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Biomedical subjects

H K van Saene

Publications and source records attributed to H K van Saene.

At least 19 recordsLinked to original sources
PubMed1992

Prevention of pneumonia by selective decontamination of the digestive tract (SDD).

Prevention of respiratory tract infections is only possible when the pathogenesis is known. Three types of infection can be distinguished: primary endogenous infections, caused by pathogens carried in the throat at the commencement of mechanical ventilation, generally develop early and can only be prevented by intravenous antibiotics. Secondary endogeneous infections, caused by hospital-acquired pathogens, generally develop later and can be prevented by selective decontamination of the digestive tract (SDD). The GI-tract is decontaminated by oral nonabsorbable antibiotics and for oropharyngeal decontamination a sticky antibiotic ointment is used. To date 16 controlled SDD trials in intensive care have been fully published. In all except one study, the pneumonia rate decreased significantly from 40%-50% in controls to about 10% in SDD-treated patients. All studies showed a consistent reduction of ventilator days, ICU-stay and an improved outcome in SDD-treated patients. However, in only few studies did these differences reach statistical significance. Selection of resistant strains has not been observed during prolonged use of SDD. Sucralfate reduces the pneumonia rate compared to H2-blockers or antacids by not interfering with the gastric barrier. However, gastric colonization is reduced rather than eliminated and sucralfate has almost no effect on oropharyngeal or tracheal colonization. Whether sucralfate is significantly better than a placebo remains to be established. SDD is superior to sucralfate in preventing both colonization and infection.

Anti-Bacterial Agents↗
PubMed1992

Selective decontamination of the digestive tract in the intensive care unit: current status and future prospects.

OBJECTIVE: To evaluate the available data on selective decontamination of the digestive tract. This therapy aims to prevent infection in critically ill patients admitted to ICUs. Microbial carriage in the oropharynx, stomach, and gut; infection; mortality rate; and antibiotic resistance are the outcome events that are being reviewed. DATA SOURCES: Published indices, abstract booklets, and conference proceedings up to the end of 1990. STUDY SELECTION: Sixteen controlled trials of selective decontamination were identified. None of these trials was conducted as a randomized, placebo-controlled, double-blind trial. DATA EXTRACTION: Each of the three authors independently conducted a meta-analysis (thorough review) of the data from the 16 studies. DATA SYNTHESIS: Of the 16 trials, 15 show significant reduction of acquired infection among patients who received selective decontamination. Of the 14 studies that consider carriage of disease-causing microorganisms as an outcome event, 13 demonstrate a reduction in carriage of Gram-negative bacilli. Only ten studies consider mortality as an end-point, of which four demonstrate that the administration of selective decontamination is associated with decreased mortality rates in certain subgroups but not in the overall mortality rate. Of 11 studies that provide data about antibiotic resistance during selective decontamination, ten reported no increase in resistant microorganisms. Selective decontamination has been reported to be effective in controlling an outbreak of multi-resistant microorganisms. CONCLUSIONS: There is a general consensus about the efficacy of selective decontamination in diminishing microbial carriage and acquired infection rates, although conclusions about benefits related to mortality rates vary. Differences in mortality rate are found in the selective decontamination studies of patients with curable diseases, including multitrauma and cardiovascular patients. More data on resistance, collected over a longer period of time, are needed. Practical problems of blinding and the major ecological effect of selective decontamination may explain the lack of a randomized, placebo-controlled, double-blind trial.

Anti-Bacterial Agents↗
PubMed1992

Selective decontamination of the digestive tract contributes to the control of disseminated intravascular coagulation in severe liver impairment.

A premature neonate with severe Coxsackie 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 (Enterobacteriaceae) 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.

Administration, Oral↗
PubMed1992

The role of oral microorganisms in cancer therapy.

It has been assumed that the principal changes that occur in the oral flora during cancer therapy are yeast and gram-positive coccal proliferation. Recent studies have shown that treatment with topical antifungals or disinfectants has failed to relieve such complications as irradiation mucositis that occur during anticancer therapy. Thus, many of the oral lesions observed during treatment are not due to candidiasis or streptococcal infection. It has been shown that anticancer therapy impairs or reduces the carriage defense of the oropharynx and is accompanied by colonization and proliferation of gram-negative bacilli. It is argued that if oral infectious complications are to be prevented during anticancer therapy, then the selective elimination of gram-negative bacilli may be indicated.

Antineoplastic Agents↗
PubMed1991

Bowel microorganisms--a target for selective antimicrobial control.

This article reviews the eight factors that determine the outcome of selective antimicrobial control (SAC) a technique aimed at the clearance of intestinal Gram-negative bacillary carriage by means of lethal faecal anti-microbial concentrations. They are as follows: (i) the carrier state; (ii) compliance; (iii) SAC aiming at prophylaxis vs treatment; (iv) minimum bactericidal concentration (MBC) of the antimicrobial; (v) dosage; (vi) pharmacokinetics; (vii) faecal inactivation; and (viii) microorganisms to be controlled. In the second part, non-absorbable SAC regimens are compared with absorbable trimethoprim/sulphamethoxazole (TMP/SMZ) and the fluoroquinolones in different clinical settings including neutropenia, intensive care, hepatic encephalopathy, liver transplantation and the salmonella carrier state. Ablation of gut carriage and superinfections are the main endpoints reviewed in this article. The newer fluoroquinolones are potent SAC agents to deal with enterobacteria. Pseudomonads are the major gap in their SAC spectrum. TMP/SMZ emerges as a SAC agent of limited value, whilst the newer non-absorbable combination of polymyxin/tobramycin seems to be the most potent SAC programme since it has activity against pseudomonads. In a third part, three current issues--the emergence of resistance, the selectivity and the tissue effect are discussed. Finally, a potent fluoroquinolone combined with oral polymyxin/tobramycin seems to be the most effective SAC programme currently available to control enterobacteria and pseudomonads in patients in whom bacterial translocation is a risk with minimal risk of resistance emerging.

4-Quinolones↗
PubMed1991

Selective decontamination of the digestive tract (SDD) in intensive care patients: a critical evaluation of the clinical, bacteriological and epidemiological benefits.

Twenty trials (17 controlled and three observational cohort studies) on selective decontamination of the digestive tract (SDD) have been undertaken to date. SDD is defined as a technique which aims to eradicate carriage of disease-causing microorganisms by means of lethal oropharyngeal and faecal antimicrobial concentrations. The SDD concept and the criteria for the choice of the antimicrobials used in the SDD programme are explained. Abolition of the carrier state is thought to provide clinical, bacteriological and epidemiological benefits. Infection-specific morbidity and mortality, emergence of antibiotic resistance and outbreaks are the main endpoints evaluated in this review. Of the 15 controlled studies that considered carriage, 14 demonstrated a significant reduction of Gram-negative bacillary (GNB) carriage. Severe infections, including pneumonia and septicaemia, caused by enterobacteria and pseudomonads have been virtually eliminated in these trials. Five of the 12 centres that evaluated mortality showed a significant decrease among patients who received SDD. Two recent trials describe the control of an outbreak with a multiresistant Klebsiella by SDD. There are three indications for the use of SDD so far: (i) in trauma patients; (ii) in certain elective surgical procedures including liver transplantation and oesophageal resection; and (iii) in control of outbreaks of ICU infection. Future lines of research may include a properly designed trial with mortality as endpoint and studies on the transfer of SDD from the ICU into the ward as part of prophylaxis in major surgery.

Carrier State↗
PubMed1991

Clinical evaluation of ticarcillin, with clavulanic acid, and gentamicin in the treatment of febrile episodes in neutropenic children.

To assess the clinical efficacy of ticarcillin, with clavulanic acid, and gentamicin, we conducted a prospective one year study of febrile episodes in neutropenic children. Seventy-five episodes were evaluated in 42 children. The response rate was 32% during persistent neutropenia, whilst another third of episodes responded with neutrophil recovery. Positive blood cultures occurred in 21 episodes and 20 of 24 micro-organisms belonged to the 'community' flora, i.e. organisms carried by healthy people (Streptococcus pneumoniae, Staphylococcus aureus, Branhamella catarrhalis and Escherichia coli). The route of pathogenesis was endogenous in 76% of the patients. There was a substantial superinfection-related morbidity (14%) and mortality (7%), related to emergence of resistance during and after parenteral antibiotic administration. The poor clinical response, combined with emergence of resistance, lead to the conclusion that this combination is of limited value as a first line regimen for neutropenic patients.

Child↗
PubMed1991

Selective decontamination of the digestive tract in cardiac surgical patients.

OBJECTIVE: To test the hypothesis that selective decontamination of the digestive tract improves outcome in cardiac surgical patients. DESIGN: Prospective, consecutive, controlled trial over two 4-month periods. SETTING: Eight-bed, open-plan postcardiac surgery ICU. PATIENTS: All patients undergoing cardiac bypass surgery were eligible. Patients requiring endotracheal intubation for greater than 4 days were included in the analysis. In the initial 4 months, 12 (8.5%) of 141 patients required greater than 4 days of intubation. These 12 patients were not treated with selective decontamination of the digestive tract. We therefore used these patients as the control group. In the second 4-month period, 12 (6.6%) of 180 patients were treated with selective decontamination of the digestive tract and formed the study group. MAIN OUTCOME MEASURES: The primary measure was mortality. Secondary measures included oropharyngeal decontamination and the presence of lower airway infection. INTERVENTIONS: Cephradine prophylaxis. The study group received every 6 hrs 4 mL orally and 20 mL intragastrically a suspension of antimicrobial agents (tobramycin 80 mg, polymyxin E 100 mg, amphotericin B 500 mg), starting on postoperative day 1. The control group did not receive any oral antimicrobial agents. RESULTS: Mortality rate was significantly (p less than .05) reduced from eight (66%) of 12 patients in the control group to two (16.7%) of 12 patients in the selective decontamination of the digestive tract group. No differences in oropharyngeal decontamination or lower airway infection rates between the two groups were found. CONCLUSIONS: There is a reduced mortality rate in patients receiving selective decontamination of the digestive tract. However, the reader should recognize the small sample size studied. A simple suspension of the antimicrobial agents failed to rid the oropharynx of bacteria.

Administration, Oral↗
PubMed1990

Review of available trials of selective decontamination of the digestive tract (SDD).

Eighteen studies on Selective Decontamination of the Digestive Tract (SDD) have been published up to now. A statistically significant reduction of infection rate was found in fourteen out of the fifteen controlled studies. Although all the studies were designed to evaluate infection-related morbidity as the end point, ten centres have reported fatality rates. Six centres out of the ten showed a statistically significant reduction in mortality in patients receiving SDD versus control. A recent French study describes the eradication of an outbreak of a multi-resistant Klebsiella with SDD. The Paris trial suggests a major impact of the SDD maneuver on the ICU ecology. Emergence of resistance to the SDD agents among gram-positive cocci has been described, although the clinical impact of this antibiotic side effect has not been reported so far. There are three indications for SDD, as follows: (i) trauma patients; (ii) liver transplant recipients and (iii) outbreaks of multi-resistant organisms.

Decontamination↗
PubMed1990

How to improve infection prevention by selective decontamination of the digestive tract (SDD).

From the point of view of prevention, it is useful to divide infections in intensive care into exogenous infections and primary or secondary endogenous infections. Exogenous infections hardly play a role nowadays. With selective decontamination of the digestive tract (SDD) secondary endogenous infections can be effectively prevented, but for primary endogenous infections SDD comes too late. Primary endogenous infection is the major infectious problem in intensive care. A large number of these infections are postoperative infections and are responsible for a high morbidity and mortality in the intensive care unit. Many of these postoperative infections might be prevented if SDD were started before instead of after the operation when the patient is admitted to the ICU. A tentative list of indications for pre-operative SDD is presented with a flow diagram to determine the optimal infection prevention regimen.

Decontamination↗
PubMed1990

Chlorhexidine inactivation by saliva.

Chlorhexidine mouth rinsing is commonly used for oral flora reduction. Indigenous microorganisms (viridans streptococci) are significantly suppressed, while "hospital-acquired" gram-negative bacilli are not affected in vivo. To explain the discrepancies between good in vitro and poor in vivo activity of chlorhexidine, minimum bactericidal concentration values for 120 isolates were studied by means of a standard dilution method in fresh whole saliva, broth, and glucose 5%. Both saliva and broth significantly reduced the bactericidal activity of chlorhexidine against all microorganisms tested as compared to glucose 5% (p less than 0.01). Minimum bactericidal concentrations for indigenous flora were significantly lower than the values obtained for the "hospital-acquired" microorganisms (p less than 0.05). These observations of chlorhexidine inactivation by saliva may explain why chlorhexidine mouth rinsing is of limited value in decontaminating the oral cavity.

Analysis of Variance↗
PubMed1990

Pathogenesis of colonization and infection in a neonatal surgical unit.

Nosocomial infection with aerobic Gram-negative bacilli is a major cause of morbidity and mortality in neonates. Few prospective studies have been undertaken in neonatal surgical units to investigate colonization and infection rates and the pathogenesis of infection. We prospectively studied 40 infants admitted to a neonatal surgical unit. Ninety-eight percent became colonized in throat/intestine with aerobic Gram-negative bacilli. Thirty-five percent developed infections, with wound and surface infections predominant (61%). Ninety-one percent of infections were caused by Gram-negative bacilli or yeasts. Severe infections (septicemia, pneumonia, meningitis) occurred in 13% of infants. The mortality rate was 5%. In all infections, the pathogenesis was found to be endogenous, and in most, three stages were distinguishable. Neonates always acquired potentially pathogenic organisms in throat/intestine (stage 1) before colonization (stage 2) and infection (stage 3) of other systems occurred. Reduction of digestive tract colonization by these potentially pathogenic microorganisms by means of successful selective decontamination may therefore reduce subsequent infection.

Bacterial Infections↗
PubMed1990

Reducing sepsis in severe combined acute renal and respiratory failure by selective decontamination of the digestive tract.

Fifteen patients with severe combined acute renal and respiratory failure (SCARRF), who required mechanical ventilation and renal replacement therapy for at least 5 days, were treated with a regimen to selectively decontaminate the digestive tract (SDD). In these patients the incidence of significant infection was compared with the infection rate in 12 similar patients with SCARRF who had not received SDD, treated over the preceding 12 months. Both groups were comparable for age, study period, sepsis score, and therapeutic intervention scoring system on admission, although the Acute Physiology and Chronic Health Evaluation score was higher (p less than .05) in the SDD-treated group. Ten (83%) of 12 control patients developed definable infections compared with five (33%) of 15 in the SDD group (p less than .05). Gram-negative bacteria and fungi were responsible for 14 of the 17 infections affecting ten control patients, compared with six of the seven infections in only four SDD patients (p less than .05). The most notable site to benefit was the respiratory tract, with only one patient in the SDD group developing a pulmonary infection compared with five in the control patients (p less than .05). Urine infections may have been reduced from six (50%) of the 12 control patients to two (13%) of the 15 SDD patients, but this difference was not significant. Although survival in the control and SDD group was comparable (42% vs. 40%), mortality overall seemed related to infection. Eleven (73%) of 15 patients with definite infection died, in contrast with five (42%) of 12 who had no infections, although this was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1990

Mucositis prevention by selective elimination of oral flora in irradiated head and neck cancer patients.

Mucositis induced by irradiation is the reactive inflammatory-like process of the oropharyngeal mucous membranes following irradiation. Bacteria colonizing the oral tissues are thought to contribute to this inflammatory process. The eradication of Gram-negative bacilli (selective elimination of oral flora) in fifteen comparably irradiated head and neck cancer patients was found to be associated with a significant reduction in mucositis compared with two groups of 15 patients receiving either placebo or chlorhexidine rinsing. Criteria used were the extent of local mucositis signs (mucositis score), as well as generalized side-effects such as the need of nasogastric tube feedings following severe feeding problems. Mucositis signs were confined to erythema only in all selectively decontaminated patients. No pseudomembranes were observed and artificial feeding was completely prevented. These promising results need further confirmation in larger (multicenter) studies.

Adult↗
PubMed1990

Cystic fibrosis, Pseudomonas aeruginosa, and selective decontamination.

We used an oral topical antibiotic preparation to try and prevent oropharyngeal carriage of Pseudomonas aeruginosa in patients with cystic fibrosis. Ten of 15 patients treated with a two week course of intravenous ceftazidime together with a 90 day course of an antibiotic containing gel continued to carry P aeruginosa in the oropharynx.

Administration, Oral↗