Risk factors and mortality of nosocomial infections of methicillin-resistant Staphylococcus aureus in an intensive care unit

Changes in tidal breathing biomarkers as indicators of treatment response in AECOPD patients in an acute care setting

PURPOSE

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a complication of COPD that typically necessitates intensified treatment and hospitalization. It is linked to higher morbidity, mortality and healthcare spending. Assessment of therapy response for AECOPD is difficult due to the variability of symptoms and limitations in current measures. Hence, there is a need for new biomarkers to aid in the management of AECOPD in acute care settings.

MATERIALS AND METHODS

Fifteen hospitalized AECOPD patients (GOLD 3-4) were enrolled in this study. Treatment response was assessed daily through clinical evaluations and by monitoring tidal breathing biomarkers (respiratory rate [RR], expiratory time [Tex], inspiratory time [Tin], expiratory pause [Trst], total breath time [Ttot]), using a novel, wearable nanosensor-based device (SenseGuard™).

RESULTS

Patients who showed significant clinical improvement had substantial changes in ΔTex/Ttot (+14%), ΔTrst/Ttot (-18%), and ΔTin/Tex (+0.09), whereas patients who showed mild or no clinical improvement had smaller changes (+5%, +3%, and -0.03, respectively). Linear regression between change in physician's assessment score and the median change in tidal breathing parameters was significant for Tin/Tex (R2 ​= ​0.449, ∗p ​= ​0.017), Tex/Ttot (R2 ​= ​0.556, ∗p ​= ​0.005) and Trst/Ttot (R2 ​= ​0.446, ∗p ​= ​0.018), while no significant regression was observed for RR, Tin/(Trst ​+ ​Tex) and Tin/Ttot.

CONCLUSIONS

Our study demonstrates the potential of the SenseGuard™ to monitor treatment response in AECOPD patients by measuring changes in tidal breathing biomarkers, which were shown to be associated with significant changes in the patients' respiratory condition as evaluated by physicians. However, further large-scale clinical studies are needed to confirm these findings.

Association of Glasgow coma scale and endotracheal intubation in predicting mortality among patients admitted to the intensive care unit

BACKGROUND

We assessed predictors of mortality in the intensive care unit (ICU) and investigated if Glasgow coma scale (GCS) is associated with mortality in patients undergoing endotracheal intubation (EI).

METHODS

From February 2020, we performed a 1-year study on 2,055 adult patients admitted to the ICU of two teaching hospitals. The outcome was mortality during ICU stay and the predictors were patients' demographic, clinical, and laboratory features.

RESULTS

EI was associated with a decreased risk for mortality compared with similar patients (adjusted odds ratio [AOR], 0.32; P=0.030). This shows that EI had been performed correctly with proper indications. Increasing age (AOR, 1.04; P<0.001) or blood pressure (AOR, 1.01; P<0.001), respiratory problems (AOR, 3.24; P<0.001), nosocomial infection (AOR, 1.64; P=0.014), diabetes (AOR, 5.69; P<0.001), history of myocardial infarction (AOR, 2.52; P<0.001), chronic obstructive pulmonary disease (AOR, 3.93; P<0.001), immunosuppression (AOR, 3.15; P<0.001), and the use of anesthetics/sedatives/hypnotics for reasons other than EI (AOR, 4.60; P<0.001) were directly; and GCS (AOR, 0.84; P<0.001) was inversely related to mortality. In patients with trauma surgeries (AOR, 0.62; P=0.014) or other surgical categories (AOR, 0.61; P=0.024) undergoing EI, GCS had an inverse relation with mortality (accuracy=82.6%, area under the receiver operator characteristic curve=0.81).

CONCLUSIONS

A variety of features affected the risk for mortality in patients admitted to the ICU. Considering GCS score for EI had the potential of affecting prognosis in subgroups of patients such as those with trauma surgeries or other surgical categories.

ICU-acquired central line-associated bloodstream infection and its associated factors in Oman

BACKGROUND

Despite the extensive use of central lines for ICU patients in Oman, no studies have been conducted among adult ICU patients to assess the prevalence, and predictors of CLABSIs.

AIM

To estimate the prevalence of ICU-acquired CLABSIs, identify the most common causative microorganisms, and define possible related risk factors associated with ICU-acquired CLABSIs among adult ICU patients in Oman.

METHOD

A retrospective case-control design was used to screen electronic medical records of for all adult ICU patients admitted over 2 years (2018-2019) in 2 tertiary hospitals in Oman. The CDC definition of CLABSIs was used to allocate a cases group (n = 58), and a randomly selected controls group (n = 174).

RESULTS

The prevalence of ICU-acquired CLABSIs was 8.9 and 8.31 per 1,000 catheter days for the years 2018 and 2019 respectively. The most common isolated microorganisms were gram-positive bacteria (46.6%). The risk factors for ICU-acquired CLABSIs are: heart failure (Odds Ratio [OR] = 11.67, P < .001), female gender (OR = 0.352, P = .035), presence of other infections (OR = 3.4, P = .009), tracheostomy (OR = 5.34, P = .004), and Total Parenteral Nutrition (OR = 3.469, P = .020).

CONCLUSIONS

The prevalence of ICU-acquired CLABSIs in developing countries like Oman is higher than most of developed countries. The current study provides baseline data that can be used as a reference for future national studies and help in building strategies to prevent and control ICU-acquired CLABSIs.

Effects of the proportion of high-risk patients and control strategies on the prevalence of methicillin-resistant Staphylococcus aureus in an intensive care unit

Background

The presence of nosocomial pathogens in many intensive care units poses a threat to patients and public health worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen endemic in many hospital settings. Patients who are colonized with MRSA may develop an infection that can complicate their prior illness.

Methods

A mathematical model to describe transmission dynamics of MRSA among high-risk and low-risk patients in an intensive care unit (ICU) via hands of health care workers is developed. We aim to explore the effects of the proportion of high-risk patients, the admission proportions of colonized and infected patients, the probability of developing an MRSA infection, and control strategies on MRSA prevalence among patients.

Results

The increasing proportion of colonized and infected patients at admission, along with the higher proportion of high-risk patients in an ICU, may significantly increase MRSA prevalence. In addition, the prevalence becomes higher if patients in the high-risk group are more likely to develop an MRSA infection. Our results also suggest that additional infection prevention and control measures targeting high-risk patients may considerably help reduce MRSA prevalence as compared to those targeting low-risk patients.

Conclusions

The proportion of high-risk patients and the proportion of colonized and infected patients in the high-risk group at admission may play an important role on MRSA prevalence. Control strategies targeting high-risk patients may help reduce MRSA prevalence.

Preadmission chronic opioid usage and its association with 90-day mortality in critically ill patients: a retrospective cohort study

BACKGROUND

The aim of this study was to investigate the association of chronic opioid usage with 90-day mortality in critically ill patients after admission to the ICU.

METHODS

This retrospective cohort study analysed the medical records of adult patients admitted to ICUs in a tertiary academic hospital between January 2012 and December 2017. Patients taking opioids regularly for more than 4 weeks before ICU admission were defined as chronic opioid users, whereas the others were defined as opioid-naïve patients.

RESULTS

We selected 18 409 patients for this study, including 757 (4.1%) chronic opioid users. After propensity matching, 2990 patients (chronic opioid users, 757; opioid-naïve, patient: 2233) were included in the analysis. The odds of 90-day mortality were higher in chronic opioid users than in opioid-naïve patients using both the generalised estimating equation model for the propensity-matched cohort (odds ratio=1.90; 95% confidence interval, 1.57-2.31; P<0.001) and the multivariable logistic regression model for the entire cohort (odds ratio=2.20; 95% confidence interval, 1.81-2.66; P<0.001). Additionally, this association was significant in cancer patients and non-chronic kidney disease (CKD) patients and was not significant in non-cancer and CKD patients.

CONCLUSIONS

Our results suggest that in a cohort of critically ill adult patients, chronic opioid use is associated with an increase in 90-day mortality. This association was more evident in cancer patients and non-CKD patients.

Risk factors of mortality in nosocomial infected traumatic patients in a trauma referral center in south of Iran

PURPOSE

Trauma-related injuries are the leading cause of death worldwide. Some risk factors make traumatic patients susceptible to infection. Furthermore, some mortality risk factors, including length of hospitalization and increasing age, were detected in non-traumatic infected patients. This study aimed to assess mortality risk factors among nosocomial infected traumatic patients in Rajaee trauma center, Shiraz, Iran.

METHODS

This prospective cohort study was conducted during a period of 2 years since April 2015 to March 2017 in Rajaee hospital, which is the center of emergency medical services for traumatic injuries in Shiraz, Iran. Centers for Disease Control and Prevention/National Healthcare Safety Network surveillance system criteria were applied to define 5 types of nosocomial infections. The variables analyzed as the risk factors of infection and mortality included sex, age, mechanism of injury, site of injury, injury severity score (ISS), surgical intervention, length of hospitalization, intensive care unit (ICU) admission, and type of pathogen. Then, the incidence of nosocomial infection and also risk factors of mortality in traumatic patients were evaluated. All data analyses were performed using the statistical package for social sciences, version 15 (SPSS Inc., Chicago) and p ≤ 0.05 is considered to be statistically significant.

RESULTS

The incidence of nosocomial infection was 7.2% (p < 0.001). Pneumonia was the most common type of infection detected in our study. Infection led to a 7.8-fold increase in mortality of the traumatic patients (p < 0.001). Admission in intensive care units and old age were the main risk factors of mortality in infected traumatic patients. Old age, gunshot and motor vehicle accidents, trauma to extremities and abdomen, higher injury severity score, and prolonged hospitalization, made the traumatic patients more susceptible to infection.

CONCLUSION

The really high incidence of nosocomial infection in traumatic patients in Iran depends on some risk factors that should be considered. Also infection increases the mortality rate in the traumatic patients, which could be reduced by eliminating its risk factors.

Central line-associated bloodstream infections in Australian ICUs: evaluating modifiable and non-modifiable risks in Victorian healthcare facilities

Central line-associated bloodstream infections (CLABSIs) in intensive care units (ICUs) result in poor clinical outcomes and increased costs. Although frequently regarded as preventable, infection risk may be influenced by non-modifiable factors. The objectives of this study were to evaluate organisational factors associated with CLABSI in Victorian ICUs to determine the nature and relative contribution of modifiable and non-modifiable risk factors. Data captured by the Australian and New Zealand Intensive Care Society regarding ICU-admitted patients and resources were linked to CLABSI surveillance data collated by the Victorian Healthcare Associated Infection Surveillance System between 1 January 2010 and 31 December 2013. Accepted CLABSI surveillance methods were applied and hospital/patient characteristics were classified as 'modifiable' and 'non-modifiable', enabling longitudinal Poisson regression modelling of CLABSI risk. In total, 26 ICUs were studied. Annual CLABSI rates were 1·72, 1·37, 1·00 and 0·93/1000 CVC days for 2010-2013. Of non-modifiable factors, the number of non-invasively ventilated patients standardised to total ICU bed days was found to be independently associated with infection (RR 1·07; 95% CI 1·01-1·13; P = 0·030). Modelling of modifiable risk factors demonstrated the existence of a policy for mandatory ultrasound guidance for central venous catheter (CVC) localisation (RR 0·51; 95% CI 0·37-0·70; P < 0·001) and increased number of sessional specialist full-time equivalents (RR 0·52; 95% CI 0·29-0·93; P = 0·027) to be independently associated with protection against infection. Modifiable factors associated with reduced CLABSI risk include ultrasound guidance for CVC localisation and increased availability of sessional medical specialists.

Staphylococcal enterotoxin P predicts bacteremia in hospitalized patients colonized with methicillin-resistant Staphylococcus aureus

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) colonization predicts later infection, with both host and pathogen determinants of invasive disease.

METHODS

This nested case-control study evaluates predictors of MRSA bacteremia in an 8-intensive care unit (ICU) prospective adult cohort from 1 September 2003 through 30 April 2005 with active MRSA surveillance and collection of ICU, post-ICU, and readmission MRSA isolates. We selected MRSA carriers who did (cases) and those who did not (controls) develop MRSA bacteremia. Generating assembled genome sequences, we evaluated 30 MRSA genes potentially associated with virulence and invasion. Using multivariable Cox proportional hazards regression, we assessed the association of these genes with MRSA bacteremia, controlling for host risk factors.

RESULTS

We collected 1578 MRSA isolates from 520 patients. We analyzed host and pathogen factors for 33 cases and 121 controls. Predictors of MRSA bacteremia included a diagnosis of cancer, presence of a central venous catheter, hyperglycemia (glucose level, >200 mg/dL), and infection with a MRSA strain carrying the gene for staphylococcal enterotoxin P (sep). Receipt of an anti-MRSA medication had a significant protective effect.

CONCLUSIONS

In an analysis controlling for host factors, colonization with MRSA carrying sep increased the risk of MRSA bacteremia. Identification of risk-adjusted genetic determinants of virulence may help to improve prediction of invasive disease and suggest new targets for therapeutic intervention.

On the role of length of stay in healthcare-associated bloodstream infection

DESIGN

We conducted a retrospective cohort study to examine the role played by length of hospital stay in the risk of healthcare-associated bloodstream infection (BSI), independent of demographic and clinical risk factors for BSI.

PATIENTS

We employed data from 113,893 admissions from inpatients discharged between 2006 and 2008.

SETTING

Large tertiary healthcare center in New York City.

METHODS

We estimated the crude and adjusted hazard of BSI by conducting logistic regression using a person-day data structure. The covariates included in the fully adjusted model included age, sex, Charlson score of comorbidity, renal failure, and malignancy as static variables and central venous catheterization, mechanical ventilation, and intensive care unit stay as time-varying variables.

RESULTS

In the crude model, we observed a nonlinear increasing hazard of BSI with increasing hospital stay. This trend was reduced to a constant hazard when fully adjusted for demographic and clinical risk factors for BSI.

CONCLUSION

The association between longer length of hospital stay and increased risk of infection can largely be explained by the increased duration of stay among those who have underlying morbidity and require invasive procedures. We should take caution in attributing the association between length of stay and BSI to a direct negative impact of the healthcare environment.

Characteristics of hospital patients colonized with livestock-associated meticillin-resistant Staphylococcus aureus (MRSA) CC398 versus other MRSA clones

Meticillin-resistant Staphylococcus aureus (MRSA) associated with the clonal complex (CC) 398 has emerged among livestock and humans exposed to these animals. MRSA CC398 has so far contributed relatively little to spread of MRSA and the burden of disease in the healthcare setting. This study aimed to assess whether demographic and clinical differences in patients colonized with MRSA CC398 and those carrying other MRSA clones contribute to the observed differences in transmission and infection rates. Age, sex, length of stay (LOS), diagnoses and medical procedures were assessed in all patients with MRSA admitted to a university hospital in 2008 and 2009. S. aureus protein A gene (spa) typing was performed on the first MRSA isolate from each patient. Patients colonized or infected with MRSA that had spa types indicative of CC398 (MRSA CC398) were compared with patients who had other MRSA clones (MRSA non-CC398). Age (53 vs 59 years), mean LOS (8 vs 13 days) and percentage of patients admitted to an intensive care unit (12% vs 17%) differed significantly between MRSA CC398 and MRSA non-CC398 patients, respectively. The mean numbers and types of diagnoses and medical procedures performed for patients in these two groups also differed significantly. The differences in patient characteristics could explain, at least in part, the relatively low rates of transmission and infection associated with MRSA CC398 in the healthcare setting.