Mechanisms of gas transfer impairment utilizing nitric oxide following severe COVID-19 pneumonitis.

Reduced carbon monoxide diffusing capacity (DLCO ) is common after recovery from severe COVID-19 pneumonitis. The extent to which this relates to alveolar membrane dysfunction as opposed to vascular injury is uncertain. Simultaneous measurement of nitric oxide diffusing capacity (DLNO ) and DLCO can partition gas diffusion into its two components: alveolar-capillary membrane conductance (DmCO ) and capillary blood volume (VC ). We sought to evaluate DmCO and VC in the early and later recovery periods after severe COVID-19. Patients attended for post-COVID-19 clinical review and lung function testing including DLNO /DLCO . Repeat testing occurred when indicated and comparisons made using t-tests. Forty-nine (eight female) subjects (mean ± SD age: 58 ± 13, BMI: 34 ± 8) who had severe COVID-19 pneumonitis, WHO severity classification of 6 ± 1, and prolonged (21 ± 22 days) hospital stay, were assessed 2 months (61 ± 35 days) post discharge. DLCO adj (z-score -1.70 ± 1.49, 25/49 < lower limit of normal [LLN]) and total lung capacity (z-score -1.71 ± 1.30) were both reduced. DmCO and VC and were reduced to a similar extent (z-score -1.19 ± 1.05 and -1.41 ± 1.20, p = 0.4). Seventeen (one female) patients returned for repeat testing 4 months (122 ± 61 days) post discharge. In this subgroup with more impaired lung function, DLCO adj improved but remained below LLN (z-score -3.15 ± 0.83 vs. -2.39 ± 0.86, p = 0.01), 5/17 improved to >LNN. DmCO improved (z-score -2.05 ± 0.89 vs. -1.41 ± 0.78, p = 0.01) but VC was unchanged (z-score -2.51 ± 0.55 vs. -2.29 ± 0.59, p = 0.16). Alveolar membrane conductance is abnormal in the earlier recovery phase following severe COVID-19 but significantly improves. In contrast, reduced VC persists. These data raise the possibility that persisting effects of acute vascular injury may contribute to gas diffusion impairment long after severe COVID-19 pneumonitis.

Analytical methods for the determination of antidepressants, antipsychotics, benzodiazepines and their metabolites through wastewater-based epidemiology

The wastewater-based epidemiology approach, popular for estimating illicit drug use, has been used to evaluate lifestyle habits such as alcohol, tobacco and caffeine consumption, health biomarkers including pharmaceuticals, plasticizers and flame retardants, and recently to track SARS-CoV-2 at the population level. Equally, the number of WBE studies investigating psychoactive pharmaceuticals such as antidepressants, antipsychotics and benzodiazepines has also increased, which can be connected to the overall growth of psychological disorders worldwide. This review aims to discuss novelties in sampling techniques and analytical methodologies, including sample preparation and analysis, developed for estimating the consumption of psychoactive pharmaceuticals in defined populations. Seventy-four peer-reviewed studies monitoring psychoactive pharmaceutical consumption published since 2010 have been systematically reviewed. Its findings show that a broad range of bioanalytical methodologies is used to simultaneously measure several antidepressants, antipsychotics, benzodiazepines, and their metabolites from influent wastewater samples in low concentrations and different time periods. The application of WBE commenting on the temporal and spatial variations worldwide, showing widespread consumption, is also discussed. Despite much progress and excellent studies, there remains a need for research, and deeper knowledge is needed to reduce method uncertainty, especially since excretion rates, their transformation, and in-sewer and in-sample stability for many psychoactive pharmaceutical biomarkers are not available.