Non-lung Organ Failure Influences Mortality in IPF Patients During Flares

Failure of organs other than the lungs can be a predictor of mortality risk in people hospitalized due to acute exacerbations of idiopathic pulmonary fibrosis (IPF), a study reported.

Elevated levels of C-reactive protein, a sign of inflammation, is also a risk factor for in-hospital mortality in these patients.

The study, “Incidence and impact of extra-pulmonary organ failures on hospital mortality in acute exacerbation of idiopathic pulmonary fibrosis,” was published in the journal Nature Scientific Reports.

IPF’s causes are unknown and its clinical course can be unpredictable. Although IPF may remain stable or progress slowly for a number of years, lung function can worsen suddenly in some patients, leading to hard-to-treat hypoxemia, or low blood oxygen content, and respiratory failure. Among these people, hospital mortality can be as high as 60%.

Most patients experiencing such sudden disease exacerbations also have other severe complications, including organ failure beyond the lungs (extra-pulmonary organ failure). But few studies have investigated the health of other organs in IPF patients with acute exacerbations.

Researchers with the Clinical College of Nanjing Medical School, in China, investigated hospital mortality and associated risk factors in this patient population.

They identified 47 records of people diagnosed with acute IPF exacerbations at their medical center from July 2014 to September 2018. Two were then excluded for missing follow-up data. The remaining 45 patients, 36 males and nine females, were between the ages of 42 and 82 (average age, 66.6), and 22 of them were smokers.

Upon hospital admission, the average ratio of arterial oxygen pressure to fractional inspired oxygen (PaO2/FiO2) — a standard test for hypoxemia — was 158.0 mmHg, which falls in the moderate severity range for acute respiratory distress syndrome.

Eighteen patients (40.0%) experienced one or more extra-pulmonary organ failures. Of these, 13 had acute cardiovascular failure, six acute liver failure, and four had acute kidney failure.

Three extra-pulmonary organ failures were reported in one patient, and two in eight patients. Nine patients had one extra-pulmonary organ failure.

Twenty-six patients (57.8%) were treated with high-dose corticosteroids (0.5–1 g/d methylprednisolone or its equivalent) for three to five days after diagnosis. Twenty-five patients (55.6%) received non-invasive ventilation and two needed invasive mechanical ventilation.

Twenty-five of these people died in the hospital, a mortality rate of 55.6%, and the other 20 were discharged.

Patients spent an average of 14.7 days hospitalized. Thirty-four patients (75.6%) were placed in the respiratory intensive care unit for two to 35 days (mean of 10.1 days).

Patients who died had higher serum C-reactive protein (CRP), lower PaO2/FiO2, a greater number of extra-pulmonary organ failures, and were more likely to need non-invasive ventilation than did patients who survived. But a statistical analysis indicated that only elevated CRP levels and extra-pulmonary organ failure were independent risk factors for hospital mortality in these patients.

These results show that “elevated CRP and extra-pulmonary organ failure were independently associated with hospital mortality,” the researchers wrote.

The team believes that lung inflammation during acute IPF exacerbations trigger a stronger systemic inflammatory response, leading to multiple organ failures and poor outcomes.

According to the researchers, how best to manage ventilation therapy and whether to withhold it in this patient population deserves more research. Although non-invasive ventilation was linked with higher mortality in this study, other studies have shown it to benefit survival.

The value of anti-inflammatory therapies should also be further investigated, the team added.