[Epidemiology, clinical aspects and prognosis of severe progressive community-acquired pneumonia]

Community-acquired pneumonia can lead to acute lung failure (parapneumonic ARDS) if the course is very severe. The clinical picture reflects a rapidly progressive and potentially fatal respiratory failure. Only occasional cases in which the clinical courses of community-acquired pneumonia lead to acute respiratory failure have been reported so far. The investigation was based on the observation that very severe progressive forms of community-acquired pneumonia are at present one of the most frequent conditions triggering ARDS.

A total of 66 patients of both sexes with an average age of 34 +/- 11 years were included in the retrospective investigation. The patients had been secondarily referred to the center for further treatment. After admission, the further course of the disease was recorded at five defined times (day of admission, 2nd day, 7th day, 14th day and day of spontaneous breathing or day of death). The degree of disturbance of pulmonary function was registered with the scores of Morel and Murray. Further disorders of organ function were evaluated with the MOF score according to Goris, the "Definition Multiple disorder of Organ Function (DeMOF)" and the appraisal of the severity of the systemic inflammatory reaction with the sepsis score according to Elebute & Stoner.

The duration of preclinical disease was 6 +/- 4 days and the duration of the pretreatment in the referring hospital was 10 +/- 10 days. A potential primary causative organism (bacteria n = 18, viruses n = 5, "atypical" pathogens n = 6, Candida species n = 4) could be isolated in 50% of the patients. A pre-existing underlying disease was found in 48% of cases. With a total lethality of 31%, this was affected neither by knowledge of the primary causative organism nor by previous diseases. The patients who died did so with improved lung function in a complete clinical picture of multiorgan failure. At the time of admission, 91% of the patients had severe ARDS (Morel III and IV). An improvement of lung function could be demonstrated between the day of admission and the second day of treatment both with the score according to Morel and according to Murray (p < 0.05). For the second day of treatment, a difference could be shown between the patients who survived and those who died (p < 0.05). Owing to the systemic inflammatory reactions, a multiorgan functional disorder was found in 89% of the patients. There were the following findings with regard to the prognostic predictions from the score used: those who died and those who survived could be correctly differentiated with the DeMOF score from the 7th day of treatment and the sepsis from the 7th day of treatment and with the score of Goris from the 14th day of treatment after referral.

The investigation proves that the most severe progressive forms of community-acquired pneumonia also occur both in patients who have previously appeared to be healthy and in younger patients. Despite the use of differentiated treatment measures, these illnesses are subject to a relatively high lethality. The results underscore the need for causal treatment of systemic inflammatory reaction, which is the most important problem in treatment of parapneumonic ARDS.