Performance, revision, and extension of the National Nosocomial Infections Surveillance system's risk index in Brazilian hospitals.

OBJECTIVE: To assess the benefit of using procedure-specific alternative cutoff points for National Nosocomial Infections Surveillance (NNIS) risk index variables and of extending surgical site infection (SSI) risk prediction models with a postdischarge surveillance indicator. DESIGN: Open, retrospective, validation cohort study. SETTING: Five private, nonuniversity Brazilian hospitals. PATIENTS: Consecutive inpatients operated on between January 1993 and May 2006 (other operations of the genitourinary system [n = 20,723], integumentary system [n = 12,408], or musculoskeletal system [n = 15,714] and abdominal hysterectomy [n = 11,847]). METHODS: For each procedure category, development and validation samples were defined nonrandomly. In the development samples, alternative SSI prognostic scores were constructed using logistic regression: (i) alternative NNIS scores used NNIS risk index covariates and cutoff points but locally derived SSI risk strata and rates, (ii) revised scores used procedure-specific alternative cutoff points, and (iii) extended scores expanded revised scores with a postdischarge surveillance indicator. Performances were compared in the validation samples using calibration, discrimination, and overall performance measures. RESULTS: The NNIS risk index showed low discrimination, inadequate calibration, and predictions with high variability. The most consistent advantage of alternative NNIS scores was regarding calibration (prevalence and dispersion components). Revised scores performed slightly better than the NNIS risk index for most procedures and measures, mainly in calibration. Extended scores clearly performed better than the NNIS risk index, irrespective of the measure or operative procedure. CONCLUSIONS: Locally derived SSI risk strata and rates improved the NNIS risk index's calibration. Alternative cutoff points further improved the specification of the intrinsic SSI risk component. Controlling for incomplete postdischarge SSI surveillance provided consistently more accurate SSI risk adjustment.

Accounting for incomplete postdischarge follow-up during surveillance of surgical site infection by use of the National Nosocomial Infections Surveillance system's risk index.

OBJECTIVE: We examined the usefulness of a simple method to account for incomplete postdischarge follow-up during surveillance of surgical site infection (SSI) by use of the National Nosocomial Infections Surveillance (NNIS) system's risk index. DESIGN: Retrospective cohort study that used data prospectively collected from 1993 through 2006. SETTING: Five private, nonuniversity healthcare facilities in Belo Horizonte, Brazil. PATIENTS: Consecutive patients undergoing the following NNIS operative procedures: 20,981 operations on the genitourinary system, 11,930 abdominal hysterectomies, 7,696 herniorraphies, 6,002 cholecystectomies, and 6,892 laparotomies. METHODS: For each operative procedure category, 2 SSI risk models were specified. First, a model based on the NNIS system's risk index variables was specified (hereafter referred to as the NNIS-based model). Second, a modified model (hereafter referred to as the modified NNIS-based model), which was also based on the NNIS system's risk index, was specified with a postdischarge surveillance indicator, which was assigned the value of 1 if the patient could be reached during follow-up and a value of 0 if the patient could not be reached. A formal comparison of the capabilities of the 2 models to assess the risk of SSI was conducted using measures of calibration (by use of the Pearson goodness-of-fit test) and discrimination (by use of receiver operating characteristic curves). Goodman-Kruskal correlations (G) were also calculated. RESULTS: The rate of incomplete postdischarge follow-up varied between 29.8% for abdominal hysterectomies and 50.5% for cholecystectomies. The modified NNIS-based model for laparotomy did not show any significant benefit over the NNIS-based model in any measure. For all other operative procedures, the modified NNIS-based model showed a significantly improved discriminatory ability and higher G statistics, compared with the NNIS-based model, with no significant impairment in calibration, except if used to assess the risk of SSI after operations on the genitourinary system or after a cholecystectomy. CONCLUSIONS: Compared with the NNIS-based model, the modified NNIS-based model added potentially useful clinical information regarding most of the operative procedures. Further work is warranted to evaluate this method for accounting for incomplete postdischarge follow-up during surveillance of SSI.

C-reactive protein-guided approach may shorten length of antimicrobial treatment of culture-proven late-onset sepsis: an intervention study.

Late-onset sepsis (LOS) (i.e., sepsis in a neonate after 72 hours of life) is associated with high mortality and significantly prolonged antibiotic exposure and hospital stay in neonates admitted to intensive care units (ICU). In this study, we assessed the reliability of serum C-reactive protein (CRP) as a determinant of antimicrobial treatment duration of LOS. From January 1996 to December 2002, all consecutive infants aged <28 days admitted to a single medical-surgical ICU and diagnosed with primary LOS were enrolled in a prospective, intervention trial with historical controls. Only blood culture-positive LOSs were included. Exclusion criteria were: age >28 days at diagnosis of LOS, development of site-specific infection, and central venous catheter-related LOS. From January 1996 to July 1998 (historical control group), antimicrobial treatment of LOS was offered for at least 14 days. From August 1998 to December 2002 (intervention group), neonates underwent serial semiquantitative measurements of serum CRP, and antimicrobial treatment was discontinued when CRP was <12 mg/L. Primary efficacy endpoint was the duration of antimicrobial therapy. Secondary efficacy endpoints were the proportion of relapsing sepsis within 72 hours of antibiotic withdrawal and the overall mortality rate. The historical control group comprised 76 neonates developing 85 episodes of LOS; 138 LOS occurring in 120 patients comprised the intervention group. Length of antimicrobial treatment of LOS was significantly shorter during the second study period (16 days vs. 9 days, p<0.001). Secondary efficacy endpoints showed similar rates of relapsing sepsis and overall mortality in both time periods.

A 10-year prospective surveillance of nosocomial infections in neonatal intensive care units.

BACKGROUND: We report on nosocomial infections (NIs), causative organisms, and antimicrobial susceptibility patterns in neonates who were admitted to neonatal intensive care units (NICUs), and assess the performance of birth weight (BW) as a variable for risk-stratified NI rate reporting. METHODS: A prospective, 10-year follow-up, open cohort study that involved six Brazilian NICUs was conducted. The NI incidence rates were calculated using different denominators. RESULTS: Six thousand two hundred forty-three newborns and 450 NICU-months of data were available for analysis. This included 3603 NIs that occurred in 2286 newborns over 121,008 patient-days. The most frequent NIs were primary bloodstream infection (pBSI; 45.9%), conjunctivitis (12.1%), skin infections (9.6%), and pneumonia (6.8%). Only the pBSI (but not pneumonia or central venous catheter-related pBSI) rate distribution differed significantly with varying BW. Gram-negative rods (mainly Klebsiella sp. and Escherichia coli) were responsible for 51.6% episodes of pBSI. Gram-positive organisms (mainly coagulase-positive staphylococci) accounted for 37.4%. Candida sp. was the fourth isolated organism. A high resistance to third-generation cephalosporins was recorded in K pneumoniae and E coli isolates. CONCLUSIONS: This report highlights the burden of NI, and identifies the major focus for future NI control and prevention programs. Except for pBSI, BW had a poor performance as a variable for risk-stratified NI rate reporting.

C-reactive protein-guided approach may shorten length of antimicrobial treatment of culture-proven late-onset sepsis: an intervention study

Late-onset sepsis (LOS) (i.e., sepsis in a neonate after 72 hours of life) is associated with high mortality and significantly prolonged antibiotic exposure and hospital stay in neonates admitted to intensive care units (ICU). In this study, we assessed the reliability of serum C-reactive protein (CRP) as a determinant of antimicrobial treatment duration of LOS. From January 1996 to December 2002, all consecutive infants aged <28 days admitted to a single medical-surgical ICU and diagnosed with primary LOS were enrolled in a prospective, intervention trial with historical controls. Only blood culture-positive LOSs were included. Exclusion criteria were: age >28 days at diagnosis of LOS, development of site-specific infection, and central venous catheter-related LOS. From January 1996 to July 1998 (historical control group), antimicrobial treatment of LOS was offered for at least 14 days. From August 1998 to December 2002 (intervention group), neonates underwent serial semiquantitative measurements of serum CRP, and antimicrobial treatment was discontinued when CRP was <12 mg/L. Primary efficacy endpoint was the duration of antimicrobial therapy. Secondary efficacy endpoints were the proportion of relapsing sepsis within 72 hours of antibiotic withdrawal and the overall mortality rate. The historical control group comprised 76 neonates developing 85 episodes of LOS; 138 LOS occurring in 120 patients comprised the intervention group. Length of antimicrobial treatment of LOS was significantly shorter during the second study period (16 days vs. 9 days, p<0.001). Secondary efficacy endpoints showed similar rates of relapsing sepsis and overall mortality in both time periods.

Risk factors for nosocomial infection in a neonatal intensive care unit.

OBJECTIVE: To determine risk factors for nosocomial infection in a neonatal intensive care unit (NICU). DESIGN: A prospective, open cohort study. SETTING: A 22-bed NICU. PATIENTS: Neonates admitted to a single NICU during 1994-1998 were included in the study. Outcome variables included central venous catheter (CVC)-associated primary bloodstream infection (BSI), non-CVC-associated primary BSI, pneumonia, and overall nosocomial infection. Independent variables included birth weight, use of mechanical ventilation (MV), duration of MV, use of a CVC, duration of CVC use, duration of NICU stay, gestational age, congenital malformation, maximum (ie, worst) base excess, and maximum and minimum fraction of inspired oxygen (FIO(2)) for maintaining appropriate blood saturation levels during the first 12 hours after NICU admission. RESULTS: A total of 1051 neonates were admitted to the NICU. Overall, 358 NIs were diagnosed. Non-CVC-associated primary BSI was the most frequent nosocomial infection (in 195 neonates [54.5%]), followed by pneumonia (46 [12.8%]), and CVC-associated primary BSI (35 [9.8%]). The mortality rate was 16%. In the final logistic regression model, the following 5 risk factors were found to be predictive of nosocomial infection development: use of MV, longer duration of MV, longer duration of CVC use, longer duration of NICU stay, and low maximum appropriate Fio(2). CONCLUSION: Invasive device use and duration of use continue to greatly influence the development of nosocomial infection in NICUs. In our cohort, birth weight showed no influence on the development of nosocomial infection. Low maximum Fio(2) influenced the occurrence of overall nosocomial infection.