The pulmonary physician in critical care * illustrative case 3: pulmonary vasculitis

ECMO Rescues Patients With Acute Respiratory Failure Related to GPA

Granulomatosis with polyangiitis (GPA) is a subtype of anti-neutrophil cytoplasmic antibody-associated vasculitis with a wide range of clinical symptoms related to the systemic involvement of small blood vessels. The respiratory system is one of the most frequently involved, and life-threatening acute respiratory failure could occur due to diffusive alveolar hemorrhage and tracheal stenosis. When maximum mechanical ventilation is unable to maintain oxygenation, extracorporeal membrane oxygenation (ECMO) should be considered as the final respiratory supportive method, if available. Here we present a 32-year-old male patient with acute respiratory failure (ARF) related to GPA, who was rescued by winning time for accurate diagnosis and appropriate treatment. Additionally, we reviewed more than 60 GPA-related ARF cases on multiple online databases, summarized the clinical manifestations of these patients, and concluded that ECMO plays an important role in further respiratory support for ARF patients with GPA and assists in accurate and timely diagnosis and appropriate treatment, thus helping them recuperate.

Glomerulonephritis in AKI: From Pathogenesis to Therapeutic Intervention

Acute kidney injury (AKI) is increasingly emerging as a global emergency. Sepsis, major surgery, and nephrotoxic drugs are the main causes of AKI in hospitalized patients. However, glomerulonephritis accounts for about 10% of AKI episodes in adults, mainly related to rapidly progressive glomerulonephritis resulting from granulomatous polyangiitis (GPA, Wegener granulomatosis), microscopic polyangiitis (MPA), and anti-glomerular basement membrane (GBM) disease. Also, diffuse proliferative lupus nephritis, immunoglobulin A nephropathy, post-streptococcal glomerulonephritis, mixed cryoglobulinemia, mesangiocapillary glomerulonephritis, membranous nephropathy, hemolytic uremic syndrome, thrombotic thrombocytopenic purpura, and scleroderma can induce acute renal failure. Early diagnosis of AKI due to glomerulonephritis is crucial for prompt, effective management to improve short- and long-term outcomes. Kidney biopsy is the gold standard for the diagnosis of glomerular disease, but it is not frequently performed in critically ill patients because of their clinical conditions. In this setting, a growing number of diagnostic assays can support the working hypothesis, including antineutrophil cytoplasmic antibodies (ANCAs), anti-double-stranded DNA antibodies, anti-GBM antibodies, antistreptolysin O and anti-DNase B antibodies, cryoglobulins, antiphospholipid antibodies, and complement levels. Therapeutic strategies in AKI patients with glomerulonephritis include high-dose corticosteroids, cyclophosphamide, and plasma exchange. This article reviews the wide spectrum of glomerulopathies associated with AKI, describing the immunological mechanisms underlying glomerular diseases and presenting an overview of the therapeutic options.

Extracorporeal membrane oxygenation for Life-threatening ANCA-positive pulmonary capillaritis. A review of UK experience

INTRODUCTION

Anti-neutrophil cytoplasmic antibody positive pulmonary capillaritis complicated by diffuse alveolar hemorrhage is a potentially fatal condition for which extracorporeal membrane oxygenation can facilitate improved outcomes and potential cure. Diffuse alveolar hemorrhage can be the initial presentation of an autoimmune disorder. The management is centered on the use of immunosuppressive therapy, which requires time, with fatality often occurring for these patients. We showed two very young patients with no previous history of vasculitis presenting with life threatening pulmonary hemorrhage due to anti-neutrophil cytoplasmic antibody positive vasculitis, whose management was facilitated with extracorporeal membrane oxygenation.

METHODS

We reviewed the clinical presentation and course of the first two patients with diffuse alveolar hemorrhage for anti-neutrophil cytoplasmic antibody positive vasculitis managed with veno-venous extracorporeal membrane oxygenation. We highlighted and analysed the unique challenges encountered in managing these patients.

RESULTS

The two patients were referred for extracorporeal membrane oxygenation since conventional ventilation was inadequate to provide physiologic support for respiratory failure. Clinical improvement was achieved without exacerbation of the pulmonary hemorrhage despite the use of anticoagulants. This provided time for the immunosuppressants to take effect. Both patients were discharged and were cured of the underlying condition.

CONCLUSIONS

Extracorporeal membrane oxygenation has a role in the management of patients with severe respiratory failure due to anti-neutrophil cytoplasmic antibody positive capillaritis. Early recognition and referral for extracorporeal membrane oxygenation are vital to achieve a favourable outcome.

Acute respiratory failure as primary manifestation of antineutrophil cytoplasmic antibodies-associated vasculitis

The systemic vasculitides are multifocal diseases characterized by the presence of blood vessel inflammation in multiple organ systems. Their clinical presentation is variable extending from self-limited illness to critical complications including diffuse alveolar hemorrhage and glomerulonephritis. Alveolar hemorrhage is a life-threatening manifestation of pulmonary vasculitis that can rapidly progress into acute respiratory failure requiring ventilatory support. We present the case of a 74-year-old patient admitted to the Intensive Care Unit with severe hypoxic respiratory failure and diffuse alveolar infiltrates in chest imaging that was later diagnosed as antineutrophil cytoplasmic antibodies-associated vasculitis. The report highlights the importance of differentiate between alveolar hemorrhage and acute respiratory distress syndrome of other etiology because alveolar hemorrhage is reversible with prompt initiation of treatment.

Pulmonary-renal syndromes: an update for respiratory physicians

Pulmonary-renal syndromes are a group of disorders characterised by necrotising glomerulonephritis and pulmonary haemorrhage. Small vessel systemic vasculitis is the most common cause of pulmonary-renal syndromes presenting to respiratory physicians. Rarer causes include systemic lupus erythematosus and connective tissue diseases though severe pneumonia or cardiac failure may mimic their presentation. Some forms of small vessel vasculitides have a predilection for the pulmonary and renal vascular beds and if left untreated can result in fulminant organ failure. Whilst the aetiology of these syndromes remains unclear, much is known about the disease mechanisms including the pathogenic role of autoantibodies, immune-complex mediated inflammation and microangiopathic in-situ thrombosis. Despite established treatments achieving successful remission induction, patient tolerability and side effect profiles have limited their use which has led to searches for more targeted treatments. Consequently newer biological therapies have gained wider acceptance despite little being known about their long term safety and efficacy. The European Vasculitis Study Group (EUVAS) have recently formulated guidelines to provide consensus on diagnosis and management in this area and work to define survival rates in these conditions with longer term follow-up studies is ongoing. This review summarises the current aetiopathogenesis thought to underlie these complex diseases, the diagnostic definitions and classification criteria currently in use and the evidence base for modern therapies. Though unusual for respiratory specialists to coordinate overall management of these patients, an update on their current management is regarded as important to their practice given the recently changing trends in treatments.

Bench-to-bedside review: pulmonary-renal syndromes--an update for the intensivist

The term Pulmonary-renal syndrome refers to the combination of diffuse alveolar haemorrhage and rapidly progressive glomerulonephritis. A variety of mechanisms such as those involving antiglomerular basement membrane antibodies, antineutrophil cytoplasm antibodies or immunocomplexes and thrombotic microangiopathy are implicated in the pathogenesis of this syndrome. The underlying pulmonary pathology is small-vessel vasculitis involving arterioles, venules and, frequently, alveolar capillaries. The underlying renal pathology is a form of focal proliferative glomerulonephritis. Immunofluorescence helps to distinguish between antiglomerular basement membrane disease (linear deposition of IgG), lupus and postinfectious glomerulonephritis (granular deposition of immunoglobulin and complement) and necrotizing vasculitis (pauci-immune glomerulonephritis). Patients may present with severe respiratory and/or renal failure and require admission to the intensive care unit. Since the syndrome is characterized by a fulminant course if left untreated, early diagnosis, exclusion of infection, close monitoring of the patient and timely initiation of treatment are crucial for the patient's outcome. Treatment consists of corticosteroids in high doses, and cytotoxic agents coupled with plasma exchange in certain cases. Renal transplantation is the only alternative in end-stage renal disease. Newer immunomodulatory agents such as those causing TNF blockade, B-cell depletion and mycophenolate mofetil could be used in patients with refractory disease.

Pulmonary involvement in microscopic polyangiitis

PURPOSE OF REVIEW

Microscopic polyangiitis is a systemic necrotizing vasculitis that affects small vessels, resulting in a wide spectrum of organ involvement including the kidneys and the lungs. This paper reviews recent insights and observations into the pathogenesis, clinical manifestations, and treatment of pulmonary involvement in microscopic polyangiitis.

RECENT FINDINGS

The spectrum of clinical presentations ranges from antecedent interstitial fibrosis to frank hemoptysis secondary to capillaritis. Computerized tomography imaging reveals a variety of pulmonary findings, including ground-glass attenuation, consolidation, thickening of bronchovascular bundles, and honeycombing. Antineutrophil cytoplasmic antibodies are important in diagnosis as well as in the pathogenesis and prognosis of microscopic polyangiitis. There is more evidence to support the various therapeutic modalities currently used in pulmonary manifestations of microscopic polyangiitis, including induction therapy with cyclophosphamide, the use of other novel pharmacologic agents such as the tumor necrosis factor-alpha blockers and rituximab, and nonpharmacologic modalities such as plasmapheresis and ventilatory management.

SUMMARY

The pulmonary manifestations of microscopic polyangiitis are diverse and often difficult to manage; however, as our understanding and experience grows so does our ability to successfully diagnose and treat these patients.

Vasculites pulmonares: novas visões de uma velha conhecida

A vasculite necrosante foi descrita em 1866 e seu espectro é muito amplo, uma vez que acomete vasos arteriais e venosos de todos os calibres e de vários órgãos, apresenta diversos tipos de infiltrados inflamatórios, tem um significante número de manifestações clínicas e pode ter ou não fatores desencadeantes identificáveis. A sempre controversa classificação das vasculites mudou radicalmente com a descoberta dos anticorpos anticitoplasma de neutrófilos em 1982, contemplando atualmente a doença de Goodpasture, as vasculites associadas aos anticorpos anticitoplasma de neutrófilos, as vasculites por imunocomplexos e outros tipos de vasculites. As evidências de que os anticorpos anticitoplasma de neutrófilos estão envolvidos na patogênese destas lesões trouxeram avanços consideráveis para o seu diagnóstico e tratamento. Granulomatose de Wegener, doença de Churg-Strauss e poliangeíte microscópica, todas vasculites associadas aos anticorpos anticitoplasma de neutrófilos, são as vasculites sistêmicas que mais acometem os pulmões. Suas manifestações clínicas comuns são tosse, hemorragia alveolar difusa ou asma de difícil controle. Na arterite de Takayasu, na doença de Behçet, na púrpura de Henoch-Schönlein e nas vasculites associadas às doenças do colágeno o acometimento pulmonar é mais raro. Em todos os casos há evidências de serem processos de origem imunológica e com base neste princípio são propostas as abordagens terapêuticas.

Clinical review: Vasculitis on the intensive care unit -- part 2: treatment and prognosis

The second part of this review addresses the treatment and prognosis of the vasculitides Wegener's granulomatosis, microscopic polyangiitis, Churg–Strauss syndrome and polyarteritis nodosa. Treatment regimens consist of an initial remission phase with aggressive immunosuppression, followed by a more prolonged maintenance phase using less toxic agents and doses. This review focuses on the initial treatment of fulminant vasculitis, the mainstay of which remains immunosuppression with steroids and cyclophosphamide. For Wegener's granulomatosis and microscopic polyangiitis plasma exchange can be considered for first-line therapy in patients with acute renal failure and/or pulmonary haemorrhage. Refractory disease is rare and is usually due to inadequate treatment. The vasculitides provide a particular challenge for the critical care team. Particular aspects of major organ support related to these conditions are discussed. Effective treatment has revolutionized the prognosis of these conditions. However, mortality is still approximately 50% for those requiring admission to intensive care unit. Furthermore, there is a high morbidity associated with both the diseases themselves and the treatment.

Clinical review: Vasculitis on the intensive care unit--part 1: diagnosis

The first part of this review addresses the diagnosis and differential diagnosis of the primary vasculitides Wegener's granulomatosis, microscopic polyangiitis, Churg–Strauss syndrome and polyarteritis nodosa. Prompt diagnosis and treatment of these conditions ensures an optimal prognosis. The development of assays for antineutrophil cytoplasmic antibodies has aided the diagnosis of Wegener's granulomatosis and microscopic polyangiitis. However, even in cases where there is high clinical likelihood that these conditions are present, up to 20% may be antibody negative, whereas alternative diagnoses may be antibody positive. The final diagnosis rests on a balance of clinical, laboratory, radiological and histological features. The exclusion of alternative diagnoses is important in assuring appropriate therapy. Particular attention is paid to the more fulminant presentations of these conditions and the role of the critical care physician in their diagnosis and management.