CVP-guided hydration reduced risk of contrast-induced nephropathy

Patients with kidney disease and heart failure who were randomized to hydration guided by central venous pressure received more fluid and had less contrast-induced nephropathy than those receiving standard hydration, according to a Chinese trial.

Using central venous pressure (CVP) to guide IV hydration reduced contrast-induced nephropathy in patients with chronic kidney disease and heart failure undergoing coronary procedures, a Chinese study found.

The trial randomized 264 patients with kidney disease and heart failure to either standard hydration or guided hydration, in which the hydration infusion rate was adjusted every hour according to CVP level. Average estimated glomerular filtration rate was 36 mL/min/1.73m2 in the guided hydration group versus 39 mL/min/1.73m2 in the standard hydration group (P=0.224). All of the patients were given 0.9% sodium chloride starting 6 hours before coronary angiography and continuing 12 hours afterward. Contrast-induced nephropathy was defined as an absolute increase in serum creatinine >0.5 mg/dL or a relative increase >25% of baseline.

The CVP group had a much lower rate of contrast-induced nephropathy than the standard hydration group: 15.9% vs. 29.5% (P=0.006). They also received significantly more fluid (mean of 1,827 mL vs. 1,202 mL) and had greater urine volume (1,461 mL vs. 806 mL). Major adverse events within 90 days of the procedure were lower in the CVP group than the control group (8.3% vs. 20.5%; P=0.004), and similar percentages of patients developed acute heart failure during hydration (3.8% vs. 3.0%). Results were published by JACC: Cardiovascular Interventions on Dec. 9.

The study authors concluded that CVP-guided fluid administration can safely and effectively reduce the risk of contrast-induced nephropathy in patients with kidney disease and heart failure. They noted that such patients are at high risk of this complication but that aggressive volume expansion is not suitable for all high-risk patients, such as those with acute decompensated heart failure. There are a number of mechanisms by which volume expansion may reduce contrast-induced nephropathy, the authors said.

This intervention is one of a number of recent efforts to maximize hydration in patients at risk for contrast-induced nephropathy without sacrificing safety, according to an accompanying editorial. Other options include measuring left ventricular end diastolic pressure or using a forced diuresis system. “These results reaffirm the importance of giving as much IV fluid as possible,” the editorial said, noting that increasing hydration does not entirely eliminate contrast-induced nephropathy, so other novel therapies are needed.

The December ACP Hospitalist has an article about strategies for preventing acute kidney injury.