Impaired renal endothelial nitric oxide synthase and reticulocyte production as modulators of hypertension induced by recombinant human erythropoietin in the rat

INTRODUCTION AND AIMS: Hypertension is a common side effect of recombinant human erythropoietin (rHuEPO) therapy; however, the exact pathways remain to be elucidated. The discovery of non-hematopoietic actions of rHuEPO increased the number of patients that could putatively benefit from this therapy; however, to achieve those effects higher doses are usually needed, which increase the risk and incidence of adverse events. Our aim was to study the effect of a broad range of rHuEPO doses on hematological and biochemical parameters, blood pressure and renal function and damage in the rat, focusing on endothelial nitric oxide synthase (eNOS) and hypoxia-inducible factors (HIFs). METHODS: Male Wistar rats were divided in 5 groups receiving different doses of rHuEPO (100, 200, 400 and 600 IU/kg body weight (BW)/week) and saline solution (control), during 3 weeks. Blood and 24h urine were collected to perform hematological and biochemical analysis. Blood pressure (BP) was measured by the tail-cuff method. The kidney tissue was collected to mRNA and protein expression assays and to characterize renal lesions. RESULTS: A dose-dependent increase in red blood cells count, hematocrit and hemoglobin levels was found with rHuEPO therapy, in rHuEPO200, rHuEPO400 and rHuEPO600 groups. Increased reticulocyte count was found in the rHuEPO400 and rHuEPO600 groups. BP raised in all groups receiving rHuEPO. The rHuEPO200 and rHuEPO600 groups presented increased kidney protein levels of HIF2α and a reduction in kidney protein levels of eNOS, along with the highest grade of vascular and tubular renal lesions. CONCLUSIONS: Our study showed that rHuEPO-induced hypertension might involve indirect (hematological) and direct (renal) effects which varies according to the dose used. Thus, rHuEPO therapy should be performed rationally and under adequate surveillance, as hypertension develops even with lower doses. Especial caution with higher doses should be taken, as rHuEPO-induced hypertension leads to early renal damage without alterations in traditional markers of renal function, thus masking the serious adverse effects and risks.

Pain assessment in surgical patients with impaired cognition

Pain is considered the 5th vital sign and its measurement/assessment and records are required and must be systematic. Ineffective pain management involves complications in clinical status of patients, longer hospitalization times and higher costs with health. In the surgical patient with impaired cognition, hetero measurements should be made, based on behavioural and physiological indicators. We used to determine the efficacy and efficiency of the Observer Scale, the Abbey Pain Scale and Pain Assessment in Advanced Dementia (PAINAD). Our study is an applied, non-experimental, quantitative, descriptive and analytical research. The data collection instrument consisted of patients’ sociodemographic and clinical data, the Observer Scale, the Abbey Pain Scale (Rodrigues, 2013) and PAINAD (Batalha et al., 2012). We assessed pain at an early phase and 45 minutes after an intervention for its relief. The sample is non-probabilistic for convenience, consisting of 76 surgical patients with impaired cognition, admitted to the surgery services of a central hospital, aged between 38 and 96 years. There was a positive correlation between the results of the three scales, most evident in the initial evaluation. Pain intensity in the same patient is higher when assessed with PAINAD (OM = 2.16) and lower when assessed with the Observer Scale (OM = 1.78). The most effective and efficient scale is PAINAD. Due to the small sample size, we suggest confirmatory studies so that the results can be generalized.