Pneumonia in hospital practice in Edinburgh 1960–1962

Abstract

Summary One hundred and fifty-six patients admitted to hospital with acute respiratory infection were investigated. Ninety per cent. had pneumonia. On admission pneumococci were isolated from blood or sputum in 44 per cent. and H˦mophilus influenz˦ was obtained from the sputum in 22 per cent.; in 13 per cent. these organisms were obtained together. Infection by Staphylococcus aureus was considered significant in 9 perc cent. of the series and in the remaining 38 per cent. no specific bacterial pathogen was identified. Lobar pneumonia was practically confined to those patients with pneumococcal infection or no specific bacterial pathogen. Chronic bronchitis and other complicating chest disease present on admission were more common in patients showing infection by H˦mophilus influenz˦ and Staphylococcus aureus than in the other groups; the difference between the incidence of other complicating chest disease in the staphylococcal and pneumococcal groups was statistically significant (P = 0·05). Antibiotics had been given immediately before admission to 39 per cent. of all patients. A significantly greater proportion in the non-pneumococcal groups had received such antibiotics than those infected by pnemococci alone; the evidence suggests that antibiotics given before admission to hospital decrease the isolation rate of pneumococci. Serological evidence of viral infection was found in 16 per cent. of all patients investigated. The incidence was greater in cases without a proved bacterial pathogen (P = 0·05). Secondary bacterial pathogens were frequently found in the sputum on the fifth and tenth days after admission. They were found more often in severely ill patients than in others. Their presence tended to be associated with slow radiological resolution. In most patients the absence of a recognized bacterial pathogen was probably due to treatment with antibiotics before admission, but in 13 per cent. of this group there was evidence of virus infection without antibiotics having been given before admission. About 10 per cent. of this group had chronic chest disease and were admitted late in the course of their acute illness. In a further 20 per cent. the acute illness was mild and consistent with a benign aspiration type pneumonia. In a few the absence of a bacterial pathogen may have been due to the difficulty of obtaining a genuine specimen of sputum on admission.