Aymen M’rad

Nitazenes represent an emerging class of new synthetic opioids characterized by a high-potency μ-opioid receptor (MOR) agonist activity. Background: We report two 20-year-old males who presented with severe neurorespiratory depression with typical opioid syndrome, but no opioid identification based on routine blood and urine screening tests. The first patient recovered with supportive care, mechanical ventilation, and naloxone infusion, whereas the second patient developed post-anoxic cardiac arrest and died from brain death. Methods: A complementary comprehensive toxicological screening using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) was performed, and data were processed using a dedicated molecular network strategy to profile the metabolites. Results: Protonitazene and protonitazepyne, two nitazenes differing in their ethylamine moieties (i.e., a diethyl versus a pyrrolidine substitution, respectively), were identified. We found an extensive metabolism of protonitazene, leading to the identification of multiple phase I (resulting from hydroxylation, N-desethylation, and O-despropylation) and phase II (resulting from glucuronidation) metabolites. By contrast, protonitazepyne metabolism appeared limited, with one metabolite annotated confidently, protonitazepyne acid, which resulted from the oxidative pyrrolidine ring cleavage. Concusions: To conclude, nitazene detection is highly challenging due to its extensive structural and metabolic diversity. Our findings highlight the contribution of the untargeted LC-HRMS screening approach and suggest that diagnostic product ions can serve as robust markers for nitazene identification.

(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.