine is advantageous for OSAS patients having bariatric surgery as it provides anesthesia and opioid-sparing effect with short recovery, adequate analgesia, and nonsignificant complications. Yet, it had no effect on post-operative pulmonary function.

Direct rotation from a fentanyl patch to a buprenorphine patch in a patient with chronic pain.

Transitioning a patient with chronic pain from a fentanyl patch to a buprenorphine patch has not been well described in the literature. Even after a patient removes their fentanyl patch, the residual fentanyl in the skin continues to be absorbed for hours. Due to the risk of precipitated withdrawal when initiating buprenorphine, this transition is a more challenging opioid rotation to plan safely. We report a case of a patient who had been using a fentanyl patch for over 10 years and was successfully rotated directly to a buprenorphine patch.

When Are "Paraphernalia" Critical Medical Supplies?

Evidence of harm reduction interventions' morbidity and mortality benefits is abundant and of high quality, so there are good reasons for regional and national groups to advocate for more widespread distribution of legally regulated "drug paraphernalia," including needles, syringes, and fentanyl test strips. But lack of consistency among states' laws means that patients' interstate travel can subject them to being charged with possession of illegal items. This commentary on a case offers guidance to clinicians looking to help patients understand legal risks of interstate travel with supplies that are prescribed or recommended to reduce harms of their drug use and explores the ethical responsibilities of physicians in jurisdictions that legally prohibit these harm reduction interventions.

Investigation of [11C]carfentanil for mu opioid receptor quantification in the rat brain.

[11C]Carfentanil ([11C]CFN) is the only selective carbon-11 labeled radiotracer currently available for positron emission tomography (PET) imaging of mu opioid receptors (MORs). Though used extensively in clinical research, [11C]CFN has not been thoroughly characterized as a tool for preclinical PET imaging. As we were occasionally observing severe vital sign instability in rat [11C]CFN studies, we set out to investigate physiological effects of CFN mass and to explore its influence on MOR quantification. In anesthetized rats (n = 15), significant dose-dependent PCO2 increases and heart rate decreases were observed at a conventional tracer dose range (IV, > 100 ng/kg). Next, we conducted baseline and retest [11C]CFN PET scans over a wide range of molar activities. Baseline [11C]CFN PET studies (n = 27) found that nondisplaceable binding potential (BPND) in the thalamus was positively correlated to CFN injected mass, demonstrating increase of MOR availability at higher injected CFN mass. Consistently, when CFN injected mass was constrained < 40 ng/kg (~ 10% MOR occupancy in rats), baseline MOR availability was significantly decreased. For test-retest variability (TRTV), better reproducibility was achieved by controlling CFN injected mass to limit the difference between scans. Taken together, we report significant cardiorespiratory depression and a paradoxical influence on baseline MOR availability at conventional tracer doses in rats. Our findings might reflect changes in cerebral blood flow, changes in receptor affinity, or receptor internalization, and merits further mechanistic investigation. In conclusion, rat [11C]CFN PET requires stringent quality assurance of radiotracer synthesis and mass injected to avoid pharmacological effects and limit potential influences on MOR quantification and reproducibility.

Opioid Administration Practice Patterns in Patients With Acute Respiratory Failure Who Undergo Invasive Mechanical Ventilation.

IMPORTANCE: The opioid crisis is impacting people across the country and deserves attention to be able to curb the rise in opioid-related deaths. OBJECTIVES: To evaluate practice patterns in opioid infusion administration and dosing for patients with acute respiratory failure receiving invasive mechanical ventilation. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: Patients from 21 hospitals in Kaiser Permanente Northern California and 96 hospitals in Philips electronic ICU Research Institute. MAIN OUTCOMES AND MEASURES: We assessed whether patients received opioid infusion and the dose of said opioid infusion. RESULTS: We identified patients with a diagnosis of acute respiratory failure who were initiated on invasive mechanical ventilation. From each patient, we determined if opioid infusions were administered and, among those who received an opioid infusion, the median daily dose of fentanyl infusion. We used hierarchical regression models to quantify variation in opioid infusion use and the median daily dose of fentanyl equivalents across hospitals. We included 13,140 patients in the KPNC cohort and 52,033 patients in the eRI cohort. A total of 7,023 (53.4%) and 16,311 (31.1%) patients received an opioid infusion in the first 21 days of mechanical ventilation in the KPNC and eRI cohorts, respectively. After accounting for patient- and hospital-level fixed effects, the hospital that a patient was admitted to explained 7% (95% CI, 3-11%) and 39% (95% CI, 28-49%) of the variation in opioid infusion use in the KPNC and eRI cohorts, respectively. Among patients who received an opioid infusion, the median daily fentanyl equivalent dose was 692 µg (interquartile range [IQR], 129-1341 µg) in the KPNC cohort and 200 µg (IQR, 0-1050 µg) in the eRI cohort. Hospital explained 4% (95% CI, 1-7%) and 20% (95% CI, 15-26%) of the variation in median daily fentanyl equivalent dose in the KPNC and eRI cohorts, respectively. CONCLUSIONS AND RELEVANCE: In the context of efforts to limit healthcare-associated opioid exposure, our findings highlight the considerable opioid exposure that accompanies mechanical ventilation and suggest potential under and over-treatment with analgesia. Our results facilitate benchmarking of hospitals' analgesia practices against risk-adjusted averages and can be used to inform usual care control arms of analgesia and sedation clinical trials.

A µ-opioid receptor modulator that works cooperatively with naloxone.

The µ-opioid receptor (µOR) is a well-established target for analgesia1, yet conventional opioid receptor agonists cause serious adverse effects, notably addiction and respiratory depression. These factors have contributed to the current opioid overdose epidemic driven by fentanyl2, a highly potent synthetic opioid. µOR negative allosteric modulators (NAMs) may serve as useful tools in preventing opioid overdose deaths, but promising chemical scaffolds remain elusive. Here we screened a large DNA-encoded chemical library against inactive µOR, counter-screening with active, G-protein and agonist-bound receptor to 'steer' hits towards conformationally selective modulators. We discovered a NAM compound with high and selective enrichment to inactive µOR that enhances the affinity of the key opioid overdose reversal molecule, naloxone. The NAM works cooperatively with naloxone to potently block opioid agonist signalling. Using cryogenic electron microscopy, we demonstrate that the NAM accomplishes this effect by binding a site on the extracellular vestibule in direct contact with naloxone while stabilizing a distinct inactive conformation of the extracellular portions of the second and seventh transmembrane helices. The NAM alters orthosteric ligand kinetics in therapeutically desirable ways and works cooperatively with low doses of naloxone to effectively inhibit various morphine-induced and fentanyl-induced behavioural effects in vivo while minimizing withdrawal behaviours. Our results provide detailed structural insights into the mechanism of negative allosteric modulation of the µOR and demonstrate how this can be exploited in vivo.

A case of severe opioid and methamphetamine use disorder in a 14 year old.

We present the case of a 14-year-old who established care at our primary care clinic after hospitalization for unintentional fentanyl overdose. They were diagnosed with severe opioid use disorder (OUD) and stimulant use disorder (StUD) and initiated buprenorphine while inpatient. They were then transitioned to the only known outpatient primary care clinic in her county who was actively providing medications for opioid use disorder (MOUD) in adolescents.At the first visit, they reported a history of 20 overdoses, struggling with adherence to buprenorphine and continued opioid cravings. An overdose safety plan was reviewed with them and their parent including providing them naloxone kits, fentanyl test strips, and education handout sheets. Due to their significant overdose history and adherence challenges with sublingual buprenorphine, they were started on long-acting injectable buprenorphine (LAIB) with weekly provider visits and urine toxicology screening. In collaboration with the treatment team, they initiated behavioral treatment with contingency management (CM), with incentives for appointment completion, expected urine results, and successful medication administration. Over the next 19 months, and to date, they have increasingly engaged with care and have remained abstinent. LAIB may be an appealing alternative for adolescents with OUD to improve adherence and reduce risk of recurrent use and overdose. Adjunctive treatment with CM may improve retention in MOUD and have the benefit of treating StUD. There is a need for further research to explore innovative, community-based treatment for youth with OUD.

Reported Xylazine Use Among Adults Aged ≥18 Years Evaluated for Substance Use Treatment - United States, July 2022-September 2023.

Xylazine has been increasingly detected in illegally manufactured fentanyl (IMF) products and overdose deaths in the United States; most xylazine-involved overdose deaths involve IMF. A convenience sample of U.S. adults aged ≥18 years was identified from those evaluated for substance use treatment during July 2022-September 2023. Data were collected using the Addiction Severity Index-Multimedia Version clinical assessment tool. Among 43,947 adults, 6,415 (14.6%) reported IMF or heroin as their primary lifetime substance-use problem; 5,344 (12.2%) reported recent (i.e., past-30-day) IMF or heroin use. Among adults reporting IMF or heroin as their primary lifetime substance-use problem, 817 (12.7%) reported ever using xylazine. Among adults reporting recent IMF or heroin use, 443 (8.3%) reported recent xylazine use. Among adults reporting IMF or heroin use recently or as their primary lifetime substance-use problem, those reporting xylazine use reported a median of two past nonfatal overdoses from any drug compared with a median of one overdose among those who did not report xylazine use; as well, higher percentages of persons who reported xylazine use reported other recent substance use and polysubstance use. Provision of nonjudgmental care and services, including naloxone, wound care, and linkage to and retention of persons in effective substance use treatment, might reduce harms including overdose among persons reporting xylazine use.

Evolution of an epidemic: Understanding the opioid epidemic in the United States and the impact of the COVID-19 pandemic on opioid-related mortality.

We conduct this research with a two-fold aim: providing a quantitative analysis of the opioid epidemic in the United States (U.S.), and exploring the impact of the COVID-19 pandemic on opioid-related mortality. The duration and persistence of the opioid epidemic lends itself to the need for an overarching analysis with extensive scope. Additionally, studying the ramifications of these concurrent severe public health crises is vital for informing policies to avoid preventable mortality. Using data from CDC WONDER, we consider opioid-related deaths grouped by Census Region spanning January 1999 to October 2022 inclusive, and later add on a demographic component with gender-stratification. Through the lens of key events in the opioid epidemic, we build an interrupted time series model to reveal statistically significant drivers of opioid-related mortality. We then employ a counterfactual to approximate trends in the absence of COVID-19, and estimate excess opioid-related deaths (defined as observed opioid-related deaths minus projected opioid-related deaths) associated with the pandemic. According to our model, the proliferation of fentanyl contributed to sustained increases in opioid-related death rates across three of the four U.S. census regions, corroborating existing knowledge in the field. Critically, each region has an immediate increase to its opioid-related monthly death rate of at least 0.31 deaths per 100,000 persons at the start of the pandemic, highlighting the nationwide knock-on effects of COVID-19. There are consistent positive deviations from the expected monthly opioid-related death rate and a sizable burden from cumulative excess opioid-related deaths, surpassing 60,000 additional deaths nationally from March 2020 to October 2022, ∼70% of which were male. These results suggest that robust, multi-faceted measures are even more important in light of the COVID-19 pandemic to prevent overdoses and educate users on the risks associated with potent synthetic opioids such as fentanyl.

Impact of general anesthesia on postoperative complications in orthognathic surgery: a retrospective comparison of total intravenous anesthesia versus volatile anesthesia.

Orthognathic surgery has a high incidence of postoperative nausea (PON) and vomiting (POV), delaying mobility initiation and postoperative recovery. Bleeding is another risk associated with this surgical procedure. We aimed to compare total intravenous anesthesia (TIVA) and volatile anesthesia in patients undergoing orthognathic surgery in terms of postoperative nausea and vomiting (PONV) incidence and hemodynamic changes. This retrospective study included 82 patients who underwent bilateral sagittal split ramus osteotomies at Saga University Hospital between April 2016 and April 2021. We compared the effects of TIVA and volatile anesthesia on PONV onset after surgery, acute postoperative hemodynamic changes (blood pressure and heart rate), and factors contributing to PONV. PON was significantly lower in the TIVA group than in the volatile anesthesia group. The total dose of fentanyl contributed to the onset of POV, while the onset of PON was associated with low volumes of fluid infusion and urine in the TIVA and volatile anesthesia groups, respectively. Furthermore, post-extubation hemodynamic change was significantly smaller in the TIVA group than in the volatile anesthesia group. Therefore, TIVA could have a reduced risk of PONV and hemodynamic changes in patients undergoing orthognathic surgery. Employing TIVA could mitigate perioperative complications and enhance patient safety.

Comparison of different concentrations of ropivacaine in epidural anesthesia for percutaneous transforaminal endoscopic discectomy: a randomized controlled trial.

BACKGROUND: This study investigated the optimal concentration of ropivacaine epidural anesthesia for clinical use in percutaneous transforaminal endoscopic discectomy (PTED) by comparing the effects of different concentrations. METHODS: Seventy patients scheduled for their first PTED procedure were enrolled in this randomized controlled trial. Patients were randomized to receive ropivacaine at varying concentrations (0.3% or 0.4%). Primary outcome measures included the numeric rating scale (NRS) and hip extension level (HEL). Secondary outcome measures included intraoperative fentanyl dosage and postoperative complications. RESULTS: One patient withdrew due to severe postoperative complications. The remaining 69 patients were allocated to the 0.3% (n = 34) and 0.4% (n = 35) groups, respectively. Baseline characteristics showed no significant differences between the two groups (P > 0.05). The NRS score was significantly lower in the 0.4% group than in the 0.3% group (P < 0.01), whereas the HEL score was significantly higher (P < 0.001). The average fentanyl dose in the 0.4% group was significantly lower than that in the 0.3% group (P < 0.01). Postoperative complications occurred in five and two patients in the 0.3% and 0.4% groups, respectively. CONCLUSION: Although 0.4% ropivacaine (20 mL) impacts muscle strength, it does not impede PTED surgery. Given its effective analgesic properties and few postoperative complications, 0.4% ropivacaine can be considered a preferred dose for PTED. TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trials Registry (Registration number: ChiCTR2200060364; Registration Date: 29/5/2022) and on chictr.org.cn ( https://www.chictr.org.cn/showproj.html?proj=171002 ).

Submersible voltammetric sensing probe for rapid and extended remote monitoring of opioids in community water systems.

The intensifying global opioid crisis, majorly attributed to fentanyl (FT) and its analogs, has necessitated the development of rapid and ultrasensitive remote/on-site FT sensing modalities. However, current approaches for tracking FT exposure through wastewater-based epidemiology (WBE) are unadaptable, time-consuming, and require trained professionals. Toward developing an extended in situ wastewater opioid monitoring system, we have developed a screen-printed electrochemical FT sensor and integrated it with a customized submersible remote sensing probe. The sensor composition and design have been optimized to address the challenges for extended in situ FT monitoring. Specifically, ZIF-8 metal-organic framework (MOF)-derived mesoporous carbon (MPC) nanoparticles (NPs) are incorporated in the screen-printed carbon electrode (SPCE) transducer to improve FT accumulation and its electrocatalytic oxidation. A rapid (10 s) and sensitive square wave voltammetric (SWV) FT detection down to 9.9 µgL-1 is thus achieved in aqueous buffer solution. A protective mixed-matrix membrane (MMM) has been optimized as the anti-fouling sensor coating to mitigate electrode passivation by FT oxidation products and enable long-term, intermittent FT monitoring. The unique MMM, comprising an insulating polyvinyl chloride (PVC) matrix and carboxyl-functionalized multi-walled carbon nanotubes (CNT-COOH) as semiconductive fillers, yielded highly stable FT sensor operation (> 95% normalized response) up to 10 h in domestic wastewater, and up to 4 h in untreated river water. This sensing platform enables wireless data acquisition on a smartphone via Bluetooth. Such effective remote operation of submersible opioid sensing probes could enable stricter surveillance of community water systems toward timely alerts, countermeasures, and legal enforcement.

Dependency of fentanyl analogue protomer ratios on solvent conditions as measured by ion mobility-mass spectrometry.

Recently, our group has shown that fentanyl and many of its analogues form prototropic isomers ("protomers") during electrospray ionization. These different protomers can be resolved using ion mobility spectrometry and annotated using mobility-aligned tandem mass spectrometry fragmentation. However, their formation and the extent to which experimental variables contribute to their relative ratio remain poorly understood. In the present study, we systematically investigated the effects of mixtures of common chromatographic solvents (water, methanol, and acetonitrile) and pH on the ratio of previously observed protomers for 23 fentanyl analogues. Interestingly, these ratios (N-piperidine protonation vs. secondary amine/O = protonation) decreased significantly for many analogues (e.g., despropionyl ortho-, meta-, and para-methyl fentanyl), increased significantly for others (e.g., cis-isofentanyl), and remained relatively constant for the others as solvent conditions changed from 100% organic solvent (methanol or acetonitrile) to 100% water. Interestingly, pH also had significant effects on this ratio, causing the change in ratio to switch in many cases. Lastly, increasing conditions to pH ≥ 4.0 also prompted the appearance of new mobility peaks for ortho- and para-methyl acetyl fentanyl, where all previous studies had only showed one single distribution. Because these ratios have promise to be used qualitatively for identification of these (and emerging) fentanyl analogues, understanding how various conditions (i.e., mobile phase selection and/or chromatographic gradient) affect their ratios is critically important to the development of advanced ion mobility and mass spectrometry methodologies to identify fentanyl analogues.

Exploring the thermally-controlled fentanyl transdermal therapy to provide constant drug delivery by physics-based digital twins.

Transdermal drug delivery is suitable for low-molecular-weight drugs with specific lipophilicity, like fentanyl, which is widely used for cancer-induced pain management. However, fentanyl's transdermal therapy displays high intra-individual variability. Factors like skin characteristics at application sites and ambient temperature contribute to this variation. In this study, we developed a physics-based digital twin of the human body to cope with this variability and propose better adapted setups. This twin includes an in-silico skin model for drug penetration, a pharmacokinetic model, and a pharmacodynamic model. Based on the results of our simulations, applying the patch on the flank (side abdominal area) showed a 15.3 % higher maximum fentanyl concentration in the plasma than on the chest. Additionally, the time to reach this maximum concentration when delivered through the flank was 19.8 h, which was 10.3 h earlier than via the upper arm. Finally, this variation led to an 18 % lower minimum pain intensity for delivery via the flank than the chest. Moreover, the impact of seasonal changes on ambient temperature and skin temperature by considering the activity level was investigated. Based on our result, the fentanyl uptake flux by capillaries increased by up to 11.8 % from an inactive state in winter to an active state in summer. We also evaluated the effect of controlling fentanyl delivery by adjusting the temperature of the patch to alleviate the pain to reach a mild pain intensity (rated three on the VAS scale). By implementing this strategy, the average pain intensity decreased by 1.1 points, and the standard deviation for fentanyl concentration in plasma and average pain intensity reduced by 37.5 % and 33.3 %, respectively. Therefore, our digital twin demonstrated the efficacy of controlled drug release through temperature regulation, ensuring the therapy toward the intended target outcome and reducing therapy outcome variability. This holds promise as a potentially useful tool for physicians.

High-performance fentanyl molecularly imprinted electrochemical sensing platform designed through molecular simulations.

BACKGROUND: Fentanyl and its derivatives are a type of potent opioid analgesics, with the characteristics of diverse structure, high toxicity, extremely low content, and high fatality rate. Currently, they have become one of the most serious problems in international drug abuse control due to their extensive use in drug production and use. Therefore, the development of a rapid, sensitive, and accurate method for detecting trace fentanyl is of great significance. In this study, in view of its complex structure and trace concentration, a new molecular imprinting electrochemical sensor was developed through molecular simulations followed by experimental validation to detect trace fentanyl. RESULTS: The process consisted of first obtaining the optimal functional monomer and its molar ratio through molecular simulations. The recognition sites of fentanyl-imprinted polymers were predicted to guide the synthesis of imprinted membranes with precision approach to ensure an efficient and accurate reaction process. Reduced graphene oxide (ErGO) was then deposited on glassy carbon electrode surface by electrochemical reduction to yield large numbers of active sites suitable for catalyzing reactions of fentanyl piperidine for promoted efficient electron transfer and amplified sensitivity of the sensor. Accordingly, fentanyl molecularly imprinted film was formed through one-step electropolymerization to yield greatly improved sensing selectivity due to the specific recognition of molecularly imprinted polymer. Under optimal experimental conditions, the fentanyl sensor showed an extended detection range of 3.84 × 10-9 mol L-1-1.72 × 10-6 mol L-1 and a detection limit of 1.28 × 10-9 mol L-1. SIGNIFICANCE: A distinctive feature of this sensor is its molecularly imprinted polymerized membrane, which offers excellent specific recognition, thereby boosting the sensor's selectivity. Throughout the sensor's development process, molecular simulations were employed to steer the synthesis of molecularly imprinted polymers and predict the recognition sites of fentanyl-imprinted polymers. The experimental outcomes proved to align with the simulation data. The final sensor exhibited outstanding selectivity, repeatability, stability, and high sensitivity. The sensor was effectively used to reliably track fentanyl in human serum samples, with acceptable analytical reliability, suggesting its potential for practical applications.

Total intravenous anesthesia with Ketofol in rabbits: a comparison of the effects of constant rate infusion of midazolam, fentanyl or dexmedetomidine.

BACKGROUND: When inhalant anesthetic equipment is not available or during upper airway surgery, intravenous infusion of one or more drugs are commonly used to induce and/or maintain general anesthesia. Total intravenous anesthesia (TIVA) does not require endotracheal intubation, which may be more difficult to achieve in rabbits. A range of different injectable drug combinations have been used as continuous infusion rate in animals. Recently, a combination of ketamine and propofol (ketofol) has been used for TIVA in both human patients and animals. The purpose of this prospective, blinded, randomized, crossover study was to evaluate anesthetic and cardiopulmonary effects of ketofol total intravenous anesthesia (TIVA) in combination with constant rate infusion (CRI) of midazolam, fentanyl or dexmedetomidine in eight New Zealand White rabbits. Following IV induction with ketofol and endotracheal intubation, anesthesia was maintained with ketofol infusion in combination with CRIs of midazolam (loading dose [LD]: 0.3 mg/kg; CRI: 0.3 mg/kg/hr; KPM), fentanyl (LD: 6 µg/kg; CRI: 6 µg/kg/hr; KPF) or dexmedetomidine (LD: 3 µg/kg; CRI: 3 µg/kg/hr; KPD). Rabbits in the control treatment (KPS) were administered the same volume of saline for LD and CRI. Ketofol infusion rate (initially 0.6 mg kg- 1 minute- 1 [0.3 mg kg- 1 minute- 1 of each drug]) was adjusted to suppress the pedal withdrawal reflex. Ketofol dose and physiologic variables were recorded every 5 min. RESULTS: Ketofol induction doses were 14.9 ± 1.8 (KPM), 15.0 ± 1.9 (KPF), 15.5 ± 2.4 (KPD) and 14.7 ± 3.4 (KPS) mg kg- 1 and did not differ among treatments (p > 0.05). Ketofol infusion rate decreased significantly in rabbits in treatments KPM and KPD as compared with saline. Ketofol maintenance dose in rabbits in treatments KPM (1.0 ± 0.1 mg/kg/min) and KPD (1.0 ± 0.1 mg/kg/min) was significantly lower as compared to KPS (1.3 ± 0.1 mg/kg/min) treatment (p < 0.05). Ketofol maintenance dose did not differ significantly between treatments KPF (1.1 ± 0.3 mg/kg/min) and KPS (1.3 ± 0.1 mg/kg/min). Cardiovascular variables remained at clinically acceptable values but ketofol infusion in combination with fentanyl CRI was associated with severe respiratory depression. CONCLUSIONS: At the studied doses, CRIs of midazolam and dexmedetomidine, but not fentanyl, produced ketofol-sparing effect in rabbits. Mechanical ventilation should be considered during ketofol anesthesia, particularly when fentanyl CRI is used.

"If it wasn't for them, I don't think I would be here": experiences of the first year of a safer supply program during the dual public health emergencies of COVID-19 and the drug toxicity crisis.

BACKGROUND: In response to the devastating drug toxicity crisis in Canada driven by an unregulated opioid supply predominantly composed of fentanyl and analogues, safer supply programs have been introduced. These programs provide people using street-acquired opioids with prescribed, pharmaceutical opioids. We use six core components of safer supply programs identified by people who use drugs to explore participant perspectives on the first year of operations of a safer supply program in Victoria, BC, during the dual public health emergencies of COVID-19 and the drug toxicity crisis to examine whether the program met drug-user defined elements of an effective safer supply model. METHODS: This study used a community-based participatory research approach to ensure that the research was reflective of community concerns and priorities, rather than being extractive. We interviewed 16 safer supply program participants between December 2020 and June 2021. Analysis was structured using the six core components of effective safer supply from the perspective of people who use drugs, generated through a prior study. RESULTS: Ensuring access to the 'right dose and right drugs' of medications was crucial, with many participants reporting success with the available pharmaceutical options. However, others highlighted issues with the strength of the available medications and the lack of options for smokeable medications. Accessing the safer supply program allowed participants to reduce their use of drugs from unregulated markets and manage withdrawal, pain and cravings. On components related to program operations, participants reported receiving compassionate care, and that accessing the safer supply program was a non-stigmatizing experience. They also reported receiving support to find housing, access food, obtain ID, and other needs. However, participants worried about long term program sustainability. CONCLUSIONS: Participants in the safer supply program overwhelmingly appreciated it and felt it was lifesaving, and unlike other healthcare or treatment services they had previously accessed. Participants raised concerns that unless a wider variety of medications and ability to consume them by multiple routes of administration became available, safer supply programs would remain unable to completely replace substances from unregulated markets.

A new pharmacological approach for tracheal intubation?

Anaesthesia induced with remimazolam and a fentanyl-series opioid can be reversed with flumazenil and naloxone. Concomitant paralysis with rocuronium can facilitate tracheal intubation whilst being reversible with sugammadex. Together, this combination might offer full reversibility of a 'routine' or a 'rapid-sequence' induction anaesthesia. Whether this is useful, or even safe, requires careful evaluation.