© Med Sci Monit, 2007; 13(6): CR251-257 PMID: 17534230
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Clinical Research
CR Received: 2006.06.20 Accepted: 2007.02.02 Published: 2007.06.01
Nosocomial bloodstream infections in a pediatric intensive care unit: 3-year survey
Authors’ Contribution: A Study Design B Data Collection C Statistical Analysis D Data Interpretation E Manuscript Preparation F Literature Search G Funds Collection
Galia Grisaru-Soen1 ADEF, Yaser Sweed2 BD, Liat Lerner-Geva3 CDE, Galit Hirsh-Yechezkel3 CD, Valentina Boyko3 CD, Amir Vardi2 A, Nathan Keller4 B, Zohar Barzilay2 A, Gideon Paret2 ADE 1
Pediatrics Infectious Diseases Unit, Dana Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel Department of Pediatric Intensive Care, Safra Childrens Hospital, Tel Hashomer, Israel 3 Women and Children Health Research Unit, Gertner Institute for Epidemiology and Health Policy Research, Tel Hashomer, Israel 4 Microbiology Laboratory, Sheba Medical Center, Tel Hashomer, Israel 2
Source of support: Departmental sources
Summary Background: Material/Methods:
Bloodstream infections (BSI) represent a major cause of hospital-acquired infections in pediatric intensive care unit (PICU) patients. This study was designed to determine the prevalence, risk factors and outcomes of these infections in one local facility. All patients admitted to one PICU between January 1, 2000-December 31, 2002 and subsequently developed a nosocomial bloodstream infection (NBSI) were consecutively recruited. The study was a retrospective study. Data retrieved from medical records included demographic information, extrinsic (invasive devices) and intrinsic risk factors, specific pathogens, therapeutic interventions and outcome.
Results:
There were 95 episodes of NBSIs in 59 patients (63/1711 PICU admissions, yielding an incidence of 56/1000). The crude mortality rate (CMR) in children with NBSIs was 52%, compared with 6% for all other children admitted to the PICU. A higher CMR was associated with hemato-oncology illness, prolonged length of hospitalization (>1 month) mechanical ventilation, dialysis and severity of illness. Most of the patients (95%) had central intravascular devices, and 73% of the episodes were catheter-related infections. The most frequent pathogens were coagulase-negative staphylococci (24%), Klebsiella pneumonia (16%), Candida spp. (15%), Pseudomonas aeruginosa (7%) and Staphylococcus aureus (6%). Thirty-three percent of the Staphylococcus aureus were methicillin resistant (MRSA) and 30% of the Klebsiella pneumonia were extended - spectrum beta-lactamase - producing (ESBL) strains.
Conclusions:
The overall incidence of NBSIs was 56 episodes per 1000 admissions. The major risk factors were hemato-oncology illness, prolonged length of hospitalization, mechanical ventilation, dialysis and severity of illness. Children with NBSI had a poor outcome when compared with children without NBSI.
key words: Full-text PDF: Word count: Tables: Figures: References: Author’s address:
pediatric intensive care unit • nosocomial • blood stream infection
http://www.medscimonit.com/fulltxt.php?IDMAN=9441 2758 4 — 24 Galia Grisaru-Soen, MD, The Pediatrics Infectious Diseases Unit, Dana Children’s Hospital, Tel Aviv Sourasky Medical Center, 6 Weizman Street, Tel Aviv 64239, Israel, e-mail:
[email protected]
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CR251
Clinical Research
Med Sci Monit, 2007; 13(6): CR251-257
BACKGROUND
Data collection
Bacteremia and fungemia represent major causes of hospital-acquired infections in pediatric intensive care (PICU) patients. These complications are associated with significant morbidity and mortality as well as with prolonged hospital stay [1–3]. The overall mortality attributable to pediatric nosocomial infections has been estimated at 11% [4]. In the past 10–15 years, there has been a reported steady increase in the frequency of bacteremia and fungemia in the inpatient setting, attributed in part to more vulnerable patient populations being hospitalized [4]. Most of those studies were done in adult and neonatal ICUs, and there is little information on the pattern of bloodstream infections (BSIs) in PICUs [2]. The incidence of bacteremia and fungemia may be a useful benchmark for intra- and inter-hospital monitoring of PICU-acquired infection rates and infection control policy. This study was designed to determine the prevalence and outcomes of these infections in one local facility.
Data on positive blood cultures, including the identification of the pathogen and antibiotic susceptibility, were identified and collected from the database of the microbiology laboratory. Demographics and clinical characteristics for these patients as well as data related to treatments and procedures during hospitalization were collected from the medical records using a preconstructed questionnaire. All medical records were abstracted by one person (YS).
MATERIAL AND METHODS
Blood cultures A BacTec9240+ continuous monitoring blood culture system (BectonDickinson, Sparks, MD) was used. Data analysis The prevalence of NBSI was calculated by dividing the number of infected patients by the total number of patients admitted to the PICU. Patients with more than 1 hospitalization during the study period were included only once at their first hospitalization.
Patient population and setting The study population was comprised of all patients admitted to the PICU at Safra Children’s Hospital, Sheba Medical Center (Israel) between January 1, 2000 and December 31, 2002 who had a nosocomial BSI (NBSI) according to the Centers for Disease Control and Prevention (CDC) criteria [6,7]. This study was approved by the Institutional Review Board. Definitions The CDC criteria [6,7] define significant bacteremia or fungemia as (1) isolation from blood cultures of one or more recognized pathogens that are not common skin flora, or (2) Patient has at least one of the following symptoms: fever ≥38° C, chills or hypotension ( for patient ≤1 year of age: fever ≥38° C, hypothermia, apnea or bradycardia) not related to infection in other site, and at least one of the following: (a) isolation of organisms that are common skin contaminants, from two or more separate blood cultures, (b) common skin contaminants from one blood culture in a patient with an intravascular device and the physician institutes appropriate antimicrobial therapy. Bacteremia and fungemia were considered as being nosocomial if the initial culture was obtained >48 h after admission to the PICU. A new episode of NBSI was defined as the isolation of the same pathogen within ≥48 hours after ceasing antimicrobial therapy with previous negative cultures or isolation of different pathogen after ≥48 hours from the first positive blood culture. A polymicrobial NBSI was considered as the isolation of more than one pathogen during the same episode. Antimicrobial therapy was considered appropriate if the infecting microorganisms were susceptible in vitro to any component of the antibiotic regimen used. The pediatric index of mortality (PIM) [8] was used as a model to predict the risk of mortality in this population. The PIM model is based on eight variables and the data on all of them were collected for each child at the time of admission to the PICU.
CR252
The crude mortality rate (CMR) was calculated as the ratio between number of deaths and the number of patients with NBSI. The 7-day mortality rate was calculated as the number of deaths occurring within 7 days of the last episode of each patient divided by the total number of patients with of NBSIs. The comparison of categorical variables was performed by using c2 tests or Fisher’s Exact test. In addition, odds ratios (OR) and 95% confidence interval (CI) were calculated to evaluate the associations between demographic and clinical characteristics and CMR\ 7-Day mortality rates. Multiple logistic regression models were used to assess the independent effect of specific factors on mortality. The model included the following factors: age (≤1 y, >1 y), gender, underlying illness (CHD, Hemato-oncology illness, Other underlying disease or no underlying illness) length of hospitalization (30days), PIM (
