Bacterial isolates from positive paired venous catheter and peripheral blood cultures taken during parenteral nutrition were the same species but different strains: A case report.

OBJECTIVE: The same microbial species isolated from blood simultaneously drawn from a central venous catheter hub and a peripheral vein (paired blood cultures) during parenteral nutrition may be assumed to represent the same strain. This case report provides an example of this assumption being incorrect along with a comparator example of it being correct. This has implications for interpretation of differential time to positivity and differential quantitative blood cultures during investigation of suspected intraluminal intravascular catheter or cannula bloodstream infection. CASE DESCRIPTION: Two patients ages ≥18 y prescribed parenteral nutrition each had positive paired blood cultures that had been taken for suspected catheter bloodstream infection because of temperature spikes ≥38°C. The paired Staphylococcus epidermidis isolates from the first patient and the paired Enterococcus faecium isolates from the second patient were each tested beyond routine clinical care to establish if they could be different strains. The central and peripheral isolates of Staphylococcus epidermidis from the first patient were different strains based on hospital-reported antibiograms, genomic DNA profiles, thermograms, and weaker growth and different sizes of colonies of the central strain compared with the peripheral strain. There were no such differences for the isolates of Enterococcus faecium from the second patient. RESULTS: The central and peripheral isolates of Staphylococcus epidermidis from the first patient were different strains based on hospital-reported antibiograms, genomic DNA profiles, thermograms, and weaker growth and different sizes of colonies of the central strain compared with the peripheral strain. There were no such differences for the isolates of Enterococcus faecium from the second patient. CONCLUSION: This case report indicates consideration should be given to reporting whether bacteria have been identified at either species or strain level if differential time to positivity or differential quantitative blood cultures are used to define catheter or cannula bloodstream infection.

Clostridium difficile in children: a review of existing and recently uncovered evidence.

The clinical significance of the presence of Clostridium difficile in children's faeces remains uncertain using current diagnostic procedures. Clostridium difficile is a relatively common finding in infants with no symptoms of gastrointestinal disease, suggesting it may be an incidental finding and form part of the normal gut micro-flora in this age group. On the other hand, particularly in older children or those with significant co-morbidity, there are examples where C. difficile causes disease and exerts considerable morbidity and even mortality (C. difficile infection, CDI). Between these extremes lie a substantial group of children who have both diarrhoea and C. difficile in their stools but where the nature of the association is not clear: Clostridium difficile associated disease (CDAD). We review the significance of C. difficile in children presenting recently uncovered paediatric data from a large UK epidemiological study that informs some key unanswered questions.

Clinical decision rules for secondary trauma triage: predictors of emergency operative management.

STUDY OBJECTIVE: Most injured patients taken by ambulance to hospital emergency departments do not require emergency surgery, yet most US trauma centers require a surgeon to be present on their arrival. If a clinical decision rule could be developed to accurately identify which injured patients require emergency operative intervention, then such "secondary triage" criteria could permit a trauma center to more efficiently use their surgeons' time. METHODS: We analyzed 7.5 years of data (8,289 consecutive trauma activations) in our prospectively maintained Level I trauma center registry. We used classification and regression tree analyses to generate clinical decision rules using standard out-of-hospital variables to identify emergency operative intervention (within 1 hour) by a general surgeon (for adults) or a pediatric surgeon (if < or =14 years). RESULTS: Emergency operative intervention occurred in 3.0% of adults and 0.35% of children. For adults, summoning a surgeon for any one of 3 criteria (penetrating mechanism, systolic blood pressure <96 mm Hg, pulse rate >104 beats/min) could reduce surgeon calls by 51.2% while failing to identify emergency operative intervention in only 0.08% (rule sensitivity 97.2% and specificity 48.6%). For children, no rule at all (ie, never automatically summoning a surgeon) would fail to identify emergency operative intervention in only 0.35% of patients, and use of a single criterion (penetrating mechanism) would reduce surgeon calls by 96.2% while failing to identify emergency operative intervention in only 0.09% (rule sensitivity 75.0% and specificity 96.5%). CONCLUSION: We have derived simple decision rules for trauma centers that, if validated, could substantially reduce the need for routine surgeon presence on trauma patient arrival. These rules demonstrate low false-negative rates.