Meta-analysis of intravascular volume expansion strategies to prevent contrast-associated acute kidney injury following invasive angiography

Objective: To perform a detailed analysis of published data regarding intravascular volume expansion to prevent contrast-associated acute kidney injury (CA-AKI) and to determine if an ideal dose of IV fluids can be recommended. Background: Administration of contrast media during invasive angiography is associated with CA-AKI. Intravascular volume expansion is the most effective intervention to prevent CA-AKI, yet evidenced based protocols are lacking. Methods: Literature review and meta-analysis of randomized controlled trials (RCT) of patients receiving IV volume expansion as prophylaxis for CA-AKI was performed. Normal saline, Lactated Ringer's and sodium bicarbonate were included. The primary outcome was incidence of CA-AKI. Results: 37 RCTs studying 12,166 patients were included. Mean age was 67 ± 5 years, 70% of the patients were male. 68% had chronic kidney disease, 41% diabetes, and 30% heart failure. The incidence of CA-AKI was 9.5% (95% CI: 8–12%). IV expansion versus no volume administration was associated with a lower risk of CA-AKI (RR:0.62; 95% CI: 0.49–0.77, p <.001). Intensive IV volume expansion was associated with a reduced risk of CA-AKI(RR: 0.66; 95%CI: 0.52–0.85, p <.01). The intensive IV volume expansion arm received significantly more fluids than the standard protocols: 1,574(1,123 – 1,913) ml versus 849(558–1,067) ml (p =.03) without significant difference in the duration of infusion (median of 12 vs. 17 hr, p =.1) or pulmonary edema (1.7% vs 1.3%, p =.7). Conclusions: Despite high variability in protocols used, IV volume expansion is effective in preventing CA-AKI. Intensive IVF expansion (median 1.6 L over 17 hr) was associated with decreased risk of CA-AKI.