Prevention of gram-negative bacillary pneumonia using aerosol polymyxin as prophylaxis. I. Effect on the colonization pattern of the upper respiratory tract of seriously ill patients

A prospective study used polymyxin B by aerosol to reduce colonization of the upper respiratory tract with nosocomial gram-negative bacilli. 58 high-risk patients from the Respiratory-Surgical Intensive Care Unit entered the trial. 33 were randomly selected to receive 2.5 mg/kg/day of polymyxin B by hand atomizer into the pharynx, and tracheal tube if present. 17 of 25 control patients became colonized with gram-negative bacilli as compared with 7 of 33 polymyxin-treated patients (p < 0.01). Control patients became colonized with a total of 33 gram-negative bacilli: 3 were Pseudomonas aeruginosa, 21 were species of Enterobacteriaceae. The polymyxin-treated patients became colonized with a total of 11 gram-negative bacilli: no P. aeruginosa and only 3 species of Enterobacteriaceae were recovered. Colonization increased with duration in Respiratory-Surgical Intensive Care Unit and with time of required controlled ventilation. Polymyxin most effectively prevented the increase in colonization in treated patients who stayed in the Respiratory-Surgical Intensive Care Unit for longer than 1 wk and who required controlled ventilation for at least 72 h.

The diagnosis and prophylaxis of pulmonary complications of surgical operation

Eighty-eight non-bronchitic and 52 bronchitic patients undergoing elective general and plastic surgical operations in two wards were studied for postoperative chest complications, which were diagnosed by increased purulence of sputum and radiological changes at 24 or 48 hours. Eighty per cent of the patients undergoing upper abdominal surgery and 30 per cent of the other patients had chest complications. Postoperative bronchitis or pneumonia severe enough to delay discharge was found in 14 patients (10 per cent). Twice-daily physiotherapy to the chest did not affect the outcome in 86 patients without chronic bronchopulmonary disease. Routine administration of ampicillin to ‘cover’ chronic bronchitics undergoing general anaesthesia was found to be of no value in a controlled trial of the 52 bronchitic patients. However, bacteriological and radiological studies lend some support to the suggestion that prophylaxis with a bactericidal antibiotic may reduce the incidence and morbidity of postoperative pulmonary infections in patients having upper abdominal operations.

The action of certain antibiotics and ether on swine enzootic pneumonia

The susceptibility of Mycoplasma hyopneumoniae to the action of three antibiotics and diethyl ether was determined. Infected swine were used in an in vivo sensitivity detection system. The parameter of susceptibility was lesion prophylaxis. In vivo, Mycoplasma hyopneumoniae appeared to be resistant to diethyl ether, tylosin tartrate, and erythromycin, but was susceptible to the action of chlortetracycline. Chlortetracycline was effective in preventing the development of lesions when given at levels which would be practical in commercial swine operations.

Swine enzootic pneumonia: age susceptibility and treatment schemata

Pigs were found to be susceptible to Mycoplasma hyopneumoniae-induced swine enzootic pneumonia (SEP) when four hours old. Chlortetracycline was incapable of preventing transmission of SEP from infected pigs on the drug to susceptible, untreated pigs. When continuous medication was started at one or two weeks postinoculation, chlortetracycline partially or completely inhibited formation of SEP lesions but did not clear M. hyopneumoniae from inoculated pigs. Chlortetracycline administered orally was capable of completely suppressing the formation of SEP lesions in inoculated pigs if given prophylactically and if milk was withheld for several hours after each treatment; lesion suppression was incomplete if milk was given ad libitum. In either case treated animals remained infected with M. hyopneumoniae.