Diltiazem infusion for renal protection in cardiac surgical patients with preexisting renal dysfunction

Objective: To evaluate if the calcium channel blocker diltiazem protects postoperatively renal function in cardiac surgical patients with preexisting mild-to-moderate renal dysfunction. Design: Prospective, randomized, placebo-controlled, double-blind, clinical study. Setting: Cardiothoracic anesthesia department at a university hospital. Participants: Adult patients undergoing elective cardiac surgery using cardiopulmonary bypass, with a preoperatively elevated serum creatinine level (n = 24). Interventions: Randomized infusions of diltiazem (bolus 0.25 mg/kg followed by a continuous infusion of 1.7 pg/kg/min) (DTZ, n = 12) or placebo (C, n = 12) were started 30 minutes before induction of anesthesia and continued for 24 hours. Measurements and Main Results: Median plasma concentrations of diltiazem (DTZ group) were 79 mug/L before cardiopulmonary bypass, 67 mug/L at the end of cardiopulmonary bypass, and 164 mug/L at 24 hours postoperatively. Serum creatinine levels; on postoperative days 1, 3, and 5; and 3 weeks postoperatively were similar between groups. lohexol clearance did not differ between the groups on day 5 but was higher in the DTZ group than in the placebo group 3 weeks after surgery (median, 51 v 40 mL/min/1.73 m(2); p < 0.05). Urinary N-acetyl-β-glucosamidase concentrations were similar between the groups during the study but were increased from baseline on days 2 and 4 and 3 weeks postoperatively. Conclusion: Diltiazem can be safely used in patients who have mild-to-moderate renal dysfunction and undergo cardiac surgery using cardiopulmonary bypass. Within the limits of this study, the data suggest that addition of prophylactic diltiazem may prevent further glomerular damage resulting from cardiopulmonary bypass and may improve glomerular function 3 weeks after cardiac surgery

Home haemodialysis and uraemic toxin removal: does a happy marriage exist?

Home-based methods of haemodialysis are becoming of increasing interest. In this article, we review theoretical and evidence-based aspects of dialysis adequacy in the home setting compared with those of standard in-centre dialysis. Owing to the flexibility it enables, home haemodialysis may allow reduced blood flow rates and the successful use of less-efficient access systems. With home haemodialysis, Kt/V-urea targets should be pursued as recommended in current guidelines, taking into account that this parameter does not reflect a number of essential elements that affect adequacy, such as dialyser pore size or alternative timeframes-factors that might be applicable to modern home haemodialysis. The use of high-flux, large-pore haemodialysers is associated with improved removal of large uremic toxins and should be considered as standard in home haemodialysis where possible, although dialysis water purity is crucial. Large molecule removal is further enhanced by applying convective strategies (such as haemo[dia]filtration), but these strategies greatly increase technical complexity. Alternate-day haemodialysis is more desirable than the usual thrice-weekly approach to avoid complications at the end of the long weekend interval, and it is easier to implement such a regime at home than in-centre. Frequent, prolonged, and combined frequent and prolonged dialysis regimes are all associated with improved removal and improved outcomes. All three alternative timeframes are easier to apply at home than in-centre. Home haemodialysis offers increased flexibility in adopting dialysis regimes that make it possible to improve solute removal and, therefore, outcomes