Systemic capillary leak syndrome during online hemodiafiltration leading to cardiac arrest

Abstract Background Systemic capillary leak syndrome (SCLS) is a rare disorder characterized by transient plasma extravasation from the intravascular space into surrounding tissues, resulting in hemoconcentration, hypoalbuminemia, and hypotension. Although SCLS most commonly affects otherwise healthy middle-aged individuals, it can cause life-threatening complications such as hypovolemic shock and compartment syndrome. We report a case of severe SCLS that became clinically manifest shortly after the initiation of maintenance online hemodiafiltration, leading to cardiac arrest, in which prompt diagnosis and early intensive treatment resulted in successful resuscitation and recovery. Case presentation A 78-year-old woman with end-stage kidney disease who had been on maintenance online hemodiafiltration for 5 years was subsequently diagnosed with SCLS after developing sudden circulatory collapse shortly after the initiation of a routine online hemodiafiltration session. She had been in her usual state of health prior to dialysis; however, 7 min after the initiation of online hemodiafiltration, she abruptly lost consciousness and subsequently developed cardiac arrest. Immediate cardiopulmonary resuscitation was initiated, and return of spontaneous circulation was achieved after intravenous administration of 1 mg of epinephrine. Upon admission to the intensive care unit, laboratory testing revealed marked hemoconcentration and hypoalbuminemia, and computed tomography demonstrated generalized edema predominantly affecting the extremities. Based on the characteristic triad of acute hypotension, hemoconcentration, and hypoalbuminemia, a diagnosis of SCLS was established. Alternative causes of shock, including sepsis and anaphylaxis, were considered unlikely based on clinical, laboratory, and imaging findings. Supportive therapy with aggressive fluid resuscitation was initiated, resulting in stabilization of hemodynamics and full recovery of consciousness. Maintenance online hemodiafiltration was resumed two days later without recurrence of SCLS, and the patient was discharged without further complications. Conclusions SCLS may become clinically manifest during maintenance online hemodiafiltration and may rapidly progress to profound hypovolemic shock and cardiac arrest. Early recognition of the characteristic clinical triad and prompt initiation of appropriate supportive therapy are crucial for survival in patients who develop SCLS in the dialysis setting.