Electron-microscopic description of accretions occurring on tips of infected and non-infected central venous catheters.

OBJECTIVE: The purpose of the study was do describe the architecture of accretions occurring on the tips of central venous catheters (CVC). DESIGN: A conservative procedure was used followed by two different techniques of electron microscopy. SETTING AND PATIENTS: the study included 19 catheters which have been used on intensive cared adults, and which were chosen among those of parallel 300 CVC study. MEASUREMENTS AND RESULTS: CVC were considered sterile, contaminated, colonized or infected according to microbiological and clinical criteria. CVC were found to remain much cleaner than in past descriptions. When present, accretions were located on the olive-shaped end, and displayed stratified structures with three types of material: amorphous material, thrombus components and inflammatory cells. Bacteria were not seen, even on culture positive CVC. Candida albicans was found on one CVC in the cytoplasm of granulocytes, and made no direct contact with the plastic surface. CONCLUSION: This technique should contribute to the understanding of the pathobiology of CVC infection and provide information proving or precluding the involvement of microbial adherence to polymers in vivo.

[Malignant hyperthermia during alcohol withdrawal]. / Hyperthermie maligne lors du sevrage alcoolique.

Heat shock is the consequence of malignant hyperthermia triggered by general anaesthesia, the use of neuroleptic drugs, or strenuous muscular exercise. Chronic alcoholism could be a contributing factor by facilitating the triggering of malignant hyperthermia. We describe two cases of malignant hyperthermia which occurred during the summer in undernourished chronic alcoholics showing withdrawal syndrome during their stay in hospital. General anaesthesia and neuroleptics were excluded as the origin of their malignant hyperthermia, and we looked for new mechanisms to explain the heat shock, other than shivering associated with the withdrawal syndrome or the high temperature of the season. These two patients were considered deficient in thiamine on admission, their plasma pyruvic acid level being sharply increased (185 mumol/l and 304 mumol/l respectively; normal range: 45.6-91.2 mumol/l). This deficiency can lead to disregulation of thermal centres. Other metabolic disorders, frequently observed in alcoholics, could facilitate heat release during withdrawal syndrome shivering. The risk of heat shock during abrupt alcohol withdrawal should not be underestimated.

[Unusual hemolytic-uremic syndrome in an adult]. / Un syndrome hémolytique et urémique inhabituel chez un adulte.

A 44-year old woman presented with haemolytic-uraemic syndrome due to predominantly arteriolar microangiopathy, with anuria lasting 48 days. The semeiology in this case was unusual: there was no anaemia and only rare schizocytes on admission, blood pressure was normal and anuria was prolonged. The severity of arteriolar thrombosis observed at renal biopsy stood in sharp contrast with the lack of arterial hypertension and the almost total recovery of renal function within three months.

[Splenic abscess. A rare pathology requiring a multidisciplinary approach]. / Abcès splénique. Une pathologie rare qui nécessite une approche multidisciplinaire.

The clinical presentation of the splenic abscess is poorly specific. Its natural evolution is often fatal. The three case reports illustrate the difficulty of the diagnosis and management of this disease. Ultra sound and C.T. scan are the procedures of choice for the diagnosis and follow-up. The choice of the treatment depends on the number of abscesses, their volume, and also the presence of extrasplenic involvement. Antibiotherapy and interventional radiology have modified its therapeutical approach. Although the conservative treatment (antibiotherapy, transparietal drainage) is often successful, splenectomy is still indicated as a first line treatment, or as a salvage procedure.

Mortality rate attributable to ventilator-associated nosocomial pneumonia in an adult intensive care unit: a prospective case-control study.

OBJECTIVE: To evaluate the mortality rate attributable to nosocomial ventilator-associated pneumonia in an intensive care unit. DESIGN: Prospective, matched, risk-adjusted cohort study. SETTING: A 18-bed adult medical-surgical intensive care unit in a 1,100-bed regional and teaching hospital in France. PATIENTS: From January 1, 1996, to April 30, 1999, 135 patients who developed nosocomial pneumonia were matched with 135 control patients without nosocomial pneumonia. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Nosocomial pneumonia was identified on the basis of results of distal bronchial samples. The matching process was conducted according to the following primary criteria: cause of admission, indication for ventilatory support, immunologic status, cardiac status, probability of death (+/-5%), Glasgow Coma Scale score (+/-2 points), age (+/-7 yrs), and duration of exposure to risk. When possible, case and control patients were matched according to five secondary criteria: respiratory and alcoholism status before admission, diagnosis categories, surgical procedure or not, and gender. The mortality rates were compared between case and control patients by using the Kaplan-Meier estimate and the log-rank test. The influence of nosocomial pneumonia on mortality rate then was tested by adjusting for the secondary criteria and other possible confounding factors by using the Cox proportional-hazards model. The matching process was successful for 1,080 of 1,080 primary criteria. The crude intensive care unit mortality rate was higher in patients with nosocomial pneumonia than in control patients (41 vs. 14%; p <.0001). In actuarial survival analysis, the probability of intensive care unit death was higher in the case patients (odds ratio = 2.7, 95% confidence interval = 1.8-3.1, p =.028). After adjustment, the occurrence of nosocomial pneumonia remained an independent risk factor of death (odds ratio = 2.1, 95% confidence interval = 1.2-3.6, p =.008). Nosocomial pneumonia attributable to multiresistant microorganisms was significantly associated with death (odds ratio = 2.6, 95% confidence interval = 1.1-5.8, p =.02). The length of intensive care unit stay was higher in case than in control patients (31 +/- 19 vs. 26 +/- 17 days, p <.0001). CONCLUSIONS: Nosocomial pneumonia is independently associated with death in the intensive care unit. In addition, it increases the length of intensive care unit stay.

[Polyurethane versus polyethylene: in vivo randomized study of infectious complications of central catheterization]. / Polyuréthanne versus polyéthylène: étude randomisée in vivo des complications infectieuses du cathétérisme central.

Polyurethane (PU) and polyethylene (PE) catheters were distributed by randomization among adult ICU patients to evaluate the impact of the catheter polymer on the rate of catheter-related sepsis (CRS). The two catheters were otherwise strictly identical. Three hundred central venous catheters were randomized and inserted in the subclavian or internal jugular vein, at the discretion of the clinician. Mean duration of insertion was 9.2 (+/- 3) days for both catheter types and mean number of line openings was 159 (+/- 60). A bacteriologic culture using a variant of Maki's technique was performed on the 205 catheters removed before patient discharge. No significant differences were found between the two catheters. Total number of tip infections was 33 and polyurethane and polyethylene prevalence ratio was 0.7. A clinical evaluation was performed for the 183 catheters inserted for a least 48 hours (in 142 patients). Patients were divided into four clinical categories according to previously reported definitions (Brun-Buisson et al., 1987). Clinical tip-infection rate was 4.4% and polyurethane and polyethylene ratio was 0.7. For three additional catheters (1.6%), only the Luer-lock was infected. These three catheters were made of polyethylene and were inserted into the internal jugular vein. The Luer-lock was made of polypropylene.

Electron microscopic description of accretions occurring in endotracheal tubes used in adults.

The purpose of the study was to describe the architecture of accretions occurring in endotracheal tubes used in adults by using a conservative procedure and transmission electron microscopy. The study included 12 tubes for which microbiological data of the tracheobronchial secretions were available. Observations were performed on inducted areas of the lumen. All tubes were covered with a several micrometers-to several millimeters-thick layer of mucus. The layers displayed stratified structures and showed granulations, neutrophils or cellular elements. When bacteria were seen, they made no contact with the polymer. This data suggest that adherence properties of bacteria towards the polymer were not involved at these stages of colonization and that a bacterial biofilms is a rare opportunity.

[Nondilated obstructive anuria complicating urethrocystopexy]. / Anuries obstructives à cavités non dilatées après urétro-cervico-cystopexie.

Anuria complicating urethrocystopexy is generally an obstructive uropathy. No urinary tract dilatation had been observed in these two following cases. The rupture of the collecting system, with urinary extravasation, is due to acute ureteral obstruction and furosemide associated. The first exam to be done is the ultrasonography. However, this exploration can fail to demonstrate obstruction. Urgent percutaneous nephrostomy appears to be the best curative method. Surgical liberation of the trapped ureters is almost necessary.

[Comparison of polyurethane and polyethylene for central venous catheter in intensive care units]. / Comparaison polyuréthane-polyéthylène pour le cathétérisme veineux central en réanimation.

Polyurethane (PU) and polyethylene (PE) central venous catheters were compared for their respective responsabilities in catheter related sepsis (CRS). From may 1988 to may 1989, 300 central venous catheters were inserted. Insertion sites were freely chosen by physicians. The polymer type was randomized. Catheters were removed after 10 days in place. Microbial loads were assessed on insertion sites, catheter hubs and tips, and blood drawn through the catheters lumen. One hundred eighty three catheters were available for complete evaluation (101 PE, 82 PE). Eleven were responsible for CRS, 4 were colonized (BB3 according to Brun-Buisson's classification), 19 were contaminated (BB2), and 149 were sterile (BB1). When comparing the "infected" group (CRS+BB3) and the "noninfected" (BB2 + BB1), no difference appeared between the tested polymers. CRS were significantly associated with insertion into the internal jugular vein. It seems useless to exclude from clinical practice any of the biomaterials tested.

[Changes in resistance of Pseudomonas aeruginosa to beta-lactams in a general intensive care unit over a three-year period. Role of piperacillin]. / Evolution de la résistance aux beta-lactamines chez Pseudomonas aeruginosa en réanimation polyvalente sur une période de trois ans. Rôle de la pipéracilline.

Nosocomial infections by Pseudomonas aeruginosa seen in a general intensive care unit from January 1987 through December 1989 were studied. Use of piperacillin, ticarcillin, cefsulodine, ceftazidime, and imipenem over the same period were recorded. Rate of infection by P. aeruginosa among the 1,844 patients admitted during the study period was 3.2%; 32% of all nosocomial infections during this period were due to P. aeruginosa. The proportion of P. aeruginosa strains exhibiting in vitro susceptibility to ticarcillin rose from 45.5% in 1987 to 59% in 1988 and 86% in 1989. Concomitantly, the proportion of P. aeruginosa strains simultaneously resistant to ticarcillin, piperacillin, cefsulodine and ceftazidime fell from 32% to 18.5% then 0%. A statistically significant correlation was found between the decrease in piperacillin use and the fall in penicillinase-producing ticarcillin-resistant strains of P. aeruginosa. Because piperacillin has undesirable effects on the intestinal flora and promotes the emergence of resistant strains of P. aeruginosa, the authors now use narrow spectrum antimicrobial agents as first line treatment of nocosomial infections.