Respiratory Failure in Patients with Pulmonary Fibrosis
Abstract & Commentary
Synopsis: In 2 retrospective series of patients with idiopathic pulmonary fibrosis who developed progressive respiratory failure and were intubated and ventilated in the ICU, only 3 (< 10%) survived, raising the question of whether such management is justified in this condition.
Source: Blivet S, et al. Outcome of patients with idiopathic pulmonary fibrosis admitted to the ICU for respiratory failure. Chest. 2001;120:209-212.
In this paper from Lyon, France, Blivet and associates report the results of a retrospective review of all patients with advanced idiopathic pulmonary fibrosis (IPF) who were admitted to their ICU because of an episode of acute hypoxemic respiratory failure (AHRF) during a 9.5-year period. Fifteen patients (age 64 ± 10 years; 11 men) met entry criteria. The diagnosis of IPF had been established histologically in 7 patients and on the basis of typical clinical, functional, and radiographic features in the remaining 8. Mean duration from diagnosis to ICU admission was 26 ± 28 months, range 1.3-81 months. All 15 patients had previously been treated with corticosteroids, and 11 had been on long-term oxygen therapy prior to the episode of AHRF. At ICU admission, the patients had mean arterial blood gas values of pH 7.32, PCO2 55 mm Hg, and PaO2/FIO2 113 mm Hg.
All 15 patients received ventilatory assistance. Of 5 treated initially with noninvasive positive-pressure ventilation (NPPV), 2 improved and were discharged from the ICU, 1 died during NPPV, and 2 were converted to invasive mechanical ventilation. In all, 12 patients were intubated for ventilatory support, and 2 of them survived to leave the unit. Of the 4 patients who were transferred out of the ICU, 2 died shortly thereafter, 1 was still alive 6 months after discharge, and 1 was lost to follow-up. Causes of death in the ICU were progressive hypoxemia in 8 patients and septic shock in 3. Length of ICU stay in this 15-patient cohort was 13.9 ± 11.2 days.
A similar patient series was reported in the same issue of Chest by Stern and colleagues.1 These investigators performed a 10-year review of all patients with IPF who were intubated and ventilated for acute respiratory failure in their respiratory ICU in Clichy, France. Their review included 23 patients (mean age, 53 years; 19 men) whose diagnoses of IPF had been made mainly on clinical grounds and radiographic imaging studies. These patients had severe disease, with mean total lung capacity of 48% of predicted and diffusing capacity of the lung for CO, 30% of predicted. Twenty-one patients (91%) had received immunosuppressive therapy for IPF, and most were on home oxygen therapy. The patients were severely hypoxemic at the time of admission, with PaO2 59 ± 5 mm Hg on high-concentration mask oxygen, and only 4 had PaO2/FIO2 ratios > 100 mm Hg. With the exception of 1 patient who received a single-lung transplant 6 hours after intubation, the remaining 22 patients all died after 1 hour to 60 days (median, 3 days) of mechanical ventilation.
Comment by David J. Pierson, MD
IPF, called cryptogenic fibrosing alveolitis in the United Kingdom, is a progressive interstitial lung disease of unknown cause with an almost invariably poor prognosis. Most patients die within 3-5 years following diagnosis. The disease is progressive and generally unresponsive to treatment, with the majority of patients succumbing to acute hypoxemic respiratory failure. These 2 case series support the widely held clinical impression that the development of AHRF is nearly always fatal in these patients.
Although Blivet et al and Stern et al saw only a few patients who had respiratory failure precipitated by such potentially reversible circumstances as a pneumothorax or general anesthesia, in most cases no specific etiology for the deterioration could be found. A sepsis-like picture was present in a number of the patients, but causative organisms were seldom identified. One could therefore conclude, as do Blivet et al and Stern et al, that acute respiratory failure in patients with advanced IPF is very unlikely to be a reversible process. In fact, Stern et al recommend that mechanical ventilation be offered only to IPF patients with acute respiratory failure who are awaiting lung transplantation, in whom this can be performed within a few days.
1. Stern JB, et al. Chest. 2001;120:213-219.