Bridge or Abyss: Extracorporeal Membrane Oxygenation for Acute Respiratory Failure in Interstitial Lung Disease

Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Acute exacerbation is a major cause of morbidity and mortality in patients with idiopathic pulmonary fibrosis. Although the real nature of it is still not clear and there is no proven effective therapy, progress has been made since the consensus definition and diagnostic criteria were proposed. The trial results of several new innovative therapies in idiopathic pulmonary fibrosis have suggested a potential for benefit in acute exacerbation of idiopathic pulmonary fibrosis, leading to double blind randomized clinical trials in this area. This article reviews the present knowledge on acute exacerbation of idiopathic pulmonary fibrosis, focusing on the triggering factors and treatment.

[What are the indications for rescue procedures? : Systemic rheumatic diseases in the intensive care unit]

Schwere, organ- oder lebensbedrohliche Manifestationen entzündlicher rheumatischer Erkrankungen, wie z. B. eine diffuse alveoläre Hämorrhagie im Rahmen einer Kleingefäßvaskulitis, sprechen nicht immer ausreichend oder mit zeitlicher Verzögerung auf eine immunsuppressive Therapie an. Bei einem drohenden oder bereits eingetretenen Organversagen besteht dann nicht selten die Notwendigkeit, die immunsuppressive Therapie auf der Intensivstation um rasch wirksame Rescue-Therapieverfahren zu ergänzen. Aufgrund der Seltenheit vieler rheumatischer Erkrankungen ist die Evidenz zum Einsatz von Rescue-Therapieverfahren wie der Plasmapherese, der extrakorporalen Membranoxygenierung (ECMO) oder der Gabe von intravenösen Immunglobulinen (IVIG) für viele Indikationen eher gering. Der Einsatz der Plasmapherese wird bei einer akuten Anti-GBM(glomeruläre Basalmembran)-Erkrankung (Goodpasture Syndrom) oder einem katastrophalen Antiphospholipidantikörpersyndrom (CAPS) als sinnvoll angesehen. Eine ECMO-Therapie kann bei persistierender respiratorischer Insuffizienz trotz mechanischer Beatmung als Folge einer diffusen alveolären Hämorrhagie oder eines Acute-Respiratory-Distress-Syndroms (ARDS) anderer Ursache erwogen werden. Eine Gabe von IVIG ist bei einer akuten kardialen Beteiligung im Rahmen einer Kawasaki-Erkrankung indiziert und kann beim CAPS sowie bei therapierefraktären Myositiden erwogen werden.

Acute exacerbations of progressive-fibrosing interstitial lung diseases

Acute exacerbation of interstitial lung disease (ILD) is associated with a poor prognosis and high mortality. Numerous studies have documented acute exacerbation in idiopathic pulmonary fibrosis (IPF), but less is known about these events in other ILDs that may present a progressive-fibrosing phenotype. We propose defining acute exacerbation as an acute, clinically significant respiratory deterioration, typically less than 1 month in duration, together with computerised tomography imaging showing new bilateral glass opacity and/or consolidation superimposed on a background pattern consistent with fibrosing ILDs. Drawing on observations in IPF, it is suspected that epithelial injury or proliferation and autoimmunity are risk factors for acute exacerbation in ILDs that may present a progressive-fibrosing phenotype, but further studies are required. Current acute exacerbation management strategies are based on recommendations in IPF, but no randomised controlled trials of acute exacerbation management have been performed. Although there are no formal strategies to prevent the development of acute exacerbation, possible approaches include antifibrotic drugs (such as nintedanib and pirfenidone), and minimising exposure to infection, airborne irritants and pollutants. This review discusses the current knowledge of acute exacerbation of ILDs that may present a progressive-fibrosing phenotype and acknowledges limitations of the data available.

Extracorporeal Membrane Oxygenation for Refractory Severe Respiratory Failure in Acute Interstitial Pneumonia

Acute interstitial pneumonia (AIP) is a rare idiopathic interstitial lung disease with rapid progressive respiratory failure and high mortality. In the present report, three cases of AIP complicated by refractory respiratory failure supported with extracorporeal membrane oxygenation (ECMO) are presented. One male and two female patients (ages 27-59) were included. Venovenous ECMO support was provided using miniaturized systems, with two-site femoro-jugular circuit configuration. Despite lung protective ventilation, prone position and neuromuscular blockade, refractory respiratory failure of unknown etiology supervened (ratio of arterial oxygen partial pressure to fractional inspired oxygen 46-130) and ECMO was initiated after 3-7 days of mechanical ventilation. AIP diagnosis was established after exclusion of infectious and noninfectious acute respiratory distress syndrome on the basis of clinical and analytical data, bronchoalveolar lavage analysis and lung imaging, with a confirmatory surgical lung biopsy revealing diffuse alveolar damage of unknown etiology. Immunosuppressive treatment consisted in high-dose corticosteroids and cyclophosphamide in one case. Two patients survived to hospital discharge. ECMO allowed AIP diagnosis and treatment in the presence of refractory respiratory failure, therefore reducing ventilator-induced lung injury and bridging lung recovery in two patients. ECMO referral should be considered in refractory respiratory failure if AIP is suspected.