Abstract: Objective The aim of this study is to investigate the effect of hybrid renal replacement treatment (HRRT) on acute pulmonary edema (APE) with acute kidney injury (AKI) following multiple wasp stings. Methods We designed a prospective study which enrolled nine patients who developed APE with AKI after multiple wasp stings between 2007 and 2010 in West China Hospital. HRRT included continuous venous-venous hemofiltration (CVVH), plasmapheresis (PE) and sustained low-efficiency dialysis (SLED). CVVH was performed for at least 72h with Baxter Accura or B. Braun Diapact CRRT machine and B. Braun Diacap Acute M hemofilter. Hemofiltration was accomplished using predilution bicarbonate replacement fluid at the rate of 3000ml/h and citrate or low-molecular-weight heparin (LMWH) for anticoagulation, with blood flow rates of 180 to 250 ml/min. PE was performed on the 1st and 2nd day after admission to hospital respectively (dose: fresh frozen plasma 2000 to 2500ml each time), then was replaced with SLED as patients in stable condition (dose: 150ml/min, for 10 to 12 hours every other day). Meanwhile, other therapeutic measures, such as regional wash and wet compress with normal saline around wounds, glucocorticoids therapy, hepatic function protection and nutritional support, were applied. Erythropoietin injection, as well as albumin and blood transfusion, were also carried out when necessary. Results One patient died unexpectedly 2h after admission to hospital. Autopsy, done 8h after sudden death, showed that the main cause of death was multiple organ failure due to the massive wasp envenomation. The other eight patients had a sharp improvement in oxygenation index after HRRT therapy, with obvious amelioration of APE as CT scan showed after an average span of 5.3±2.6 days. Among them, five ventilator dependent patients successfully weaned from mechanical ventilation 2 to 7 days after that. All the patients had distinct decrease in BNP, CK, myoglobin (Myo) and LDH after initiation of HRRT. They progressed to the commence of diuretic phase, renal function recovery and Myo decreasing to normal at 18±7d, 29±12d and 37±21d after admission to hospital, respectively. No organ dysfunction was found after an average follow-up span of 92±68 days. Conclusion We conclude that the coalition of APE and AKI is a severe complication of multiple wasp stings, and active HRRT therapy (CVVH+PE+SLED) as early intervention can bring significant benefits.

Key words: Acute kidney injury, Acute pulmonary edema, Hybrid renal replacement treatment