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Massive drug overdoses provide a unique opportunity to observe human pharmacokinetic data not otherwise ethically available. They can also provide practical examples for teaching thoughtful application of the principles of clinical pharmacology. Following a case of clozapine overdose in which onset of toxicity was delayed by 72 hours, a probable explanation was found in an exploration of three cases with unusual concentration-time profiles and revealed unexpected implications for the management of clozapine overdoses. The authors systematically addressed the possible mechanisms proposed in the literature for an unusual plateau in concentrations observed in three clozapine overdoses. The effects that the most commonly suggested explanations (i.e., delayed absorption and saturated or impaired metabolism) would have on both clozapine and norclozapine concentrations were then modeled using the data available from those three cases to provide an objective illustration for comparison. This exercise was then used as a teaching seminar, leading students through the steps required to reach a logical explanation for the observed delayed toxicity and to consider the implications for therapy. Delayed absorption best predicted the sustained serum clozapine and norclozapine concentrations observed in three cases, and modeling suggests that much of the drug remains in the gut, available for absorption for days following an overdose. As a seminar, the exercise provides students with a practical example of the value of systematically ruling out possible explanations by considering what effects various pharmacokinetic alterations would have on observed data. Absorption following massive clozapine overdose appears fundamentally different from that with conventional dosing. This suggests a potential for delayed or prolonged toxicity, extending well beyond the time frame predicted by its half-life, unless aggressive and sustained efforts are applied to remove clozapine from the gut. Data from drug overdoses provide opportunities to explore unusual aspects of pharmacokinetics, better understand future overdoses of the same agent, and present excellent material for teaching. A seminar illustrating the role that thoughtful application of pharmacologic principles had in addressing this case is now used to introduce the clinical aspects of pharmacology to students at our institutions. [ABSTRACT FROM AUTHOR]

Background: Few studies have assessed the dose ratio of calcium gluconate to calcium chloride or defined the time course of change in serum ionized calcium concentration after intravenous injection., Methods: In a bioequivalence (dose ratio) trial, parturients undergoing cesarean delivery were randomly assigned to receive calcium chloride (0.5 g) or calcium gluconate (1.5 or 2 g) by 10-min intravenous infusion. Venous serum ionized calcium concentration was measured before calcium infusion and approximately 5, 10, 15, 30, and 60 min after infusion start. These data were combined with serum ionized calcium concentration measurements in parturients who received 1 g calcium chloride or saline placebo in two recent clinical trials to define the pharmacokinetics of intravenous calcium over the first hour during and after drug administration., Results: The bioequivalence study enrolled 34 participants, from whom were collected 181 serum ionized calcium concentration measurements. The dose ratio of calcium gluconate to calcium chloride was 3.11 (95% CI, 2.77 to 3.48). Population pharmacokinetics of calcium were determined using 311 serum ionized calcium concentration measurements from 70 parturients. The pharmacokinetics of intravenous calcium were described by a two-compartment model with systemic clearance of 0.18 (95% CI, 0.07 to 0.27) l/min, distributional clearance of 1.25 (95% CI, 1.03 to 1.56) l/min, central volume of 10.9 (95% CI, 9.3 to 12.6) l, and peripheral volume of 16.5 (95% CI, 12.5 to 24.7) l. After adjusting for the dose ratio, calcium gluconate and calcium chloride had identical time courses. A 1-g infusion of calcium chloride resulted in a peak increase in serum ionized calcium concentration of 0.39 (0.38 to 0.42 mM), which decreased by half (29 [23 to 40] min) after initiation of the 10-min infusion., Conclusions: This study confirmed a 3:1 dose ratio of calcium gluconate to calcium chloride and estimated the pharmacokinetics over the first hour after intravenous delivery. These data inform clinical care and may guide future trials assessing calcium efficacy to reduce bleeding in obstetric patients., (Copyright © 2024 American Society of Anesthesiologists. All Rights Reserved.)

Background: Nonopioid management of postsurgical pain remains a major unmet need. Few studies have evaluated transient receptor potential vanilloid subfamily member 1 agonists for analgesia after surgery. This study examines intraoperative vocacapsaicin, a novel prodrug of the transient receptor potential vanilloid subfamily member 1 agonist capsaicin, in a validated model of postsurgical pain., Methods: This was a triple-blinded, randomized, placebo-controlled, dose-ranging trial in patients undergoing bunionectomy. Patients were randomized 1:1:1:1 to surgical site administration of 14 ml of placebo or one of three vocacapsaicin concentrations: 0.30, 0.15, or 0.05 mg/ml. The prespecified primary endpoint was the area-under-the-curve of the numerical rating scale pain score at rest through 96 h for the 0.30 mg/ml group. Prespecified ordered, secondary endpoints for the 0.30 mg/ml group included the percentage of patients who did not require opioids from 0 to 96 h, total opioid consumption through 96 h, and the area-under-the-curve of the numerical rating scale pain score for the first week., Results: The 147 patients were randomized. During the first 96 h, vocacapsaicin (0.30 mg/ml) reduced pain at rest by 33% versus placebo (primary endpoint, 95% CI [10%, 52%], effect size [Cohen's d] = 0.61, P = 0.005). Of patients receiving vocacapsaicin (0.30 mg/ml), 26% did not require postoperative opioids for analgesia (P = 0.025) versus 5% of patients receiving placebo. Vocacapsaicin (0.30 mg/ml) reduced opioid consumption over the first 96 h by 50% versus placebo (95% CI [26%, 67%], effect size = 0.76, P = 0.002). Vocacapsaicin (0.30 mg/ml) reduced pain over the first week by 37% versus placebo (95% CI [12%, 57%], effect size = 0.62, P = 0.004). The treatment effect persisted for at least 2 weeks. All study endpoints showed an administered concentration-versus-response relationship. Vocacapsaicin was well tolerated with no differences between groups in any safety parameter., Conclusions: A single, local administration of vocacapsaicin during surgery reduced pain and opioid consumption for at least 96 h after surgery compared to control., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc., on behalf of the American Society of Anesthesiologists.)

Plant macrofossils from packrat (Neotoma spp.) middens provide direct evidence of past vegetation changes in arid regions of North America. Here we describe the newest version (version 5.0) of the U.S. Geological Survey (USGS) North American Packrat Midden Database. The database contains published and contributed data from 3,331 midden samples collected in southwest Canada, the western United States, and northern Mexico, with samples ranging in age from 48 ka to the present. The database includes original midden-sample macrofossil counts and relative-abundance data along with a standardized relative-abundance scheme that makes it easier to compare macrofossil data across midden-sample sites. In addition to the midden-sample data, this version of the midden database includes calibrated radiocarbon ( 14 C) ages for the midden samples and plant functional type (PFT) assignments for the midden taxa. We also provide World Wildlife Fund ecoregion assignments and climate and bioclimate data for each midden-sample site location. The data are provided in tabular (.xlsx), comma-separated values (.csv), and relational database (.mdb) files., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Background: Most of the 1.1 million women who deliver by cesarean in the United States each year have an uncomplicated recovery. However, severe pain resistant to standard multimodal therapy within the first days after surgery is associated with an increased risk for prolonged pain and opioid use. The best outpatient management for parturients with severe resistant early onset pain is not known., Methods: We performed a prospective, double-blind, placebo-controlled, randomized trial of up to 12 weeks of outpatient treatment with gabapentin to evaluate its effectiveness to facilitate opioid cessation in women with at least 2 reports of severe pain during the immediate postpartum period resistant to standard multimodal pain management. Time to opioid cessation was the primary outcome. Time to pain resolution; time to discontinuation of gabapentin, acetaminophen, and ibuprofen; time to self-reported recovery; and National Institute of Health Patient-Reported Outcomes System (PROMIS) surveys for anxiety, depression, fatigue, and physical function were assessed as secondary outcomes., Results: There was no difference in time to opioid cessation between patients who were randomly assigned to be treated with gabapentin (Kaplan-Meier estimated median of 2 [25th-75th percentiles of 1-3] weeks, n = 35) versus those who were treated with placebo (2 [1-3] weeks, n = 35). The hazard ratio was 1.1 (95% confidence interval [CI], 0.67-1.8), P = .65. There were no differences in any secondary end points between the study groups., Conclusions: Outpatient supplementation with gabapentin did not reduce time to opioid cessation, pain, anxiety, depression, fatigue, or improve physical function in women with severe pain after cesarean delivery. Gabapentin should not be routinely added to the standard outpatient multimodal regimen of ibuprofen, acetaminophen, and opioids., (Copyright © 2023 International Anesthesia Research Society.)

Background: Night float call systems are becoming increasingly common at training programs with the goal of reducing fatigue related to sleep deprivation and sleep disturbance. Previous studies have shown that trainees obtain less sleep during the night float rotation and have decreased sleep efficiency for several days after the rotation. The impact on physical and emotional well-being has not been documented., Methods: Twenty-seven anesthesia residents were enrolled in a study using wearable sleep and activity trackers and National Institutes of Health Patient-Reported Outcome Measurement Information System (NIH PROMIS) surveys for sleep disturbance, fatigue, and positive affect to record data the week before ("baseline"), during ("night float"), and 1 week after ("recovery") their night float rotation. Each subject's data during the night float week and recovery week were compared to his or her own baseline week data using a paired, nonparametric analysis. The primary outcome variable was the change in average daily sleep hours during the night float week compared to the baseline week. Average daily rapid eye movement (REM) sleep, daily steps, and NIH PROMIS scores comparing night float and recovery weeks to baseline week were prespecified secondary outcomes. NIH PROMIS scores range from 0 to 100 with 50 as the national mean and more of the construct having a higher score., Results: There was no difference in average daily sleep hours between the night float and the baseline weeks (6.7 [5.9-7.8] vs 6.7 [5.5-7.7] hours, median [interquartile range]; P = .20). Residents had less REM sleep during the night float compared to the baseline weeks (1.1 [0.7-1.5] vs 1.4 [1.1-1.9] hours, P = .002). NIH PROMIS fatigue scores were higher during the night float than the baseline week (58.8 [54.6-65.1] vs 48.6 [46.0-55.1], P = .0004) and did not return to baseline during the recovery week (51.0 [48.6-58.8], P = .029 compared to baseline). Sleep disturbance was not different among the weeks. Positive affect was reduced after night float compared to baseline (39.6 [35.0-43.5] vs 44.8 [40.1-49.6], P = .0009), but returned to baseline during the recovery week (43.6 [39.6-48.2], P = .38)., Conclusions: The residents slept the same number of total hours during their night float week but had less REM sleep, were more fatigued, and had less positive affect. All of these resolved to baseline except fatigue, that was still greater than the baseline week. This methodology appears to robustly capture psychophysiological data that might be useful for quality initiatives., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 International Anesthesia Research Society.)

Objectives: Clinical trials evaluating the safety and effectiveness of sedative medication use in critically ill adults undergoing mechanical ventilation differ considerably in their methodological approach. This heterogeneity impedes the ability to compare results across studies. The Sedation Consortium on Endpoints and Procedures for Treatment, Education, and Research Recommendations convened a meeting of multidisciplinary experts to develop recommendations for key methodologic elements of sedation trials in the ICU to help guide academic and industry clinical investigators., Design: A 2-day in-person meeting was held in Washington, DC, on March 28-29, 2019, followed by a three-round, online modified Delphi consensus process., Participants: Thirty-six participants from academia, industry, and the Food and Drug Administration with expertise in relevant content areas, including two former ICU patients attended the in-person meeting, and the majority completed an online follow-up survey and participated in the modified Delphi process., Measurements and Main Results: The final recommendations were iteratively refined based on the survey results, participants' reactions to those results, summaries written by panel moderators, and a review of the meeting transcripts made from audio recordings. Fifteen recommendations were developed for study design and conduct, subject enrollment, outcomes, and measurement instruments. Consensus recommendations included obtaining input from ICU survivors and/or their families, ensuring adequate training for personnel using validated instruments for assessments of sedation, pain, and delirium in the ICU environment, and the need for methodological standardization., Conclusions: These recommendations are intended to assist researchers in the design, conduct, selection of endpoints, and reporting of clinical trials involving sedative medications and/or sedation protocols for adult ICU patients who require mechanical ventilation. These recommendations should be viewed as a starting point to improve clinical trials and help reduce methodological heterogeneity in future clinical trials., Competing Interests: The views expressed in this article are those of the authors, none of whom have financial conflicts of interest specifically related to the issues discussed in this article. At the time of the meeting (March 28–29, 2019) on which this article is based, several participants were employed by a pharmaceutical company or had received consulting fees or honoraria from one or more pharmaceutical or device companies. Meeting participants of this article who were not employed by industry at the time of the meeting received (or their Universities received) travel stipends, hotel accommodations, and meals during the meeting from the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks public-private partnership with the Food and Drug Administration. Drs. Ward, Aitken, Colantuoni, Maze, and Needham received funding from Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, and Networks (ACTTION). Dr. Ward received support for article research from the University of Rochester Maine Medical Center Spectrum Medical Partners. Dr. Absalom’s institution received funding from The Medicines Company, Carefusion (BD), and Rigel; he received support for article research from Philips, Janssen Pharma, Johnson & Johnson, Ever Pharma, Orion, and Paion. Drs. Aitken, Brown, and Coursin received funding from Innovations Consulting Group LLC. Dr. Aitken also received funding from Elsevier Australia. Dr. Balas’ institution received funding from the National Institutes of Health (NIH), the National Heart, Lung, and Blood Institute, AACN research grant; she received funding from H3C and received support for article research from the NIH. Dr. Colantuoni received support for article research from ACTTION. Dr. Dexter received funding from the Division of Management Consulting of the University of Iowa’s Department of Anesthesia. Dr. Dworkin’s institution received funding from the U.S. Food and Drug Administration (FDA); he received funding from Abide, Acadia, Adynxx, Analgesic Solutions, Aptinyx, Aquinox, Asahi Kasei, Astellas, AstraZeneca, Biogen, Biohaven, Boston Scientific, Braeburn, Celgene, Centrexion, Chromocell, Clexio, Collegium, Concert, Coronado, Daiichi Sankyo, Decibel, Dong-A, Editas, Eli Lilly, Eupraxia, Glenmark, Grace, Hope, Hydra, Immune, Johnson & Johnson, Lotus Clinical Research, Mainstay, Medavante, Merck, Neumentum, Neurana, NeuroBo, Novaremed, Novartis, NSGene, Olatec, Periphagen, Pfizer, Phosphagenics, Quark, Reckitt Benckiser, Regenacy, Relmada, Sanifit, Scilex, Semnur, SK Life Sciences, Sollis, Spinifex, Syntrix, Teva, Thar, Theranexus, Trevena, Vertex, and Vizuri. Dr. Girard received funding from Haisco Pharmaceutical. Dr. Hopkins’ institution received funding from Intermountain Medical and Research Foundation. Dr. Maze received funding from the University of California Office of the President and Cambridge University Press; he received support for article research from the NIH. Dr. Needham received funding from the FDA, Haisco-USA Pharmaceuticals, GlaxoSmithKline, and Novartis Pharma; he disclosed he is a principal investigator on a NIH-funded, multicentered randomized trial (R01HL132887) funded by Baxter Healthcare Corporation and Reck Medical Devices. Dr. Pandharipande’s institution received funding from Pfizer. Dr. Shehabi’s institution received funding from Orion Pharma and Pfizer; he received funding from Pfizer, Orion Pharma, Abbott Laboratories, and Ever Pharma. Dr. Sun received funding from UpToDate; she disclosed she is the Editor in Chief for UpToDate/Anesthesiology. Dr. Tung received funding from Anesthesia and Analgesia. Dr. Urman’s institution received funding from Medtronic/Covidien and AcelRx; he received funding from Merck, Sandoz, Heron, Takeda, and Pfizer. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine and Wolters Kluwer Health, Inc.)

Background: Previous studies examining the time to initiate chemoradiation (CRT) after surgical resection of glioblastoma have been conflicting. To better define the effect that the timing of adjuvant treatment may have on outcomes, the authors examined patients within the National Cancer Database (NCDB) stratified by a validated prognostic classification system., Methods: Patients with glioblastoma in the NCDB who underwent surgery and CRT from 2004 through 2013 were analyzed. Radiation Therapy Oncology Group recursive partitioning analysis (RPA) class (III, IV, V) was extrapolated for the cohort. Time intervals were grouped weekly, with weeks 4 to 5 serving as the reference category for analyses. Kaplan-Meier analysis, log-rank testing, and multivariate (MVA) Cox proportional hazards regression were performed., Results: In total, 30,414 patients were included. RPA classes III, IV, and V contained 5250, 20,855, and 4309 patients, respectively. On MVA, no time point after week 5 was associated with a change in overall survival for the entire cohort or for any RPA class subgroup. The periods of weeks 0 to 1 (hazard ratio [HR], 1.18; 95% CI, 1.02-1.36), >1 to 2 (HR, 1.23; 95% CI, 1.16-1.31), and >2 to 3 (HR, 1.11; 95% CI, 1.07-1.15) demonstrated slightly worse overall survival (all P < .03). The detriment to early initiation was consistent across each RPA class subgroup., Conclusions: The current data provide insight into the optimal timing of CRT in patients with glioblastoma and describe RPA class-specific outcomes. In general, short delays beyond 5 weeks did not negatively affect outcomes, whereas early initiation before 3 weeks may be detrimental., (© 2020 American Cancer Society.)

Background: Evidence suggests that obstructive sleep apnea promotes postoperative pulmonary complications by enhancing vulnerability to opioid-induced ventilatory depression. We hypothesized that patients with moderate-to-severe obstructive sleep apnea are more sensitive to remifentanil-induced ventilatory depression than controls., Methods: After institutional approval and written informed consent, patients received a brief remifentanil infusion during continuous monitoring of ventilation. We compared minute ventilation in 30 patients with moderate-to-severe obstructive sleep apnea diagnosed by polysomnography and 20 controls with no to mild obstructive sleep apnea per polysomnography. Effect site concentrations were estimated by a published pharmacologic model. We modeled minute ventilation as a function of effect site concentration and the estimated carbon dioxide. Obstructive sleep apnea status, body mass index, sex, age, use of continuous positive airway pressure, apnea/hypopnea events per hour of sleep, and minimum nocturnal oxygen saturation measured by pulse oximetry in polysomnography were tested as covariates for remifentanil effect site concentration at half-maximal depression of minute ventilation (Ce50) and included in the model if a threshold of 6.63 (P < 0.01) in the reduction of objective function was reached and improved model fit., Results: Our model described the observed minute ventilation with reasonable accuracy (22% median absolute error). We estimated a remifentanil Ce50 of 2.20 ng · ml (95% CI, 2.09 to 2.33). The estimated value for Ce50 was 2.1 ng · ml (95% CI, 1.9 to 2.3) in patients without obstructive sleep apnea and 2.3 ng · ml (95% CI, 2.2 to 2.5) in patients with obstructive sleep apnea, a statistically nonsignificant difference (P = 0.081). None of the tested covariates demonstrated a significant effect on Ce50. Likelihood profiling with the model including obstructive sleep apnea suggested that the effect of obstructive sleep apnea on remifentanil Ce50 was less than 5%., Conclusions: Obstructive sleep apnea status, apnea/hypopnea events per hour of sleep, or minimum nocturnal oxygen saturation measured by pulse oximetry did not influence the sensitivity to remifentanil-induced ventilatory depression in awake patients receiving a remifentanil infusion of 0.2 μg · kg of ideal body weight per minute.

Cooling during most of the past two millennia has been widely recognized and has been inferred to be the dominant global temperature trend of the past 11,700 years (the Holocene epoch). However, long-term cooling has been difficult to reconcile with global forcing, and climate models consistently simulate long-term warming. The divergence between simulations and reconstructions emerges primarily for northern mid-latitudes, for which pronounced cooling has been inferred from marine and coastal records using multiple approaches. Here we show that temperatures reconstructed from sub-fossil pollen from 642 sites across North America and Europe closely match simulations, and that long-term warming, not cooling, defined the Holocene until around 2,000 years ago. The reconstructions indicate that evidence of long-term cooling was limited to North Atlantic records. Early Holocene temperatures on the continents were more than two degrees Celsius below those of the past two millennia, consistent with the simulated effects of remnant ice sheets in the climate model Community Climate System Model 3 (CCSM3). CCSM3 simulates increases in 'growing degree days'-a measure of the accumulated warmth above five degrees Celsius per year-of more than 300 kelvin days over the Holocene, consistent with inferences from the pollen data. It also simulates a decrease in mean summer temperatures of more than two degrees Celsius, which correlates with reconstructed marine trends and highlights the potential importance of the different subseasonal sensitivities of the records. Despite the differing trends, pollen- and marine-based reconstructions are correlated at millennial-to-centennial scales, probably in response to ice-sheet and meltwater dynamics, and to stochastic dynamics similar to the temperature variations produced by CCSM3. Although our results depend on a single source of palaeoclimatic data (pollen) and a single climate-model simulation, they reinforce the notion that climate models can adequately simulate climates for periods other than the present-day. They also demonstrate that amplified warming in recent decades increased temperatures above the mean of any century during the past 11,000 years.

Considerable attention has been drawn to poor reproducibility in the biomedical literature. One explanation is inadequate reporting of statistical methods by authors and inadequate assessment of statistical reporting and methods during peer review. In this narrative review, we examine scientific studies of several well-publicized efforts to improve statistical reporting. We also review several retrospective assessments of the impact of these efforts. These studies show that instructions to authors and statistical checklists are not sufficient; no findings suggested that either improves the quality of statistical methods and reporting. Second, even basic statistics, such as power analyses, are frequently missing or incorrectly performed. Third, statistical review is needed for all papers that involve data analysis. A consistent finding in the studies was that nonstatistical reviewers (eg, "scientific reviewers") and journal editors generally poorly assess statistical quality. We finish by discussing our experience with statistical review at Anesthesia & Analgesia from 2006 to 2016.

In July 2015, personnel in the Alaska Division of Public Health's Section of Epidemiology became aware of an increase in the number of patients being treated in Anchorage hospital emergency departments for adverse reactions associated with use of synthetic cannabinoids (SCs). SCs are a chemically diverse class of designer drugs that bind to the same cannabinoid receptors as tetrahydrocannabinol, the main psychoactive component of cannabis. A public health investigation was initiated to describe clinical outcomes, characterize the outbreak, and identify SC chemicals circulating in Anchorage. During July 15, 2015-March 15, 2016, a total of 1,351 ambulance transports to Anchorage emergency departments for adverse SC reactions were identified. A review of charts obtained from two Anchorage hospitals determined that among 167 emergency department visits for adverse SC reactions during July 15-September 30, 2015, 11 (6.6%) involved a patient who required endotracheal intubation, 17 (10.2%) involved a patient who was admitted to the intensive care unit, and 66 (39.5%) involved a patient classified as being homeless. Testing of 25 product and paraphernalia samples collected from patients at one hospital identified 11 different SC chemicals. Educational outreach campaigns focused on the considerable health risks of using SCs need to complement judicial and law enforcement actions to reduce SC use.