Life-threatening antineutrophil cytoplasmic antibody-associated vasculitis after influenza A H1N1 infection requiring veno-venous extracorporeal membrane oxygenation.

INTRODUCTION: Antineutrophil cytoplasmic autoantibody-associated vasculitis is an immune-mediated necrotizing vasculitis, affecting small- and medium-sized vessels. CASE REPORT: A 22-year-old female patient with free medical history presented with life-threatening pulmonary hemorrhage due to antineutrophil cytoplasmic autoantibody-associated vasculitis, temporarily associated with influenza A H1N1 infection. Due to rapidly worsening respiratory failure, despite conventional management, veno-venous peripheral extracorporeal membrane oxygenation was initiated and continued for 26 days, with subsequent renal replacement therapy. DISCUSSION: We present a case of severe antineutrophil cytoplasmic autoantibody-associated pulmonary vasculitis, managed with veno-venous extracorporeal membrane oxygenation at the initial phase. Despite the significant challenges raised with the use of extracorporeal membrane oxygenation in pulmonary hemorrhage cases, extracorporeal membrane oxygenation may have a significant impact on outcome in this setting, by providing adequate time for a successful immunosuppressive treatment.

Hemodynamic and Respiratory Changes following Prone Position in Acute Respiratory Distress Syndrome Patients: A Clinical Study.

BACKGROUND: Limited data are available for the oxygenation changes following prone position in relation to hemodynamic and pulmonary vascular variations in acute respiratory distress syndrome (ARDS), using reliable invasive methods. We aimed to assess oxygenation and hemodynamic changes between the supine and prone posture in patients with ARDS and identify parameters associated with oxygenation improvement. METHODS: Eighteen patients with ARDS under protective ventilation were assessed using advanced pulmonary artery catheter monitoring. Physiologic parameters were recorded at baseline supine position, 1 h and 18 h following prone position. RESULTS: The change in the Oxygenation Index (ΔOI) between supine and 18 h prone significantly correlated to the concurrent change in shunt fraction (r = 0.75, p = 0.0001), to the ΔOI between supine and 1 h prone (r = 0.73, p = 0.001), to the supine acute lung injury score and the OI (r = -0.73, p = 0.009 and r = 0.69, p = 0.002, respectively). Cardiac output did not change between supine and prone posture. Moreover, there was no change in pulmonary pressure, pulmonary vascular resistances, right ventricular (RV) volumes and the RV ejection fraction. CONCLUSIONS: The present investigation provides physiologic clinical data supporting that oxygenation improvement following prone position in ARDS is driven by the shunt fraction reduction and not by changes in hemodynamics. Moreover, oxygenation improvement was not correlated with RV or pulmonary circulation changes.