A combined toxicokinetic and metabolic approach to investigate deschloro-N-ethylketamine exposure in a multidrug user

The use of new psychoactive substances derived from ketamine is rarely reported in France. A chronic GHB, 3-MMC, and methoxetamine consumer presented a loss of consciousness in a chemsex context and was referred to the intensive care unit with a rapid and favorable outcome. To investigate the chemicals responsible for the intoxication, a comprehensive analysis was conducted on the ten plasma samples collected over a 29.5-hour period, urine obtained upon admission, a 2-cm hair strand sample, and a seized crystal. These analyses were performed using liquid chromatography hyphenated to high resolution tandem mass spectrometry operating in targeted and untargeted modes. Additionally, analyses using gas chromatography coupled to mass spectrometry and nuclear magnetic resonance were conducted to probe the composition of the seized crystal. The molecular network-based approach was employed for data processing in non-targeted analyses. It allowed to confirm a multidrug exposure encompassing GHB, methyl-(aminopropyl)benzofuran (MAPB), (aminopropyl)benzofuran (APB), methylmethcathinone, chloromethcathinone, and a new psychoactive substance belonging to the arylcyclohexylamine family namely deschloro-N-ethyl-ketamine (O-PCE). Molecular network analysis facilitated the annotation of 27 O-PCE metabolites, including phase II compounds not previously reported. Plasma kinetics of O-PCE allowed the estimation of the elimination half-life of ∼5 hours. Kinetics of O-PCE metabolites was additionally characterized, possibly useful as surrogate biomarkers of consumption. We also observed marked alterations in lipid metabolism related to poly consumption of drugs. In conclusion, this case report provides a comprehensive analysis of exposure to O-PCE in a multidrug user including kinetic and metabolism data in human.

Treatment of COVID-19-associated ARDS with umbilical cord-derived mesenchymal stromal cells in the STROMA-CoV-2 multicenter randomized double-blind trial: long-term safety, respiratory function, and quality of life

BACKGROUND

The STROMA-CoV-2 study was a French phase 2b, multicenter, double-blind, randomized, placebo-controlled clinical trial that did not identify a significant efficacy of umbilical cord-derived mesenchymal stromal cells in patients with SARS-CoV-2-induced acute respiratory distress syndrome. Safety on day 28 was found to be good. The aim of our extended study was to assess the 6- and 12-month safety of UC-MSCs administration in the STROMA-CoV-2 cohort.

METHODS

A detailed multi-domain assessment was conducted at 6 and 12 months following hospital discharge focusing on adverse events, lung computed tomography-scan, pulmonary and muscular functional status, and quality of life in the STROMA-CoV-2 cohort including SARS-CoV-2-related early (< 96 h) mild-to-severe acute respiratory distress syndrome.

RESULTS

Between April 2020 and October 2020, 47 patients were enrolled, of whom 19 completed a 1-year follow-up. There were no significant differences in any endpoints or adverse effects between the UC-MSCs and placebo groups at the 6- and 12-month assessments. Ground-glass opacities persisted at 1 year in 5 patients (26.3%). Furthermore, diffusing capacity for carbon monoxide remained altered over 1 year, although no patient required oxygen or non-invasive ventilatory support. Quality of life revealed declines in mental, emotional and physical health throughout the follow-up period, and the six-minute walking distance remained slightly impaired at the 1-year patient assessment.

CONCLUSIONS

This study suggests a favorable safety profile for the use of intravenous UC-MSCs in the context of the first French wave of SARS-CoV-2-related moderate-to-severe acute respiratory distress syndrome, with no adverse effects observed at 1 year.

Brain PET imaging using 11C-flumazenil and 11C-buprenorphine does not support the hypothesis of a mutual interaction between buprenorphine and benzodiazepines at the neuroreceptor level

Among opioids, buprenorphine presents a favorable safety profile with a limited risk of respiratory depression. However, fatalities have been reported when buprenorphine is combined to a benzodiazepine. Potentiation of buprenorphine interaction with opioid receptors (ORs) with benzodiazepines, and/or vice versa, is hypothesized to explain this drug-drug interaction (DDI). The mutual DDI between buprenorphine and benzodiazepines was investigated at the neuroreceptor level in nonhuman primates (n = 4 individuals) using brain PET imaging and kinetic modelling. The binding potential (BPND) of benzodiazepine receptor (BzR) was assessed using 11C-flumazenil PET imaging before and after administration of buprenorphine (0.2 mg, i.v.). Moreover, the brain kinetics and receptor binding of buprenorphine were investigated in the same individuals using 11C-buprenorphine PET imaging before and after administration of diazepam (10 mg, i.v.). Outcome parameters were compared using a two-way ANOVA. Buprenorphine did not impact the plasma nor brain kinetics of 11C-flumazenil. 11C-flumazenil BPND was unchanged following buprenorphine exposure, in any brain region (p > 0.05). Similarly, diazepam did not impact the plasma or brain kinetics of 11C-buprenorphine. 11C-buprenorphine volume of distribution (VT) was unchanged following diazepam exposure, in any brain region (p > 0.05). To conclude, our PET imaging findings do not support a neuropharmacokinetic or neuroreceptor-related mechanism of the buprenorphine/benzodiazepine interaction.

Cerebral microbleeds in the poisoned patient: An observational magnetic resonance imaging study

Critical illness-associated cerebral microbleeds of poorly understood pathophysiology have been observed on magnetic resonance imaging (MRI) in severely hypoxaemic patients similarly to high-altitude cerebral oedema patients. The prevalence and circumstances of occurrence of such cerebral microbleeds in the severely poisoned patients are unknown. We retrospectively reviewed all cerebral MRIs performed in the poisoned patients with atypical neurological presentation or outcome admitted to our intensive care unit in 2014-2021. Three out of 64 patients (4.7%) investigated with cerebral MRI among the 2986 severely poisoned patients presented cerebral microbleeds. Microbleeds were localized in the white cerebral matter mainly in the corpus callosum. Ingested toxicants included dichlorvos, methadone and tramadol. Patients were found comatose with possibly prolonged severe hypoxaemia requiring prompt tracheal intubation and mechanical ventilation. They presented delayed arousal and dysexecutive syndrome leading to sequelae. Microbleeds on MRI can occur in the critically ill poisoned patients and seems to be a multifactorial phenomenon. A direct relationship with the toxicant seems improbable. Physicians should be aware of such a non-specific complication accounting for sequelae.

Are there differences in the relationship between respiratory rate and oxygen saturation between patients with COVID-19 and those without COVID-19? Insights from a cohort-based correlational study

BACKGROUND

Physicians have observed patients with COVID-19 without respiratory distress despite marked hypoxaemia and extensive radiographic abnormalities, a controversial phenomenon called 'silent hypoxaemia'. We aimed to compare the relationship between RR and peripheral oxygen saturation (SpO2) in patients with COVID-19 versus patients without COVID-19 when breathing air on admission.

METHODS

We conducted a retrospective multicentre ED cohort correlational study.We used the Spanish Investigators on Emergency Situations TeAm network cohort of patients with COVID-19 admitted to 61 Spanish EDs between March and April 2020. The non-COVID-19 cohort included patients with lower respiratory tract bacterial infections admitted between January 2016 and April 2018.We built a multivariable linear model to investigate the independent predictive factors related to RR and a logistic multivariate regression model to analyse the presence of 'silent hypoxaemia'.

RESULTS

We included 1094 patients with COVID-19 and 477 patients without COVID-19. On admission, RR was lower (20±7 vs 24±8/min, p<0.0001), while SpO2 higher (95±5% vs 90±7%, p<0.0001) in patients with COVID-19 versus patients without COVID-19. RR was negatively associated with SpO2 (RR decreasing with increasing age, beta=-0.37, 95% CI (-0.43; -0.31), p<0.0001), positively associated with age (RR increasing with increasing age, beta=0.05, 95% CI (0.03; 0.07), p<0.0001) and negatively associated with COVID-19 status (RR lower in patients with COVID-19, beta=-1.90, 95% CI (-2.65; -1.15), p<0.0001). The negative RR/SpO2 correlation differed between patients with COVID-19 aged <80 and ≥80 years old (p=0.04). Patients with COVID-19 aged ≥80 years old had lower RR than patients without COVID-19 aged ≥80 years old at SpO2 values <95% (22±7 vs 24±8/min, p=0.004). 'Silent hypoxaemia' defined as RR <20/min with SpO2 <95% was observed in 162 (14.8%) patients with COVID-19 and in 79 (16.6%) patients without COVID-19 (p=0.4). 'Silent hypoxaemia' was associated with age ≥80 years (OR=1.01 (1.01; 1.03), p<0.0001) but not with gender, comorbidities and COVID-19 status.

CONCLUSION

The RR/SpO2 relationship before oxygen administration does not differ between patients with COVID-19 and those without COVID-19, except in elderly patients.

Bothrops venom-induced hemostasis disorders in the rat: Between Scylla and Charybdis

Hemostasis impairment represents the most threatening consequence of Viperidae envenoming, notably with Bothrops genus. In the French departments of America, B. atrox envenomation in French Guiana may lead to bleeding while B. lanceolatus envenomation in Martinique to thrombosis. Bleeding related to B. atrox envenomation is attributed to vascular damage mediated by venom metalloproteinases and blood uncoagulable state resulting from thrombocytopenia and consumptive coagulopathy. Thrombosis related to B. lanceolatus envenomation are poorly understood. We aimed to compare the effects of B. atrox and B. lanceolatus venoms in the rat to identify the determinants of the hemorrhagic versus thrombotic complications. Viscoelastometry (ROTEM), platelet count, plasma fibrinogen, thrombin generation assay, fibrinography, endothelial (von Willebrand factor, ADAMTS13 activity, ICAM-1, and soluble E-selectin), and inflammatory biomarkers (IL-1β, IL-6, TNF-α, MCP-1, and PAI-1) were determined in blood samples obtained at H3, H6, and H24 after the subcutaneous venom versus saline injection. In comparison to the control, initial fibrinogen consumption was observed with the two venoms while thrombocytopenia and reduction in the clot amplitude only with B. atrox venom. Moreover, we showed an increase in thrombin generation at H3 with the two venoms, an increase in fibrin generation accompanied with hyperfibrinogenemia at H24 and an increase in inflammatory biomarkers with B. lanceolatus venom. No endothelial damage was found with the two venoms. To conclude, our data support two-sided hemostasis complications in Bothrops envenoming with an initial risk of hemorrhage related to platelet consumption and hypocoagulability followed by an increased risk of thrombosis promoted by the activated inflammatory response and rapid-onset fibrinogen restoration.

Bothrops atrox and Bothrops lanceolatus Venoms In Vitro Investigation: Composition, Procoagulant Effects, Co-Factor Dependency, and Correction Using Antivenoms

Bothrops venoms are rich in enzymes acting on platelets and coagulation. This action is dependent on two major co-factors, i.e., calcium and phospholipids, while antivenoms variably neutralize venom-related coagulopathy effects. Our aims were (i) to describe the composition of B. atrox and B. lanceolatus venoms; (ii) to study their activity on the whole blood using rotational thromboelastometry (ROTEM); (iii) to evaluate the contribution of calcium and phospholipids in their activity; and (iv) to compare the effectiveness of four antivenoms (Bothrofav™, Inoserp™ South America, Antivipmyn™ TRI, and PoliVal-ICP™) on the procoagulant activity of these two venoms. Venom composition was comparable. Both venoms exhibited hypercoagulant effects. B. lanceolatus venom was completely dependent on calcium but less dependent on phospholipids than B. atrox venom to induce in vitro coagulation. The four antivenoms neutralized the procoagulant activity of the two venoms; however, with quantitative differences. Bothrofav™ was more effective against both venoms than the three other antivenoms. The relatively similar venom-induced effects in vitro were unexpected considering the opposite clinical manifestations resulting from envenomation (i.e., systemic bleeding with B. atrox and thrombosis with B. lanceolatus). In vivo studies are warranted to better understand the pathophysiology of systemic bleeding and thrombosis associated with Bothrops bites.

Late dihydroartemisinin-piperaquine treatment failure of P. falciparum malaria attack related to insufficient dosing in an obese patient

We report the case of an obese patient who experienced late failure on day28 of a well-conducted treatment with artesunate, followed by dihydroartemisinin-piperaquine (DHA-PPQ) for a severe P. falciparum malaria attack. The same P. falciparum strain was evidenced at day0 and day28. Genotypic and phenotypic resistance tests could not explain this treatment failure. The low plasma piperaquine concentration at failure may explain the poor elimination of residual parasites.

Lipid Emulsion to Treat Acute Poisonings: Mechanisms of Action, Indications, and Controversies

Biodetoxification using intravenous lipid emulsion (ILE) in acute poisoning is of growing interest. As well as for local anesthetics, ILE is currently used to reverse toxicity caused by a broad-spectrum of lipophilic drugs. Both pharmacokinetic and pharmacodynamic mechanisms have been postulated to explain its possible benefits, mainly combining a scavenging effect called "lipid sink" and cardiotonic activity. Additional mechanisms based on ILE-attributed vasoactive and cytoprotective properties are still under investigation. Here, we present a narrative review on lipid resuscitation, focusing on the recent literature with advances in understanding ILE-attributed mechanisms of action and evaluating the evidence supporting ILE administration that enabled the international recommendations. Many practical aspects are still controversial, including the optimal dose, the optimal administration timing, and the optimal duration of infusion for clinical efficacy, as well as the threshold dose for adverse effects. Present evidence supports the use of ILE as first-line therapy to reverse local anesthetic-related systemic toxicity and as adjunct therapy in lipophilic non-local anesthetic drug overdoses refractory to well-established antidotes and supportive care. However, the level of evidence is low to very low, as for most other commonly used antidotes. Our review presents the internationally accepted recommendations according to the clinical poisoning scenario and provides the precautions of use to optimize the expected efficacy of ILE and limit the inconveniences of its futile administration. Based on their absorptive properties, the next generation of scavenging agents is additionally presented. Although emerging research shows great potential, several challenges need to be overcome before parenteral detoxifying agents could be considered as an established treatment for severe poisonings.

A 24-Year-Old Woman With Cough, Arthralgia, and Skin Ulcerations

CASE PRESENTATION

A 24-year-old Senegalese woman without remarkable history except anemia and iron deficiency related to excessive menstrual bleeding and sickle cell trait was admitted to our internal medicine department with 4-month fever, weight loss (-13 kg), dyspnea for limited efforts, intermittent productive cough, and bilateral metacarpophalangeal (MCP) and interphalangeal arthralgia. She was born and lived in France. She traveled previously to Senegal in 2015. She had no history of tobacco, alcohol, or drug use nor proximity with animals. She was taking no medication.

New Trend in Toxicological Screening Using Volumetric Absorptive Microsampling (VAMS) and High-Resolution Mass Spectrometry (HR/MS) Combination

In toxicology, screenings are routinely performed using chromatographic methods coupled to detection systems such as high-resolution mass spectrometry (HR/MS). The increase in specificity and sensitivity of HRMS is responsible for the development of methods for alternative samples such as Volumetric Adsorptive Micro-Sampling. Whole blood overloaded with 90 drugs was sampled with 20 µL Mitra^TM to optimize the pre-analytical step as well as to determine the identification limits of drugs. Elution of chemicals was carried out in a solvent mixture through agitation and sonication. After dissolution, 10 μL was injected into the chromatographic system coupled to the Orbitrap^TM HR/MS. Compounds were confirmed against the laboratory library. The clinical feasibility was assessed in fifteen poisoned patients using the simultaneous sampling of plasma, whole blood and Mitra^TM. The optimized extraction procedure allowed us to confirm 87 compounds out of the 90 present in the spiked whole blood. Cannabis derivatives were not detected. For 82.2% of the investigated drugs, the identification limits were below 12.5 ng·mL^-1, with the extraction yields ranging from 80.6 to 108.7%. Regarding the patients' analysis, 98% of the compounds in plasma were detected in Mitra^TM compared to whole blood, with a satisfying concordance (R² = 0.827). Our novel screening approach opens new insights into different toxicologic fields appropriate for pediatrics, forensics or to perform mass screening.

Pharmacobezoar: a rare cause of body packing misdiagnosis

INTRODUCTION

Diagnosis of body packing based on the misinterpretation of imaging is rare.

CASE REPORT

An unaccompanied 55-year-old woman presented with uncontrolled vomiting in the airport transit area. An abdominal radiograph and computed tomography scan revealed multiple radiopaque foreign bodies in the colon. History was unobtainable due to the language barrier. The patient was referred to our institution as a body packer who required surgical extraction of the packets. In the absence of symptoms, she was managed conservatively with antiemetic drugs and whole bowel irrigation. The final diagnosis was radiopaque pharmacobezoars caused by an over-the-counter barium-containing anticancer medication in the setting of severe hypokalemia-associated paralytic ileus following post-chemotherapy vomiting. After the correction of her potassium concentration, the patient was discharged and resumed her trip.

CONCLUSION

Clinicians should be warned that pharmacobezoars might be mistaken for drug packets on abdominal imaging leading to body packing misdiagnosis.

High-dose insulin should be used before vasopressors/inotropes in calcium-channel blocker toxicity

High-dose insulin (HDI) therapy with adapted glucose supplementation to maintain euglycaemia has been suggested to treat calcium-channel blocker (CCB) poisonings. Its underlying mechanisms of action are now well documented. We present a narrative review of the published experimental studies, case reports and experts' opinions to support the effectiveness and safety of HDI in the treatment of CCB poisoning. Our review strongly encourages the use of HDI as first-line therapy in CCB-poisoned patients in the presence of cardiovascular compromise, especially if cardiac function impairment has been diagnosed, before, but without delaying, the administration of vasopressors/inotropic drugs.

Critically ill severe hypothyroidism: a retrospective multicenter cohort study

BACKGROUND

Severe hypothyroidism (SH) is a rare but life-threatening endocrine emergency. Only a few data are available on its management and outcomes of the most severe forms requiring ICU admission. We aimed to describe the clinical manifestations, management, and in-ICU and 6-month survival rates of these patients.

METHODS

We conducted a retrospective, multicenter study over 18 years in 32 French ICUs. The local medical records of patients from each participating ICU were screened using the International Classification of Disease 10th revision. Inclusion criteria were the presence of biological hypothyroidism associated with at least one cardinal sign among alteration of consciousness, hypothermia and circulatory failure, and at least one SH-related organ failure.

RESULTS

Eighty-two patients were included in the study. Thyroiditis and thyroidectomy represented the main SH etiologies (29% and 19%, respectively), while hypothyroidism was unknown in 44 patients (54%) before ICU admission. The most frequent SH triggers were levothyroxine discontinuation (28%), sepsis (15%), and amiodarone-related hypothyroidism (11%). Clinical presentations included hypothermia (66%), hemodynamic failure (57%), and coma (52%). In-ICU and 6-month mortality rates were 26% and 39%, respectively. Multivariable analyses retained age > 70 years [odds ratio OR 6.01 (1.75-24.1)] Sequential Organ-Failure Assessment score cardiovascular component ≥ 2 [OR 11.1 (2.47-84.2)] and ventilation component ≥ 2 [OR 4.52 (1.27-18.6)] as being independently associated with in-ICU mortality.

CONCLUSIONS

SH is a rare life-threatening emergency with various clinical presentations. Hemodynamic and respiratory failures are strongly associated with worse outcomes. The very high mortality prompts early diagnosis and rapid levothyroxine administration with close cardiac and hemodynamic monitoring.

Mechanisms of Neurorespiratory Toxicity Induced by Fentanyl Analogs—Lessons from Animal Studies

In 2020, fentanyl and its analogs contributed to ~65% of drug-attributed fatalities in the USA, with a threatening increasing trend during the last ten years. These synthetic opioids used as potent analgesics in human and veterinary medicine have been diverted to recreational aims, illegally produced and sold. Like all opioids, central nervous system depression resulting from overdose or misuse of fentanyl analogs is characterized clinically by the onset of consciousness impairment, pinpoint miosis and bradypnea. However, contrasting with what observed with most opioids, thoracic rigidity may occur rapidly with fentanyl analogs, contributing to increasing the risk of death in the absence of immediate life support. Various mechanisms have been proposed to explain this particularity associated with fentanyl analogs, including the activation of noradrenergic and glutamatergic coerulospinal neurons and dopaminergic basal ganglia neurons. Due to the high affinities to the mu-opioid receptor, the need for more elevated naloxone doses than usually required in morphine overdose to reverse the neurorespiratory depression induced by fentanyl analogs has been questioned. This review on the neurorespiratory toxicity of fentanyl and analogs highlights the need for specific research focused on these agents to better understand the involved mechanisms of toxicity and develop dedicated strategies to limit the resulting fatalities.

Impact of renal replacement therapy strategy on beta-lactam plasma concentrations: the BETAKIKI study-an ancillary study of a randomized controlled trial

BACKGROUND

Sepsis prognosis correlates with antibiotic adequacy at the early phase. This adequacy is dependent on antibacterial spectrum, bacterial resistance profile and antibiotic dosage. Optimal efficacy of beta-lactams mandates concentrations above the minimal inhibitory concentration (MIC) of the targeted bacteria for the longest time possible over the day. Septic acute kidney injury (AKI) is the most common AKI syndrome in ICU and often mandates renal replacement therapy (RRT) initiation. Both severe AKI and RRT may increase outside target antibiotic concentrations and ultimately alter patient's prognosis.

PATIENTS AND METHODS

This is a secondary analysis of a randomized controlled trial that compared an early RRT initiation strategy with a delayed one in 620 critically ill patients undergoing severe AKI (defined by KDIGO 3). We compared beta-lactam trough concentrations between the two RRT initiation strategies. The primary outcome was the proportion of patients with sufficient trough plasma concentration of beta-lactams defined by trough concentration above 4 times the MIC. We hypothesized that early initiation of RRT could be associated with an insufficient antibiotic plasma trough concentration compared to patients allocated to the delayed strategy.

RESULTS

One hundred and twelve patients were included: 53 in the early group and 59 in the delayed group. Eighty-three patients (74%) had septic shock on inclusion. Trough beta-lactam plasma concentration was above 4 times the MIC breakpoint in 80.4% (n = 90) of patients of the whole population, without differences between the early and the delayed groups (79.2% vs. 81.4%, respectively, p = 0.78). On multivariate analysis, the presence of septic shock and a higher mean arterial pressure were significantly associated with a greater probability of adequate antibiotic trough concentration [OR 3.95 (1.14;13.64), p = 0.029 and OR 1.05 (1.01;1.10), p = 0.013, respectively). Evolution of procalcitonin level and catecholamine-free days as well as mortality did not differ whether beta-lactam trough concentration was above 4 times the MIC or not.

CONCLUSIONS

In this secondary analysis of a randomized controlled trial, renal replacement therapy initiation strategy did not significantly influence plasma trough concentrations of beta-lactams in ICU patients with severe AKI. Presence of septic shock on inclusion was the main variable associated with a sufficient beta-lactam concentration.

TRIAL REGISTRATION

The AKIKI trial was registered on ClinicalTrials.gov (Identifier: NCT01932190) before the inclusion of the first patient.

Does lithium poisoning induce brain injuries?-A histopathological rat study

Due to a narrow therapeutic index, prolonged lithium treatment and overdose may result in neurotoxicity. Neurotoxicity is deemed reversible with lithium clearance. However, echoing the report of syndrome of irreversible lithium-effectuated neurotoxicity (SILENT) in rare severe poisonings, lithium-induced histopathological brain injuries including extensive neuronal vacuolization, spongiosis and ageing-like neurodegenerative changes were described in the rat following acute toxic and pharmacological exposure. We aimed to investigate the histopathological consequences of lithium exposure in rat models mimicking prolonged treatment and all three patterns of acute, acute-on-chronic and chronic poisonings observed in humans. We performed histopathology and immunostaining-based analyses using optic microscopy of brains obtained from male Sprague-Dawley rats randomly assigned to lithium or saline (controls) and treated according to the therapeutic or to the three poisoning models. No lesion was observed in any brain structure in any of the models. Neuron and astrocyte counts did not differ significantly between lithium-treated rats and controls. Our findings support that lithium-induced neurotoxicity is reversible and brain injury not a common feature of toxicity.

Human plasma ricinine quantification by LC-HRMS after micro-solid-phase elution

A rapid, sensitive and specific method for ricinine identification and quantification in plasma has been developed by LC-HRMS. Deuterated ricinine was used as the internal standard. From 100 μL of plasma, ricinine was extracted using micro-solid-phase elution, which allows a reduced extraction time, by eliminating the evaporation step. Eluate is directly injected into the LC-HRMS system. Chromatographic separation was performed using a reverse-phase C₁₈ column with a 4.5 min gradient elution. The method was validated according to European Medicines Agency guidelines. Linearity was verified between 0.25 and 500.0 ng/mL; the maximum precision calculated was 19.9% for the lower limit of quantitation and 9.6% for quality control, and accuracy was within ± 5.6% of the nominal concentrations. Selectivity, carryover, matrix effect and stability were also verified according to European Medicines Agency guidelines. The method allows the rapid and reliable identification of ricin-exposed victims in case of terrorist attacks or poisonings: three intoxication cases are reported.

Extracorporeal treatment for ethylene glycol poisoning: systematic review and recommendations from the EXTRIP workgroup

Ethylene glycol (EG) is metabolized into glycolate and oxalate and may cause metabolic acidemia, neurotoxicity, acute kidney injury (AKI), and death. Historically, treatment of EG toxicity included supportive care, correction of acid-base disturbances and antidotes (ethanol or fomepizole), and extracorporeal treatments (ECTRs), such as hemodialysis. With the wider availability of fomepizole, the indications for ECTRs in EG poisoning are debated. We conducted systematic reviews of the literature following published EXTRIP methods to determine the utility of ECTRs in the management of EG toxicity. The quality of the evidence and the strength of recommendations, either strong ("we recommend") or weak/conditional ("we suggest"), were graded according to the GRADE approach. A total of 226 articles met inclusion criteria. EG was assessed as dialyzable by intermittent hemodialysis (level of evidence = B) as was glycolate (Level of evidence = C). Clinical data were available for analysis on 446 patients, in whom overall mortality was 18.7%. In the subgroup of patients with a glycolate concentration ≤ 12 mmol/L (or anion gap ≤ 28 mmol/L), mortality was 3.6%; in this subgroup, outcomes in patients receiving ECTR were not better than in those who did not receive ECTR. The EXTRIP workgroup made the following recommendations for the use of ECTR in addition to supportive care over supportive care alone in the management of EG poisoning (very low quality of evidence for all recommendations): i) Suggest ECTR if fomepizole is used and EG concentration > 50 mmol/L OR osmol gap > 50; or ii) Recommend ECTR if ethanol is used and EG concentration > 50 mmol/L OR osmol gap > 50; or iii) Recommend ECTR if glycolate concentration is > 12 mmol/L or anion gap > 27 mmol/L; or iv) Suggest ECTR if glycolate concentration 8-12 mmol/L or anion gap 23-27 mmol/L; or v) Recommend ECTR if there are severe clinical features (coma, seizures, or AKI). In most settings, the workgroup recommends using intermittent hemodialysis over other ECTRs. If intermittent hemodialysis is not available, CKRT is recommended over other types of ECTR. Cessation of ECTR is recommended once the anion gap is < 18 mmol/L or suggested if EG concentration is < 4 mmol/L. The dosage of antidotes (fomepizole or ethanol) needs to be adjusted during ECTR.

Development and validation of a multivariable model predicting the required catheter dwell time among mechanically ventilated critically ill patients in three randomized trials

BACKGROUND

The anatomic site for central venous catheter insertion influences the risk of central venous catheter-related intravascular complications. We developed and validated a predictive score of required catheter dwell time to identify critically ill patients at higher risk of intravascular complications.

METHODS

We retrospectively conducted a cohort study from three multicenter randomized controlled trials enrolling consecutive patients requiring central venous catheterization. The primary outcome was the required catheter dwell time, defined as the period between the first catheter insertion and removal of the last catheter for absence of utility. Predictors were identified in the training cohort (3SITES trial; 2336 patients) through multivariable analyses based on the subdistribution hazard function accounting for death as a competing event. Internal validation was performed in the training cohort by 500 bootstraps to derive the CVC-IN score from robust risk factors. External validation of the CVC-IN score were performed in the testing cohort (CLEAN, and DRESSING2; 2371 patients).

RESULTS

The analysis was restricted to patients requiring mechanical ventilation to comply with model assumptions. Immunosuppression (2 points), high creatinine > 100 micromol/L (2 points), use of vasopressor (1 point), obesity (1 point) and older age (40-59, 1 point; ≥ 60, 2 points) were independently associated with the required catheter dwell time. At day 28, area under the ROC curve for the CVC-IN score was 0.69, 95% confidence interval (CI) [0.66-0.72] in the training cohort and 0.64, 95% CI [0.61-0.66] in the testing cohort. Patients with a CVC-IN score ≥ 4 in the overall cohort had a median required catheter dwell time of 24 days (versus 11 days for CVC-IN score < 4 points). The positive predictive value of a CVC-IN score ≥ 4 was 76.9% for > 7 days required catheter dwell time in the testing cohort.

CONCLUSION

The CVC-IN score, which can be used for the first catheter, had a modest ability to discriminate required catheter dwell time. Nevertheless, preference of the subclavian site may contribute to limit the risk of intravascular complications, in particular among ventilated patients with high CVC-IN score. Trials Registration NCT01479153, NCT01629550, NCT01189682.

Golgi localization of SARS-CoV-2 spike protein and interaction with furin in cerebral COVID-19 microangiopathy: a clue to the central nervous system involvement?

In a neuropathological series of 20 COVID-19 cases, we analyzed six cases (three biopsies and three autopsies) with multiple foci predominantly affecting the white matter as shown by MRI. The cases presented with microhemorrhages evocative of small artery diseases. This COVID-19 associated cerebral microangiopathy (CCM) was characterized by perivascular changes: arterioles were surrounded by vacuolized tissue, clustered macrophages, large axonal swellings and a crown arrangement of aquaporin-4 immunoreactivity. There was evidence of blood-brain-barrier leakage. Fibrinoid necrosis, vascular occlusion, perivascular cuffing and demyelination were absent. While no viral particle or viral RNA was found in the brain, the SARS-CoV-2 spike protein was detected in the Golgi apparatus of brain endothelial cells where it closely associated with furin, a host protease known to play a key role in virus replication. Endothelial cells in culture were not permissive to SARS-CoV-2 replication. The distribution of the spike protein in brain endothelial cells differed from that observed in pneumocytes. In the latter, the diffuse cytoplasmic labeling suggested a complete replication cycle with viral release, notably through the lysosomal pathway. In contrast, in cerebral endothelial cells the excretion cycle was blocked in the Golgi apparatus. Interruption of the excretion cycle could explain the difficulty of SARS-CoV-2 to infect endothelial cells in vitro and to produce viral RNA in the brain. Specific metabolism of the virus in brain endothelial cells could weaken the cell walls and eventually lead to the characteristic lesions of COVID-19 associated cerebral microangiopathy. Furin as a modulator of vascular permeability could provide some clues for the control of late effects of microangiopathy.

Development and validation of a multivariable prediction model of central venous catheter-tip colonization in a cohort of five randomized trials

Background

The majority of central venous catheters (CVC) removed in the ICU are not colonized, including when a catheter-related infection (CRI) is suspected. We developed and validated a predictive score to reduce unnecessary CVC removal.

Methods

We conducted a retrospective cohort study from five multicenter randomized controlled trials with systematic catheter-tip culture of consecutive CVCs. Colonization was defined as growth of ≥103 colony-forming units per mL. Risk factors for colonization were identified in the training cohort (CATHEDIA and 3SITES trials; 3899 CVCs of which 575 (15%) were colonized) through multivariable analyses. After internal validation in 500 bootstrapped samples, the CVC-OUT score was computed by attaching points to the robust (> 50% of the bootstraps) risk factors. External validation was performed in the testing cohort (CLEAN, DRESSING2 and ELVIS trials; 6848 CVCs, of which 588 (9%) were colonized).

Results

In the training cohort, obesity (1 point), diabetes (1 point), type of CVC (dialysis catheter, 1 point), anatomical insertion site (jugular, 4 points; femoral 5 points), rank of the catheter (second or subsequent, 1 point) and catheterization duration (≥ 5 days, 2 points) were significantly and independently associated with colonization . Area under the ROC curve (AUC) for the CVC-OUT score was 0.69, 95% confidence interval (CI) [0.67–0.72]. In the testing cohort, AUC for the CVC-OUT score was 0.60, 95% CI [0.58–0.62]. Among 1,469 CVCs removed for suspected CRI in the overall population, 1200 (82%) were not colonized. The negative predictive value (NPV) of a CVC-OUT score < 6 points was 94%, 95% CI [93%–95%].

Conclusion

The CVC-OUT score had a moderate ability to discriminate catheter-tip colonization, but the high NPV may contribute to reduce unnecessary CVCs removal. Preference of the subclavian site is the strongest and only modifiable risk factor that reduces the likelihood of catheter-tip colonization and consequently the risk of CRI.

Clinical Trials Registration: NCT00277888, NCT01479153, NCT01629550, NCT01189682, NCT00875069.

Investigation of the Mechanisms of Tramadol-Induced Seizures in Overdose in the Rat

Tramadol overdose is frequently associated with the onset of seizures, usually considered as serotonin syndrome manifestations. Recently, the serotoninergic mechanism of tramadol-attributed seizures has been questioned. This study’s aim was to identify the mechanisms involved in tramadol-induced seizures in overdose in rats. The investigations included (1) the effects of specific pretreatments on tramadol-induced seizure onset and brain monoamine concentrations, (2) the interaction between tramadol and γ-aminobutyric acid (GABA)A receptors in vivo in the brain using positron emission tomography (PET) imaging and 11C-flumazenil. Diazepam abolished tramadol-induced seizures, in contrast to naloxone, cyproheptadine and fexofenadine pretreatments. Despite seizure abolishment, diazepam significantly enhanced tramadol-induced increase in the brain serotonin (p < 0.01), histamine (p < 0.01), dopamine (p < 0.05) and norepinephrine (p < 0.05). No displacement of 11C-flumazenil brain kinetics was observed following tramadol administration in contrast to diazepam, suggesting that the observed interaction was not related to a competitive mechanism between tramadol and flumazenil at the benzodiazepine-binding site. Our findings do not support the involvement of serotoninergic, histaminergic, dopaminergic, norepinephrine or opioidergic pathways in tramadol-induced seizures in overdose, but they strongly suggest a tramadol-induced allosteric change of the benzodiazepine-binding site of GABAA receptors. Management of tramadol-poisoned patients should take into account that tramadol-induced seizures are mainly related to a GABAergic pathway.

Extracorporeal life support in cardiotoxicant poisoning - a narrative review

Extracorporeal life support (ECLS) improves circulation in life-threatening cardiac dysfunction or arrest patients. Its benefits in drug-induced cardiovascular complications are debated. Indications and outcomes are poorly established. We performed a narrative review discussing ECLS indications, timing, and results in cardiotoxicant-poisoned patients. The review was focused on antiarrhythmic drugs and aluminum phosphide. Literature analysis was limited to the past 30 years in adults. Most reports were single cases and retrospective except one prospective case series of limited size, two of them controlled. ECLS indications and timing were at the discretion of physicians in charge but mostly included persistent cardiovascular failure despite elevated doses of inotropic/vasopressor support associated with elevated blood lactate concentrations (usually, >5mmol/L) and collapsed left ventricular ejection fraction (LVEF; usually, ≤40%). Survival improved using ECLS versus standard care in one study. Survival was ~80% if ECLS was implemented in refractory cardiovascular failure and 25-66% if implemented in cardiac arrest. In two controlled studies, survival of ECLS-treated aluminum phosphide-poisoned patients was improved versus standard care, if implemented in the presence of systolic blood pressure≤80mmHg despite inotropic/vasopressor treatment, arterial pH≤7.0, and LVEF≤40%. Despite low-to-moderate level of evidence, ECLS seems effective to improve survival in selected cardiotoxicant-poisoned patients. Selection criteria need clarification.

Traitement de substitution des usagers dépendants des opiacés

La méthadone et la buprénorphine sont les deux traitements de substitution des opiacés autorisés en France depuis la fin des années 1990. Plus récemment, certains pays africains, comme le Sénégal, ont mis en place une nouvelle politique de santé axée sur la réduction des risques, en encourageant le recours aux traitements de substitution des opiacés. Les objectifs de la substitution sont de réduire la morbi-mortalité liée à la consommation d’héroïne ou d’autres opioïdes de rue, de favoriser l’insertion des usagers de drogue dans le système de soins, et, plus généralement, de faciliter leur insertion sociale. Cette nouvelle stratégie trouve néanmoins des limites dans la pratique. Nous rapportons dans cette revue l’expérience du Centre de prise en charge intégré des addictions de Dakar, au Sénégal, et proposons une réflexion éthique, tant individuelle que collective, afin d’améliorer le traitement de substitution des opiacés, notamment en Afrique.

Impact of Early Limitation of Therapeutic Effort in Elderly COVID-19 Patients Admitted to the Intensive Care Unit-A Cohort Study

(1) Background: Admission to the ICU and intensity of care provided to elderly COVID-19 patients are difficult choices guided by the expected patient-centered benefits. However, the impact of an early discussion of limitation of therapeutic effort (LTE) has been poorly investigated. (2) Methods: We performed a single-center retrospective cohort study including all ≥70-year-old COVID-19 patients admitted to the ICU. Factors associated with early LTE discussion (defined as before or up to 2 days post-ICU admission) and in-hospital mortality were evaluated. (3) Results: Eighty-two patients (59 M/23 F; 78 years (74−82) [median (interquartile range)]; 43/82 with LTE) were included. The in-hospital mortality rate was 55%. Early LTE was decided upon for 22/82 patients (27%), more frequently in older (p < 0.001) and frailer patients (p = 0.004). Using a multivariable logistic regression model including clinical frailty scale grade ≥4, hospital acquisition of COVID-19, ventilation support modality and SOFA score on admission, early LTE was not associated with mortality (adjusted odds ratio = 0.57 (0.15−2.00), p = 0.39). LTE resulted in less frequent invasive mechanical ventilation (23% versus 65%, p = 0.001), renal replacement therapy (5% versus 27%, p = 0.03) and norepinephrine infusion (23% versus 60%, p = 0.005), and shorter ICU stay (6 days (2−12) versus 14 days (7−24), p = 0.001). (4) Conclusions: In this small sample exploratory study, we were unable to demonstrate any increase in in-hospital mortality associated with early LTE discussion in elderly COVID-19 patients while reducing the use of organ support techniques. These findings require confirmation in larger studies.

Molecular Bases of Serotonin Reuptake Inhibitor Antidepressant-Attributed Effects in COVID-19: A New Insight on the Role of Bradykinins

Widely available effective drugs to treat coronavirus disease-2019 (COVID-19) are still limited. Various studies suggested the potential contribution of selective serotonin-reuptake inhibitor (SSRI) antidepressants to alleviate the clinical course of COVID-19. Initially, SSRI antidepressant-attributed anti-COVID-19 activity was attributed to their direct agonistic or indirect serotonin-mediated stimulation of sigma-1 receptors (Sig1-R). Thereafter, attention was drawn to the property of SSRI antidepressants to decrease ceramide production, as functional inhibitors of acid sphingomyelinase. Ceramides are cell membrane waxy lipids formed by sphingosine and a fatty acid, playing a major role in receptor signaling and infection. In COVID-19 patients, ceramide production is increased due to acid sphingomyelinase activation. Here, we aimed to review the relationships between bradykinins and the proposed pathways supporting SSRI antidepressant-attributed effectiveness in COVID-19. In COVID-19 patients, bradykinin receptor-B1 stimulation is enhanced following the downregulation of angiotensin-converting enzyme-2, which is responsible for the inactivation of des-Arg9-bradykinin, a bradykinin metabolite, contrasting with the decrease in bradykinin receptor-B2 (BDKRB2) stimulation, which results from the inhibition of cathepsin L, a kininogenase involved in bradykinin production and present at the infection site. Sig1-R stimulation modulates the inflammatory response by regulating cytokine production and counterbalances COVID-19-attributed BDKRB2 inhibition by potentiating its effects on the cytosolic calcium concentration. Moreover, the beneficial effects obtained with acid sphingomyelinase inhibition are parallel to those expected with BDKRB2 stimulation in COVID-19. Altogether, these findings suggest that one ultimate pathway of SSRI antidepressant-attributed anti-COVID-19 activity is the potentiation of BDKRB2 effects shown to be inhibited in COVID-19. In conclusion, SSRI antidepressants are able to interact positively with the pathophysiological mechanisms involved in COVID-19. However, their exact benefits in preventing morbidities or improving the outcome in COVID-19 patients remain unknown.

High-Dose Dexamethasone and Oxygen Support Strategies in Intensive Care Unit Patients With Severe COVID-19 Acute Hypoxemic Respiratory Failure: The COVIDICUS Randomized Clinical Trial

IMPORTANCE

The benefit of high-dose dexamethasone and oxygenation strategies vs standard of care for patients with severe acute hypoxemic respiratory failure (AHRF) caused by COVID-19 pneumonia is debated.

OBJECTIVES

To assess the benefit of high-dose dexamethasone compared with standard of care dexamethasone, and to assess the benefit of high-flow nasal oxygen (HFNo2) or continuous positive airway pressure (CPAP) compared with oxygen support standard of care (o2SC).

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, placebo-controlled randomized clinical trial was conducted in 19 intensive care units (ICUs) in France from April 2020 to January 2021. Eligible patients were consecutive ICU-admitted adults with COVID-19 AHRF. Randomization used a 2 × 3 factorial design for dexamethasone and oxygenation strategies; patients not eligible for at least 1 oxygenation strategy and/or already receiving invasive mechanical ventilation (IMV) were only randomized for dexamethasone. All patients were followed-up for 60 days. Data were analyzed from May 26 to July 31, 2021.

INTERVENTIONS

Patients received standard dexamethasone (dexamethasone-phosphate 6 mg/d for 10 days [or placebo prior to RECOVERY trial results communication]) or high-dose dexamethasone (dexamethasone-phosphate 20 mg/d on days 1-5 then 10 mg/d on days 6-10). Those not requiring IMV were additionally randomized to o2SC, CPAP, or HFNo2.

MAIN OUTCOMES AND MEASURES

The main outcomes were time to all-cause mortality, assessed at day 60, for the dexamethasone interventions, and time to IMV requirement, assessed at day 28, for the oxygenation interventions. Differences between intervention groups were calculated using proportional Cox models and expressed as hazard ratios (HRs).

RESULTS

Among 841 screened patients, 546 patients (median [IQR] age, 67.4 [59.3-73.1] years; 414 [75.8%] men) were randomized between standard dexamethasone (276 patients, including 37 patients who received placebo) or high-dose dexamethasone (270 patients). Of these, 333 patients were randomized among o2SC (109 patients, including 56 receiving standard dexamethasone), CPAP (109 patients, including 57 receiving standard dexamethasone), and HFNo2 (115 patients, including 56 receiving standard dexamethasone). There was no difference in 60-day mortality between standard and high-dose dexamethasone groups (HR, 0.96 [95% CI, 0.69-1.33]; P = .79). There was no significant difference for the cumulative incidence of IMV criteria at day 28 among o2 support groups (o2SC vs CPAP: HR, 1.08 [95% CI, 0.71-1.63]; o2SC vs HFNo2: HR, 1.04 [95% CI, 0.69-1.55]) or 60-day mortality (o2SC vs CPAP: HR, 0.97 [95% CI, 0.58-1.61; o2SC vs HFNo2: HR, 0.89 [95% CI, 0.53-1.47]). Interactions between interventions were not significant.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial among ICU patients with COVID-19-related AHRF, high-dose dexamethasone did not significantly improve 60-day survival. The oxygenation strategies in patients who were not initially receiving IMV did not significantly modify 28-day risk of IMV requirement.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04344730; EudraCT: 2020-001457-43.

Impact of doubling peptide length on in vivo hydrogel stability and sustained drug release

Peptide-based hydrogels represent promising systems for the sustained release of different types of drugs, ranging from small molecules to biologicals. Aiming at subcutaneous injection, which is a desirable parenteral administration route, especially for biologicals, we herein focus on physically crosslinked systems possessing thixotropic behaviour. The purpose of this study was to evaluate the in vitro and in vivo properties of hydrogels based on the amphipathic hexapeptide H-FQFQFK-NH₂, which served as the lead sequence. Upon doubling the length of this peptide, the dodecapeptide H-FQFQFKFQFQFK-NH₂ gave a significant improvement in terms of in vivo stability of the hydrogel post-injection, as monitored by nuclear SPECT/CT imaging. This increased hydrogel stability also led to a more prolonged in vivo release of encapsulated peptide cargoes. Even though no direct link with the mechanical properties of the hydrogels before injection could be made, an important effect of the subcutaneous medium was noticed on the rheological properties of the hydrogels in post in vivo injection measurements. The results were validated in vivo for a therapeutically relevant analgesic peptide using the hot-plate test as an acute pain model. It was confirmed that elongation of the hydrogelator sequence induced more extended antinociceptive effects. Altogether, this simple structural modification of the hydrogelating peptide could provide a basis for reaching longer durations of action upon use of these soft biomaterials.

Effects of mean arterial pressure target on mottling and arterial lactate normalization in patients with septic shock: a post hoc analysis of the SEPSISPAM randomized trial

Background

In patients with septic shock, the impact of the mean arterial pressure (MAP) target on the course of mottling remains uncertain. In this post hoc analysis of the SEPSISPAM trial, we investigated whether a low-MAP (65 to 70 mmHg) or a high-MAP target (80 to 85 mmHg) would affect the course of mottling and arterial lactate in patients with septic shock.

Methods

The presence of mottling was assessed every 2 h from 2 h after inclusion to catecholamine weaning. We compared mottling and lactate time course between the two MAP target groups. We evaluated the patient’s outcome according to the presence or absence of mottling.

Results

We included 747 patients, 374 were assigned to the low-MAP group and 373 to the high-MAP group. There was no difference in mottling and lactate evolution during the first 24 h between the two MAP groups. After adjustment for MAP and confounding factors, the presence of mottling ≥ 6 h during the first 24 h was associated with a significantly higher risk of death at day 28 and 90. Patients without mottling or with mottling < 6 h and lactate ≥ 2 mmol/L have a higher probability of survival than those with mottling ≥ 6 h and lactate < 2 mmol/L.

Conclusion

Compared with low MAP target, higher MAP target did not alter mottling and lactate course. Mottling lasting for more than 6 h was associated with higher mortality. Compared to arterial lactate, mottling duration appears to be a better marker of mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01053-1.

Acute Rubigine® Poisoning in Martinique a French Overseas Department of America: Clinical Characteristics and Prognostic Factors

Rubigine® is an anti-rust stain remover containing fluorides which is believed to have been the cause of many deaths in Martinique. However, after the modification of its composition in 2006, serious poisoning from old formulas containing fluorides persisted. Our main objective was to determine the clinical characteristics and prognostic factors of these intoxications. Methods: Any patient admitted to the Martinique University Hospital for acute Rubigine® poisoning was included from 1 January 2000 to 31 December 2016. Usual demographic and clinical data were collected and comparisons between surviving and deceased patients made using a univariate analysis and logistic regression. Results: Fifty-five patients were included (mean age: 43 years; sex ratio M/F: 1.1), and the main clinical characteristics were: changes in electrocardiogram (ECG) (80%), digestive system disorders (75%), and neurological disorders (12%). The main features linked to death were the presence of hydrofluoric acid (p < 0.0001), age over 55 years (p = 0.01), hypocalcemia after the initial intravenous calcium supplementation (p = 0.0003), diarrhea (p < 0.0001), hypersialorrhea (p < 0.0001), myocardial excitability (p < 0.0001), and state of shock (p < 0.0001). Three patients required circulatory support by venous-arterial ECMO. Mortality was 10.9%. Conclusions: Rubigine® poisoning is responsible for significant morbidity and mortality. Fortunately, its incidence as well as mortality has sharply decreased in Martinique thanks to the measures taken by the French state. This retrospective work nevertheless shows that acute intoxication by the old formula of Rubigine® remains the main factor of poor prognosis.

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome Associated with COVID-19: An Emulated Target Trial Analysis

Rationale: Whether patients with coronavirus disease (COVID-19) may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. Objectives: To estimate the effect of ECMO on 90-day mortality versus IMV only. Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO versus no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 < 80 or PaCO2 ⩾ 60 mm Hg). We controlled for confounding using a multivariable Cox model on the basis of predefined variables. Measurements and Main Results: A total of 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability on Day 7 from the onset of eligibility criteria (87% vs. 83%; risk difference, 4%; 95% confidence interval, 0-9%), which decreased during follow-up (survival on Day 90: 63% vs. 65%; risk difference, -2%; 95% confidence interval, -10 to 5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand and when initiated within the first 4 days of IMV and in patients who are profoundly hypoxemic. Conclusions: In an emulated trial on the basis of a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and regions with ECMO capacities specifically organized to handle high demand.

Molecular Network-Based Identification of Tramadol Metabolites in a Fatal Tramadol Poisoning

Identification of xenobiotics and their phase I/II metabolites in poisoned patients remains challenging. Systematic approaches using bioinformatic tools are needed to detect all compounds as exhaustively as possible. Here, we aimed to assess an analytical workflow using liquid chromatography coupled to high-resolution mass spectrometry with data processing based on a molecular network to identify tramadol metabolites in urine and plasma in poisoned patients. The generated molecular network from liquid chromatography coupled to high-resolution tandem mass spectrometry data acquired in both positive and negative ion modes allowed for the identification of 25 tramadol metabolites in urine and plasma, including four methylated metabolites that have not been previously reported in humans or in vitro models. While positive ion mode is reliable for generating a network of tramadol metabolites displaying a dimethylamino radical in their structure, negative ion mode was useful to cluster phase II metabolites. In conclusion, the combined use of molecular networks in positive and negative ion modes is a suitable and robust tool to identify a broad range of metabolites in poisoned patients, as shown in a fatal tramadol-poisoned patient.

A two-decade review of butane toxicity as a substance of abuse

Butane, an aliphatic hydrocarbon with explosive and flammable properties, is widely misused especially by young people. Acting as an asphyxiant gas, butane mainly targets the central nervous and cardiovascular systems. We aimed to review butane-attributed toxicities due to its harmful use or misuse reported in a two-decade period. We searched English-language publications reporting butane toxicities from 2000 up to 2021 and collected data on age, gender, route and source of exposure, country of origin, clinical presentation and outcome. Among 54 butane's harmful use/misuse cases identified in the literature, there were 11 survivors successfully discharged from the hospital. Patients were predominantly males with a mean age ± SD of 23 ± 13 years. The main route of exposure was inhalation. Manifestations were mainly cardiac and neurological. Majority of the cases were reported from Europe and Japan. To conclude, butane exposure is at risk of severe central nervous system and cardiac toxicities, which may result in a fatal outcome. Therefore, in the event of a sudden or suspicious death in a young individual, our findings suggest that butane's harmful use/misuse should be considered as a potential differential diagnosis.

Case series of massive direct oral anticoagulant ingestion-Treatment and pharmacokinetics data

BACKGROUND

Direct oral anticoagulants (DOAC) are widely used due to favourable benefit/risk ratio. However, consequences of massive ingestion have been poorly investigated.

OBJECTIVES

We aimed to report outcome and pharmacokinetic parameters in patients who massively ingested DOACs.

METHODS

We conducted a 5-year cohort study including consecutive massive DOAC ingestion patients admitted to two critical care departments. Patients were managed in accordance with standards of care. We collected the main history, clinical, laboratory, management and outcome data. The time-course of plasma DOAC concentrations measured using specific assays was modelled.

RESULTS

Twelve patients (3F/9M; age, 55 years [41-63], median [25th-75th percentiles]) were included. Ingestions involved rivaroxaban (n = 7), apixaban (n = 3) and dabigatran (n = 2), with presumed doses of 9.4-fold [5.0-22.0] the full daily dose. Six patients received activated charcoal but no antidote nor blood-derived product. No bleeding was observed. One patient died due to refractory cardiogenic shock related to bisoprolol co-intoxication. Highest observed peak plasma concentrations were 1720 ng/ml (rivaroxaban), 750 ng/ml (apixaban) and 644 ng/ml (dabigatran). Times to reach DOAC concentration below 50 ng/ml were ~20-45 h (rivaroxaban), ~125 h (apixaban) and ~30-50 h (dabigatran). Elimination half-lives were 2.5-25.5 h (rivaroxaban), 22.0 and 36.5 h (apixaban), and 5.8 and 15.5 h (dabigatran), with substantial interindividual variability and prolongation in case of cardiovascular failure related to co-intoxicants. Charcoal administration, even if delayed, may have contributed to limit toxicity, possibly by reducing absorption and/or enteroenteric recycling.

CONCLUSION

No bleeding was observed in this series of massive DOAC ingestions despite elevated plasma concentrations. No patient required specific haemostatic agents. Charcoal administration should be considered to limit toxicity.

The risk of COVID-19 death is much greater and age dependent with type I IFN autoantibodies

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection fatality rate (IFR) doubles with every 5 y of age from childhood onward. Circulating autoantibodies neutralizing IFN-α, IFN-ω, and/or IFN-β are found in ∼20% of deceased patients across age groups, and in ∼1% of individuals aged <70 y and in >4% of those >70 y old in the general population. With a sample of 1,261 unvaccinated deceased patients and 34,159 individuals of the general population sampled before the pandemic, we estimated both IFR and relative risk of death (RRD) across age groups for individuals carrying autoantibodies neutralizing type I IFNs, relative to noncarriers. The RRD associated with any combination of autoantibodies was higher in subjects under 70 y old. For autoantibodies neutralizing IFN-α2 or IFN-ω, the RRDs were 17.0 (95% CI: 11.7 to 24.7) and 5.8 (4.5 to 7.4) for individuals <70 y and ≥70 y old, respectively, whereas, for autoantibodies neutralizing both molecules, the RRDs were 188.3 (44.8 to 774.4) and 7.2 (5.0 to 10.3), respectively. In contrast, IFRs increased with age, ranging from 0.17% (0.12 to 0.31) for individuals <40 y old to 26.7% (20.3 to 35.2) for those ≥80 y old for autoantibodies neutralizing IFN-α2 or IFN-ω, and from 0.84% (0.31 to 8.28) to 40.5% (27.82 to 61.20) for autoantibodies neutralizing both. Autoantibodies against type I IFNs increase IFRs, and are associated with high RRDs, especially when neutralizing both IFN-α2 and IFN-ω. Remarkably, IFRs increase with age, whereas RRDs decrease with age. Autoimmunity to type I IFNs is a strong and common predictor of COVID-19 death.

Massive tramadol ingestion resulting in fatal brain injury - a pharmacokinetic study with discussion on the involved mechanisms of toxicity

BACKGROUND

Tramadol-attributed toxicity may involve opioid-like, serotoninergic, and noradrenergic mechanisms. We investigated the mechanisms of toxicity in a massive tramadol ingestion case by examining serial clinical, imaging, electroencephalography, pharmacokinetics, and genotyping data.

CASE REPORT

A 32-year-old female who presumably ingested 9000 mg sustained-release tramadol was found comatose without hypoglycemia, bradypnea, hypotension, marked hypoxemia or seizures. She developed eyelid myoclonus and non-reactive mydriasis. Electroencephalogram showed non-reactive encephalopathy. MRI showed extensive brain injury. Despite supportive care and ventricular derivation, brain death occurred on day 12.

METHODS

Plasma concentrations of tramadol and metabolites were measured using a liquid chromatography-tandem mass spectrometry assay. Genotyping for the presence of metabolizing cytochrome P450 (CYP) gene polymorphisms was performed.

RESULTS

Plasma concentrations of tramadol and metabolites were extremely high (∼70-fold the therapeutic concentrations) and slowly decreased during the first ∼146 h post-admission, possibly due to prolonged gastrointestinal absorption. Elimination half-lives were 2-3-fold longer than usual values. The patient was an intermediate CYP2D6 metabolizer with decreased CYP3A4 and CYP2B6 activities. Clinical and electroencephalographic data did not support the hypotheses of opioid or serotoninergic toxicity nor prolonged/repeated seizures. Based on serial imaging showing progressive extension of ischemic edema in the context of prolonged high plasma concentrations, we hypothesized a cerebral vasospasm as mechanism of injury.

CONCLUSION

Massive tramadol ingestion with prolonged high plasma concentrations can result in severe brain injury, possibly involving vasospasm.

Factors associated with prolonged intensive care stay among self-poisoned patients

CONTEXT

Since recovery or death is generally observed within a few days after intensive care unit (ICU) admission of self-poisoned patients in the developed countries, reasons for the prolonged ICU stay are of interest as they have been poorly investigated. We aimed to identify the characteristics, risk factors, outcome, and predictors of death in self-poisoned patients requiring prolonged ICU management.

METHODS

We conducted an eight-year single-center cohort study including all self-poisoned patients who stayed at least seven days in the ICU. Patients admitted with drug adverse events and chronic overdoses were excluded. Using multivariate analyses, we investigated risk factors for prolonged ICU stay in comparison with a group of similar size of self-poisoned patients with <7day-ICU stay and studied risk factors for death.

RESULTS

Among 2,963 poisoned patients admitted in the ICU during the study period, the number who stayed beyond seven days was small (398/2,963, 13.1%), including 239 self-poisoned patients (125 F/114M; age, 51 years [38-65] (median [25th-75th percentiles]); SAPSII, 56 [43-69]). Involved toxicants included psychotropic drugs (59%), cardiotoxicants (31%), opioids (15%) and street drugs (13%). When compared with patients who stayed <7days in the ICU, acute kidney injury (odds ratio (OR), 3.15; 95% confidence interval (1.36-7.39); p = .008), multiorgan failure (OR, 8.06 (3.43-19.9); p < .001), aspiration pneumonia (OR, 8.48 (4.28-17.3); p < .001), and delayed awakening related to the persistent toxicant effects, hypoxic encephalopathy and/or oversedation (OR, 8.64 (2.58-40.7); p = .002) were independently associated with prolonged ICU stay. In-hospital mortality rate was 9%. Cardiac arrest occurring in the prehospital setting and during the first hours of ICU management (OR, 27.31 (8.99-158.76); p < .001) and delayed awakening (OR, 14.94 (6.27-117.44); p < .001) were independently associated with increased risk of death, whereas exposure to psychotropic drugs (OR, 0.08 (0.02-0.36); p = .002) was independently associated with reduced risk of death.

CONCLUSION

Self-poisoned patients with prolonged ICU stay of ≥7days are characterized by concerning high rates of morbidities and poisoning-attributed complications. Acute kidney injury, multiorgan failure, aspiration pneumonia, and delayed awakening are associated with ICU stay prolongation. Cardiac arrest occurrence and delayed awakening are predictive of death. Further studies should focus on the role of early goal-directed therapy and patient-targeted sedation in reducing ICU length of stay among self-poisoned patients.

Tocilizumab plus dexamethasone versus dexamethasone in patients with moderate-to-severe COVID-19 pneumonia: A randomised clinical trial from the CORIMUNO-19 study group

BACKGROUND

In moderate-to-severe COVID-19 pneumonia, dexamethasone (DEX) and tocilizumab (TCZ) reduce the occurrence of death and ventilatory support. We investigated the efficacy and safety of DEX+TCZ in an open randomized clinical trial.

METHODS

From July 24, 2020, through May 18, 2021, patients with moderate-to-severe COVID-19 pneumonia requiring oxygen (>3 L/min) were randomly assigned to receive DEX (10 mg/d 5 days tapering up to 10 days) alone or combined with TCZ (8 mg/kg IV) at day 1, possibly repeated with a fixed dose of 400 mg i.v. at day 3. The primary outcome was time from randomization to mechanical ventilation support or death up to day 14, analysed on an intent-to-treat basis using a Bayesian approach. ClinicalTrials.gov number, NCT04476979.

FINDINGS

A total of 453 patients were randomized, 3 withdrew consent, 450 were analysed, of whom 226 and 224 patients were assigned to receive DEX or TCZ+DEX, respectively. At day 14, mechanical ventilation or death occurred in 32/226 (14%) and 27/224 (12%) in the DEX and TCZ+DEX arms, respectively (hazard ratio [HR] 0·85, 90% credible interval [CrI] 0·55 to 1·31). At day 14, the World health Organization (WHO) clinical progression scale (CPS) was significantly improved in the TCZ+DEX arm (OR 0·69, 95% CrI, 0·49 to 0.97). At day 28, the cumulative incidence of oxygen supply independency was 82% in the TCZ+DEX arms and 72% in the DEX arm (HR 1·36, 95% CI 1·11 to 1·67). On day 90, 24 deaths (11%) were observed in the DEX arm and 18 (8%) in the TCZ+DEX arm (HR 0·77, 95% CI 0·42-1·41). Serious adverse events were observed in 25% and 21% in DEX and TCZ+DEX arms, respectively.

INTERPRETATION

Mechanical ventilation need and mortality were not improved with TCZ+DEX compared with DEX alone. The safety of both treatments was similar. However, given the wide confidence intervals for the estimate of effect, definitive interpretation cannot be drawn.

FUNDING

Programme Hospitalier de Recherche Clinique [PHRC COVID-19-20-0151, PHRC COVID-19-20-0029], Fondation de l'Assistance Publique - Hôpitaux de Paris (Alliance Tous Unis Contre le Virus) and from Fédération pour la Recherche Médicale" (FRM). Tocilizumab was provided by Roche.

Cytological patterns of bronchoalveolar lavage fluid in mechanically ventilated COVID-19 patients on extracorporeal membrane oxygenation

Introduction

Coronavirus disease‐2019 (COVID‐19) may lead to acute respiratory distress syndrome requiring extracorporeal membrane oxygenation (ECMO). Patterns of inflammatory bronchoalveolar cells in COVID‐19 patients treated with ECMO are not well described.

Objective

We aimed to describe inflammatory cell subpopulations in blood and bronchoalveolar lavages (BALs) obtained in critically ill COVID‐19 patients shortly after ECMO implementation.

Methods

BAL was performed in the middle lobe in 12 consecutive ECMO‐treated COVID‐19 patients. Trained cytologists analyzed peripheral blood and BAL cells using flow cytometry and routine staining, respectively. Data were interpreted in relation to dexamethasone administration and weaning from ECMO and ventilator.

Results

High neutrophil proportions (66% to 88% of total cells) were observed in the absence of bacterial superinfection and more frequently in dexamethasone‐free patients (83% [82–85] vs. 29% [8–68], P = 0.006), suggesting that viral infection could be responsible of predominantly neutrophilic lung inflammation. Successful weaning from ECMO/ventilator could not be predicted by the peripheral white blood and BAL cell pattern.

Conclusion

High neutrophil proportions can be observed in critically ill COVID‐19 patients despite the lack of microbiological evidence on BAL of bacterial superinfection. Dexamethasone was associated with lower neutrophil proportions in BAL. Our study was probably underpowered to provide BAL cell pattern helpful to predict weaning from ECMO/ventilator.

Cumulative Radiation Exposure in Covid-19 Patients Admitted to the Intensive Care Unit

Medical imaging plays a major role in coronavirus disease-2019 (COVID-19) patient diagnosis and management. However, the radiation dose received from medical procedures by these patients has been poorly investigated. We aimed to estimate the cumulative effective dose (CED) related to medical exposure in COVID-19 patients admitted to the intensive care unit (ICU) in comparison to the usual critically ill patients. We designed a descriptive cohort study including 90 successive ICU COVID-19 patients admitted between March and May 2020 and 90 successive non-COVID-19 patients admitted between March and May 2019. In this study, the CED resulting from all radiological examinations was calculated and clinical characteristics predictive of higher exposure risk identified. The number of radiological examinations was 12.0 (5.0–26.0) [median (interquartile range) in COVID-19 vs.4.0 (2.0–8.0) in non-COVID-19 patient (P &lt; 0.001)]. The CED during a four-month period was 4.2 mSv (1.9–11.2) in the COVID-19 vs. 1.2 mSv (0.13–6.19) in the non-COVID-19 patients (P &lt; 0.001). In the survivors, the CED in COVID-19 vs. non-COVID-19 patients was ≥100 mSv in 3% vs. 0%, 10–100 mSv in 23% vs. 15%, 1–10 mSv in 56% vs. 30% and &lt;1 mSv in 18% vs. 55%. The CED (P &lt; 0.001) and CED per ICU hospitalization day (P = 0.004) were significantly higher in COVID-19 than non-COVID-19 patients. The CED correlated significantly with the hospitalization duration (r = 0.45, P &lt; 0.001) and the number of conventional radiological examinations (r = 0.8, P &lt; 0.001). To conclude, more radiological examinations were performed in critically ill COVID-19 patients than non-COVID-19 patients resulting in higher CED. In COVID-19 patients, contribution of strategies to limit CED should be investigated in the future.