Near-infrared spectroscopy parameters in patients undergoing continuous venovenous hemodiafiltration / Espectroscopia no infravermelho próximo em pacientes sob hemodiafiltração venovenosa contínua

ABSTRACT Objective To investigate the impacts of continuous venovenous hemodiafiltration on the microcirculation in patients with acute kidney injury. Methods A prospective observational pilot study conducted in a 40-bed, open clinical-surgical intensive care unit of a private tertiary care hospital located in the city of São Paulo (SP), Brazil. Microcirculation was assessed using near-infrared spectroscopy by means of a 15mm probe placed over the thenar eminence. Vascular occlusion test was performed on the forearm to be submitted to near-infrared spectroscopy by inflation of a sphygmomanometer cuff to 30mmHg higher than the systolic arterial pressure. The primary endpoint was the assessment of near-infrared spectroscopy-derived parameters immediately before, 1, 4 and 24 hours after the initiation of continuous venovenous hemodiafiltration. Results Nine patients were included in this pilot study over a period of 2 months. Minimum tissue oxygen saturation measured during the vascular occlusion test was the only near-infrared spectroscopy-derived parameter to differed over the time (decrease compared to baseline values up to 24 hours after initiation of continuous venovenous hemodiafiltration). Conclusion The impacts of microcirculatory dysfunction on clinical outcomes of patients undergoing to continuous venovenous hemodiafiltration need to be further investigated.

RESUMO Objetivo Avaliar o impacto da hemodiafiltração venovenosa contínua na microcirculação de pacientes com lesão renal aguda. Métodos Estudo piloto, prospectivo e observacional conduzido em uma unidade de terapia intensiva clínico-cirúrgica aberta, com 40 leitos, localizada em um hospital terciário, privado, na cidade de São Paulo (SP), Brasil. A microcirculação foi avaliada empregando-se a espectroscopia no infravermelho próximo, por meio de uma sonda de 15mm posicionada sobre a eminência tenar. O teste de oclusão vascular foi realizado no antebraço a ser submetido à espectroscopia no infravermelho próximo, inflando-se o manguito de um esfigmomanômetro a um valor 30mmHg acima da pressão arterial sistólica. O desfecho primário foi a avaliação dos parâmetros derivados por espectroscopia no infravermelho próximo imediatamente antes, 1, 4 e 24 horas após o início da hemodiafiltração venovenosa contínua. Resultados Foram incluídos nove pacientes neste estudo piloto ao longo de 2 meses. A saturação de oxigênio tecidual mínima mensurada durante o teste de oclusão vascular foi o único parâmetro derivado por espectroscopia no infravermelho próximo que diferiu ao longo do tempo, com queda em relação aos valores iniciais nas primeiras 24 horas após o início da hemodiafiltração venovenosa contínua. Conclusão A influência da disfunção microcirculatória sobre os desfechos clínicos de pacientes submetidos à hemodiafiltração venovenosa contínua precisa ser melhor investigada.

Contrast-Induced Acute Kidney Injury after Coil Embolization for Aneurysmal Subarachnoid Hemorrhage

PURPOSE: Contrast-induced acute kidney injury (CI-AKI) is associated with poor outcomes after percutaneous coronary intervention. However, CI-AKI has rarely been evaluated within the neurovascular field. The aim of this study was to investigate the incidence and clinical implication of CI-AKI after coil embolization in patients with an aneurysmal subarachnoid hemorrhage (aSAH). MATERIALS AND METHODS: Between January 2005 and March 2016, 192 patients who underwent coil embolization were enrolled in this study. CI-AKI was defined as an increase from baseline serum creatinine concentration of >25% or >0.5 mg/dL within 72 hours after coil embolization. A poor clinical outcome was defined as a score of ≥3 on the modified Rankin Scale at one-year post-treatment. RESULTS: A total of 16 patients (8.3%) died as a result of medical problems within one year. CI-AKI was identified in 14 patients (7.3%). Prominent risk factors for one-year mortality included CI-AKI [odds ratio (OR): 16.856; 95% confidence interval (CI): 3.437–82.664] and an initial Glasgow Coma Scale (GCS) score ≤8 (OR: 5.565; 95% CI: 1.703–18.184). A poor clinical outcome was associated with old age (≥65 years) (OR: 7.921; 95% CI: 2.977–21.076), CI-AKI (OR: 11.281; 95% CI: 2.138–59.525), an initial GCS score ≤8 (OR 31.02; 95% CI, 10.669–90.187), and a ruptured aneurysm (p=0.016, OR: 4.278) in posterior circulation. CONCLUSION: CI-AKI seems to be an independent predictor of the overall outcomes of aSAH after endovascular treatment.

Attenuation of partial unilateral ureteral obstruction - induced renal damage with hyperbaric oxygen therapy in a rat model

ABSTRACT Objective: The objective of the present study was to evaluate the effectiveness of HBO therapy on biochemical parameters, renal morphology and renal scintigraphy in rats undergoing chronic unilateral partial ureteral obstruction (UPUO). Material and methods: Thirty-five rats were divided into five equal groups: Control group; Sham group; HBO group; UPUO group and UPUO/HBO group. The effects of HBO therapy were examined using biochemical parameters and histopathological changes. After calculating the score for each histopathological change, the total histopathological score was obtained by adding all the scores. In addition, dynamic renal scintigraphy findings were evaluated. Results: Serum parameters indicating inflammation, serum tumor necrosis factor- alpha, ischemia modified-albumin, IMA/albumin ratio and Pentraxin-3 levels, were observed to be high in the UPUO group and low in the UPUO/HBO treatment group. Similarly, in the treatment group, the reduction in malondialdehyde, total oxidant status and oxidative stress index levels and increase in total antioxidant capacity values were observed to be statistically significant compared to the UPUO group (p<0.001, p=0.007, p<0.001, p=0.001, respectively). The total score and apoptosis index significantly decreased after administration of HBO treatment. Dynamic 99mTc-MAG3 renal scintigraphy also showed convincing evidence regarding the protective nature of HBO against kidney injury. In the UPUO/HBO therapy group, the percentage contribution of each operated kidney increased significantly compared to the UPUO group (41.73% versus 32.72%). Conclusion: The findings of this study indicate that HBO therapy had a reno-protective effect by reducing inflammation and oxidative stress, and preserving renal function after renal tissue damage due to induction of UPUO.