In an effort to define our patient population, we have utilized the classification system in Table 2. The classification we propose separates patient populations based on the duration of the ARDS. We reason that by defining established ARDS as beginning at 72 hours, the causative process will have been controlled in those patients. We further divided the established ARDS group into those with isolated ARDS or complicated ARDS (additional organ dysfunction) since we reasoned mortality should be related to the complexity of the clinical problems. Five of our patients had uncomplicated ARDS which may be an explanation for our good results. Since our report is an uncontrolled experience, we used the work of Montgomery and associates on the natural history of ARDS for comparison. It is the only data from which mortality of patients with what we have defined as established ARDS can be calculated.
Further complicating the picture, several works which argue against the use of ACS in ARDS studied a different population of patients. They studied the treatment of conditions that are highly associated with ARDS to see if ACS would lessen the incidence or severity of the ARDS which developed in their populations. In addition, they used high dose, short duration therapy. These works were not designed to study the treatment of ARDS, but rather the prevention or the amelioration of it. They provide evidence that short-term, high-dose treatment does not prevent ARDS or ameliorate its severity if it subsequently occurs, but they do not address the question of whether a longer therapeutic course of ACS is effective for established ARDS.
The ^Ga citrate lung scans we performed demonstrated significant pulmonary uptake of the isotope. The ^Ga uptake is an indicator of active inflammation. Although the mechanism of gallium uptake by the lungs is not clear, leukocytes are known to concentrate the isotope and uptake is thought to be dependent upon the leukocyte mass available to bind the radioisotope. While isolated descriptions of significant Са uptake in ARDS patients have been reported, no organized study has been published.<sup> </sup>The finding does conform with current knowledge of pathology and pathogenesis. The magnitude of the uptake in our ARDS patients suggests an intense inflammatory response to their lung injuries. The active inflammatory condition demonstrated by Са in our patients is additional evidence that an appropriately administered anti-inflammatory agent should, if the injuring process is controlled, benefit individuals with ARDS.
viagra soft tabs online
The ACS therapy is employed in a variety of disease states because of its anti-inflammatory properties. Two principles of ACS therapy learned from the treatment of inflammatory diseases should be applicable to their use in established ARDS. In the initiation of therapy, a satisfactory dosage at frequent enough intervals over a long enough period of time is required to achieve a suppression of inflammatory activity. And, if suppression is not achieved prior to its reduction or cessation, relapse is often observed. In many inflammatory disease states, a treatment course of weeks is required to bring the disease process under control. Before ACS is dismissed as ineffective in the treatment of established ARDS, sustained therapy should be employed.
We believe that a sustained course of ACS is effective in the treatment of selected patients with established ARDS. It has been extremely effective in this limited, uncontrolled, anecdotal experience. We believe there is a subpopulation of ARDS patients with established disease who benefit from the use of a sustained course of ACS. Controlled investigations are indicated to define this population and its appropriate treatment.