Elhanan Nahum

Use of the NOW Streptococcus pneumoniae urinary antigen test in cerebrospinal fluid for rapid diagnosis of pneumococcal meningitis

Streptococcus pneumoniae is one of the most common pathogens in bacterial meningitis. Rapid diagnosis is critical for effective treatment. The aim of this study was to assess the accuracy of the NOW S. pneumoniae Urinary Antigen Test, (Binax, Portland, ME, USA) originally developed for urine testing, in detecting the S. pneumoniae antigen in cerebrospinal fluid (CSF). The study included 519 patients with suspected meningitis. CSF, blood and urine samples were cultured according to standard methods. CSF viral culture was also performed. CSF and urine specimens were tested for pneumococcal antigen with the NOW S. pneumoniae test.S. pneumoniae was isolated from the CSF of 22 patients. The direct antigen test was positive in CSF in 21/22 patients (95.4% sensitivity), and in urine, in 12/21 (57.1% sensitivity). Direct CSF smear was positive in 15/22 (68% sensitivity). CSF samples that cultured negative for S. pneumoniae (n = 470) or positive for other bacteria (n = 27) were also negative on the NOW test (100% specificity). By contrast, urine samples of 63/470 of patients with negative CSF culture were positive on the NOW test, as were 5/27 urine samples of patients with CSF culture positive for other bacteria (p = 0.45). The NOW S. pneumoniae antigen test in CSF yields a rapid and very reliable diagnosis of pneumococcal meningitis, enabling prompt and adequate treatment. Its low sensitivity in urine indicates that this mode of testing is not useful for the diagnosis of pneumococcal meningitis. These data have been included in the FDA application for approval of the NOW test for use in the CSF for the diagnosis of pneumococcal meningitis.

Computerized Order Entry With Limited Decision Support to Prevent Prescription Errors in a PICU

OBJECTIVE: The value of computerized physician order entry (CPOE) and clinical decision support systems (CDSSs) in preventing prescription errors in pediatrics is unclear. We investigated the change in prescription error rates with the introduction of CPOE with and without a CDSS limited to weight-based dosing in a PICU. METHODS: In a PICU of a major tertiary-care pediatric medical center, 5000 orders were reviewed, that is, 1250 orders from each of 4 periods: period 1, before CPOE implementation; period 2, 1 year after CPOE implementation; period 3, after CDSS implementation; and period 4, after a change in prescription authorization. Prescription errors were identified and classified into: potential adverse drug events (ADEs), medication prescription errors (MPEs), and rule violations (RVs). RESULTS: We identified 273 errors (5.5%). The rate of potential ADEs decreased slightly between periods 1 and 2 (from 2.5% to 2.4%) and significantly in periods 3 and 4 (to 0.8% and 0.7%, respectively; P < .005). The rate of MPEs decreased slightly between periods 1 and 2 (from 5.5% to 5.3%), but new types of MPEs appeared. There was a significant decrease in period 3 (to 3.8%; P < .05) and a dramatically significant decrease in period 4 (to 0.7%; P < .0005). Only 3 RVs were found. Interrater agreement (κ statistic) was 0.788 between evaluators. CONCLUSIONS: CPOE implementation decreased prescription errors only to a small extent. However, the addition of a CDSS that limits doses by weight significantly reduced prescription error rates and, most importantly, potential ADEs. This finding emphasizes the major impact of weight-based calculation errors in pediatrics.

Hemophagocytic lymphohistiocytic syndrome: Unrecognized cause of multiple organ failure.

Objective To describe an often-unrecognized clinical picture of multiple organ failure in hemophagocytic lymphohistiocytic syndrome (HLS). Design Retrospective chart review. Setting A ten-bed pediatric intensive care unit (PICU) in a tertiary children’s university hospital. Patients A total of 11 children (age, 5 months to 13 yrs) who fulfilled the criteria for the diagnosis of familial- or infectious-associated hemophagocytic lymphohistiocytosis and who required intensive care support for organ failure. Intervention None. Main Results During a 10-yr period, 5,439 children were hospitalized in our PICU. A total of 11 children were diagnosed as suffering with HLS. Of these 11 patients, three (27%) had the familial form and eight had the infectious-associated form. After admission to the PICU, seven patients (63%) were diagnosed as suffering with HLS and each had one or more organ failures (patients 3–7, 9, and 10). All presented with fever, hepatomegaly, and splenomegaly; in addition, all had at least two of the following: anemia, neutropenia, or thrombocytopenia. All 11 had lymphohistiocytic accumulation in bone marrow (n = 10), lymph node (n = 2), lung (n = 2), and/or liver (n = 1). Organ failure was noted most often in the respiratory system (n = 7) attributable to severe, acute respiratory distress syndrome and pleural effusion. Of the 11 patients, six had cardiovascular involvement that manifested as shock in three and as capillary leak syndrome in three. Renal failure occurred in four patients. Of these, two required hemodiafiltration and one required peritoneal dialysis. Liver failure occurred in three and central nervous system involvement and coma in three. Most of the patients required massive therapeutic intervention, including assisted ventilation (n = 6), inotropic support (n = 3), and hemofiltration (n = 3). A total of seven patients (63%) died. Conclusions Hemophagocytic lymphohistiocytic syndrome in the pediatric population may have a dramatic clinical picture, with multiple organ failure as a presenting symptom or early in the disease course, mandating intensive support in the PICU.

Computerized Scoring System for the Diagnosis of Foreign Body Aspiration in Children

Objectives: Foreign body aspiration (FBA) is a life-threatening event in children. The gold standard for diagnosis is bronchoscopy, but there is no consensus regarding indications for the procedure. The aim of this study was to formulate a predictive model for assessing the probability of FBA in suspected cases as an aid in the decision to perform diagnostic bronchoscopy. Methods: The files of 150 patients who underwent bronchoscopy for suspected FBA at our center between 1996 and 2004 were reviewed for medical history, physical examination, and radiologic studies. The findings were analyzed by logistic regression. Results: Using the file data, we formulated a predictive model wherein each parameter received a numeric coefficient representing its significance in evaluating suspected FBA. The most significant parameters were age 10 to 24 months, foreign body in the childs mouth and severe respiratory complaints during the choking episode, hypoxemia, dyspnea or stridor following the acute event, unilateral signs on lung auscultation, abnormal tracheal radiogram, unilateral infiltrate or atelectasis, and local hyperinflation or obstructive emphysema on chest radiogram. Conclusions: In our predictive model, every case of suspected FBA can be assigned a score based on the specific parameters present, which is then entered into a probability formula to determine the likelihood of a positive diagnosis. This model may serve as a useful tool for deciding on the use of bronchoscopy in all children with suspected FBA.

Bi-Level Positive Airway Pressure Ventilation in Pediatric Oncology Patients With Acute Respiratory Failure

The aim of the study was to describe our experience with bi-level positive airway pressure (BiPAP) ventilation in oncology children with acute respiratory failure, hospitalized in a single tertiary pediatric tertiary center. This was a retrospective cohort study of all pediatric oncology patients in our center admitted to the intensive care unit with acute hypoxemic or hypercarbic respiratory failure from January 1999 through May 2006, who required mechanical ventilation with BiPAP. Fourteen patients met the inclusion criteria with a total of 16 events of respiratory failure or impending failure: 12 events were hypoxemic, 1 was combined hypercarbic and hypoxemic, and 3 had severe respiratory distress. Shortly after BiPAP ventilation initiation, there was a statistically significant improvement in the respiratory rate (40.4 ± 9.3 to 32.5 ± 10.1, P < .05] and a trend toward improvement in arterial partial pressure of oxygen (PaO 2; 71.3 ± 32.7 to 104.6 ± 45.6, P = .055). The improvement in the respiratory status was sustained for at least 12 hours. In 12 (75%) events there was a need for sedation during ventilation; 12 children needed inotropic support during the BiPAP ventilation. Bi-level positive airway pressure ventilation failed in 3 (21%) children who were switched to conventional ventilation. All of them have died during the following days. One child was recategorized to receive palliative care while on BiPAP ventilator and was not intubated. In 12 of 16 BiPAP interventions (75%; 11 patients), the children survived to pediatric intensive care unit (PICU) discharge without invasive ventilation. No major complications were noted during BiPAP ventilation. Bi-level positive airway pressure ventilation is well tolerated in pediatric oncology patients suffering from acute respiratory failure and may offer noninferior outcomes compared with those previously described for conventional invasive ventilation. It appears to be a feasible initial option in children with malignancy experiencing acute respiratory failure.

Central apnoeas in infants with bronchiolitis admitted to the paediatric intensive care unit

Aim:  To further characterize apnoea(s) complicating bronchiolitis because of respiratory syncytial virus (RSV), to describe the incidence of this complication and identify possible risk factors for apnoea(s) and its development.

Acute diaphragmatic paralysis caused by chest-tube trauma to phrenic nerve.

Abstract A 31/2-year-old child developed unilateral diaphragmatic paralysis after chest drain insertion. Plain chest X-ray demonstrated paravertebral positioning of the chest-tube tip, and magnetic resonance imaging revealed hematomas in the region of the chest-tube tip and the phrenic nerve fibers. The trauma to the phrenic nerve was apparently secondary to malposition of the chest tube. This is a rare complication and has been reported mainly in neonates. Radiologists should notify the treating physicians that the correct position of a chest drain tip is at least 2 cm distant from the vertebrae.

Oral amphotericin B for the prevention of Candida bloodstream infection in critically ill children

Objectives: To determine the efficacy of oral amphotericin B for the prevention of Candida bloodstream infection in the pediatric intensive care unit. Design: Retrospective, nonrandomized, historic-control study. Setting: Multidisciplinary pediatric intensive care unit at a university-affiliated children’s medical center. Patients: Study group included all patients admitted to the pediatric intensive care unit from January 1, 1998, to December 31, 1999, who required mechanical ventilation and who were admitted for >7 days. The control group included all patients admitted for >7 days who needed mechanical ventilation from January 1, 1994, to December 31, 1997. Interventions: Oral amphotericin B suspension, 50 mg every 8 hrs, administered to all study group patients soon after initiation of mechanical ventilation and terminating after weaning. Measurements: The rates of Candida bloodstream infection were compared between the study and control groups. Main Results: Candida species were isolated from blood cultures in 5 of 185 (2.1%) and 21 of 196 (10.7%) patients in the study and control groups, respectively (p= .0038). There was also a statistically significant (p= .017) decrease in Candida bloodstream infection rate in all patients admitted to the pediatric intensive care unit for >7 days during the study period compared with the Candida bloodstream infection rate during the control period. Conclusion: Prophylactic administration of oral amphotericin B may lead to a significant decrease in the rate of Candida bloodstream infection in ventilated pediatric intensive care unit patients.

Polymerase-chain-reaction-based diagnosis of viral pulmonary infections in immunocompromised children.

Viral pneumonia is a serious complication in immunocompromised children. Its aetiology is difficult to identify owing to the limitations of conventional microbiological tests. The aim of this study was to determine whether polymerase chain reaction (PCR) assays for respiratory viruses increase the diagnostic yield of bronchoalveolar lavage (BAL) in immunocompromised children.

Role of C-Reactive Protein Velocity in the Diagnosis of Early Bacterial Infections in Children After Cardiac Surgery

Received November 20, 2009, Received Revised August 18, 2010, Submitted August 19, 2010 Fever after cardiac surgery in children may be due to bacterial infection or noninfectious origin like systemic inflammatory response syndrome (SIRS) secondary to bypass procedure. A marker to distinguish bacterial from nonbacterial fever in these conditions is clinically important. The purpose of our study was to evaluate, in the early postcardiac surgery period, whether serial measurement of C-reactive protein (CRP) and its change over time (CRP velocity) can assist in detecting bacterial infection. A series of consecutive children who underwent cardiac surgery with bypass were tested for serum levels of CRP at several points up to 5 days postoperatively and during febrile episodes (>38.0°C). Findings were compared among febrile patients with proven bacterial infection (FWI group; sepsis, pneumonia, urinary tract infection, deep wound infection), febrile patients without bacterial infection (FNI group), and patients without fever (NF group). In all, 121 children were enrolled in the study, 31 in the FWI group, 42 in the FNI group, and 48 patients in the NF group. Ages ranged from 4 days to 17.8 years (median 19.0, mean 46 ± 56 months). There was no significant difference among the groups in mean CRP level before surgery, 1 hour, and 18 hours after. A highly significant interaction was found in the change in CRP over time by FWI group compared with FNI group (P < .001). Mean CRP velocity ([fCRP – 18hCRP]/[fever time (days) – 0.75 day]) was significantly higher in the infectious group (4.0 ± 4.2 mg/dL per d) than in the fever-only group (0.60 ± 1.6 mg/dL per d; P < .001). A CRP velocity of 4 mg/dL per d had a positive predictive value (PPV) of 85.7% for bacterial infection with 95.2% specificity. Serial measurements of CRP/CRP velocity after cardiac surgery in children may assist clinicians in differentiating postoperative fever due to bacterial infection from fever due to noninfectious origin.