Chien-Chang Lee

Multiplex PCR System for Rapid Detection of Pathogens in Patients with Presumed Sepsis – A Systemic Review and Meta-Analysis

Background Blood culture is viewed as the golden standard for the diagnosis of sepsis but suffers from low sensitivity and long turnaround time. LightCycler SeptiFast (LC-SF) is a real-time multiplex polymerase chain reaction test able to detect 25 common pathogens responsible for bloodstream infections within hours. We aim to assess the accuracy of LC-SF by systematically reviewing the published studies. Method Related literature on Medline, Embase, and Cochrane databases was searched up to October 2012 for studies utilizing LC-SF to diagnose suspected sepsis and that provided sufficient data to construct two-by-two tables. Results A total of 34 studies enrolling 6012 patients of suspected sepsis were included. The overall sensitivity and specificity for LC-SF to detect bacteremia or fungemia was 0·75 (95% CI: 0·65–0·83) and 0·92 (95%CI:0·90–0·95), respectively. LC-SF had a high positive likelihood ratio (10·10) and a moderate negative likelihood ratio (0·27). Specifically, LC-SF had a sensitivity of 0·80 (95%CI: 0·70–0·88) and a specificity of 0·95(95%CI: 0·93–0·97) for the bacteremia outcome, and a sensitivity of 0·61 (95%CI: 0·48–0·72) and a specificity of 0·99 (95%CI: 0·99–0·99) for the fungemia outcome. High heterogeneity was found in the bacteremia outcome subgroup but not in the fungemia outcome subgroup. Conclusion LC-SF is of high rule-in value for early detection of septic patients. In a population with low pretest probability, LC-SF test can still provide valuable information for ruling out bacteremia or fungemia.

Systematic review and meta-analysis of the diagnostic accuracy of procalcitonin, C-reactive protein and white blood cell count for suspected acute appendicitis

The aim was to evaluate the diagnostic value of procalcitonin, C‐reactive protein (CRP) and white blood cell count (WBC) in uncomplicated or complicated appendicitis by means of a systematic review and meta‐analysis.

Cranberry-containing products for prevention of urinary tract infections in susceptible populations: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND Urinary tract infection (UTI) is one of the most commonly acquired bacterial infections. Cranberry-containing products have long been used as a folk remedy to prevent UTIs. The aims of this study were to evaluate cranberry-containing products for the prevention of UTI and to examine the factors influencing their effectiveness. METHODS MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were systemically searched from inception to November 2011 for randomized controlled trials that compared prevention of UTIs in users of cranberry-containing products vs placebo or nonplacebo controls. There were no restrictions for language, population, or publication year. RESULTS Thirteen trials, including 1616 subjects, were identified for qualitative synthesis from 414 potentially relevant references; 10 of these trials, including a total of 1494 subjects, were further analyzed in quantitative synthesis. The random-effects pooled risk ratio (RR) for cranberry users vs nonusers was 0.62 (95% CI, 0.49-0.80), with a moderate degree of heterogeneity (I(2) = 43%) after the exclusion of 1 outlier study. On subgroup analysis, cranberry-containing products seemed to be more effective in several subgroups, including women with recurrent UTIs (RR, 0.53; 95% CI, 0.33-0.83) (I(2) = 0%), female populations (RR, 0.49; 95% CI, 0.34-0.73) (I(2) = 34%), children (RR, 0.33; 95% CI, 0.16-0.69) (I(2) = 0%), cranberry juice drinkers (RR, 0.47; 95% CI, 0.30-0.72) (I(2) = 2%), and subjects using cranberry-containing products more than twice daily (RR, 0.58; 95% CI, 0.40-0.84) (I(2) = 18%). CONCLUSIONS Our findings indicate that cranberry-containing products are associated with protective effect against UTIs. However, this result should be interpreted in the context of substantial heterogeneity across trials.

Comparison of the Test Characteristics of Procalcitonin to C-Reactive Protein and Leukocytosis for the Detection of Serious Bacterial Infections in Children Presenting With Fever Without Source: A Systematic Review and Meta-analysis

STUDY OBJECTIVE We determine the usefulness of the procalcitonin for early identification of young children at risk for severe bacterial infection among those presenting with fever without source. METHODS The design was a systematic review and meta-analysis of diagnostic studies. Data sources were searches of MEDLINE and EMBASE in April 2011. Included were diagnostic studies that evaluated the diagnostic value of procalcitonin alone or compared with other laboratory markers, such as C-reactive protein or leukocyte count, to detect severe bacterial infection in children with fever without source who were aged between 7 days and 36 months. RESULTS Eight studies were included (1,883 patients) for procalcitonin analysis, 6 (1,265 patients) for C-reactive protein analysis, and 7 (1,649 patients) for leukocyte analysis. The markers differed in their ability to predict serious bacterial infection: procalcitonin (odds ratio [OR] 10.6; 95% confidence interval [CI] 6.9 to 16.0), C-reactive protein (OR 9.83; 95% CI 7.05 to 13.7), and leukocytosis (OR 4.26; 95% CI 3.22 to 5.63). The random-effect model was used for procalcitonin analysis because heterogeneity across studies existed. Overall sensitivity was 0.83 (95% CI 0.70 to 0.91) for procalcitonin, 0.74 (95% CI 0.65 to 0.82) for C-reactive protein, and 0.58 (95% CI 0.49 to 0.67) for leukocyte count. Overall specificity was 0.69 (95% CI 0.59 to 0.85) for procalcitonin, 0.76 (95% CI 0.70 to 0.81) for C-reactive protein, and 0.73 (95% CI 0.67 to 0.77) for leukocyte count. CONCLUSION Procalcitonin performs better than leukocyte count and C-reactive protein for detecting serious bacterial infection among children with fever without source. Considering the poor pooled positive likelihood ratio and acceptable pooled negative likelihood ratio, procalcitonin is better for ruling out serious bacterial infection than for ruling it in. Existing studies do not define how best to combine procalcitonin with other clinical information.

Staphylococcus colonization in atopic dermatitis treated with fluticasone or tacrolimus with or without antibiotics

BACKGROUND The skin of patients with atopic dermatitis (AD) exhibits a striking susceptibility to colonization and infection by Staphylococcus aureus. Treatment with topical anti-inflammatory drugs alone can reduce S. aureus colonization. OBJECTIVES To compare the clinical severity of AD and the S. aureus colonization rate between AD patients treated with topical glucocorticoids and those treated with tacrolimus and to evaluate the effects of complementary topical antistaphylococcal antibiotic therapy and the development of fusidic acid-resistant S. aureus. METHODS Sixty AD patients were enrolled in a prospective, parallel, randomized study of an 8-week treatment with topical 0.05% fluticasone propionate or 0.03% tacrolimus, with or without complementary fusidic acid. Disease severity scoring of AD based on SCORing of Atopic Dermatitis (SCORAD), colonization rate and density of S. aureus on the skin, and antibiotic susceptibility of S. aureus isolates were evaluated. RESULTS The reduction in SCORAD scores correlated with the reduction of S. aureus numbers. Treatment with topical tacrolimus resulted in a comparable reduction in SCORAD scores to fluticasone but a slower eradication of S. aureus. Complementary fusidic acid had no additional benefit compared with fluticasone or tacrolimus alone. Two patients developed fusidic acid-resistant S. aureus after 8 weeks of fusidic acid treatment. CONCLUSION Tacrolimus is an appropriate alternative treatment for chronic AD. Topical anti-inflammatory therapy alone to improve the allergic skin inflammation of AD can reduce S. aureus colonization of the skin. Topical antibiotics should be reserved for short-term use in obvious secondary bacterial infection.

Liberal versus restricted fluid resuscitation strategies in trauma patients: a systematic review and meta-analysis of randomized controlled trials and observational studies*.

Objective:Hemorrhage is responsible for most deaths that occur during the first few hours after trauma. Animal models of trauma have shown that restricting fluid administration can reduce the risk of death; however, studies in patients are difficult to conduct due to logistical and ethical problems. To maximize the value of the existing evidence, we performed a meta-analysis to compare liberal versus restricted fluid resuscitation strategies in trauma patients. Data Sources:Medline and Embase were systemically searched from inception to February 2013. Study Selection:We selected randomized controlled trials and observational studies that compared different fluid administration strategies in trauma patients. There were no restrictions for language, population, or publication year. Data Extraction:Four randomized controlled trials and seven observational studies were identified from 1,106 references. One of the randomized controlled trials suffered from a high protocol violation rate and was excluded from the final analysis. Data Synthesis:The quantitative synthesis indicated that liberal fluid resuscitation strategies might be associated with higher mortality than restricted fluid strategies, both in randomized controlled trials (risk ratio, 1.25; 95% CI, 1.01–1.55; three trials; I2, 0) and observational studies (odds ratio, 1.14; 95% CI, 1.01–1.28; seven studies; I2, 21.4%). When only adjusted odds ratios were pooled for observational studies, odds for mortality with liberal fluid resuscitation strategies increased (odds ratio, 1.19; 95% CI, 1.02–1.38; six studies; I2, 26.3%). Conclusions:Current evidence indicates that initial liberal fluid resuscitation strategies may be associated with higher mortality in injured patients. However, available studies are subject to a high risk of selection bias and clinical heterogeneity. This result should be interpreted with great caution.

Association of secondhand smoke exposure with pediatric invasive bacterial disease and bacterial carriage: a systematic review and meta-analysis.

Majid Ezzati and colleagues report the findings of a systematic review and meta-analysis that probes the association between environmental exposure to secondhand smoke and the epidemiology of pediatric invasive bacterial disease.

Epidemiology and prognostic determinants of patients with bacteremic cholecystitis or cholangitis.

OBJECTIVES:To compare mortalities in patients with sepsis due to biliary tract infections (BTIs) and due to infections from other sources, and to identify independent predictors of mortality in these patients.METHODS:This study was part of a community-acquired bloodstream infection (BSI) study that prospectively collected comprehensive clinical, laboratory, and outcome data from 937 consecutive patients with microbiologically documented BSI in the emergency department. BTI was the confirmed source of 145 of the 937 BSIs. We determined the independent prognostic factors by evaluating the correlation between 30-day mortality and various factors, for example, comorbidity, clinical severity, related hepatobiliary complication, and decompressive procedures.RESULTS:Patients with biliary sepsis had a high percentage of Gram-negative (88.3%), polymicrobial (26.9%), and anaerobic infections (6.9%). The 30-day overall mortality was 11.7%. Cox proportional hazard regression analysis disclosed five significant independent predictors: acute renal failure (hazard ratio, 95% confidence interval: 6.86, 6.02–25.5), septic shock (5.83, 4.36–15.64), malignant obstruction (4.35, 1.89–12.96), direct type hyperbilirubinemia (1.26, 1.1–1.42), and Charlson score ≥6 (1.57, 1.12–2.22). Compared with the remaining 792 patients in the source population, patients with bacteremic BTI had significantly better prognosis (log-rank test, P = 0.007). Adjusting for age, comorbidity, and clinical severity, BTI was still independently associated with better 30-day survival (0.25–0.76).CONCLUSIONS:Though the mortality rate in patients with bacteremic BTI is substantial, survival is better than in those with bacteremia from other sources. The main prognostic factors identified in this study may help clinicians recognize patients at high risk for early mortality so that they can give prompt, appropriate treatment.

Effect of different resuscitation fluids on cytokine response in a rat model of hemorrhagic shock

This study was designed to determine the effects of different resuscitation fluids on the production of proinflammatory and anti-inflammatory cytokines in an animal model of hemorrhagic shock. Wistar male rats (n = 24; 8/group) were subjected to a volume-controlled hemorrhagic shock for 30 minutes and resuscitated as follows: (1) sham group without resuscitation, (2) lactated Ringer solution (LR), 3:1; (3) 4% hydroxyethyl starch (HES) solution, 1:1; and (4) 4% modified fluid gelatin (GEL), 1:1. Hemodynamic parameters were recorded, and blood samples were collected at 0 min and 30, 90, 150, 210, 270, and 330 min after hemorrhage for plasma levels of IL-6, IL-10, and TNFα. The circulating concentrations of IL-6 at 90, 150, 210, 270, and 330 min and TNFα levels at 150, 210, and 270 min after hemorrhage were significantly elevated in animals resuscitated with GEL compared with HES or LR (P < 0.05). At 210, 270, and 330 min, IL-10 concentration was decreased significantly in GEL-resuscitated rats compared with rats resuscitated with LR or HES (P < 0.05). Mean blood pressure and serum levels of lactate after resuscitation were not different among three kinds of fluids. LR, HES, and GEL are comparable in volume efficacy for resuscitation of hemorrhagic shock but are associated with different postresuscitation immune responses. Resuscitation with GEL may be associated with cytokine production favoring a proinflammatory response. The marked elevation of IL-6 observed in the GEL-treated animals may play a role in the relatively high frequency of anaphylactoid reaction in clinical use of GEL.

Real-time tracheal ultrasonography for confirmation of endotracheal tube placement during cardiopulmonary resuscitation

OBJECTIVE This study aimed to evaluate the accuracy of tracheal ultrasonography for assessing endotracheal tube position during cardiopulmonary resuscitation (CPR). METHODS We performed a prospective observational study of patients undergoing emergency intubation during CPR. Real-time tracheal ultrasonography was performed during the intubation with the transducer placed transversely just above the suprasternal notch, to assess for endotracheal tube positioning and exclude esophageal intubation. The position of trachea was identified by a hyperechoic air-mucosa (A-M) interface with posterior reverberation artifact (comet-tail artifact). The endotracheal tube position was defined as endotracheal if single A-M interface with comet-tail artifact was observed. Endotracheal tube position was defined as intraesophageal if a second A-M interface appeared, suggesting a false second airway (double tract sign). The gold standard of correct endotracheal intubation was the combination of clinical auscultation and quantitative waveform capnography. The main outcome was the accuracy of tracheal ultrasonography in assessing endotracheal tube position during CPR. RESULTS Among the 89 patients enrolled, 7 (7.8%) had esophageal intubations. The sensitivity, specificity, positive predictive value, and negative predictive value of tracheal ultrasonography were 100% (95% confidence interval [CI]: 94.4-100%), 85.7% (95% CI: 42.0-99.2%), 98.8% (95% CI: 92.5-99.0%) and 100% (95% CI: 54.7-100%), respectively. Positive and negative likelihood ratios were 7.0 (95% CI: 1.1-43.0) and 0.0, respectively. CONCLUSIONS Real-time tracheal ultrasonography is an accurate method for identifying endotracheal tube position during CPR without the need for interruption of chest compression. Tracheal ultrasonography in resuscitation management may serve as a powerful adjunct in trained hands.