Jin Young Ahn

RED BLOOD CELL DISTRIBUTION WIDTH IS AN INDEPENDENT PREDICTOR OF MORTALITY IN PATIENTS WITH GRAM-NEGATIVE BACTEREMIA

ABSTRACT Red blood cell distribution width (RDW) is known to be a predictor of severe morbidity and mortality in some chronic diseases such as congestive heart failure. However, to our knowledge, little is known about RDW as a predictor of mortality in patients with Gram-negative bacteremia, a major nosocomial cause of intra-abdominal infections, urinary tract infections, and primary bacteremia. Therefore, we investigated whether RDW is an independent predictor of mortality in patients with Gram-negative bacteremia. Clinical characteristics, laboratory parameters, and outcomes of 161 patients with Gram-negative bacteremia from November 2010 to March 2011 diagnosed at Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, were retrospectively analyzed. The main outcome measure was 28-day all-cause mortality. The 28-day mortality rate was significantly higher in the increased RDW group compared with the normal RDW group (P < 0.001). According to multivariate Cox proportional hazard analysis, RDW levels at the onset of bacteremia (per 1% increase, P = 0.036), the Charlson index (per 1-point increase, P < 0.001), and the Sequential Organ Failure Assessment score (per 1-point increase, P = 0.001) were independent risk factors for 28-day mortality. Moreover, the nonsurvivor group had significantly higher RDW levels 72 h after the onset of bacteremia than did the survivor group (P = 0.001). In addition, the area under the curve of RDW at the onset of bacteremia, the 72-h RDW, and the Sequential Organ Failure Assessment score for 28-day mortality were 0.764 (P = 0.001), 0.802 (P < 0.001), and 0.703 (P = 0.008), respectively. Red blood cell distribution width at the onset of bacteremia was an independent predictor of mortality in patients with Gram-negative bacteremia. Also, 72-h RDW could be a predictor for all-cause mortality in patients with Gram-negative bacteremia.

Risk factors for the acquisition of carbapenem-resistant Escherichia coli at a tertiary care center in South Korea: A matched case-control study

BACKGROUND Carbapenem resistance among gram-negative bacilli is an emerging threat worldwide. The objective of this study was to identify risk factors for the acquisition of carbapenem-resistant Escherichia coli (CRE). METHODS We conducted a matched case-control study comprising 57 cases of acquisition of CRE and 114 controls (1:2 matched) selected from patients with a culture of carbapenem-susceptible E coli between January 2006 and December 2010 at a 2000-bed tertiary care center in South Korea. RESULTS On univariate analysis, previous use of carbapenem (P < .01), fluoroquinolone (P < .01), and glycopeptide (P < .01), as well as length of hospital stay (P < .05), were significantly associated with CRE acquisition. On multivariate analysis, previous use of carbapenem (odds ratio [OR], 4.56; 95% confidence interval [CI] 1.44-14.46; P = .01) and previous use of fluoroquinolone (OR, 2.81; 95% CI, 1.14-6.99; P = .03) were independent risk factors. CONCLUSIONS At this institute, the antibiotic selective pressure of carbapenems and fluoroquinolones was shown to be an important risk factor for the acquisition of CRE.

The C-Reactive Protein/Albumin Ratio as an Independent Predictor of Mortality in Patients with Severe Sepsis or Septic Shock Treated with Early Goal-Directed Therapy

Background Sepsis, including severe sepsis and septic shock, is a major cause of morbidity and mortality. Albumin and C-reactive protein (CRP) are considered as good diagnostic markers for sepsis. Thus, initial CRP and albumin levels were combined to ascertain their value as an independent predictor of 180-day mortality in patients with severe sepsis and septic shock. Materials and Methods We conducted a retrospective cohort study involving 670 patients (>18 years old) who were admitted to the emergency department and who had received a standardized resuscitation algorithm (early goal-directed therapy) for severe sepsis and septic shock, from November 2007 to February 2013, at a tertiary hospital in Seoul, Korea. The outcome measured was 180-day all-cause mortality. A multivariate Cox proportional hazard model was used to identify the independent risk factors for mortality. A receiver operating characteristic (ROC) curve analysis was conducted to compare the predictive accuracy of the CRP/albumin ratio at admission. Results The 180-day mortality was 28.35% (190/670). Based on the multivariate Cox proportional hazard analysis, age, the CRP/albumin ratio at admission (adjusted HR 1.06, 95% CI 1.03–1.10, p<0.001), lactate level at admission (adjusted HR 1.10, 95% CI 1.05–1.14, p<0.001), and the Sequential Organ Failure Assessment (SOFA) score at admission (adjusted HR 1.12, 95% CI 1.07–1.18, p<0.001) were independent predictors of 180-day mortality. The area under the curve of CRP alone and the CRP/albumin ratio at admission for 180-day mortality were 0.5620 (P<0.001) and 0.6211 (P<0.001), respectively. Conclusion The CRP/albumin ratio was an independent predictor of mortality in patients with severe sepsis or septic shock.

HIV‐associated neurocognitive disorder in HIV‐infected Koreans: the Korean NeuroAIDS Project

HIV‐associated neurocognitive disorder (HAND) is an independent predictor of early mortality and is associated with many difficulties in activities of daily living. We sought to determine the prevalence of and risk factors for HAND in HIV‐infected Koreans. In addition, we investigated the performance of screening tools and components of neuropsychological (NP) tests for diagnosing HAND.

Risk factors for 28-day mortality in elderly patients with extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae bacteremia.

Gram-negative bacteremia is common in elderly patients and, compared with younger patients, mortality rates in bacteremic elderly patients are high. ESBL-producing organisms were one of the most important risk factors associated with mortality. In addition, older age is one of risk factors for colonization or infection with ESBL-producing organisms. We conducted a retrospective cohort study to evaluate risk factors of all-cause 28-day mortality in elderly patients with ESBL-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) bacteremia. Patients aged 65 years or older, who had one or more blood cultures positive for E. coli and K. pneumoniae and who were hospitalized between January 2006 and December 2010 at a tertiary-care teaching hospital, were included. 191 bacteremic elderly patients were eligible for the study. The all-cause 28-day mortality rate was 24.6% (47/191). In multivariate analysis, prior antimicrobial therapy (p=0.014) and an elevated SOFA score (p<0.001) were independent risk factors for increased mortality, while urinary tract infection (UTI) was an independent determinant for non-mortality (p=0.011). In the current study, prior antimicrobial therapy within 30 days, an elevated SOFA score and nonurinary source of infection were significantly associated with adverse outcomes in elderly patients with ESBL-producing gram-negative bacteremia.

Characteristics of Resting-State Functional Connectivity in HIV-Associated Neurocognitive Disorder.

Background HIV-associated neurocognitive disorder (HAND) can occur in patients without prior AIDS defining illness and can be debilitating. This study aimed to evaluate the difference in the patterns of intrinsic brain activity between patients with or without HAND for deepening our understanding of HAND. Methods We evaluated 24 HIV-infected individuals, 12 with previously diagnosed HAND and 12 previously diagnosed without HAND, and 11 seronegative individuals. These individuals then underwent repeat NP testing and a functional brain MRI scan. For functional MRI analysis, seed-based analysis with bilateral precuneus cortex seed was applied. Results Among the 12 individuals with previously diagnosed HAND, 3 showed improvement of their neurocognitive function and 1 was excluded for worsening liver disease. Among the 12 patients who previously had normal neurocognitive function, 2 showed neurocognitive impairment. Overall, the HAND group, who had impaired cognitive function at the time of MRI scan, showed significant decrease of resting status functional connectivity between bilateral precuneus and prefrontal cortex (PFC) compared with nonHAND group, those who had normal neurocognitive function (Corrected P<0.05). The functional connectivity with the right inferior frontal operculum and right superior frontal gyrus was positively correlated with memory and learning ability. Conclusions This cross-sectional study found a significant difference in fMRI patterns between patients with and without HAND. Decreased functional connectivity between precuneus and PFC could be possible functional substrate for cognitive dysfunction in HIV patients, which should be characterized in a longitudinal study.

Utility of the Montreal Cognitive Assessment (MoCA) and its subset in HIV-associated neurocognitive disorder (HAND) screening

OBJECTIVES The Montreal Cognitive Assessment (MoCA) is a useful screening tool for mild cognitive impairment. We aimed to know whether the full MoCA and subsets of the full test are effective for detecting HIV-associated neurocognitive disorder (HAND). METHODS We examined the socio-demographic, clinical, functional, and neuropsychological levels of 194 HIV-infected patients. We compared total scores and scores from each cognitive domain of MoCA between patients with and without HAND. We also examined the utility of subsets of the full test using a few selective domains. The diagnostic accuracies of MoCA and subset composition were evaluated. RESULTS The total scores of MoCA (P<0.001) and scores from Trail Making Test-B (P=0.020), attention domain (P=0.005), and immediate (P=0.003) and delayed recall (P=0.002) differed between patients with and without HAND. A subset composed of Trail Making Test-B, rescored serial subtraction, and immediate/delayed recall showed a 69.2% accuracy. CONCLUSIONS Our results suggest that the MoCA and its subsets alone are not sufficient in screening for HAND. Further studies will be needed to develop a simpler and easier screening tool for HAND based on this study.

Mathematical Modeling of HIV Prevention Measures Including Pre-Exposure Prophylaxis on HIV Incidence in South Korea

Background Multiple prevention measures have the possibility of impacting HIV incidence in South Korea, including early diagnosis, early treatment, and pre-exposure prophylaxis (PrEP). We investigated how each of these interventions could impact the local HIV epidemic, especially among men who have sex with men (MSM), who have become the major risk group in South Korea. A mathematical model was used to estimate the effects of each these interventions on the HIV epidemic in South Korea over the next 40 years, as compared to the current situation. Methods We constructed a mathematical model of HIV infection among MSM in South Korea, dividing the MSM population into seven groups, and simulated the effects of early antiretroviral therapy (ART), early diagnosis, PrEP, and combination interventions on the incidence and prevalence of HIV infection, as compared to the current situation that would be expected without any new prevention measures. Results Overall, the model suggested that the most effective prevention measure would be PrEP. Even though PrEP effectiveness could be lessened by increased unsafe sex behavior, PrEP use was still more beneficial than the current situation. In the model, early diagnosis of HIV infection was also effectively decreased HIV incidence. However, early ART did not show considerable effectiveness. As expected, it would be most effective if all interventions (PrEP, early diagnosis and early treatment) were implemented together. Conclusions This model suggests that PrEP and early diagnosis could be a very effective way to reduce HIV incidence in South Korea among MSM.

Incidence of and risk factors for infectious complications in patients with cardiac device implantation

OBJECTIVES The use of cardiac implantable electronic device (CIED; pacemakers, implantable cardioverter-defibrillators [ICD], cardiac re-synchronized therapy [CRT]) implantation, one essential treatment for cardiac arrhythmias, is increasing. Infectious complications related to implants are the main reason for device removal and patient morbidity. We sought to identify the incidence of infectious complications among patients with cardiac device implantation and analyze the risk factors for infectious complications. METHODS A retrospective analysis was conducted of 1307 patients (61.5±14.2 years-old, 49.6% male) with cardiac device implantation from January 1990 to April 2013. We analyzed the incidence of infectious complications during the follow-up period. To investigate risk factors associated with infectious complications, we conducted a 1:2 matched case-control study of patients with infectious complications and controls without infectious complications who had the same implantation period and physician. RESULTS Among 1307 patients, 12 had a confirmed device-related infection: 7 with a pocket infection and 5 with infective endocarditis. Over a total of 9091.9 device-years, the incidence of infectious complications was 1.3/1000 device-years, based on the 12 patients with an infection. ICD (5.1/1000 device-year) had a higher incidence of infectious complications than other cardiac devices, and no infectious complications were observed among patients with CRT implantation. Mean duration from the time of implantation to infection was 2.02±1.65 years. In a multivariate analysis, the number of prior procedures including wound revision or scar revision was an independent risk factor for infectious complications (OR=10.88, 95% CI 1.11->999, p=0.040). CONCLUSIONS Infection was a rare complication of cardiac device implantation, but repeated procedures were associated with infectious complications.

Risk Factors for Mortality in Patients with Serratia marcescens Bacteremia

Purpose Over the last 30 years, Serratia marcescens (S. marcescens) has emerged as an important pathogen, and a common cause of nosocomial infections. The aim of this study was to identify risk factors associated with mortality in patients with S. marcescens bacteremia. Materials and Methods We performed a retrospective cohort study of 98 patients who had one or more blood cultures positive for S. marcescens between January 2006 and December 2012 in a tertiary care hospital in Seoul, South Korea. Multiple risk factors were compared with association with 28-day all-cause mortality. Results The 28-day mortality was 22.4% (22/98 episodes). In a univariate analysis, the onset of bacteremia during the intensive care unit stay (p=0.020), serum albumin level (p=0.011), serum C-reactive protein level (p=0.041), presence of indwelling urinary catheter (p=0.023), and Sequential Oran Failure Assessment (SOFA) score at the onset of bacteremia (p<0.001) were significantly different between patients in the fatal and non-fatal groups. In a multivariate analysis, lower serum albumin level and an elevated SOFA score were independently associated with 28-day mortality [adjusted odds ratio (OR) 0.206, 95% confidential interval (CI) 0.044-0.960, p=0.040, and adjusted OR 1.474, 95% CI 1.200-1.810, p<0.001, respectively]. Conclusion Lower serum albumin level and an elevated SOFA score were significantly associated with adverse outcomes in patients with S. marcescens bacteremia.