Bacterial colonization profile in endo-tracheally intubated patients in the intensive-care unit,Kenyatta National Hospital, and the rationale for antibiotic therapy

Abstract

A prospective study on the bacterial colonization profile of the respiratory tract was carried out on fifty-six (56) patients admitted to the Kenyatta National Hospital, Intensive- Care unit, and intubated for at least two days. between January 1992 and March 1993. During this period, a total number of four hundred and fifty-eight (458) patients were admitted to the Intensive- Care Unit. Out of these 25.7% (118) fell within the study criteria, but only 47.4% of the eligible patients were actually studied. • Twenty-nine (29) were male and twenty-seven (27) were female. The male to female ratio was 1.07:1. The patients' ages ranged from eight (8) months to eighty (80) years, with a peak in the 11-20year and another in the 31-40 year age groups. There were eight (8) different species of organisms isolated during the study, most of which were gram-negative bacilli. The most frequently isolated organism was proteus 29.1% (30) and the least common was enterococcus 3.9% (4). Out of the fifty-six (56) patients, the colonization rate was 30.4% (17). trache9-bronch~t~s 33.9% (19), and pneumonia 35.7% (20). The severity of infection was found to depend on the severitj .of illness. Of the eleven (11) patients without organ fail~re, none developed pneumonia, while 27% (3) had colonization and 73% (8) had tracheo- bronchitis. There was a total of thirteen (11) uatients with organ failure invoJving two or more systems; 69.2~ of t~ese (9) had pneumonia, 30.7~ (4) had tracheo-bronchitis ann none had colonization. The duration of intubation varied from ~ to 9~ days in this study. There was no clear relationship he tween the duration of intubation and the severity of respiratory infection. Duration of intubation of less than thirty davs was associated wit~ 25~ (4) cases of colonization. 100% (19) of tracheo-bronchitis and 90~ (lA) of uneumonia. Intuhation for thirty days or more was associated with 75~ (13) cases of colonization. 10% (2) of pneumonia and no case of tracheo-bronchitis. Ceftazidime (Fortum) was found to he the most effective of the antihiotics tested against the isolated organisms; 100% effective in five (5) out of the eight (8) species isolated. Patients with either colonization or tracheo-bronchitis were found to have a favourable outcome without antibiotics. Of the 36 patients with either colonization or tracheobronchitis, 83% (30) made good recovery on conservative management: regular 'chest phvsiotherapy and tracheo-bronchial suctioning. One developed septicaemia and died despite antibiotics. The other five died from multiple complications. Twenty (20) patients diagnosed to have pneumonia were put on specific antibiotic therapy. Only 16.6% (6) recovered.