Customized bicarbonate buffered dialysate and replacement solutions for continuous renal replacement therapies: effect of crystallization on the measured levels of electrolytes and buffer.

The aim of this study was to investigate the impact of the addition of calcium to bicarbonate solutions for continuous renal replacement therapy (CRRT). We tested single bag (bicarbonate and calcium mixed 24 h before testing) and double bag solutions (mixed immediately before) with and without the addition of 4 mEq/L of acetate. Prescribed calcium varied from 0 to 5 mEq/L. All test solutions containing calcium showed crystallization at light microscopy. The double bag solutions decreased but did not prevent crystallization. The addition of acetate did not interfere with crystallization. Crystallization, as measured by the weight of the crystals after filtration of the solutions, showed a significant positive correlation with the calcium deficit (prescribed minus measured) and with partial pressure of carbon dioxide. The measured level of calcium was lower than expected and correlated with crystallization. Our results suggest that the use of bicarbonate solutions containing calcium as replacement fluids for CRRT is a potentially unsafe procedure.

The effects of isradipine and spirapril as monotherapy and combined therapy on blood pressure, renal hemodynamics, natriuresis, and urinary kallikrein in hypertensive nephropathy.

In this cross-over, double-blind study, 12 essential hypertensive patients (stage I, II, and III) with glomerular filtration rate (GFR) between 50 to 80 mL/min/1.73 m2, were submitted to 4 weeks of placebo followed by 12 weeks with isradipine SRO (IS) 5 mg, spirapril (SP) 6 mg, and isradipine plus spirapril (IS + SP). The study evaluated the effects of these drugs on GFR ((99m)Tc DTPA), effective renal plasma flow (ERPF) ((131)I-orthoiodohippurate), urinary sodium excretion (UNaV), urinary kallikrein excretion (UKal), urinary albumin excretion (UAE), and plasma renin activity (PRA). The three protocols significantly reduced mean blood pressure (128 v 107 mm Hg; 126 v 112 mm Hg; 129 v 104 mm Hg with IS, SP and IS + SP, respectively). ERPF and GFR did not change. UNaV increased significantly after IS (0.17 v 0.22 mEq/min) and IS + SP (0.18 v 0.24 mEq/min). UKal increased significantly after IS (58.6%) and IS + SP (53.6%). UAE decreased significantly only after SP. PRA increased significantly after IS (1.31 v 2.84 ng/mL/h), SP (1.10 v 2.15 ng/mL/h), and after IS + SP (1.23 v 3.21 ng/mL/min). In conclusion, IS, SP and IS + SP were effective in reducing blood pressure while keeping renal function stable. Only SP significantly decreased UAE. Enhanced UKal may have played a role in natriuresis observed after IS and IS + SP.

Early gestational hemolytic uremic syndrome: case report and review of literature.

Hemolytic uremic syndrome (HUS) is a rare condition which most frequently follows gastrointestinal or respiratory infection episodes in young children, but it can also occur in other settings such as the postpartum period and during use of drugs such as oral contraconceptives, immunosuppressors, and antineoplastics. In early pregnancy, however, its frequency is thought to be very low. The authors report a case of a 30-year-old woman who developed HUS early in her first pregnancy. She had persistent aqueous diarrhea from the beginning of the pregnancy. At the 21st week she developed hypertension which in 2 weeks was followed by seizures, oliguria, and acute pulmonary edema despite intensive medical efforts to control her blood pressure. Surgical intervention for fetal delivery was performed. The patient was initially kept on continuous hemodialysis (CVVHD) followed by an alternate-day conventional hemodialysis schedule. A peripheral blood analysis showed a microangiopathic hemolytic anemia with thrombocytopenia; blood coagulation tests were completely normal. A brain CT scan and an abdominal MRI showed no major abnormalities. HUS was confirmed by a percutaneal kidney biopsy, performed at the 21st day of anuria. Techniques for identification of verotoxin-producing E. coli were not available. Renal function did not recover and the patient has been undergoing regular maintenance hemodialysis for a year.