Prospective study of nosocomial colonization and infection due to Pseudomonas aeruginosa in mechanically ventilated patients.

OBJECTIVE: To investigate the respective contribution of endogenous and exogenous transmission of Pseudomonas aeruginosa in the colonization of lungs in the mechanically ventilated patient, to estimate the role of P. aeruginosa colonization in the occurrence of severe infections, and to extrapolate appropriate control measures for the prevention of P. aeruginosa ventilator-associated pneumonia. DESIGN: Prospective study of the presence of P. aeruginosa (in stomach fluid, throat specimens, stool, and sputum) on admission, twice a week throughout the patient's stay, and in their environment. O-serotyping, pulsed-field gel electrophoresis, and arbitrarily-primed polymerase chain reaction were used to characterize the strains. SETTING: The two intensive care units (ICUs 1 and 2) of a university hospital. PATIENTS: During a 6-month period, 59 patients were included (21 in ICU 1 and 38 in ICU 2). RESULTS: P. aeruginosa was isolated in 26 patients, including ten pneumonia cases and seven colonizations on admission. The incidence of acquired colonization was statistically different between the two ICUs: 5.5 and 20.5 per 1000 days of mechanical ventilation, in ICUs 1 and 2, respectively. Endogenous acquisition was the main origin of P. aeruginosa colonization (21 of 26 patients) and the upper respiratory tract was the main bacterial reservoir in broncho-pulmonary colonization and infection. However, during the 6-month period of the study, a multidrug-resistant strain of P. aeruginosa O:11, isolated in the sink of the room of 12 patients, was found responsible for two colonizations (1 digestive, 1 throat/lungs) and one pneumonia. As a whole, from 26 cases of colonization/infection with P. aeruginosa, 5 were related to an exogenous contamination (environmental reservoir in 4 patients and cross-contamination in one patient). CONCLUSIONS: These results emphasize the need for applying various infection control measures to prevent colonization of patients with P. aeruginosa, including strategies to limit the potential of sinks from acting as a source or reservoir for this bacterium.

Endotoxaemia in patients with severe sepsis or septic shock.

OBJECTIVE: To examine the incidence and the bacteriological and clinical significance of endotoxaemia in ICU patients with severe sepsis or septic shock. DESIGN: Prospective review. SETTING: A 15-bed general ICU in a university hospital. PATIENTS: One hundred sixteen patients hospitalised in our ICU fulfilling Bone's criteria for severe sepsis or septic shock and with an available early endotoxin assay (chromogenic limulus assay). INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The clinical characteristics of the population were: age 63.6 +/- 11.4 years; SAPS II: 45.4 +/- 15.6; mechanical ventilation: 72.4%; septic shock: 51.7% (n = 60); bacteraemia: 28.4% (n = 33); gram-negative bacteria (GNB) infection 47.4% (n = 55); ICU mortality: 39.6% (n = 46). Detectable endotoxin occurred in 61 patients (51.2%; mean level: 310 +/- 810 pg/ml). There was no relationship between detectable endotoxin and severity of infection at the moment of the assay. Endotoxaemia was associated with a higher incidence of bacteraemia (39.3% vs 16.3%; p = 0.01). There was a trend (p = 0.09) towards an association between positive endotoxin and gram-negative bacteraemia or GNB infection but this was non-significant. This relationship became significant only in the case of bacteraemia associated with GNB infection irrespective of the site of infection. CONCLUSION: Early detection of endotoxaemia appeared to be associated with GNB infection only in cases of bacteraemic GNB infection. Early endotoxaemia correlated neither to occurrence of organ dysfunction nor mortality in patients with severe sepsis or septic shock. This study suggests that the use of endotoxaemia as a diagnostic or a prognostic marker in daily practice remains difficult.

[Catheter infection in intensive care: influence of systematic replacement of central venous catheters on a guide wire every 4 days]. / Infections sur cathéters en réanimation: influence de l'échange systématique sur guide métallique tous les 4 jours de voies veineuses centrales.

OBJECTIVES: Determine whether systematic replacement of central venous catheters on a guide wire every 4 days leads to a lower rate of catheter infection. METHODS: We conducted a prospective randomized study comparing systematic catheter replacement with the standard procedure where one-way catheters are left in situ as needed. RESULTS: The study included 150 patients and 170 catheters. Catheter replacement on a guide wire was performed 169 times. The rate of infection was not significantly different between the group of patients with replacement (3.7 for 1000 catheter days) and the group with systematic replacement (5.4 for 1000 catheter days). No mechanical complications occurred during the replacement procedures on guide wires. CONCLUSION: We do not recommend systematically replacing catheters on a guide wire for the prevention of catheter infection. This procedure may however be indicated in case of suspected catheter infection as no mechanical of infectious complications occurred.

Effects of pentoxifylline on circulating cytokine concentrations and hemodynamics in patients with septic shock: results from a double-blind, randomized, placebo-controlled study.

OBJECTIVE: To determine whether a continuous intravenous infusion of pentoxifylline, a methylxanthine derivative, alters the serum cytokine concentrations and/or hemodynamic measurements in patients with septic shock. DESIGN: A prospective, randomized, double-blind, placebo-controlled study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: Sixteen patients with septic shock. INTERVENTIONS: Patients were randomly assigned to receive either pentoxifylline (1 mg/kg) followed by an infusion of 1.5 mg/kg/hr for 24 hrs (n = 8), or placebo (n = 8). MEASUREMENTS AND MAIN RESULTS: Tumor necrosis factor (TNF) and interleukin (IL)-6 concentrations were measured by radioimmunoassays; IL-8 concentrations by an enzyme-linked immunosorbent assay (ELISA) and pentoxifylline concentrations by high-performance liquid chromatography at 0, 3, 6, 12, 18, 24 and 48 hrs after study entry. Pulmonary artery catheter-derived hemodynamics were measured at 0, 0.75, 3, 6, 12, 18, and 24 hrs. In pentoxifylline-treated patients, at 24 hrs, serum concentrations of TNF were significantly lower compared with controls (12 +/- 2 vs. 42 +/- 12 pg/mL, respectively, p = .04). Serum concentrations of IL-6 and IL-8 did not differ between the two treatment groups. There were also no significant differences in any hemodynamic and oxygenation measurements comparing the two treatment groups. Pentoxifylline concentrations were 1,544 +/- 241 ng/mL after the initial dose, and 5,776 +/- 1,781 ng/mL at the end of the 24-hr infusion. Five patients in the pentoxifylline group and four patients in the placebo group died. CONCLUSIONS: Pentoxifylline is able to decrease serum TNF but not IL-6 or IL-8 serum concentrations during septic shock. Pentoxifylline was well tolerated by all eight patients with no adverse effect. Further studies are needed to determine if pentoxifylline's ability to lower circulating TNF concentration without altering hemodynamics will improve outcome in septic shock.

Acinetobacter baumannii outbreak isolates characterized by three typing methods.

Forty-two strains of Acinetobacter baumannii were isolated from 15 patients hospitalized in a French intensive care unit. An epidemiological study based on the typing of these isolates was carried out using biotyping, antibiotyping, and ribotyping to recognize the transmission of multiresistant strains by transfer of a patient from one hospital to another. Fifteen strains from the outbreak (1 strain for each patient), five Acinetobacter baumannii strains isolated before the outbreak in Bellevue Hospital (St. Etienne), and five strains isolated in Cochin Hospital (Paris) were included. The three methods gave a good correlation: the epidemic strains had the same antibiotic resistance pattern, the same biotype, and the same ribotypes obtained with three different endonucleases.

[Anesthesia and general surgery in cardiac patients]. / Anesthésie et chirurgie générale chez le cardiaque.

Close cooperation is necessary between the cardiologist and anesthesiologist preoperatively in order to identify the risks associated with a surgical procedure. This article reviews the various types of anesthesia and their effects on the cardiovascular system, in particular in relation to the category of cardiovascular disease. Accurate definition of the operative risk involves thorough evaluation of three essential parameters: cardiovascular status, the type of surgery and the type of anesthesia. These high-risk patients require management not only pre- and peroperatively, but also postoperatively, which is the period when the majority of complications occur. Mention is also made of drug interactions between anesthetic and cardiovascular agents.

Molecular and genetic studies on the euchromatin-heterochromatin transition region of the X chromosome of Drosophila melanogaster. 1. A cloned entry point near to the uncoordinated (unc) locus.

A recombinant Charon 4 bacteriophage has been isolated on the basis of RNAs which are enriched in the head of the adult Drosophila melanogaster and hence are likely to be of neural origin. The cloned insert maps to the near vicinity of the uncoordinated locus in polytene chromosome band 19E8. This band is within the transition zone between the euchromatic and heterochromatic regions of the X chromosome, a region which has been well characterized cytogenetically. The insert contains both repetitious and low copy number sequences, some of which vary extensively in both frequency and restriction fragment size between different laboratory strains. One particular family of moderately repeated sequences occurs predominantly in divisions 19 and 20 of the X chromosome and perhaps the distally located X heterochromatin. The molecular landscape surrounding the initial entry point contains many repeated sequences and is thus unlike those observed in most published chromosomal walks. The possible significance of the presence of repeated families in the distinct properties of this region are discussed.