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Biomedical subjects

Nasia Safdar

Publications and source records attributed to Nasia Safdar.

At least 19 recordsLinked to original sources

Prevalence-dependent diagnostic accuracy measures.

We study prevalence-dependent diagnostic accuracy measures, specifically, positive and negative predictive values. These measures permit an assessment of the clinical utility of diagnostic tests across populations with different disease prevalences. In many cases, prevalence may not be known with certainty and the evaluation of the diagnostic tests must account for this uncertainty. A sensitivity analysis may be desired across a prevalence continuum defining low to high-risk populations. For this scenario, simultaneous inference about the predictive values across a range of prevalences is proposed. For situations where a non-point prior distribution on prevalence is specified, we suggest inferences based on averaging the accuracy measures with respect to the prior, leading to simple numerical summaries. The methods are illustrated in a meta-analysis of diagnostic tests for intravascular device-related bloodstream infection, where the prevalence may vary widely both within and across populations.

Diagnostic Errors↗

Topical chlorhexidine for prevention of ventilator-associated pneumonia: a meta-analysis.

OBJECTIVE: To assess the efficacy of topical chlorhexidine for prevention of ventilator-associated pneumonia (VAP) in a meta-analysis. DATA SOURCE: Computerized PubMed and MEDLINE search supplemented by manual searches for relevant articles. STUDY SELECTION: Randomized controlled trials evaluating efficacy of topical chlorhexidine applied to the oropharynx vs. placebo or standard care for prevention of VAP. DATA EXTRACTION: Data were extracted on patient population, inclusion and exclusion criteria, diagnostic criteria for VAP, form and concentration of topical chlorhexidine used, incidence of VAP, and overall mortality. DATA SYNTHESIS: Data on incidence of VAP and mortality were abstracted as dichotomous variables. Pooled estimates of the relative risk and 95% confidence intervals were obtained using the DerSimonian and Laird random effects model and the Mantel-Haenszel fixed effects model. Heterogeneity was assessed using the Cochran Q statistic and I. Subgroup analyses were used to explore heterogeneity. RESULTS: Seven randomized controlled trials met the inclusion criteria. Topical chlorhexidine resulted in a reduced incidence of VAP (relative risk, 0.74; 95% confidence interval, 0.56-0.96; p=.02) using a fixed effects model. Using the more conservative random effects model, the point estimate was similar (relative risk, 0.70; 95% confidence interval, 0.47-1.04; p=.07), but the results failed to achieve statistical significance. The I test showed moderate heterogeneity. Subgroup analysis showed that the benefit of chlorhexidine was most marked in cardiac surgery patients (relative risk, 0.41; 95% confidence interval, 0.17-0.98; p=.04). There was no mortality benefit with chlorhexidine although the sample size was small. CONCLUSIONS: Our analysis showed that topical chlorhexidine is beneficial in preventing VAP; the benefit is most marked in cardiac surgery patients. A large randomized trial is needed to determine the impact of topical chlorhexidine on mortality.

Administration, Topical↗

Use of vancomycin-containing lock or flush solutions for prevention of bloodstream infection associated with central venous access devices: a meta-analysis of prospective, randomized trials.

BACKGROUND: Prolonged exposure to central venous access devices carries significant risk of device-associated bloodstream infection (BSI), which is associated with morbidity, added health care costs, and attributable mortality. We aimed to determine the efficacy of vancomycin-heparin lock or flush solution in preventing BSI in patients being treated with long-term central venous intravascular devices (IVDs). METHODS: We collected data from January 1966 to January 2006 from multiple computerized databases and compiled reference lists of identified articles. We identified prospective, randomized controlled trials comparing a vancomycin-heparin lock or flush solution with heparin alone for prevention of BSI associated with long-term central venous IVDs. Using a standardized form, we abstracted data regarding study quality, patient characteristics, and incidence of BSI. RESULTS: Seven randomized, controlled trials involving a total of 463 patients being treated with IVDs met the inclusion criteria; 5 studies were conducted among patients with cancer, 1 among a critically ill neonatal population, and 1 among patients with cancer or who required parenteral nutrition. We could not detect publication bias. The summary risk ratio with a vancomycin heparin-lock solution for IVD-associated BSI was 0.49 (95% confidence interval [CI], 0.26-0.95; P = .03). Results of the test for heterogeneity were statistically significant; however, when a single study was removed from the analysis, heterogeneity was no longer present. Use of vancomycin as a true lock solution--instilling it for a defined period, rather than simply flushing it directly through the device--conferred a much greater benefit, with a risk ratio of 0.34 (95% CI, 0.12-0.98; P = .04). The 2 studies that performed prospective surveillance cultures to identify colonization or infection by vancomycin-resistant organisms did not find an increased risk. CONCLUSIONS: Use of a vancomycin lock solution in high-risk patient populations being treated with long-term central IVDs reduces the risk of BSI. The use of an anti-infective lock solution warrants consideration for patients who require central access but who are at high risk of BSI, such as patients with malignancy or low-birthweight neonates.

Adult↗

Diagnosis of invasive aspergillosis using a galactomannan assay: a meta-analysis.

BACKGROUND: A double-sandwich enzyme-linked immunosorbent galactomannan assay has been approved for surveillance for invasive aspergillosis in immunocompromised patients. We undertook a meta-analysis to assess the accuracy of a galactomannan assay for diagnosing invasive aspergillosis. METHODS: Studies of the galactomannan assay that used the European Organization for Research and Treatment of Cancer or similar criteria as a reference standard and provided data to calculate sensitivity and specificity were included. Pooled sensitivity and specificity and summary measures of accuracy, Q* (the upper left-most point on the summary receiver-operating characteristic curve), mean D (a log odds ratio), and Youden index were calculated. Subgroup analyses were performed to explore heterogeneity. RESULTS: Twenty-seven studies from 1966 to 28 February 2005 were included. Overall, the galactomannan assay had a sensitivity of 0.71 (95% confidence interval [CI], 0.68-0.74) and specificity of 0.89 (95% CI, 0.88-0.90) for proven cases of invasive aspergillosis. The Youden index, mean D, and Q* were 0.54 (95% CI, 0.41-0.65), 2.74 (95% CI, 21.12-3.36), and 0.80 (95% CI, 0.74-0.86), respectively, indicating moderate accuracy. Subgroup analyses showed that the performance of the test differed by patient population and type of reference standard used. Significant heterogeneity was present. CONCLUSIONS: The galactomannan assay has moderate accuracy for diagnosis of invasive aspergillosis in immunocompromised patients. The test is more useful in patients who have hematological malignancy or who have undergone hematopoietic cell transplantation than in solid-organ transplant recipients. Further studies with attention to the impact of antifungal therapy, rigorous assessment of false-positive test results, and assessment of the utility of the test under nonsurveillance conditions are needed.

Aspergillosis↗

Combination of voriconazole and caspofungin as primary therapy for invasive aspergillosis in solid organ transplant recipients: a prospective, multicenter, observational study.

BACKGROUND: : The efficacy of the combination of voriconazole and caspofungin when used as primary therapy for invasive aspergillosis in organ transplant recipients has not been defined. METHODS: : Transplant recipients who received voriconazole and caspofungin (n=40) as primary therapy for invasive aspergillosis (proven or probable) in a prospective multicenter study between 2003 and 2005 were compared to a control group comprising a cohort of consecutive transplant recipients between 1999 and 2002 who had received a lipid formulation of AmB as primary therapy (n=47). In vitro antifungal testing of Aspergillus isolates to combination therapy was correlated with clinical outcome. RESULTS: : Survival at 90 days was 67.5% (27/40) in the cases, and 51% (24/47) in the control group (HR 0.58, 95% CI, 0.30-1.14, P=0.117). However, in transplant recipients with renal failure (adjusted HR 0.32, 95% CI: 0.12-0.85, P=0.022), and in those with A. fumigatus infection (adjusted HR 0.37, 95% CI: 0.16-0.84, P=0.019), combination therapy was independently associated with an improved 90-day survival in multivariate analysis. No correlation was found between in vitro antifungal interactions of the Aspergillus isolates to the combination of voriconazole and caspofungin and clinical outcome. CONCLUSIONS: : Combination of voriconazole and caspofungin might be considered preferable therapy for subsets of organ transplant recipients with invasive aspergillosis, such as those with renal failure or A. fumigatus infection.

Adult↗

Device-associated nosocomial infection rates in intensive care units in four Mexican public hospitals.

BACKGROUND: Routine surveillance of nosocomial infections has become an integral part of infection control and quality assurance in US hospitals. METHODS: As part of the International Nosocomial Infection Control Consortium, we performed a prospective nosocomial infection surveillance cohort study in 5 adult intensive care units of 4 Mexican public hospitals using the Centers for Disease Control and Prevention National Nosocomial Infections Surveillance system definitions. Site-specific nosocomial infection rates were calculated. RESULTS: The overall nosocomial infection rate was 24.4% (257/1055) and 39.0 (257/6590) per 1000 patient days. The most common infection was catheter-associated bloodstream infection, 57.98% (149/257), followed by ventilator-associated pneumonia, 20.23% (52/257), and catheter-associated urinary tract infection, 21.79% (56/257). The overall rate of catheter-associated bloodstream infections was 23.1 per 1000 device-days (149/6450); ventilator-associated pneumonia rate was 21.8 per 1000 device-days (52/2390); and catheter-associated urinary tract infection rate was 13.4 per 1000 device-days (56/4184). CONCLUSION: Our rates are similar to other hospitals of Latin America and higher than US hospitals.

Catheterization, Central Venous↗

Effectiveness of preemptive barrier precautions in controlling nosocomial colonization and infection by methicillin-resistant Staphylococcus aureus in a burn unit.

BACKGROUND: We report the effectiveness of preemptive enhanced barrier precautions in containing a methicillin-resistant Staphylococcus aureus (MRSA) outbreak in a university hospital burn unit and further controlling endemic nosocomial MRSA infection in the unit during the succeeding 27 months. METHODS: During a 6-month period, 12 patients in a 7-bed burn unit were found to be colonized (7) or infected (5) by MRSA. An epidemiologic study was undertaken. RESULTS: Seven of the 10 strains of MRSA from patients that were available for DNA typing were clonally identical. Early in the outbreak, a health care worker was found to be a concordant nasal carrier and was successfully decolonized with nasal mupirocin. However, despite stringent compliance with isolation of MRSA-positive patients (targeted precautions), new cases of MRSA colonization or infection continued to occur. The outbreak was rapidly terminated after implementing preemptive barrier precautions with all patients in the unit: a new, clean gown and gloves for any physical contact with the patient or their environment. Although 25% of all nosocomial S aureus isolates in our hospital are resistant to methicillin, the incidence of endemic MRSA colonization and infection in the burn unit has remained very low since implementing barrier precautions unit wide (baseline rate, 2.2 [95% CI: 1.0-4.2] cases per 1000 patient-days; outbreak rate, 7.2 [95% CI: 4.4-11.0] cases per 1000 patient-days; post-outbreak termination endemic rate, 1.1 (95% CI: 0.4-2.3) cases per 1000 patient-days). The rate ratio comparing the outbreak and the baseline period was 3.20 (95% CI: 1.40-7.95, P = .002); the rate ratio comparing the post-outbreak period with the baseline period was 0.48 (95% CI: 0.14-1.53, P = .10), and it has not been necessary to screen personnel for MRSA carriage to prevent nosocomial MRSA infections in this highly vulnerable population. CONCLUSION: Preemptive barrier precautions were highly effective in controlling the outbreak and, most notably, have also been highly effective in maintaining a very low incidence of nosocomial MRSA infection endemically in the succeeding 27 months of follow-up. Use of clean gloves, with or without a gown, bears consideration for all high-risk hospitalized patients to prevent cross transmission of all multiresistant nosocomial pathogens.

Burn Units↗

Late-onset invasive aspergillosis in organ transplant recipients in the current era.

We assessed predictive factors and characteristics of patients with late-onset invasive aspergillosis in the current era of novel immunosuppressive agents. Forty transplant recipients with invasive aspergillosis were included in this prospective, observational study initiated in 2003 at our institutions. In 50% (20/40) of these patients, the infections were late-occurring. Receipt of sirolimus in conjunction with tacrolimus for refractory rejection or cardiac allograft vasculopathy (P=0.047) was significantly associated with late-onset infection. The use of depleting or non-depleting T or B-cell antibodies, either as induction or as antirejection therapy did not correlate with time to onset of invasive aspergillosis. Mortality at 90 days was 20% (4/20) for the patients with early-onset infection and 45% (9/20) for those with late-onset infection (P=0.17). Thus, nearly one-half of the Aspergillus infections in transplant recipients in the current era are late-occurring. These data have implications relevant for prophylactic strategies and guiding clinical management of transplant recipients presenting with pulmonary infiltrates.

Adult↗

Meta-analysis: methods for diagnosing intravascular device-related bloodstream infection.

BACKGROUND: No consensus exists on the best methods for diagnosis of intravascular device (IVD)-related bloodstream infection. PURPOSE: To identify the most accurate methods for diagnosis of IVD-related bloodstream infection. DATA SOURCES: 51 English-language studies published from 1966 to 31 July 2004. STUDY SELECTION: Studies of diagnostic tests for IVD-related bloodstream infection that described a reference standard and provided sufficient data to calculate sensitivity and specificity. DATA EXTRACTION: Study quality, diagnostic tests examined, patient characteristics, prevalence, sensitivity, and specificity. DATA SYNTHESIS: Pooled sensitivity and specificity were calculated for 8 diagnostic methods. Summary measures of accuracy were Q* (the upper leftmost point on the summary receiver-operating characteristic curve) and mean D (a log odds ratio). Subgroup analyses were used to assess heterogeneity. Overall, the most accurate test was paired quantitative blood culture (Q* = 0.94 [95% CI, 0.88 to 1.0]), followed by IVD-drawn quantitative [corrected] blood culture (Q* = 0.89 [CI, 0.79 to 0.99]) and the acridine orange leukocyte cytospin test (Q* = 0.89 [CI, 0.79 to 0.91]). The most accurate catheter segment culture test was quantitative culture (Q* = 0.87 [CI, 0.81 to 0.93]), followed by semi-quantitative culture (Q* = 0.84 [CI, 0.80 to 0.88]). Significant heterogeneity in pooled sensitivity and specificity was observed across all test categories. LIMITATIONS: The limited number of studies of some of the diagnostic methods precludes precise estimates of accuracy. CONCLUSIONS: Paired quantitative blood culture is the most accurate test for diagnosis of IVD-related bloodstream infection. However, most other methods studied showed acceptable sensitivity and specificity (both >0.75) and negative predictive value (>99%). The positive predictive value of all tests increased greatly with high pretest clinical probability. Catheters should not be cultured routinely but rather only if IVD-related bloodstream infection is suspected clinically.

Catheterization, Central Venous↗

The attributable cost and length of hospital stay because of nosocomial pneumonia in intensive care units in 3 hospitals in Argentina: a prospective, matched analysis.

BACKGROUND: No information is available on the financial impact of nosocomial pneumonia in Argentina. To calculate the cost of nosocomial pneumonia in intensive care units, a 5-year, matched cohort study was undertaken at 3 hospitals in Argentina. SETTING: Six adult intensive care units (ICU). METHODS: Three hundred seven patients with nosocomial pneumonia (exposed) and 307 patients without nosocomial pneumonia (unexposed) were matched for hospital, ICU type, year admitted to study, length of stay more than 7 days, sex, age, antibiotic use, and average severity of illness score (ASIS). The patient's length of stay (LOS) in the ICU was obtained prospectively in daily rounds, the cost of a day was provided by the hospital's finance department, and the cost of antibiotics prescribed for nosocomial pneumonia was provided by the hospital's pharmacy department. RESULTS: The mean extra LOS for 307 cases (compared with controls) was 8.95 days, the mean extra antibiotic defined daily doses (DDD) was 15, the mean extra antibiotic cost was $996, the mean extra total cost was $2255, and the extra mortality was 30.3%. CONCLUSIONS: Nosocomial pneumonia results in significant patient morbidity and consumes considerable resources. In the present study, patients with nosocomial pneumonia had significant prolongation of hospitalization, cost, and a high extra mortality. The present study illustrates the potential cost savings of introducing interventions to reduce nosocomial pneumonia. To our knowledge, this is the first study evaluating this issue in Argentina.

Aged↗

Reduction in nosocomial infection with improved hand hygiene in intensive care units of a tertiary care hospital in Argentina.

BACKGROUND: Hand hygiene is a fundamental measure for the control of nosocomial infection. However, sustained compliance with hand hygiene in health care workers is poor. We attempted to enhance compliance with hand hygiene by implementing education, training, and performance feedback. We measured nosocomial infections in parallel. METHODS: We monitored the overall compliance with hand hygiene during routine patient care in intensive care units (ICUs); 1 medical surgical ICU and 1 coronary ICU, of 1 hospital in Buenos Aires, Argentina, before and during implementation of a hand hygiene education, training, and performance feedback program. Observational surveys were done twice a week from September 2000 to May 2002. Nosocomial infections in the ICUs were identified using the National Nosocomial Infections Surveillance (NNIS) criteria, with prospective surveillance. RESULTS: We observed 4347 opportunities for hand hygiene in both ICUs. Compliance improved progressively (handwashing adherence, 23.1% (268/1160) to 64.5% (2056/3187) (RR, 2.79; 95% CI: 2.46-3.17; P < .0001). During the same period, overall nosocomial infection in both ICUs decreased from 47.55 per 1000 patient-days (104/2187) to 27.93 per 1000 patient days (207/7409) RR, 0.59; 95% CI: 0.46-0.74, P < .0001). CONCLUSION: A program consisting of focused education and frequent performance feedback produced a sustained improvement in compliance with hand hygiene, coinciding with a reduction in nosocomial infection rates in the ICUs.

Argentina↗

The Wisconsin Upper Respiratory Symptom Survey is responsive, reliable, and valid.

OBJECTIVE: To assess reliability, responsiveness, importance to patients, and convergent validity for the Wisconsin Upper Respiratory Symptom Survey (WURSS-44) and to develop a short-form WURSS. STUDY DESIGN AND SETTING: Community-based recruitment of participants with colds. Prospective monitoring from within 48 hours of first symptom until 2 days after end of cold. The WURSS-44 includes 1 global illness severity item, 32 symptom-based items, 10 functional quality-of-life items, and 1 item assessing global change. The SF-36, SF-8, and the Jackson cold scale were used as external comparators. RESULTS: Participants included 104 women and 45 men, aged 18 to 80 years, self-reporting on 1,681 person-days of illness. Factor analysis suggested 10 dimensions, with reliability coefficients from 0.62 to 0.93. Comparing daily WURSS-44 to Jackson and SF-8 yielded Pearson correlation coefficients from 0.73 to 0.93, and from -0.60 to -0.84, respectively. Importance to patients and responsiveness assessment yielded a short version, the WURSS-21. Guyatt's responsiveness index was 0.54 for the SF-8, 0.61 for the Jackson, 0.71 for the WURSS-44, and 0.80 for the WURSS-21, suggesting that a two-armed trial would require 74 participants for the WURSS-21, 92 for the WURSS-44, 124 for the Jackson scale, and 156 for the SF-8. CONCLUSIONS: The construct validity of WURSS-44 is supported by measures of reliability, responsiveness, importance to patients, and convergence. A shorter version, the WURSS-21, may be even more responsive.

Adolescent↗

The effect of process control on the incidence of central venous catheter-associated bloodstream infections and mortality in intensive care units in Mexico.

PURPOSE: To ascertain the effect of an infection control program including process control on intensive care unit (ICU) rates of intravascular device (IVD)-associated bloodstream infection (BSI). SETTING: Two level III adult ICUs in one public university hospital in Mexico: one medical surgical ICU and one neurosurgical ICU. POPULATION STUDY: All adult patients admitted to study units who had a central venous catheter (CVC) in place for at least 24 hrs. METHODS: A prospective before/after trial in which rates of IVD-associated BSI are determined during a period of active surveillance without process control (phase 1) were compared with rates of IVD-associated BSI after implementing an infection control program applying process control (phase 2). RESULTS: Six hundred five IVD-days were accumulated in phase 1, and 2824 IVD-days were accumulated during phase 2. Compliance with CVC site care and hand hygiene improved significantly from baseline during the study period: placing a gauze dressing over the catheter insertion site (99.24% vs. 86.69%, respectively; relative risk [RR] = 1.14; 95% confidence interval [CI] = 1.07-1.22; p = .0000), proper use of gauze for vascular catheter insertion site (97.87% vs. 84.21%, respectively; RR = 1.16; 95% CI = 1.09-1.24; p = .0000), documentation of the duration of the administration set of the vascular catheter (93.85% vs. 40.69%, respectively; RR = 2.34; 95% CI = 2.14-2.56; p = .0000), and hand hygiene before contact with the patient (84.9% vs. 62%, respectively; RR = 1.37; 95% CI = 1.21-1.51; p = .0000). Overall rates of IVD-associated BSI were lowered significantly from baseline rates after implementation of process control (19.5 vs. 46.3 BSIs per 1000 IVD-days, respectively; RR = 0.42; 95% CI = 0.27-0.66; p = .0001). Overall rates of crude unadjusted mortality were lowered significantly from baseline rates (48.5% vs. 32.8% per 100 discharges, respectively; RR = 0.68; 95% CI = 0.50-0.31; p = .01). CONCLUSION: Implementation of an infection control program utilizing education, process control, and performance feedback was associated with significant reductions in rates of IVD-associated BSI and mortality.

Adult↗

Clinical and economic consequences of ventilator-associated pneumonia: a systematic review.

BACKGROUND: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in critically ill patients. The clinical and economic consequences of VAP are unclear, with a broad range of values reported in the literature OBJECTIVE: To perform a systematic review to determine the incidence of VAP and its attributable mortality rate, length of stay, and costs. DATA SOURCE: Computerized PUBMED and MEDLINE search supplemented by manual searches for relevant articles, limited to articles published after 1990. STUDY SELECTION: English-language observational studies and randomized trials that provided data on the incidence of VAP were included. Matched cohort studies were included for calculation of attributable mortality rate and length of stay. DATA EXTRACTION: Data were extracted on patient population, diagnostic criteria for VAP, incidence, outcome, type of intensive care unit, and study design. DATA SYNTHESIS: The cumulative incidence of VAP was calculated by combining the results of several studies using standard formulas for combining proportions, in which the weighted average and variance are calculated. Results from studies comparing intensive care unit and hospital mortality due to VAP, additional length of stay, and additional days of mechanical ventilation were pooled using a random effects model, with assessment of heterogeneity. RESULTS: Our findings indicate a) between 10% and 20% of patients receiving >48 hrs of mechanical ventilation will develop VAP; b) critically ill patients who develop VAP appear to be twice as likely to die compared with similar patients without VAP (pooled odds ratio, 2.03; 95% confidence interval, 1.16-3.56); c) patients with VAP have significantly longer intensive care unit lengths of stay (mean = 6.10 days; 95% confidence interval, 5.32-6.87 days); and d) patients who develop VAP incur > or = USD $10,019 in additional hospital costs. CONCLUSIONS: Ventilator-associated pneumonia occurs in a considerable proportion of patients undergoing mechanical ventilation and is associated with substantial morbidity, a two-fold mortality rate, and excess cost. Given these findings, strategies that effectively prevent VAP are urgently needed.

Critical Care↗

Risk of catheter-related bloodstream infection with peripherally inserted central venous catheters used in hospitalized patients.

BACKGROUND: Peripherally inserted central venous catheters (PICCs) are now widely used for intermediate and long-term access in current-day health care, especially in the inpatient setting, where they are increasingly supplanting conventional central venous catheters (CVCs) placed percutaneously into the internal jugular, subclavian, or femoral veins. Data on the risk of PICC-related bloodstream infection (BSI) with PICCs used in hospitalized patients are limited. STUDY OBJECTIVES: To determine the risk of PICC-related BSI in hospitalized patients. STUDY DESIGN: Prospective cohort study using data from two randomized trials assessing the efficacy of chlorhexidine-impregnated sponge dressing and chlorhexidine for cutaneous antisepsis. METHODS: PICCs inserted into the antecubital vein in two randomized trials during from 1998 to 2000 were prospectively studied; most patients were in an ICU. PICC-related BSI was confirmed in each case by demonstrating concordance between isolates colonizing the PICC at the time of removal and from blood cultures by restriction-fragment DNA subtyping. RESULTS: Overall, 115 patients had 251 PICCs placed. Mean duration of catheterization was 11.3 days (total, 2,832 PICC-days); 42% of the patients were in an ICU at some time, 62% had urinary catheters, and 49% had received mechanical ventilation. Six PICC-related BSIs were identified (2.4%), four with coagulase-negative staphylococcus, one with Staphylococcus aureus, and one with Klebsiella pneumoniae, a rate of 2.1 per 1,000 catheter-days. CONCLUSION: This prospective study shows that PICCs used in high-risk hospitalized patients are associated with a rate of catheter-related BSI similar to conventional CVCs placed in the internal jugular or subclavian veins (2 to 5 per 1,000 catheter-days), much higher than with PICCs used exclusively in the outpatient setting (approximately 0.4 per 1,000 catheter-days), and higher than with cuffed and tunneled Hickman-like CVCs (approximately 1 per 1,000 catheter-days). A randomized trial of PICCs and conventional CVCs in hospitalized patients requiring central access is needed. Our data raise the question of whether the growing trend in many hospital hematology and oncology services to switch from use of cuffed and tunneled CVCs to PICCs is justified, particularly since PICCs are more vulnerable to thrombosis and dislodgment, and are less useful for drawing blood specimens. Moreover, PICCs are not advisable in patients with renal failure and impending need for dialysis, in whom preservation of upper-extremity veins is needed for fistula or graft implantation.

Bacteremia↗

The pathogenesis of ventilator-associated pneumonia: its relevance to developing effective strategies for prevention.

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in the intensive care unit and is associated with major morbidity and attributable mortality. Strategies to prevent VAP are likely to be successful only if based upon a sound understanding of pathogenesis and epidemiology. The major route for acquiring endemic VAP is oropharyngeal colonization by the endogenous flora or by pathogens acquired exogenously from the intensive care unit environment, especially the hands or apparel of health-care workers, contaminated respiratory equipment, hospital water, or air. The stomach represents a potential site of secondary colonization and reservoir of nosocomial Gram-negative bacilli. Endotracheal-tube biofilm formation may play a contributory role in sustaining tracheal colonization and also have an important role in late-onset VAP caused by resistant organisms. Aspiration of microbe-laden oropharyngeal, gastric, or tracheal secretions around the cuffed endotracheal tube into the normally sterile lower respiratory tract results in most cases of endemic VAP. In contrast, epidemic VAP is most often caused by contamination of respiratory therapy equipment, bronchoscopes, medical aerosols, water (eg, Legionella) or air (eg, Aspergillus or the severe acute respiratory syndrome virus). Strategies to eradicate oropharyngeal and/or intestinal microbial colonization, such as with chlorhexidine oral care, prophylactic aerosolization of antimicrobials, selective aerodigestive mucosal antimicrobial decontamination, or the use of sucralfate rather than H(2) antagonists for stress ulcer prophylaxis, and measures to prevent aspiration, such as semirecumbent positioning or continuous subglottic suctioning, have all been shown to reduce the risk of VAP. Measures to prevent epidemic VAP include rigorous disinfection of respiratory equipment and bronchoscopes, and infection-control measures to prevent contamination of medical aerosols. Hospital water should be Legionella-free, and high-risk patients, especially those with prolonged granulocytopenia or organ transplants, should be cared for in hospital units with high-efficiency-particulate-arrestor (HEPA) filtered air. Routine surveillance of VAP, to track endemic VAPs and facilitate early detection of outbreaks, is mandatory.

Anti-Bacterial Agents↗