Role of acetylcysteine in the prevention of contrast-media-induced nephrotoxicity.

The role of acetylcysteine in the prevention of contrast-media-induced nephrotoxicity was retrospectively studied. The medical records of patients undergoing cardiac catheterization between January 2000 and March 2002 were reviewed. The outcomes of patients with serum creatinine (SCr) concentrations above 1.2 mg/dL who were undergoing cardiac catheterization with contrast agents and received prophylactic acetylcysteine with i.v. hydration were compared with those of a control group who did not receive acetylcysteine. SCr concentrations were recorded 24 hours before administration of the contrast agent and 48-72 hours afterward for both groups. Sixty patients were included in the study: 32 in the acetylcysteine group and 28 in the control group. Both groups were comparable in demographics, disease states, drug regimens, and risk factors for developing contrast-agent-induced nephrotoxicity. In the acetylcysteine group, the median SCr concentration before receiving the contrast agent was 1.7 mg/dL and remained the same afterward. The median SCr concentration in the control group before administration of the contrast agent and 48-72 hours afterward was 1.6 and 1.9 mg/dL, respectively. The median change in SCr concentrations was greater in the control group than in the acetylcysteine group (0.25 and 0 mg/dL, respectively) (p = 0.001). The percentage of patients developing acute renal failure was greater in the control group than in the treatment group (25% versus 12.5%, respectively) (p = 0.21). The use of prophylactic oral acetylcysteine, combined with i.v. hydration, significantly reduced SCr levels after the administration of contrast media.

Alteplase versus urokinase in restoring blood flow in hemodialysis-catheter thrombosis.

The effectiveness of alteplase and urokinase in restoring adequate hemodialysis blood-flow rates was examined. A retrospective review of the medical records of hemodialysis patients with central venous catheters receiving alteplase or urokinase for presumed catheter thrombosis between June 1997 and December 2000 was conducted. Patients received 1 mL of alteplase 1 mg/mL or 1 mL of urokinase 5000 units/mL in each catheter port. The choice of the thrombolytic agent was left to the prescriber. Effectiveness of thrombolysis was defined as achieving a posttreatment hemodialysis blood-flow rate of > 300 mL/min, maintained for at least 30 minutes during the dialysis session. Inclusion criteria included adherence to the thrombolytic protocol and the inability to achieve a hemodialysis blood-flow rate of > 300 mL/min during the first 60 minutes of the hemodialysis session despite at least one attempt to reposition the catheter. Both thrombolytic agents significantly increased the hemodialysis blood-flow rates. Patients with alteplase-treated catheters were twice as likely to achieve hemodialysis blood-flow rates of > 300 mL/min (p = 0.0134) and were more likely to complete hemodialysis during that session (93% versus 70%, p = 0.0234). The percentage of functioning catheters at a subsequent hemodialysis session did not significantly differ between groups (p = 0.0806). The majority of patients in both treatment groups required no further interventions. Hemodialysis blood-flow rates increased after either alteplase 1 mg/mL per port or urokinase 5000 units per port was used to clear presumed catheter thrombosis. Alteplase was more likely than urokinase to result in a hemodialysis blood-flow rate of > 300 mL/min.