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Prognosis of Patients With Advanced Idiopathic Pulmonary Fibrosis Requiring Mechanical Ventilation for Acute Respiratory Failure: Discussion

Our results indicate that in patients with end-stage IPF presenting with ARF, MV does not lead to improvement in gas exchange and is associated with a poor prognosis. We also found that the precipitating cause of ARF was not identified in the majority of our patients.
Thus, this current study suggests that natural progression of IPF was the most frequent cause of clinical deterioration. This fact has already been reported in the meta-analysis conducted by Panos and colleagues. In this study, which included 543 patients, respiratory failure secondary to IPF progression and pulmonary infection were the cause of death in 38% and 2.8% of patients, respectively. The differential diagnosis between progression of IPF and pulmonary infection is quite difficult in such patients. In the present series, among 14 patients without identified cause of ARF, 4 patients presented at hospital admission with an influenza-like syndrome associated with blood leukocytosis > 15,000μL and new pulmonary infiltrate on chest radiograph. This presentation mimicked pulmonary infection but the microbiological culture results of blood and tracheobronchial aspirates remained negative. Kondoh and coworkers described an influenza-like syndrome in three patients corresponding to an exacerbation of IPF. The histology findings in the lungs showed an association of acute lung injury and usual interstitial pneumonia pattern. Such changes were also noted in three of our patients on autopsy study (data not shown). According to Kondoh et al, the influenza-like syndrome may correspond to either an acute exacerbation of the inflammatory process of the IPF or to a viral infection. In a study including 156 cases of IPF, lung cancer represented 12.8% of causes of death, and a recent study also reported that the incidence of lung cancer was markedly increased in IPF patients. Nevertheless, lung cancer was not identified in any of our patients, even in those who underwent autopsy. Obviously, since all investigations have not been performed on a systematic basis in each patient, we cannot exclude that, in some patients, the cause of ARF has been missed. canada health and care mall

The effectiveness of MV in IPF patients presenting with ARF has not been fully evaluated. The general belief is that this management strategy is not beneficial to patients with IPF, but to our knowledge, no published data are available to support this theory. The fact that all patients in our series (except one who underwent LTx) died after various durations of MV strongly suggests that MV is not an appropriate strategy in these patients. Based on our experience, we recommend that patients with end-stage IPF presenting with ARF should not undergo intensive cardiopulmonary resuscitation unless LTx can be performed urgently.
The initial tidal volumes delivered by the ventilator were relatively high. By analogy with what is already known in patients presenting with ARDS, it is therefore not excluded that the initial ventilator settings may have contributed to lung injury and death. Ventilator strategy based on the use of lower tidal volume might have resulted in a lower mortality rate. If MV is considered in patients with end-stage IPF presenting with ARF, we recommend the use of very low tidal volumes and high ventilator rates (if necessary for adequate ventilation).