Added value of multi-pathogen probe-based real-time PCR SeptiFast in the rapid diagnosis of bloodstream infections in patients with bacteraemia.

The commercial multi-pathogen probe-based real-time PCR SeptiFast (SF) was evaluated as a rapid and complementing tool for the microbiological diagnosis of bloodstream infections (BSIs) in a series of 138 matched blood samples from 65 patients with bacteraemia, hospitalized in an intensive care unit, when antibiotics had already been administered. SF was positive in 32.6 % of the samples, whereas blood culture (BC) was positive in 21.7 % (P < 0.05). SF identified more pathogens (11 versus 5; specificity, 90.7 %) and reduced the time of aetiological diagnosis, with a mean of 16.3 versus 55.4 h needed for BC (P < 0.05). SF enabled appropriate pathogen-oriented therapy in 72 % (36/50) of the BSI group of patients on the basis of epidemiological data. According to our data, the use of SF provided important added value to BC, in terms of earlier aetiological diagnosis of BSIs, enabling pathogen-oriented therapy in patients receiving empirical antibiotic treatment.

Carbapenem and multidrug resistance in Gram-negative bacteria in a single centre in Italy: considerations on in vitro assay of active drugs.

In intensive care units (ICUs), the most important causes of nosocomial bacterial infections are mainly multidrug-resistant (MDR) and extensively drug-resistant (XDR) Acinetobacter baumannii and Klebsiella pneumoniae strains. Mortality related to these infections is very high due to lack of effective therapy and the severity of patient conditions. This study aimed to assess the prevalence of carbapenem resistance genes in 77 carbapenem-resistant Gram-negative bacteria isolated from severe infections (bloodstream, pulmonary and urinary tract) during the period 1 January to 31 July 2013 in a general ICU in Catania, Italy, and to examine their susceptibility to tigecycline and colistin using two different methods. In total, 52 A. baumannii belonging to the same sequence type (ST) 2 clone and carrying the bla(OXA-23) gene as well as 25 K. pneumoniae carrying bla(KPC-3) were isolated. Four distinct pulsotypes were identified in K. pneumoniae, which correlated with four distinct STs: ST258 and ST512, spread worldwide, and ST147 and ST395 detected for the first time in Italy. A. baumannii isolates showed an XDR profile and were fully susceptible only to colistin; all KPC-producing K. pneumoniae isolates were MDR, whilst colistin was active against 19 of 25 strains. These results show that broth microdilution (BMD) is a reliable in vitro susceptibility test for colistin, above all K. pneumoniae, whilst both the gradient test and BMD are suitable for tigecycline susceptibility testing of A. baumannii.

Individual patient data systematic review and meta-analysis of optic nerve sheath diameter ultrasonography for detecting raised intracranial pressure: protocol of the ONSD research group.

BACKGROUND: The purpose of the optic nerve sheath diameter (ONSD) research group project is to establish an individual patient-level database from high quality studies of ONSD ultrasonography for the detection of raised intracranial pressure (ICP), and to perform a systematic review and an individual patient data meta-analysis (IPDMA), which will provide a cutoff value to help physicians making decisions and encourage further research. Previous meta-analyses were able to assess the diagnostic accuracy of ONSD ultrasonography in detecting raised ICP but failed to determine a precise cutoff value. Thus, the ONSD research group was founded to synthesize data from several recent studies on the subject and to provide evidence on the diagnostic accuracy of ONSD ultrasonography in detecting raised ICP. METHODS: This IPDMA will be conducted in different phases. First, we will systematically search for eligible studies. To be eligible, studies must have compared ONSD ultrasonography to invasive intracranial devices, the current reference standard for diagnosing raised ICP. Subsequently, we will assess the quality of studies included based on the QUADAS-2 tool, and then collect and validate individual patient data. The objectives of the primary analyses will be to assess the diagnostic accuracy of ONSD ultrasonography and to determine a precise cutoff value for detecting raised ICP. Secondly, we will construct a logistic regression model to assess whether patient and study characteristics influence diagnostic accuracy. DISCUSSION: We believe that this IPD MA will provide the most reliable basis for the assessment of diagnostic accuracy of ONSD ultrasonography for detecting raised ICP and to provide a cutoff value. We also hope that the creation of the ONSD research group will encourage further study. TRIAL REGISTRATION: PROSPERO registration number: CRD42012003072.

Ocular ultrasound to detect intracranial hypertension in trauma patients.

BACKGROUND: Increases in intracranial pressure (ICP) after head trauma require a rapid recognition to allow for adequate treatments. The aim of this study was to determine whether dilation of the optic nerve sheath, as detected by ocular ultrasound at the bedside, could reliably identify increases in ICP assessed with an intraparenchymal probe in adult head trauma patients. METHODS: Eleven head trauma injured adult patients admitted to the intensive care unit with a Glasgow Coma Scale score ≤8, with cerebral contusion confirmed by computed tomography scan, and that required invasive ICP monitoring, were enrolled in the study. ICP values ≤20 mm Hg were considered as normal. Patients with acute or chronic ocular lesion were excluded. Ten nontrauma intensive care unit patients, with no ICP monitoring, were enrolled as control group. Invasive arterial pressure was monitored, and optic nerve sheath diameter (ONSD) was assessed by ocular ultrasound in all the patients. RESULTS: Head trauma patients without intracranial hypertension had ONSD values, assessed by ultrasound, equivalent to those measured in control patients (5.52 mm ± 0.36 mm vs. 5.51 mm ± 0.32 mm). ONSD, instead, significantly increased to 7.0 mm ± 0.58 mm, when ICP rose in value to >20 mm Hg (p < 0.0001 vs. normal ICP and control). ONSD values were significantly correlated to ICP values (r = 0.74, p < 0.001). CONCLUSIONS: When ICP was higher than 20 mm Hg, the ONSD diameter increased, whereas when the ICP was below 20 mm Hg, the ONSD returned to values equivalent to those assessed in control nontrauma patients. Accordingly, ocular ultrasound may be considered as a good alternative for a rapid indirect evaluation of head trauma patients' ICP.

Selective medicated (saline + natural surfactant) bronchoalveolar lavage in unilateral lung contusion. A clinical randomized controlled trial.

OBJECTIVE: Open lung and low tidal volume ventilation appear to be a promising ventilation for chest trauma as it can reduce ARDS and improve outcome. Local therapy (e.g. BAL) can be synergic to remove from the lung the debris, mitigate inflammatory cascade and avoid damage spreading to not compromised lung areas. MATERIALS AND METHODS: 44 pulmonary contused patients were randomized to receive broncho-suction and volume controlled low tidal volume ventilation-VCLTVV (Control Group) or the same ventilation plus medicated (saline + surfactant) BAL (Treatment Group). Tidal volume <10 ml/kg, PEEP of 10-12 cm H(2)O and PaO(2) 60-100 mm Hg and PaCO(2) 35-45 mm Hg were used in both groups. BAL was performed using a fiberscope. 4 boluses of 25 ml saline with 2.4 mg/ml of surfactant were introduced into each contused lobe in which, subsequently, 240 mg of surfactant was instilled. RESULTS: All patients survived. In the Control Group 18 patients developed pneumonia, 5 ARDS and days of intubation were 11.50 (3.83) compared to 5.05 (1.21) of Treatment Group in which OI and PaO(2)/FiO(2) significantly improved from 36 h. CONCLUSIONS: VCLTVV alone was not able to prevent ARDS and infection in the Control Group as the reduction of intubation. In the Treatment Group, VCLTVV and medicated BAL facilitated the removal of degradated lung material and recruited the contused lung regions, enabling the healing of the lung pathology.

Acquisition and spread of Acinetobacter baumannii and Stenotrophomonas maltophilia in intensive care patients.

Acinetobacter baumannii and Stenotrophomonas maltophilia are increasingly important pathogens, especially in the intensive care units (ICUs). This study was designed to investigate the clonality, the mode of transmission and the patients' risk profile for acquisition of A. baumannii and S. maltophilia at the ICU of an Italian Hospital. Patterns of A. baumannii and S. maltophilia acquisition in the ICU during the period of the survey were carriage, colonization and infection. Characterization of A. baumannii was performed by ARDRA and genotyping of both pathogens by PFGE. Our study provided evidence for the occurrence of an outbreak sustained by the two organisms in study involving 27.3% of patients enrolled into the surveillance. The spread of a unique A. baumannii epidemic clone was demonstrated. A major clone of S. maltophilia was responsible for the epidemic spread of S. maltophilia (55.5% of isolates), thus confirming A. baumannii cross-transmission and showing--among few published reports--the clonal spread of S. maltophilia. Outliers analysis suggested colonized patients as the probable epidemic sources. Mechanical ventilation was confirmed as risk factor for infection (OR 8.4; 95%C.I.: 2.6-27.5). A multimodal intervention program was introduced, followed in later months with a drastic restriction of infection and colonization due to A. baumannii and S. maltophilia and subsequently with the successful control of the outbreak. Active surveillance of infection and colonization by high-risk clones, together with implementation of control strategies, including strict hand hygiene, proved to be effective to reduce the epidemic spread of both alert pathogens in our ICU.

Pseudomonas aeruginosa carriage, colonization, and infection in ICU patients.

OBJECTIVE: We evaluated whether Pseudomonas aeruginosa associated nosocomial infections in our ICU originate mainly from patients' endogenous flora or from exogenous cross-transmission. DESIGN AND SETTING: A 6-month prospective surveillance survey was performed according to standardized protocols at the interdisciplinary ICU of the Azienda Ospedaliera Cannizzaro. PATIENTS: The study analyzed 121 patients and focused on three different states: carriage upon admission, colonization of sterile sites, and infections during ICU stay. RESULTS: We identified 138 P. aeruginosa isolates from 45 patients. The cumulative incidence of P. aeruginosa sustained colonization in the ICU was 29.9/100 patients, and the incidence density was 16.2/1,000 patient-days. The cumulative incidence of P. aeruginosa-sustained infections in the ICU was 36.7/100 patients, and the incidence density was 19.9/1,000 patient-days. The most frequent infection type was ventilator-associated pneumonia. PFGE analysis of P. aeruginosa isolates led to the identification of a major clone represented by 60.8% of isolates involving 45.9% of patients. The impact of cross-transmission, i.e., the preventable proportion of P. aeruginosa acquisition, was estimated to be at least 59.5% of all colonization or infection episodes. Acquisition of multidrug-resistant P. aeruginosa was significantly associated with cross-transmission. CONCLUSIONS: Our results suggest that the ICU personnel and environment served as reservoirs for cross-transmission and emphasize the importance of exogenous acquisition of multidrug-resistant P. aeruginosa, of reduction in antibiotic pressure, and prompt enforcement of infection control measures.