Typical phenotypes of patients with acute respiratory failure with and without COVID-19 and their relationship with outcomes: a cohort study / Fenótipos característicos em pacientes com insuficiência respiratória aguda com e sem COVID-19 e sua relação com os desfechos: um estudo de coorte

ABSTRACT Objective: To compare, within a cohort of patients with acute respiratory failure, the phenotypes of patients with and without COVID-19 in the context of the pandemic and evaluate whether COVID-19 is an independent predictor of intensive care unit mortality. Methods: This historical cohort study evaluated 1001 acute respiratory failure patients with suspected COVID-19 admitted to the intensive care unit of 8 hospitals. Patients were classified as COVID-19 cases and non-COVID-19 cases according to real-time polymerase chain reaction results. Data on clinical and demographic characteristics were collected on intensive care unit admission, as well as daily clinical and laboratory data and intensive care unit outcomes. Results: Although the groups did not differ in terms of APACHE II or SOFA scores at admission, the COVID-19 group had more initial symptoms of fever, myalgia and diarrhea, had a longer duration of symptoms, and had a higher prevalence of obesity. They also had a lower PaO2/FiO2 ratio, lower platelet levels than non-COVID-19 patients, and more metabolic changes, such as higher levels of blood glucose, C-reactive protein, and lactic dehydrogenase. Patients with non-COVID-19 acute respiratory failure had a higher prevalence of chronic obstructive pulmonary disease/asthma and cardiopathy. Patients with COVID-19 stayed in the hospital longer and had more complications, such as acute kidney failure, severe acute respiratory distress syndrome and severe infection. The all-cause mortality rate was also higher in this group (43.7% in the COVID-19 group versus 27.4% in the non-COVID-19 group). The diagnosis of COVID-19 was a predictor of intensive care unit mortality (odds ratio, 2.77; 95%CI, 1.89 - 4.07; p < 0.001), regardless of age or Charlson Comorbidity Index score. Conclusion: In a prospective cohort of patients admitted with acute respiratory failure, patients with COVID-19 had a clearly different phenotype and a higher mortality than non-COVID-19 patients. This may help to outline more accurate screening and appropriate and timely treatment for these patients.

RESUMO Objetivo: Comparar, em uma coorte de pacientes com insuficiência respiratória aguda, os fenótipos de pacientes com e sem COVID-19, no contexto da pandemia, e avaliar se a COVID-19 é um preditor independente de mortalidade na unidade de terapia intensiva. Métodos: Este estudo de coorte histórico avaliou 1.001 pacientes com insuficiência respiratória aguda e suspeita de COVID-19 internados na unidade de terapia intensiva de oito hospitais. Os pacientes foram classificados como casos com e sem COVID-19 segundo os resultados da RT-PCR. Foram coletados dados sobre características clínicas e demográficas na admissão à unidade de terapia intensiva, bem como dados clínicos e laboratoriais diários e desfechos da unidade de terapia intensiva. Resultados: Embora os grupos não tenham diferido nos escores APACHE II ou SOFA na admissão, o grupo COVID-19 apresentou mais sintomas iniciais de febre, mialgia e diarreia e teve maior duração dos sintomas e maior prevalência de obesidade. Eles também apresentaram menor relação PaO2/FiO2 e níveis mais baixos de plaquetas do que os pacientes sem COVID-19 e mais alterações metabólicas, como níveis mais altos de glicemia, proteína C-reativa e desidrogenase lática. Os pacientes com insuficiência respiratória aguda sem COVID-19 apresentaram maior prevalência de doença pulmonar obstrutiva crônica/asma e cardiopatia. Os pacientes com COVID-19 permaneceram mais tempo no hospital e tiveram mais complicações, como insuficiência renal aguda, síndrome do desconforto respiratório agudo grave e infecção grave. A taxa de mortalidade por todas as causas também foi maior nesse grupo (43,7% no grupo com COVID-19 versus 27,4% no grupo sem COVID-19). O diagnóstico de COVID-19 foi um preditor de mortalidade na unidade de terapia intensiva (razão de chances de 2,77; IC95% 1,89 - 4,07; p < 0,001), independentemente da idade ou da pontuação do Índice de Comorbidade de Charlson. Conclusão: Em uma coorte prospectiva de pacientes admitidos com insuficiência respiratória aguda, os pacientes com COVID-19 apresentaram fenótipo claramente diferente e uma mortalidade mais alta do que os pacientes sem COVID-19. Isso pode ajudar a traçar uma triagem mais precisa e um tratamento adequado e oportuno para esses pacientes.

Blockade of kappa opioid receptors reduces mechanical hyperalgesia and anxiety-like behavior in a rat model of trigeminal neuropathic pain.

It has been shown that kappa opioid receptor (KOR) antagonists, such as nor-binaltorphimine (nor-BNI), have antinociceptive effects in some pain models that affect the trigeminal system. Also, its anxiolytic-like effect has been extensively demonstrated in the literature. The present study aimed to investigate the systemic, local, and central effect of nor-BNI on trigeminal neuropathic pain using the infraorbital nerve constriction model (CCI-ION), as well as to evaluate its effect on anxiety-like behavior associated with this model. Animals received nor-BNI systemically; in the trigeminal ganglion (TG); in the subarachnoid space to target the spinal trigeminal nucleus caudalis (Sp5C) or in the central amygdala (CeA) 14 days after CCI-ION surgery. Systemic administration of nor-BNI caused a significant reduction of facial mechanical hyperalgesia and promoted an anxiolytic-like effect, which was detected in the elevated plus-maze and the light-dark transition tests. When administered in the TG or CeA, the KOR antagonist was able to reduce facial mechanical hyperalgesia induced by CCI-ION, but without changing the anxiety-like behavior. Moreover, no change was observed on nociception and anxiety-like behavior after nor-BNI injection into the Sp5C. The present study demonstrated antinociceptive and anxiolytic-like effects of nor-BNI in a model of trigeminal neuropathic pain. The antinociceptive effect seems to be dissociated from the anxiolytic-like effect, at both the sites involved and at the dose need to achieve the effect. In conclusion, the kappa opioid system may represent a promising target to be explored for the control of trigeminal pain and associated anxiety. However, further studies are necessary to better elucidate its functioning and modulatory role in chronic trigeminal pain states.

Effects of curcumin on short-term spatial and recognition memory, adult neurogenesis and neuroinflammation in a streptozotocin-induced rat model of dementia of Alzheimer's type.

Curcumin is a natural polyphenol with evidence of antioxidant, anti-inflammatory and neuroprotective properties. Recent evidence also suggests that curcumin increases cognitive performance in animal models of dementia, and this effect would be related to its capacity to enhance adult neurogenesis. The aim of this study was to test the hypothesis that curcumin treatment would be able to preserve cognition by increasing neurogenesis and decreasing neuroinflammation in the model of dementia of Alzheimer's type induced by an intracerebroventricular injection of streptozotocin (ICV-STZ) in Wistar rats. The animals were injected with ICV-STZ or vehicle and curcumin treatments (25, 50 and 100mg/kg, gavage) were performed for 30days. Four weeks after surgery, STZ-lesioned animals exhibited impairments in short-term spatial memory (Object Location Test (OLT) and Y maze) and short-term recognition memory (Object Recognition Test - ORT), decreased cell proliferation and immature neurons (Ki-67- and doublecortin-positive cells, respectively) in the subventricular zone (SVZ) and dentate gyrus (DG) of hippocampus, and increased immunoreactivity for the glial markers GFAP and Iba-1 (neuroinflammation). Curcumin treatment in the doses of 50 and 100mg/kg prevented the deficits in recognition memory in the ORT, but not in spatial memory in the OLT and Y maze. Curcumin treatment exerted only slight improvements in neuroinflammation, resulting in no improvements in hippocampal and subventricular neurogenesis. These results suggest a positive effect of curcumin in object recognition memory which was not related to hippocampal neurogenesis.