[Acute Renal Failure, Lactic Acidosis, and Metformin: Two Case Reports and Literature Review].

Lactic acidosis is a potential adverse event related to metformin therapy. Although metformin-associated lactic acidosis (MALA) is a rare condition (about 10 cases / 100,000 patients / year), new cases continue to be reported, with a mortality of 40-50%. We describe two clinical cases characterized by severe metabolic acidosis, hyperlactacidemia, and acute renal injury. The first also with NSTEMI, successfully treated.

[Alström syndrome, a rare cause of renal failure: case report and review of the literature].

We describe the case of a 26-year-old male patient with a previous diagnosis of Alström Syndrome who presented drowsiness, dyspnea, tremors, and a dull abdominal pain, without signs of peritoneal irritation. The patient also presented sensorineural hearing loss, decreased vision, due to chorioretinal dystrophy, difficulty walking with back-lumbar double curve scoliosis, impaired glycemic homeostasis, and a significant deterioration of renal function. Alström syndrome is a multisystem disease characterized by rod-cone dystrophy, hearing loss, obesity, insulin resistance and hyperinsulinemia, type 2 diabetes mellitus, dilated cardiomyopathy, and progressive renal and hepatic dysfunction. Around 450 cases have been identified worldwide. Clinical signs, age of onset and severity can vary significantly between different families and within the same family. Careful nephrological follow-up is necessary in patients with syndromic ciliopathies, since long-term kidney problems can have an impact on other diseases, eg. cardiovascular disease.

[Lithium sulfate poisoning treated with hemodialysis in a patient with normal renal function: a case report].

Lithium is the milestone of psychiatric patients' therapy, in particular in bipolar disorder. Despite its high therapeutic efficacy, there are several side effects (renal, thyroid, parathyroid, dermatological) and management problems linked to its narrow therapeutic range, which exposes patients to a high risk of toxicity. We describe the case of a male patient with bipolar disorder in therapy with lithium sulfate who developed a severe acute-on-chronic intoxication. He came to our attention in a somnolent state with lithemia >3 mEq/L and therefore underwent hemodialysis. In view of the high toxicity of lithium, a timely and correct therapeutic choice is important to improve the patient's outcome. In this context, considering lithemia, but also kidney function and the patient's clinical status, it is necessary to consider extracorporeal treatments, of which hemodialysis is the most preferable.

Zaleplon improves sleep quality in maintenance hemodialysis patients.

BACKGROUND/AIM: A recent survey has shown that insomnia is still a very common problem in maintenance hemodialysis (MHD) patients. The aim of the present study was to test the effects of zaleplon (ZAL), a new nonbenzodiazepine hypnotic drug, on the sleep quality of MHD patients with insomnia. METHODS: The sleep quality was assessed by the Pittsburgh questionnaire in 10 patients (6 males/4 females) with insomnia on MHD; these patients underwent a randomized double-blind crossover study versus placebo (PLA). The main exclusion criterion was the presence of any possible cause of insomnia related to other concurrent diseases. RESULTS: Treatment with ZAL significantly improved the total score of sleep quality (p < 0.03 vs. PLA). The analysis of the single components revealed that treatment with ZAL was associated with a higher subjective sleep quality (p < 0.01 vs. PLA) and a reduced sleep latency (p < 0.01 vs. PLA). The duration of sleep was not modified by ZAL, whereas a significant improvement was detected in habitual sleep efficacy (p < 0.05 vs. PLA). No peculiar side effect was recorded on ZAL. Blood parameters did not change, nor were differences recorded in the dialysis parameters (body weight gain, blood pressure) throughout the study. CONCLUSIONS: This study suggests that ZAL has a positive effect on the sleep quality in MHD patients. The absence of side effects and its pharmacodynamic properties make ZAL a useful drug in uremic patients.

Arginase inhibition slows the progression of renal failure in rats with renal ablation.

Exogenous arginine slows the progression of chronic renal failure (CRF) in remnant rats through a nitric oxide (NO)-dependent mechanism. We tested whether the inhibition of arginase could induce similar results through the increased availability of endogenous arginine. Three groups of remnant rats were studied for 8 wk: 1) untreated rats (REM); 2) remnant rats treated with 1% l-arginine (ARG); and 3) remnant rats administered a Mn(2+)-free diet to inhibit arginase (MNF). Normal rats (NOR) were used as controls. Liver arginase activity was depressed in MNF rats (-35% vs. REM, P < 0.01). No difference in metabolic data was detected among the groups throughout the study; blood pressure was significantly lower in MNF vs. ARG and REM rats after 6 wk (P < 0.001). The glomerular filtration rate (GFR) was greatly depressed in REM rats (-47% vs. NOR, P < 0.03) but was higher in ARG and MNF rats (+40 and +43% vs. REM, respectively, P < 0.05), with comparable changes in renal hemodynamics. Despite the better GFR, proteinuria was decreased in both ARG and MNF rats (-42%, P < 0.05, and -57%, P < 0.01, respectively, vs. REM rats). Arginine plasma levels, significantly reduced in REM rats (-41% vs. NOR, P < 0.01), were partially restored in MNF rats (+38% vs. REM), and urinary nitrite excretion, greatly depressed in REM rats (-76% vs. NOR, P < 0.01), was significantly increased in MNF rats (+209% vs. REM, P < 0.05). At the renal level, arginase activity was only slightly depressed in MNF rats (-18% vs. REM), but intrarenal concentrations of arginine were lower in this latter group (P < 0.05 vs. other groups). Beyond the hemodynamic modifications, MNF rats showed a lower glomerular sclerosis index (P < 0.05 vs. REM and ARG). Inhibition of arginase slows the progression of CRF in remnant rats similarly to arginine-treated rats; the better histological protection in MNF rats, however, suggests that additional factors are involved in these modifications.

Insomnia in maintenance haemodialysis patients.

BACKGROUND: Studies in the last 15 years have shown a high prevalence of sleep disorders in maintenance haemodialysis (HD) patients. METHODS: To investigate whether the new technical and therapeutic advances of the last decade have had a positive impact on sleep disturbances in HD patients: 694 patients (384 males, 310 females) were surveyed using a specific questionnaire; their clinical, lifestyle and dialysis data were also recorded. RESULTS: Forty-five per cent of patients (n=311; 156 males, 155 females) complained of insomnia, defined either by delayed sleep onset and/or night-time waking, and were included in the insomnia group; the remainder were used as controls (control group). There was a significantly higher risk of insomnia in patients with >12 months on dialysis, in patients dialysed in the morning (P<0.003), and in patients with higher parathyroid hormone (PTH) levels (P<0.05). Body mass index, body weight gain and blood pressure did not differ between the groups, and neither did the dialysis parameters. Creatinine and urea plasma levels were higher in the control group vs the insomnia group (P<0.001), but there was no difference in haemoglobin concentrations or use of erythropoietin, calcitriol and antihypertensive drugs. Cigarette smoking, caffeine or alcohol intake were comparable in the two groups. The most frequently recorded sleep disorders were night-time waking (92%), trouble falling asleep (67%) and early morning waking (62%). Restless leg symptoms were described in 52% of patients with insomnia. CONCLUSIONS: The prevalence of insomnia in HD patients is still very high; elderly patients, and those with longer time on dialysis and high levels of PTH are at major risk of insomnia, whereas type of dialysis, haemoglobin levels and behavioural factors do not seem to play a critical role in determining this sleep disorder.