Beyond the microcirculation: sequestration of infected red blood cells and reduced flow in large draining veins in experimental cerebral malaria.

Sequestration of infected red blood cells (iRBCs) in the microcirculation is a hallmark of cerebral malaria (CM) in post-mortem human brains. It remains controversial how this might be linked to the different disease manifestations, in particular brain swelling leading to brain herniation and death. The main hypotheses focus on iRBC-triggered inflammation and mechanical obstruction of blood flow. Here, we test these hypotheses using murine models of experimental CM (ECM), SPECT-imaging of radiolabeled iRBCs and cerebral perfusion, MR-angiography, q-PCR, and immunohistochemistry. We show that iRBC accumulation and reduced flow precede inflammation. Unexpectedly, we find that iRBCs accumulate not only in the microcirculation but also in large draining veins and sinuses, particularly at the rostral confluence. We identify two parallel venous streams from the superior sagittal sinus that open into the rostral rhinal veins and are partially connected to infected skull bone marrow. The flow in these vessels is reduced early, and the spatial patterns of pathology correspond to venous drainage territories. Our data suggest that venous efflux reductions downstream of the microcirculation are causally linked to ECM pathology, and that the different spatiotemporal patterns of edema development in mice and humans could be related to anatomical differences in venous anatomy.

Survey to describe variability in early onset scoliosis cast practices.

PURPOSE: To investigate paediatric orthopaedists' cast practices for early onset scoliosis regarding patient selection, cast application, radiographic evaluation, treatment cessation and adjunctive bracing. METHODS: A casting survey was distributed to all paediatric orthopaedists in Children's Spine and Growing Spine Study Groups (n = 92). Questions included physician and patient characteristics, technique, treatment, outcomes, radiographic measurements and comparison to other treatments. A total of 55 orthopaedists (60%) responded, and descriptive statistics were calculated on the subset who cast (n = 45). RESULTS: A majority of respondents use cast treatment for idiopathic and syndromic scoliosis patients, but not for neuromuscular or congenital scoliosis patients. Major curve angle ranked most important in orthopaedists' decision to commence cast treatment, in comparison with rib-vertebra angle difference or clinical observations. The major curve angle threshold to initiate casting was a median of 30° (20° to 70°), and the minimum patient age was median ten months (3 to 24). First in-cast and out-of-cast radiographs are taken standing, supine, awake, under anesthesia and/or in traction. In all, 58% consistently cast over or under the arm, while 44% vary position by patient. Respondents were divided about the use of a brace after cast treatment: 22% do not prescribe a brace, 31% always do and 36% do in some patients. CONCLUSIONS: Future multicentre research studies must standardize radiographic practices and consider age and major curve angle at cast initiation and termination, scoliosis aetiology, shoulder position and treatment duration. Practices need to be aligned or compared in these areas in order to distinguish what makes for the best cast treatment possible.Level of Evidence: V, Expert opinion.

Clinically apparent adverse reactions to intra-wound vancomycin powder in early onset scoliosis are rare.

PURPOSE: Spine surgeons have increasingly used intraoperative application of topical vancomycin powder (TVP) to prevent surgical site infections (SSIs). The goals of this study were to define the rate of pharmacological adverse reaction to TVP in young patients undergoing posterior spinal surgery and to summarise institutional variation in TVP dosing. METHODS: This retrospective observational study included ten spine centres in the United States and one in Europe. Patients with early onset scoliosis who underwent posterior spine surgery were eligible for inclusion. Age, weight, TVP dose and surgery type were recorded. Surgeries where patient age was > 12 years were excluded. Pharmacological adverse reactions were defined as clinical instances of Red Man Syndrome, rash, nephrotoxicity, proteinuria, hepatotoxicity or ototoxicity. The rate of pharmacological adverse reaction to TVP was calculated. Dosing practices were summarised. RESULTS: Patient age was in the range of seven months to 12 years (median ten years). Of 1398 observations, there was one possible pharmacological adverse reaction. This was in a ten-year-old, 20.4-kg female patient with neuromuscular sco-liosis undergoing growing rod implantation. She was dosed with 1500 mg of TVP and immediately developed a transient rash without systemic symptoms. This abated over minutes without any medical intervention. There were no other adverse reactions in the sample. The population rate of pharmacological adverse reaction was 0.072% (95% confidence interval 0 to 0.4). Significant variability in dosing practices existed between centres. CONCLUSION: Pharmacological adverse reactions to TVP are rare. Future work may establish evidence-based guidelines for TVP dosing based on patient weight and other variables.

Predicting the pain continuum after adolescent idiopathic scoliosis surgery: A prospective cohort study.

BACKGROUND: Chronic postsurgical pain (CPSP) affects half a million children annually in the United States, with dire socioeconomic consequences, including long-term disability into adulthood. The few studies of CPSP in children are limited by sample size, follow-up duration, non-homogeneity of surgical procedure and factors evaluated. METHODS: In a prospective study of 144 adolescents undergoing a single major surgery (spine fusion), we evaluated demographic, perioperative, surgical and psychosocial factors as predictors of a continuum of postsurgical pain: immediate, pain maintenance at 2-3 months (chronic pain/CP) and persistence of pain a year (persistent pain/PP) after surgery. RESULTS: We found an incidence of 37.8% and 41.8% for CP and PP. CP and acute pain were both significant predictors for developing PP (p-value <0.001 and 0.003). Preoperative pain and higher postoperative opioid requirement was significantly associated with CP (p = 0.015, p = 0.002), while Childhood Anxiety Sensitivity Index (p = 0.002) and surgical duration (p = 0.014) predicted PP. The final regression models had reasonable predictive accuracy (c-statistic of 0.73 and 0.83 for CP and PP, respectively). Anxiety scores and catastrophizing for child and parent were found to be significantly correlated (p = 0.005, p = 0.013 respectively). Pain trajectories revealed that 65% of patients who developed PP reported CP and high pain trends; however, 33% of those who developed PP could not be identified using solely pain criteria. CONCLUSION: Persistent postsurgical pain in children is a significant problem. It can be predicted in part by combinations of psychological and clinical variables, which may provide evidence-based measures to prevent development of CPSP in the future. SIGNIFICANCE: In a homogeneous cohort of adolescents undergoing spine fusion, we report a high incidence of persistent postsurgical pain (41.8%) predicted by child anxiety, perioperative pain, and surgical duration. Our results stress timely preventive and therapeutic strategies.

Comparison of contamination of femoral heads and pre-processed bone chips during hip revision arthroplasty.

With bone impaction grafting, cancellous bone chips made from allograft femoral heads are impacted in a bone defect, which introduces an additional source of infection. The potential benefit of the use of pre-processed bone chips was investigated by comparing the bacterial contamination of bone chips prepared intraoperatively with the bacterial contamination of pre-processed bone chips at different stages in the surgical procedure. To investigate baseline contamination of the bone grafts, specimens were collected during 88 procedures before actual use or preparation of the bone chips: in 44 procedures intraoperatively prepared chips were used (Group A) and in the other 44 procedures pre-processed bone chips were used (Group B). In 64 of these procedures (32 using locally prepared bone chips and 32 using pre-processed bone chips) specimens were also collected later in the procedure to investigate contamination after use and preparation of the bone chips. In total, 8 procedures had one or more positive specimen(s) (12.5 %). Contamination rates were not significantly different between bone chips prepared at the operating theatre and pre-processed bone chips. In conclusion, there was no difference in bacterial contamination between bone chips prepared from whole femoral heads in the operating room and pre-processed bone chips, and therefore, both types of bone allografts are comparable with respect to risk of infection.

Clinical and laboratory evaluation of a real-time PCR for Clostridium difficile toxin A and B genes.

Many laboratories use enzyme immunoassays (EIAs) for the diagnosis of Clostridium difficile infection (CDI). More recently, polymerase chain reaction (PCR)-based diagnosis has been described as a sensitive test. Real-time PCR for the detection of C. difficile toxin A and B genes was evaluated. A prospective evaluation was performed on stool samples from 150 hospitalized adult patients and 141 healthy volunteers. PCR was compared to toxigenic culture (TC), direct cytotoxicity test (CTT), ImmunoCard® Toxin A and B (Meridian Bioscience), and enzyme-linked immunosorbent assay (ELISA) (Vidas). The results were correlated with clinical data using a standardized questionnaire. The diagnostic yield of the PCR was further evaluated after implementation. Using toxigenic culture as the gold standard, the sensitivity and specificity of PCR were 100 and 99.2%, respectively. Patients were categorized as follows: TC/PCR-positive (n = 17) and negative TC (n = 133). The differences in these groups were more frequent use of antibiotics and leukocytosis (p < 0.05). The diagnostic yield of PCR was evaluated during a period of 6 months and showed an increase of positive patients by 50%. PCR for the detection of toxigenic C. difficile has a high sensitivity and can rule out CDI, but cannot differentiate CDI from asymptomatic carriage. Clinicians should be aware of this in order to prevent inappropriate treatment and delay of other diagnostics.

Non-adherence to antimicrobial treatment guidelines results in more broad-spectrum but not more appropriate therapy.

Mortality in patients admitted with sepsis is high and the increasing incidence of infections with multiresistant bacteria is a worldwide problem. Many hospitals have local antimicrobial guidelines to assure effective treatment and limit the use of broad-spectrum antibiotics, thereby reducing the selection of resistant bacteria. We evaluated adherence to the antimicrobial treatment guidelines of our hospital in patients presenting to the emergency department (ED) with sepsis and assessed the in vitro susceptibility of isolated pathogens to the guideline-recommended treatment and the prescribed treatment. We included all adult patients with a known or suspected infection and two or more extended systemic inflammatory response syndrome (SIRS) criteria. Patients who did not receive antimicrobial treatment, presented with infections not included in the guidelines, or had more than one possible focus of infection were excluded. A total of 276 ED visits (262 patients) were included. Guideline-concordant treatment was prescribed in 168 visits (61%). In the case of guideline-disconcordant treatment, 87% was more broad-spectrum than guideline-recommended treatment. A microbiological diagnosis was established in 96 visits (35%). The susceptibility of the pathogens isolated from patients treated with guideline-concordant treatment (n=68) and guideline-disconcordant treatment (n=28) to guideline-recommended treatment (91% versus 89%) and to prescribed treatment (91% versus 93%) was similar (p=0.77 and p=0.79, respectively). In conclusion, non-adherence to the guidelines occurred frequently and resulted in more broad-spectrum empirical therapy. This did not result in a higher rate of susceptibility of the isolated pathogens to the prescribed empirical therapy.

Endocarditis: effects of routine echocardiography during Gram-positive bacteraemia.

BACKGROUND: Despite firm recommendations to perform echocardiography in high-risk patients with Gram-positive bacteraemia, routine echocardiography is not embedded in daily practice in many settings. The aim of this study was to evaluate whether a regime including routine echocardiography results in better outcome. METHODS: A total of 115 patients with Gram-positive bacteraemia and at least one risk factor for developing metastatic infection were prospectively included. Routine echocardiography was advocated and facilitated in these patients. Results were compared with a matched historical control group of 230 patients in whom echocardiography was performed at the discretion of the attending physician. Endocarditis was diagnosed according to the Duke criteria. RESULTS: Echocardiography was performed more often in the study group (82 vs 27%, p.

How prompt is prompt in daily practice? Earlier initiation of empirical antibacterial therapy for the febrile neutropenic patient.

With fever being the most common manifestation of early sepsis, clinical practice guidelines emphasise the prompt institution of broad-spectrum antibacterial therapy at its onset. An audit was performed on the haematology ward to determine whether there was any delay in starting antibiotic treatment during neutropenia in clinical patients and to define the main reasons for this. Strategies were developed, implemented and evaluated on short- and long-term implications on the delay in the start of antibacterial therapy. The procedures specified in the protocol for starting empirical antibacterial therapy were audited to assess whether the target for starting therapy within 30 min of fever was achieved. Initial results indicated that two major changes to the protocol were necessary to achieve a reduction in the delay between detection of fever and starting antibacterial therapy. This modified protocol was evaluated 4 months after implementation by means of a consecutive audit. After 3 years, a third audit was performed to determine the long-term implications of the improved protocol. In the initial audit, the mean time interval between the onset of fever and the administration of antibacterial therapy was 75 min. With the modified protocol, the mean time to starting therapy was shortened to 32 min (P < 0.05). Changing the protocol for starting antibacterial therapy allowed nurses to administer the first dose of antibiotic significantly earlier.

Highly resistant gram-negative microorganisms: incidence density and occurrence of nosocomial transmission (TRIANGLe Study).

OBJECTIVES: The objectives of this study were to determine the incidence density and the occurrence of horizontal spread of highly resistant gram-negative rods (HR-GNRs) in Dutch hospitals. The factors that influence these outcome measures were also investigated. METHODS: All patients with HR-GNRs, as determined by sample testing, who were hospitalized in 1 of 18 hospitals during a 6-month period (April through October 2007) were included in this study. For all available isolates, the species was identified, susceptibility was determined (including the presence of extended-spectrum ß-lactamases [ESBLs]), and molecular typing was performed. On the basis of a combination of species identification, molecular typing, and epidemiological data, the occurrence of nosocomial transmission was determined. RESULTS: The mean incidence density of patients with HR-GNRs was 55 per 100,000 patient-days (cumulative incidence, 39 per 10,000 patients admitted). A facility being a university hospital was a statistically significant (P = .03) independent determinant of a higher incidence of patients with HR-GNRs. The majority of HR-GNR isolates were ESBL producers. The adjusted transmission index-the ratio between secondary and primary cases-in the participating hospitals ranged from 0.0 to 0.2. The overall adjusted transmission index of HR-GNRs was 0.07. No determinants for a higher transmission index were identified. DISCUSSION: The nosocomial transmission rate of HR-GNRs was relatively low in all hospitals where well-established transmission-based precautions were used. The incidence density of patients with HR-GNRs was higher in university hospitals, probably due to the patient population and the complexity of the care provided.

Analysis of postural stability following posterior spinal fusion in adolescents with idiopathic scoliosis.

This study uses experimental data acquired from adolescents with idiopathic scoliosis to assess their postural control during quiet standing before and after posterior spinal fusion. Statistically significant differences were seen when comparing the pre- and post-surgical measures of balance calculated from data for three different test conditions.

Prevalence and molecular mechanism of macrolide resistance in beta-haemolytic streptococci in The Netherlands.

The prevalence of resistance to erythromycin and clindamycin as well as the presence of the resistance genes mef(A), mef(E), erm(A) and erm(B) were determined in 1076 consecutive isolates of beta-haemolytic streptococci of Lancefield groups A (n=219), B (n=562),C (n=58) and G (n=237) collected during 2005 and 2006. The prevalence of macrolide resistance was highest in group C streptococci (6.9%), followed by group B (5.3%), group G (4.6%) and group A (1.4%). Eighty-eight percent of resistance was mediated by erm(A) and erm(B) genes. Macrolide resistance in beta-haemolytic streptococci in The Netherlands is low, but increasing macrolide resistance was observed in group B streptococci.

Using a bi-planar postural stability model to assess children with scoliosis.

This study examines the postural stability of children with idiopathic scoliosis, using experimental data and a model of sway that includes mediolateral (ML) and anterioposterial (AP) components. The experimental data includes center of pressure (COP) measurements calculated from data acquired using two Advanced Medical Technology, Inc. (AMTI) force plates. Sway metrics are computed and compared with the model simulation, which successfully reproduced the clinical data from 16 children with scoliosis and 20 typically-developing children. This study is part of the first phase of a multi-year study designed to systematically assess whether fusing the spine to L4 in children with scoliosis has a significant impact on physical function and quality of life.

Decontamination of the digestive tract and oropharynx in ICU patients.

BACKGROUND: Selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) are infection-prevention measures used in the treatment of some patients in intensive care, but reported effects on patient outcome are conflicting. METHODS: We evaluated the effectiveness of SDD and SOD in a crossover study using cluster randomization in 13 intensive care units (ICUs), all in The Netherlands. Patients with an expected duration of intubation of more than 48 hours or an expected ICU stay of more than 72 hours were eligible. In each ICU, three regimens (SDD, SOD, and standard care) were applied in random order over the course of 6 months. Mortality at day 28 was the primary end point. SDD consisted of 4 days of intravenous cefotaxime and topical application of tobramycin, colistin, and amphotericin B in the oropharynx and stomach. SOD consisted of oropharyngeal application only of the same antibiotics. Monthly point-prevalence studies were performed to analyze antibiotic resistance. RESULTS: A total of 5939 patients were enrolled in the study, with 1990 assigned to standard care, 1904 to SOD, and 2045 to SDD; crude mortality in the groups at day 28 was 27.5%, 26.6%, and 26.9%, respectively. In a random-effects logistic-regression model with age, sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, intubation status, and medical specialty used as covariates, odds ratios for death at day 28 in the SOD and SDD groups, as compared with the standard-care group, were 0.86 (95% confidence interval [CI], 0.74 to 0.99) and 0.83 (95% CI, 0.72 to 0.97), respectively. CONCLUSIONS: In an ICU population in which the mortality rate associated with standard care was 27.5% at day 28, the rate was reduced by an estimated 3.5 percentage points with SDD and by 2.9 percentage points with SOD. (Controlled Clinical Trials number, ISRCTN35176830.)

Performance of two tube coagulase methods for rapid identification of Staphylococcus aureus from blood cultures and their impact on antimicrobial management.

Test parameters and clinical impact of the direct tube coagulase test (DTCT) for rapid identification of Staphylococcus aureus from blood culture were investigated. The sensitivity of the DTCT at 4 h using saline dilution was 96%, compared with 93% using serum separator tubes; specificity was 100% for both methods. Among 32 patients with S. aureus bacteraemia, treatment modifications were based on microbiology results from the primary source of infection in 12 patients, on a Gram's stain from blood culture in seven patients, and on the DTCT in nine patients. The DTCT is a valuable adjunct in the routine microbiology laboratory because of its good performance, technical simplicity and low cost.

Microbiological cultures of allografts of the femoral head just before transplantation.

Allografts of bone from the femoral head are often used in orthopaedic procedures. Although the donated heads are thoroughly tested microscopically before release by the bone bank, some surgeons take additional cultures in the operating theatre before implantation. There is no consensus about the need to take these cultures. We retrospectively assessed the clinical significance of the implantation of positive-cultured bone allografts. The contamination rate at retrieval of the allografts was 6.4% in our bone bank. Intra-operative cultures were taken from 426 femoral head allografts before implantation; 48 (11.3%) had a positive culture. The most frequently encountered micro-organism was coagulase-negative staphylococcus. Deep infection occurred in two of the 48 patients (4.2%). In only one was it likely that the same micro-organism caused the contamination and the subsequent infection. In our study, the rate of infection in patients receiving positive-cultured allografts at implantation was not higher than the overall rate of infection in allograft surgery suggesting that the positive cultures at implantation probably represent contamination and that the taking of additional cultures is not useful.

Shiga toxin-producing Escherichia coli isolated from patients with diarrhoea in Bangladesh.

The prevalence of Shiga toxin-producing Escherichia coli (STEC) and its characteristics were determined among hospitalized patients with diarrhoea and children with diarrhoea in an urban slum community of Dhaka city using sensitive culture and PCR methods. Stool samples were collected from 410 patients with diarrhoea enrolled in the 2% surveillance system (every 50th patient attending the hospital with diarrhoeal disease is included) at the ICDDR,B hospital and from 160 children of 2-5 years of age with diarrhoea living in an urban slum in Dhaka, between September 2004 and April 2005. Shiga toxin genes (stx) were detected by multiplex PCR in the enrichment broth of nine samples (2.2%) from hospitalized patients and 11 samples (6.9%) from the community patients. STEC was isolated from five stool samples with positive PCR results using a colony patch technique. All five isolates were positive in the Vero cell assay and PCR fragments of stx genes were confirmed by sequencing. Two isolates were positive for the E. coli attaching-and-effacing (eae) gene and four were positive for the enterohaemolysin (hlyEHEC) gene and enterohaemolysin production. The five isolates belonged to five different serotypes:O32:H25, O2:H45, O76:H19, ONT:H25 and ONT:H19. It can be concluded that STEC is not a common pathogen in Bangladesh among hospitalized patients with diarrhoea nor among mild cases of diarrhoea in the community.