Chronic pulmonary disease is common among dialysis patients, and constitutes an important risk factor for respiratory failure. Rates of hospitalization for a primary discharge diagnosis of acute respiratory failure increased during the early portion of the study era, plateaued, and subsequently declined. Unlike many other conditions, in which rates estimated with contrasting definitions have tended to converge since the advent of MS-DRGs, the rate of hospitalization for either a primary or leading secondary discharge diagnosis of acute respiratory failure has recently diverged from the corresponding rate for a primary discharge diagnosis alone. This divergence creates uncertainty about the true frequency of respiratory failure among dialysis patients. The totality of the data, however, as well as the high prevalence of mechanisms that may lead to respiratory failure, suggest that the event is not rare. Fluid overload, as might be observed among patients with heart failure or pneumonia, clearly increases the risk of respiratory failure. And with stroke another risk factor, it is perhaps unsurprising that the absolute magnitude of hospitalization for acute respiratory failure among prevalent dialysis patients in 2011 is similar to the corresponding magnitude of hospitalization for stroke.
There is some regional variation in admission rates. Areas with the highest rates include the East North Central, West North Central, and East South Central divisions. In the case of the first two divisions, an important commonality is the Ohio River Valley, an area with historical pollution, including air pollution from industrial processes. Particulate matter is an established factor for exacerbations of pulmonary disease, including acute respiratory failure.
The aberrant increase in hospitalizations for acute respiratory failure during the winter of 2011 is of unclear etiology, and certainly might represent anomalous coding practices that were quickly resolved. On the other hand, the peak coincides perfectly with a spike in hospitalizations for heart failure, underscoring the connection between volume status, cardiac function, and pulmonary function.