Hkf Vansaene

The effect of oropharyngeal decontamination using topical nonabsorbable antibiotics on the incidence of nosocomial respiratory tract infections in multiple trauma patients.

The incidence of respiratory tract infections was determined in 59 multiple trauma patients requiring prolonged intensive care (greater than 5 days) and receiving no antibiotic prophylaxis. Early pneumonia (less than 48 hr) with S. aureus, S. pneumoniae, and/or H. influenzae was found in 44% of patients. Secondary colonization of the oropharynx and respiratory tract with ICU-associated Gram-negative bacilli followed by pneumonia occurred in 12 patients (20%). The overall incidence of respiratory tract infections was 59%. In a prospective open trial three prophylactic antibiotic regimens were compared: 17 patients were treated with intestinal decontamination using nonabsorbable antibiotics (polymyxin E 400 mg, tobramycin 320 mg, amphotericin B 2,000 mg/day). No difference in infection rate was found. Twenty-five patients were treated with intestinal and oropharyngeal decontamination using an ointment containing 2% of the same antibiotics. Secondary colonization and infection of the respiratory tract with Gram-negative bacilli was significantly reduced (p less than 0.001). The incidence of early (Gram-positive) infections, however, was unchanged. Another group of 63 patients was treated with systemic antibiotic prophylaxis during the first days in combination with oropharyngeal and intestinal decontamination. The incidence of early pneumonia was significantly reduced (p less than 0.001). Five patients (8%) developed an infection. Superinfections were not observed.

SELECTIVE DECONTAMINATION OF THE DIGESTIVE-TRACT CONTRIBUTES TO THE CONTROL OF DISSEMINATED INTRAVASCULAR COAGULATION IN SEVERE LIVER IMPAIRMENT

A premature nconate with severe Coxsackic B1 hepatitis acquired in utero developed disseminated intravascular coagulation a few days after birth. The neonate did not respond to conventional treatment. Eradication of aerobic gram-negative bacilli (Enterobacteriaccae) from the gut with oral nonabsorbable polymyxin E and tobramycin (selective decontamination of the digestive tract) was followed by clinical improvement; disseminated intravascular coagulation was controlled. After an unstable convalescence, the neonate recovered and was discharged in good general condition. A correlation between oral feeding, gut carriage of Enterobacteriaceae, fecal endotoxin pool, and platelet counts was observed. The eradication of gut carriage of aerobic gram-negative bacilli was associated with a significant decrease of the intestinal endotoxin pool and paralleled the recovery from thrombocytopenia. Selective decontamination is discussed as a method of possible value for controlling systemic endotoxin-induced symptoms in the critically ill with intestinal endotoxemia.

Enterobacteriaceae suppression by three different oral doses of polymyxin E in human volunteers

Polymyxin E is frequently used as an oral drug for flora suppression of the gastrointestinal canal. The suppression effect is dose dependent because polymyxin E is moderately inactivated by faecal and food compounds. Three oral polymyxin E doses (150, 300, 600 mg daily) were given to six volunteers for 6 days. The Enterobacteriaceae suppression effect was compared by means of the suppression index i.e. ratio of total number of faecal samples free of Enterobacteriaceae to the total number of faecal samples. The impact on the indigenous (mostly anaerobic) flora was measured in four ways: (i) beta-aspartylglycine content; (ii) volatile fatty acid pattern; (iii) yeast overgrowth and (iv) Streptococcus faecalis decrease. Enterobacteriaceae suppression was most successful during 600 mg oral polymyxin E (suppression indices during 150, 300 and 600 mg were 0.32, 0.55 and 0.89 respectively). None of the four markers of indigenous flora alterations were positive. However, using this dosage half of the volunteers suffered rather severe gastrointestinal side-effects. Oral polymyxin E in a dosage of minimum 600 mg daily seems to possess the ideal properties of a flora suppression agent, if the gastrointestinal side-effects could be mitigated.

Cefotaxime Combined with Selective Decontamination in Long-term Intensive Care Unit Patients: Virtual Absence of Emergence of Resistance

Intensive care units (ICUs) commonly have problems with the emergence of antibiotic-resistant strains of microorganisms. Patients who need long-term mechanical ventilation usually suffer severe underlying disease (e.g. multiple trauma, malignancy, surgery). These serious conditions often need medical interventions such as dialysis, H2-antagonists, chemotherapeutic agents and antibiotics. This combination of factors decreases the defence mechanisms of the host, making the ICU patient at high risk of acquisition of ICU-associated microorganisms (often multiresistant Serratia, Pseudomonas and Acinetobacter species). Acquisition is readily followed by colonization and infection. The contaminated environment and, more particularly, the colonized and infected long-stay ICU patients are the major sources.

Selective decontamination of the digestive tract improves survival in patients receiving differential lung ventilation

In a review of the literature on differential lung ventilation (DLV) the average mortality was found to be 47%. The major cause of death (66%) was infection. The effect of a novel infection prevention regimen on the colonisation and infection rate of the respiratory tract and on outcome was studied in polytrauma patients. Nineteen patients who presented with asymmetric pulmonary contusion were treated with DLV (103±72 h) and conventional mechanical ventilation (CMV) (16±10 days). They were treated with selective decontamination of the digestive tract with topical non-absorbable antibiotics in combination with systemic antibiotic prophylaxis starting immediately after admission. In one patient colonisation of the respiratory tract was found with Staphylococcus aureus. This disappeared after continued systemic antibiotic prophylaxis. Colonisation with hospital-acquired Gram-negative bacteria or yeasts was not observed. No patient developed pneumonia throughout the period on conventional mechanical ventilation or on DLV. One patient died from cerebral injury. It is concluded that prolonged endobronchial intubation for DLV can be used without increased risk for pneumonia with this antibiotic regimen and that the very low mortality in this study may be attributed to the prevention of infectious complications.

Effect of chlorhexidine and acetic acid on phagocytosis by polymorphonuclear leucocytes

The effect of two disinfectants, chlorhexidine and acetic acid, on host leucocytes and bacteria was studied. At a concentration of 50 mg/l, chlorhexidine was found to be bactericidal without interfering with leucocyte function. A concentration of 500 mg/l of acetic acid was neither leucotoxic nor bactericidal. Effects equivalent to the aforementioned were achieved in serum by increasing the chlorhexidine concentration by a factor of 20 and the acetic acid concentration by a factor of 5. Acetic acid reduced leucocyte function more rapidly than it killed bacteria. On the basis of these findings, chlorhexidine is to be preferred for local application in burn wounds to prevent colonisation and infection.