Effect of intravenous iron on haemodialysis catheter microbial colonization and blood-borne infection

BACKGROUND: Intravenous (i.v.) iron is employed to treat absolute and relative iron deficiency in end-stage renal disease patients. However, there exists the possibility that i.v. iron increases infection risk. This pilot study examines whether i.v. iron gluconate acutely increases tunnelled haemodialysis catheter colonization, microbial growth, or blood-borne infection. METHODS: Nineteen patients with haemodialysis catheters who met criteria to receive an i.v. iron load entered the study. Six matched patients with catheters who did not receive iron were controls. Blood aspirated from the catheter prior to initiation of haemodialysis was sent for qualitative/quantitative cultures. The study consisted of three baseline cultures, five cultures during iron (125 mg of ferric gluconate per treatment), and three cultures following iron administration. Patients were monitored for infection for 30 days following iron. RESULTS: Fifteen iron-treated patients and six controls completed the study. Thirty-three per cent of treated patients were colonized at baseline; 66% were colonized following iron. Thirty-three per cent of controls (2/6) were colonized at baseline; no new colonization developed during follow up. Neither treated patients nor controls had significant microbial growth within catheters; one patient in the iron-treated group developed candidaemia. CONCLUSION: Intravenous iron is not associated with acute microbial growth in catheters or clinical infection. However, a trend towards increased catheter colonization following iron administration exists.     

Prevention of central venous catheter sepsis: a prospective randomized trial

A prospective randomized trial was undertaken to evaluate the influence of routine 72-hour catheter exchange and the use of an implantable collagen cuff in preventing central venous catheter infection in critically ill patients requiring multiple lumen central venous access. Patients were randomized to one of four groups, which determined whether the central venous catheter placed would be removed at 3 or 7 days and whether an implantable collagen cuff would be used or not. Upon removal, cultures of the central line tip, the insertion site, and peripheral blood were obtained. One hundred and fifty-nine catheters were studied in 85 patients during a 14-month period. There were 26 (16.4%) episodes of catheter colonization and four (2.5%) episodes of catheter infection in the entire population. Catheter colonization rates (same organisms cultured from catheter tip and skin site) were 14.5 per cent at 3 days and 18.4 per cent at 7 days. Infection rates (same organism cultured from catheter tip and peripheral blood culture) were 2.4 per cent at 3 days and 2.6 per cent at 7 days. With regard to the use of the collagen cuff, colonization rates were 14.5 per cent with the use of the cuff and 18.1 per cent without the use of the cuff. Infection rates were 5.3 per cent with the use of the cuff and 0 per cent without the use of the cuff. None of these differences reached statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)     

A central venous catheter coated with benzalkonium chloride for the prevention of catheter-related microbial colonization

In an attempt to overcome infections associated with central venous catheters, a new antiseptic central venous catheter coated with benzalkonium chloride on the internal and external surfaces has been developed and evaluated in a clinical trial. Patients (235) randomly received either a triple-lumen central venous catheter coated with benzalkonium chloride (117) or a polyurethane non-antiseptic catheter (118). The incidence of microbial colonization of both catheters and retained antiseptic activity of the benzalkonium chloride device following removal were determined. The benzalkonium chloride resulted in a significant reduction of the incidence of microbial colonization on both the internal and external catheter surfaces. The reduction in colonization was detected at both the intradermal (21 benzalkonium chloride catheters vs. 38 controls, P = 0.0016) and distal segments of the antiseptic-coated catheters. Following catheter removal retained activity was demonstrated in benzalkonium chloride catheters which had been in place for up to 12 days. No patients developed adverse reactions to the benzalkonium chloride catheters. The findings demonstrate that the benzalkonium chloride catheter significantly reduced the incidence of catheter-associated colonization.     

Insufficient penetration of systemic vancomycin into the PermCath lumen.

BACKGROUND: Catheter infection is a major cause of morbidity and catheter loss in chronic haemodialysis patients. There has been a large discrepancy in the catheter salvage rate, after an episode of documented bacteraemia, whether the patients receive systemic antibiotic alone or systemic antibiotics concomitant with 'antibiotic-lock technique' (20-30% vs 100%, respectively). To test the hypothesis that vancomycin may not adequately penetrate into the lumen of the catheter, despite therapeutic plasma levels, a series of in-vivo, ex-vivo, and in-vitro experiments were performed. METHODS: We compared serum and intralumenal (0.3-0.5 ml aspirate from venous port of the catheter) vancomycin concentrations in 24 chronic haemodialysis patients, with documented bacteraemia, who had received prior systemic vancomycin therapy with 14 similar patients who had additionally received 'vancomycin-lock technique' (100 microg/ml of vancomycin in heparin solution) after each haemodialysis session. RESULTS: Despite serum vancomycin concentration of approximately 17 microg/ml in each group, the vancomycin concentration in the venous hub of the catheter was only 0.2+/-0.6 microg/ml in the former group, in sharp contrast to 125. 6+/-13 microg/ml in the latter group. In the ex-vivo experiment, four uninfected PermCaths which had been removed were immediately fixed and studied with scanning electron microscopy. No cellular or fibrin barrier could be found at the terminal pore of the catheter interfering with the diffusion of vancomycin from plasma into the catheter lumen. In the in-vitro experiments, three PermCaths filled with standard heparin solution were incubated for 48 h in 100 ml of plasma containing 20 microg/ml of vancomycin. Vancomycin concentration was measured in 0.3-0.5 ml solution aspirated from each port of the catheters. Vancomycin concentration was 0.2+/-0.1 microg/ml in the aspirated samples. Finally, two PermCaths filled with the standard heparin solution were incubated for 48 h in 100 ml of plasma containing 20 microg/ml of vancomycin, after which the catheters were sectioned at 4-cm intervals. Only the distal 4 cm of the catheters had vancomycin concentrations of 2 and 5 microg/ml, the remaining segments had levels 相似文献   

Outcome and complications of temporary haemodialysis catheters.

BACKGROUND: The use of temporary haemodialysis catheters is often complicated by mechanical or infectious complications. Risk factors for these complications and optimal management to reduce their incidence are largely unknown. METHODS: We conducted a prospective study of 105 haemodialysis catheters (79 subclavian, 26 jugular) inserted in 52 patients in order to identify patient outcomes and to analyse the effect of patient and catheter factors on the incidence of infectious complications by multivariate analysis. RESULTS: Fifty-nine per cent of catheters were removed for a suspected complication. Catheter-related bacteraemia (CRB) was diagnosed in 17 catheters (16%), giving a bacteraemia rate of 6.5 episodes per 1000 catheter days. Subgroup analysis revealed a higher risk of CRB with the use of the internal jugular compared with the subclavian site (hazard ratio 3.97, P=0.02). Age, diabetes or catheter exchange over a guidewire did not alter the risk of CRB. The cumulative risk of developing CRB increased in a linear fashion as the period of catheterization increased. Exit-site infection was the cause for removal in eight catheters (8%). Although the number of exit-site infections was small, the risk of exit-site infection was increased in diabetic patients (hazard ratio 10, P=0.03) and the jugular position (hazard ratio 6.5, P=0.01) but not by age or catheter exchange over a guidewire. Staphylococcus aureus and coagulase-negative staphylococcus accounted for all proven episodes of CRB. Exit-site infection was associated with a mixture of Gram-positive and Gram-negative organisms. CONCLUSIONS: Temporary haemodialysis catheters have a high failure rate associated with a significant rate of complications. Use of the internal jugular site is associated with a significantly higher risk of infectious complications and methods to reduce this risk should be considered if this site is used.     

Catheter-related infections in burn patients at the Burn Centre of the University Hospital in Ostrava

We need central venous catheters (CVCs) in management of critically ill patients with severe burns, either for the administration of fluids or monitoring hemodynamic status. Central venous catheterization may cause different early or late complications, which depend on the physician's erudition, the quality of the catheters and quality of Intensive Care Unit (ICU) nursing care for insertion. 272 CVCs were inserted in 114 both adult and pediatric patients from 2004 to 2006 in the ICU of the Burn Centre in Ostrava. The average insertion length of the catheter was 10.2 days, and the average total length of catheterization was 24 days. The total number of catheter-days was 2768. All catheter tips removed were routinely cultured. The most frequent infecting pathogens were coagulase-negative Staphylococci. Peripheral blood cultures were examined in case of fever. Bacterial findings from wounds, sputa and urine were monitored in all patients. No exogenous catheter sepsis according to Maki's criteria occurred in our study group. Endogenous catheter colonization with positive peripheral blood culture and bacteraemia occurred in 4 cases, which means an incidence density of 1.44 endogenous colonizations per 1000 catheter-days. The quality of used catheters and particularly the technique of placement and maintenance of catheters are considered crucial for good results in the ICU of Burn centre in Ostrava.     

Comparison of antimicrobial impregnation with tunneling of long-term central venous catheters: a randomized controlled trial

OBJECTIVE: We sought to compare the impact of antimicrobial impregnation to that of tunneling of long-term central venous catheters on the rates of catheter colonization and catheter-related bloodstream infection. SUMMARY BACKGROUND DATA: Tunneling of catheters constitutes a standard of care for preventing infections associated with long-term vascular access. Although antimicrobial coating of short-term central venous catheters has been demonstrated to protect against catheter-related bloodstream infection, the applicability of this preventive approach to long-term vascular access has not been established. METHODS: A prospective, randomized clinical trial in 7 university-affiliated hospitals of adult patients who required a vascular access for > or = 2 weeks. Patients were randomized to receive a silicone central venous catheter that was either impregnated with minocycline and rifampin or tunneled. The occurrence of catheter colonization and catheter-related bloodstream infection was determined. RESULTS: Of a total of 351 inserted catheters, 346 (186 antimicrobial-impregnated and 160 tunneled) were analyzed for catheter-related bloodstream infection. Clinical characteristics were comparable in the 2 study groups, but the antimicrobial-impregnated catheters remained in place for a shorter period of time (mean, 30.2 versus 43.8 days). Antimicrobial-impregnated catheters were as likely to be colonized as tunneled catheters (7.9 versus 6.3 per 1000 catheter-days). Bloodstream infection was 4 times less likely to originate from antimicrobial-impregnated than from tunneled catheters (0.36 versus 1.43 per 1000 catheter-days). CONCLUSIONS: Antimicrobial impregnation of long-term central venous catheters may help obviate the need for tunneling of catheters.     

Central venous catheters for haemodialysis: looking for optimal blood flow

Central venous catheters are commonly used for haemodialysis patients and represent, in our centre, about 15% of the permanent vascular accesses with a total number of more than 230 central venous catheters over the last 10 years. Inadequate blood flow may occur and upsets the nurses, the patients, and the nephrologist. The aim of this study was to identify the factors of the catheter dysfunction. We studied prospectively 25 chronic haemodialysed patients with central venous catheters, 14 women and 11 men, 65±16 (55-89) years of age, treated with haemodialysis for 6.7±7 (1-26) years. Catheters were tunnelled silicone twin catheters (Permcath Quinton® n=18, Twincath Hemotec® n=7) in right (n=19) and left internal jugular (n=6) inserted by percutaneous Seldinger techniques. We studied the localization of the catheter tip (superior vena cava, right atrium, right ventricular, inferior vena cava), the central venous pressure before and after haemodialysis, the blood pressure (BP) before and after haemodialysis, the interdialytic weight gain, the number of symptomatic hypotensions during the 10 last dialyses. The patients were divided into two groups: group I with usual adequate catheter function (n=18) and group I with frequent dysfunctions (n=7). Central venous pressure before dialysis was significantly higher in group I with adequate blood flow and the catheter's tip was more frequently found localized in the right cardiac cavities than in the vena cava. When central venous pressure before dialysis was over 5 mmHg, no dysfunction occurred. Blood pressure was not different between the two groups. We found no correlation between central venous pressure and BP, interdialytic weight gain and symptomatic hypotensions. We could not predict the central venous pressure from the mean BP but there was a higher frequency of hypotensions in the hypovolaemic patients. Optimal haemodynamic conditions will be provided by a catheter tip in the right cardiac cavities and a central venous pressure over 5 mmHg which can be provided with vascular filling or dry weight revaluation.     

A randomized controlled trial of topical exit site mupirocin application in patients with tunnelled, cuffed haemodialysis catheters.

BACKGROUND: Central venous catheters are frequently needed for the provision of haemodialysis, but their clinical usefulness is severely limited by infectious complications. The risk of such infections can be reduced by topical application of mupirocin to the exit sites of non-cuffed catheters or by the use of tunnelled, cuffed catheters. Whether mupirocin offers any additional protection against infection in patients with tunnelled, cuffed haemodialysis catheters has not been studied. METHODS: An open-label, randomized controlled trial was performed comparing the effect of thrice-weekly exit site application of mupirocin (mupirocin group) vs no ointment (control group) on infection rates and catheter survival in patients receiving haemodialysis via a newly inserted, tunnelled, cuffed central venous catheter. All patients were followed until catheter removal and were monitored for the development of exit site infections and catheter-associated bacteraemias. RESULTS: Fifty patients were enrolled in the study. Both the mupirocin (n=27) and control (n=23) groups were similar at baseline with respect to demographic characteristics, comorbid illnesses and causes of renal failure. Compared with controls, mupirocin-treated patients experienced significantly fewer catheter-related bacteraemias (7 vs 35%, P<0.01) and a longer time to first bacteraemia (log rank score 8.68, P<0.01). The beneficial effect of mupirocin was entirely attributable to a reduction in staphylococcal infection (log rank 10.69, P=0.001) and was still observed when only patients without prior nasal Staphylococcus aureus carriage were included in the analysis (log rank score 6.33, P=0.01). Median catheter survival was also significantly longer in the mupirocin group (108 vs 31 days, log rank score 5.9, P<0.05). Mupirocin use was not associated with any adverse patient effects or the induction of antimicrobial resistance. CONCLUSIONS: Thrice-weekly application of mupirocin to tunnelled, cuffed haemodialysis catheter exit sites is associated with a marked reduction in line-related sepsis and a prolongation of catheter survival.     

Bacterial colonization of chronic hemodialysis catheters: Evaluation with endoluminal brushes and heparin aspirate

Tunneled catheters serve as interim access during maturation of a graft or fistula, or as a permanent vascular access in those patients who have exhausted their traditional access sites. However, bacteremia rates are high in patients with chronic catheters and indiscriminate removal of catheters during bacteremia increases morbidity and costs. A method to identify whether a catheter was colonized with the offending bacteria, without requiring catheter removal is desirable. We compared endoluminal brushing and heparin aspiration, to detect catheter colonization, in 24 asymptomatic patients undergoing elective tunneled hemodialysis catheter removal. The incidence of catheter colonization was highly correlated with catheter duration of inverted exclamation markY 30 days (p=0.03). Staphylococcus epidermidis represented 68% of the organisms isolated. No other organism accounted for more than 7% of the total. Fifteen (62.5%) of the 24 catheters had positive cultures. Eleven of the catheters were positive by culture of heparin aspirate and eight were positive by endoluminal brushing. Only four of the catheters were positive by both methods. The arterial lumen was more likely to have positive cultures than the venous lumen using either method. In this prospective investigation of tunneled hemodialysis catheters in asymptomatic patients we have demonstrated that a heparin aspirate sample is more likely to detect catheter colonization than a sample obtained using an endoluminal brush. Furthermore, 75% of catheters present for more than 30 days were colonized. Further study is needed to determine if the heparin aspirate method could be used in patients with bacteremia to accurately identify catheters that need removal.     

Azygos arch cannulation by central venous catheters for hemodialysis

Cannulation of central veins and placement of catheters for temporary haemodialysis is a common procedure in the management of patients with end stage renal failure. The internal jugular vein is the site of choice for central venous catheter placement, being associated with the lowest complication rate. This procedure can be associated with a variety of malpositions of the catheter and rarely, can lead to significant morbidity and even mortality, if this is not recognised and corrected early. For anatomical reasons, the risk of azygos arch cannulation is substantially increased if catheters are inserted via left-sided veins. We report a case with a rare complication associated with the insertion of a catheter for temporary haemodialysis.     

Central venous access for long-term haemodialysis

Long-term central venous catheterization has been used as the sole method of vascular access in nine chronic dialysis patients with severe access difficulties. The catheters were inserted into the right atrium via external or internal jugular veins by a simple operative technique and have remained in situ for 1-33 months. Although three catheters required replacement for incorrect positioning (two patients) and catheter-associated thrombosis (one patient) no patient failed with the technique. Catheter-related complications were infrequent. The study demonstrates that it is possible to undertake adequate and safe haemodialysis through a permanently indwelling central venous catheter in patients in whom conventional methods of vascular access, and other modes of renal replacement therapy, have failed repeatedly.     

Favourable outcomes in episodes of Pseudomonas bacteraemia when associated with tunnelled cuffed catheters (TCCs) in chronic haemodialysis patients.

BACKGROUND: Pseudomonas is regarded as a particularly lethal bacterial isolate. High mortality rates have been reported in episodes of Pseudomonas sepsis when associated with visceral infections as seen in immunosuppressed, hospitalized patients. In comparison, lower mortality rates have been reported with catheter-associated Pseudomonas bacteraemia in non-dialysis patients. The purpose of this study was to determine the risk factors and the outcomes for episodes of Pseudomonas bacteraemia associated with the use of tunnelled cuffed haemodialysis catheters (TCCs) in a chronic out-patient population. METHODS: We performed a prospective observational study in seven chronic haemodialysis units over a 2.5 year period. Patients who were diagnosed as having their initial TCC-associated bacteraemia within the study period were followed for 3 months. All episodes of Pseudomonas TCC bacteraemia were identified, and univariate analyses were performed to compare Pseudomonas bacteraemia with non-Pseudomonas bacteraemia. RESULTS: During the study period, 219 episodes of TCC bacteraemia were identified; 18 had a Pseudomonas isolate (8%). Pseudomonas bacteraemia episodes were associated with a significantly higher risk of not receiving appropriate initial antibiotics (odds ratio = 3.6, P = 0.02). There were no deaths in the Pseudomonas bacteraemia group, whereas 19% died in the non-Pseudomonas group. The TCC was removed in 89% of Pseudomonas bacteraemias. There were no significant risk factors for acquiring a Pseudomonas isolate, and no difference in recurrent bacteraemia or infectious complication rates between the groups. CONCLUSIONS: In haemodialysis patients with a TCC-associated Pseudomonas bacteraemia, outcomes are remarkably good. This may be because the source of Pseudomonas infection was removed in most cases. Initial antibiotic coverage lacking anti-Pseudomonas activity was not associated with increased mortality.     

Central venous catheterization for parenteral nutrition.

To define the risks associated with central venous catheterization for total parenteral nutrition (TPN) 3291 patient days of this therapy, delivered by an established nutrition support team, were evaluated. One hundred and seventy-five catheters placed in 104 patients were reviewed over an 18 month period. Positive cultures were reported on 11 cannulae for a 6.4% incidence of colonization; five catheters (2.8%) were considered septic. Pleural or mediastinal complications of subclavian or internal jugular venipuncture occurred in eight patients (4.8%). Misdirection of the catheter tip occurred in 11.5% of insertions. Five patients (4.8%) had clinically apparent thrombosis in the superior vena cava, innominate and/or subclavian veins during hospitalization; four others had evidence of thrombosis at autopsy examination, giving an incidence of 8.7% in the entire series. No death directly resulted from the use of this therapy. Compliance with a rigid protocol by an experienced team can allow safe and effective use of central venous catheters and parenteral nutrition therapy.     

Incidence and predictors of central venous catheter related infection in intensive care patients

This study investigated the incidence of and risk factors for central venous catheter (CVC) infection in intensive care. CVCs were prospectively studied in patients who had lines inserted in general or neurosurgical intensive care and were expected to have the line in situ for at least 72 hours. Catheters (n = 119) were cultured for CVC-related infection (CRI; > 15 colony forming units) and blood cultures done when indicated. CRI was identified in 32 (26.9%) catheters, CVC related bacteraemia in five cases (4.2%) and CVC related sepsis in none. After adjustment for duration of catheterization, independent predictors of CVC related infection were catheter insertion site, with jugular sites having the highest risk, and primary diagnosis, with neurosurgical patients at least risk.     

External Ventricular Drainage Catheters: Effect of Surface Heparinization on Bacterial Colonization and Infection

Summary  Surface heparinization of central venous catheters has earlier been shown to reduce the frequency of bacterial colonization and septicaemia. The present study was undertaken to investigate the benefit of surface heparinization of external ventricular drainage (EVD) catheters in relation to bacterial colonization, as measured by bacterial growth and examination by a 16S-rRNA PCR assay, of catheters and of samples of cerebrospinal fluid (CSF). Ninety-eight heparinized and one hundred unheparinized EVD catheters from the same batch of catheters were used. Twenty point five percent of the heparinized and 22.8% (p=0.63) of the unheparinized EVD catheters were colonized with bacteria. Culture of CSF, which is the definition of clinical infection in this study, yielded growth in 10.3% of patients with heparinized and in 6.3% (p=0.18) of those with unheparinized catheters. PCR examination yielded positive signal in 31.3% of patients with heparinized catheters and in 37.7% (p=0.061) of patients without (CSF and catheters). In the subgroup of patients with subarachnoid haemorrhages, there was a tendency, though not statistically significant, towards a lowered frequency of colonization with 23.1% for heparinized and 33.3% (p=0.31) for unheparinized catheters. PCR examination did not contribute any further to the diagnostic procedure in the patients concerned. The EVD catheters are skin-penetrating devices and contamination from the skin flora is common. Skin cultures, obtained after skin disinfection and insertion of catheters, showed growth of bacteria in 62% of the patients.     

Catheter-related bacteraemia in haemodialysis patients with HIV infection.

BACKGROUND: Tunnelled catheters are used for dialysis in over 25% of haemodialysis (HD) patients and are a major risk factor for bacteraemia. HIV-positive patients may be at particularly increased risk of catheter-related bacteraemia (CRB) due to their immunocompromised state. The present case-controlled study compared catheter-related bacteraemia with HIV-positive and HIV-negative haemodialysis patients. METHODS: Using a prospective computerized vascular access database, we identified 33 HIV-positive haemodialysis patients who had a tunneled dialysis catheter placed during a 6.5-year period. Their catheter outcomes were compared with those observed in 55 age-, sex- and access date-matched control haemodialysis patients. RESULTS: The two groups were similar in terms of age, sex, diabetes, hypertension and peripheral vascular disease, but the HIV patients were more likely to be black (94 vs 76%, P=0.03). CRB occurred in 52% of the HIV patients and 49% of the controls (P=0.83). The median infection-free catheter survival was similar in HIV-positive and negative patients (165 vs 119 days, P=0.12). Among patients with CRB, the likelihood of a Gram-negative infection was similar in both groups (18 vs 30%, P=0.37). However, polymicrobial CRB was more likely in HIV patients (41 vs 15%, P=0.049). HIV-positive patients were more likely to be hospitalized for treatment of CRB than HIV-negative patients (29 vs 7%, P=0.05). CONCLUSION: CRB is equally likely in HIV-positive and control haemodialysis patients. However, CRB is likely to be more severe in HIV-positive patients, as judged from the greater likelihood of polymicrobial infection and of hospitalization.     

Staphylococcus aureus bacteraemia among patients undergoing dialysis-focus on dialysis catheter-related cases

Background: Central venous catheter-related infections are the most common cause of nosocomial S. aureus bacteraemia in Denmark. Central venous catheters are often used for dialysis, and patients on dialysis often run into staphylococcal infections. The purpose of this study was to investigate S. aureus bacteraemia among dialysis patients, especially those related to dialysis catheters. Methods: This was a retrospective study of 14 387 consecutive S. aureus bacteraemia cases during the period 1976-93, of which 793 cases occurred among dialysis patients. By reviewing the case records, 65 dialysis catheter-related cases were described more thoroughly. Results: The number of S. aureus bacteraemia cases among dialysis patients as a proportion of all cases in Denmark has increased from 5.2 to 14.7% during the study period, but the annual incidence among these patients has been almost stable during the period (median 5.7% (3.2-9.0%)). Patients on dialysis had a lower mortality than other patients with S. aureus bacteraemia (18.8 vs 29.0%), but a four times higher mortality from central venous catheter-related S. aureus bacteraemia (5.3 vs 1.3%, P <0.001). The mortality from dialysis catheter-related S. aureus bacteraemia was correlated with greater age (median 71 years (57-73) vs median 56.5 years (15-76), P <0.01) and with septic shock (55.5 vs 7.1%, P <0.05). Patients on dialysis had a lower frequency of S. aureus endocarditis (3.3 vs 5.4%, P <0.01) and of S. aureus bone and joint infections (3.3 vs 8.2%, P <0.001) than other patients. Patients undergoing dialysis had a later onset of catheter-related S. aureus bacteraemia than other patients (median 15 days (1-145) vs 5 days (1-134), P <0.05). Conclusions: Patients on dialysis are at a high risk of S. aureus bacteraemia and they have a four times higher mortality from central venous catheter-related S. aureus bacteraemia than other patients. There is need for prospective studies in which patients as well as catheters are followed more thoroughly to study the pathogenesis of dialysis catheter-related infections.     

Enterobacter bacteremia in surgical patients

The records of 63 surgical patients with one or more positive blood cultures for Enterobacter organisms were reviewed to determine clinical, epidemiologic, and mortality risk factors. Enterobacter bacteremia occurred, on the average, on the twenty-third day of hospitalization, most frequently in male patients (47), after antibiotic therapy (48 patients), placement of central venous catheters (38 patients), gastrointestinal tract operations (36 patients), and respiratory failure (31 patients). Portals of entry were most commonly sputum (25 patients), open skin wounds (16 patients), and central venous lines (12 patients). Mortality risk (22 patients, 35%) was increased with Enterobacter bacteremia occurring after the fifteenth day of hospitalization (18 of 45 patients versus 4 of 28 patients, p less than 0.01), a preceding Enterobacter focus (13 of 22 patients versus 9 of 41 patients, p less than 0.05), preceding non-Enterobacter bacteremia (10 of 15 patients versus 12 of 48 patients, p less than 0.02), preceding total parenteral nutrition (11 of 21 patients versus 11 of 42 patients p less than 0.01), respiratory failure (19 of 36 patients versus 3 of 27 patients p less than 0.01), and renal failure (11 of 12 patients versus 11 of 51 patients p less than 0.01). The mortality risk was not diminished by specific antibiotic therapy. Enterobacter is emerging as an important pathogen in surgical patients. Prolonged antibiotic administration, particularly that of cephalosporins, may promote Enterobacter colonization of the tracheobronchial tree and skin with subsequent invasion enhanced by respiratory failure, open skin wounds, or central venous catheters traversing the skin. Mortality risk is determined primarily by factors associated with critical illness rather than effects of Enterobacter organisms and their specific treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

A dilemma: prophylaxis for pulmonary embolism after surgical or invasive interventions for hemodialysis

AIM: This study was designed to investigate if it needs to do prophylaxis for pulmonary embolism in the patients treated with different kinds of dialysis or not, and if it is, to find a proper method for prophylaxis. METHODS: Ten numbers of patients with central venous catheters (CVC group), 13 numbers of patients with arteriovenous fistula (AVF group) were enrolled in this study. Eleven patients treated with peritoneal dialysis (PD group) were utilized as a control group. Clinical and laboratory examinations to exclude pulmonary embolism were carried out in both AVF and PD groups at the onset and after three months. Same examinations were performed in CVC group at the onset and after 3 weeks (mean: 21 days). Examinations to exclude pulmonary embolism consist of medical history, clinical examinations, d-dimer measures, chest x-ray, respiratory function tests, blood gas analyses, ventilation-perfusion scintigraphies. RESULTS: Neither clinical nor laboratory findings in any stages reflected any suspicion for pulmonary embolism. None of the patients in any groups was admitted with pulmonary embolism in any period of follow-up. There was not any statistically difference between the outcomes of all first examinations and of all second ones (P>0.005). Neither obvious nor subclinical pulmonary embolism was detected in any case. None of the patients had deep venous thrombosis in any stage of follow-up. CONCLUSIONS: Conventional techniques of haemodialysis do not lead to pulmonary embolism unless deep venous thrombosis due to any intervention occurs in the patients. Thus, prophylactic anticoagulant usage to prevent pulmonary embolism is not necessary in haemodialysis patients. To shorten the length of stay of central venous catheters is the most important factors for pulmonary embolism prophylaxis in haemodialysis patients.