Intensive care unit acquired infection: a prevalence and impact on morbidity and mortality

Epidemiology of Intensive Care Unit-acquired Infections in a Tertiary Care Hospital of North India

Background

The majority of nosocomial infections in the hospital setting are found in intensive care units (ICUs). The present study was undertaken to determine the incidence, risk factors, causative microorganisms, and outcome of various ICU-acquired infections.

Materials and methods

The patients admitted to the ICU of a teaching hospital in North India were prospectively studied. Detailed history, clinical examination, acute physiology and chronic health evaluation score II, simplified acute physiology score II, sequential organ failure assessment score, and baseline investigations were recorded. Patients were assessed daily till 14th day for nosocomial infection as per Centers for Disease Control and Prevention (CDC) guidelines and were followed till death or discharge. Incidence, risk factors, and outcome parameters were calculated using Student t-test, Chi-square test, and stepwise multivariate logistic regression model.

Results

The overall incidence rate of ICU infections was 27.9%. The most common ICU-acquired infection was ventilator-associated pneumonia followed by catheter-related bloodstream infection and catheter-associated urinary tract infection. Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae were implicated in most of the infections. ICU length of stay (LOS) >7 days, neurological dysfunction, endotracheal intubation, ischemic heart disease, and use of antacids/H₂ blockers were significantly associated with ICU-acquired infections. The mortality rate was 32.8 and 28.8% in patients with and without ICU infections, respectively (p = 0.531). The ICU LOS (19.23 ± 12.79 days) was significantly higher in the ICU infections group (p <0.001).

Conclusion

Ventilator-associated pneumonia was the most common nosocomial infection in our study. Gram-negative microorganisms were the predominant causative agents for various ICU-acquired infections. Mortality was not found to be affected but ICU LOS was significantly prolonged as a consequence of the development of ICU-acquired infection.

How to cite this article

Kumar A, Chaudhry D, Goel N, Tanwar S. Epidemiology of Intensive Care Unit-acquired Infections in a Tertiary Care Hospital of North India. Indian J Crit Care Med 2021;25(12):1427-1433.

Using smart speakers to contactlessly monitor heart rhythms

Heart rhythm assessment is indispensable in diagnosis and management of many cardiac conditions and to study heart rate variability in healthy individuals. We present a proof-of-concept system for acquiring individual heart beats using smart speakers in a fully contact-free manner. Our algorithms transform the smart speaker into a short-range active sonar system and measure heart rate and inter-beat intervals (R-R intervals) for both regular and irregular rhythms. The smart speaker emits inaudible 18–22 kHz sound and receives echoes reflected from the human body that encode sub-mm displacements due to heart beats. We conducted a clinical study with both healthy participants and hospitalized cardiac patients with diverse structural and arrhythmic cardiac abnormalities including atrial fibrillation, flutter and congestive heart failure. Compared to electrocardiogram (ECG) data, our system computed R-R intervals for healthy participants with a median error of 28 ms over 12,280 heart beats and a correlation coefficient of 0.929. For hospitalized cardiac patients, the median error was 30 ms over 5639 heart beats with a correlation coefficient of 0.901. The increasing adoption of smart speakers in hospitals and homes may provide a means to realize the potential of our non-contact cardiac rhythm monitoring system for monitoring of contagious or quarantined patients, skin sensitive patients and in telemedicine settings.

Anran Wang et al. present a contact-free method of monitoring individual heart beats by converting smart-speakers into active sonar systems. Their approach is capable of measuring heart rhythms with high accuracy in both healthy participants and hospitalized patients, and may be a useful healthcare tool for remote diagnosis or patient monitoring.

Pseudomonas aeruginosa infection in intensive care: Epidemiology, outcomes, and antimicrobial susceptibilities

BACKGROUND

Pseudomonas aeruginosa (PA) infection in the intensive care unit (ICU) contributes to substantial mortality. In this study, we describe the epidemiology, antimicrobial susceptibilities, and outcomes of ICU patients with pseudomonal infection.

METHODS

ICU patients with PA were identified and classified as colonized or infected. Infected patients were reviewed for source, patient characteristics, antimicrobial susceptibilities, appropriateness of empiric antimicrobial therapy, and 30-day mortality. Independent predictors of mortality were identified using multivariable logistic regression.

RESULTS

One hundred forty (71%) patients with PA were infected. Mean patient age was 55 (SD 18) years; 62% were male. Admission categories included medical (71%), surgical (20%), and trauma or neurological (9%). Mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 19 (SD 10). One hundred twenty-six (90%) patients were mechanically ventilated, 102 (73%) required vasopressors, and 27 (19%) received renal replacement; 32 (23%) died within 30 days. Infection was nosocomial in 101 (72%) cases. Sources were respiratory (66%), skin-soft tissue (11%), urinary (10%), blood (5%), surgical (5%), gastrointestinal (2%), or unknown (1%). Twenty (14%) isolates were multi-drug resistant; 6 (4%) were extensively drug resistant. Empiric antimicrobial therapy was effective in 97 (69%) cases. Liver disease (adjusted OR [aOR] 6.2, 95% CI 1.5 to 25.7; p = 0.01), malignancy (aOR 5.0, 95% CI 1.5 to 17.3; p = 0.01), and higher APACHE II score (aOR 1.1, 95% CI 1.0 to 1.1; p = 0.02) were independently associated with 30-day mortality.

CONCLUSIONS

PA infection in ICU is most commonly respiratory and associated with substantial mortality. Existing malignancy, liver disease, and higher APACHE II score were independently associated with mortality.

Preclinical Evaluation of a Noncontact Simultaneous Monitoring Method for Respiration and Carotid Pulsation Using Impulse-Radio Ultra-Wideband Radar

There has been the possibility for respiration and carotid pulsation to be simultaneously monitored from a distance using impulse-radio ultra-wideband (IR-UWB) radar. Therefore, we investigated the validity of simultaneous respiratory rates (RR), pulse rates (PR) and R-R interval measurement using IR-UWB radar. We included 19 patients with a normal sinus rhythm (NSR) and 14 patients with persistent atrial fibrillation (PeAF). The RR, PR, R-R interval and rhythm were obtained simultaneously from the right carotid artery area in a supine position and under normal breathing conditions using IR-UWB radar. There was excellent agreement between the RR obtained by IR-UWB radar and that manually counted by a physician (intraclass correlation coefficient [ICC] 0.852). In the NSR group, there was excellent agreement between the PR (ICC 0.985), average R-R interval (ICC 0.999), and individual R-R interval (ICC 0.910) measured by IR-UWB radar and electrocardiography. In the PeAF group, PR (ICC 0.930), average R-R interval (ICC 0.957) and individual R-R interval (ICC 0.701) also agreed well between the two methods. These results demonstrate that IR-UWB radar can simultaneously monitor respiration, carotid pulse and heart rhythm with high precision and may thus be utilized as a noncontact continuous vital sign monitoring in clinical practice.

Emergence of antibiotic resistance Pseudomonas aeruginosa in intensive care unit; a critical review

The emergence of antibiotic resistant bacteria in the healthcare is a serious concern. In the Healthcare premises precisely intensive care unit are major sources of microbial diversity. Recent findings have demonstrated not only microbial diversity but also drug resistant microbes largely habitat in ICU. Pseudomonas aeruginosa found as a part of normal intestinal flora and a significant pathogen responsible for wide range of ICU acquired infection in critically ill patients. Nosocomial infection associated with this organism including gastrointestinal infection, urinary tract infections and blood stream infection. Infection caused by this organism are difficult to treat because of the presence of its innate resistance to many antibiotics (β-lactam and penem group of antibiotics), and its ability to acquire further resistance mechanism to multiple class of antibiotics, including Beta-lactams, aminoglycosides and fluoroquinolones. In the molecular evolution microbes adopted several mechanism to maintain genomic plasticity. The tool microbe use for its survival is mainly biofilm formation, quorum sensing, and horizontal gene transfer and enzyme promiscuity. Such genomic plasticity provide an ideal habitat to grow and survive in hearse environment mainly antibiotics pressure. This review focus on infection caused by Pseudomonas aeruginosa, its mechanisms of resistance and available treatment options. The present study provides a systemic review on major source of Pseudomonas aeruginosa in ICU. Further, study also emphasizes virulence gene/s associated with Pseudomonas aeruginosa genome for extended drug resistance. Study gives detailed overview of antibiotic drug resistance mechanism.

A Novel Non-contact Heart Rate Monitor Using Impulse-Radio Ultra-Wideband (IR-UWB) Radar Technology

We discovered that impulse-radio ultra-wideband (IR-UWB) radar could recognize cardiac motions in a non-contact fashion. Therefore, we measured the heart rate (HR) and rhythms using an IR-UWB radar sensor and evaluated the validity and reliability of the measurements in comparison to electrocardiography. The heart beats were measured in 6 healthy volunteers (18 samples) with normal sinus rhythm (NSR) and 16 patients (36 samples) with atrial fibrillation (AF) using both an IR-UWB radar sensor and electrocardiography simultaneously. The participants hold their breath for 20 seconds during the data acquisition. In subjects with NSR, there was excellent agreement of HR (intraclass correlation coefficient [ICC] 0.856), average R-R interval (ICC 0.997) and individual R-R intervals between the two methods (ICC 0.803). In subjects with AF, HR (ICC 0.871) and average R-R interval (ICC 0.925) from the radar sensor also agreed well with those from electrocardiography, though there was a small disagreement in the individual R-R intervals between the two methods (ICC 0.697). The rhythms computed by the signal-processing algorithm showed good agreement between the two methods (Cohen’s Kappa 0.922). The IR-UWB radar sensor is precise and accurate for assessing HR and rhythms in a non-contact fashion.

Impact of garlic tablets on nosocomial infections in hospitalized patients in intensive care units

Background

Nosocomial infections are one of the main causes of mortality and morbidity in hospitals, especially in intensive care units (ICUs).

Objective

The aim of this study was to examine the impact of garlic tablets on nosocomial infections in hospitalized patients in intensive care units.

Methods

This clinical trial was carried out on 94 patients, admitted to the intensive care units in Kashani and Al-Zahra hospitals from January 21, 2014 to December 20, 2014. Firstly, the patients were randomly selected by simple sampling, then they were assigned into case and control groups. The case group administered one 400 mg garlic tablet daily for 6 days and the control group received placebo. During the study, inflammatory blood factors and infection occurrence in the two groups were compared. The Data were analyzed by SPSS software version 22 through descriptive tests such as independent t-test, Chi-square test, ANOVA and exact Fisher test for the analyses of primary and secondary outcomes.

Results

During the study period, 78 cases of intravenous catheter tip were sent to laboratory for culture, of which, 37 cases were in the intervention group and 41 in the control group. Culture results of Catheter tips was positive in 5 cases and all five cases were in the control group. Frequency distribution of catheter tip culture was significantly higher in the control group than that of the intervention group (p=0.03).

Conclusion

Based on the results of our study, in people with weakened immune systems and in people with high incidence of opportunistic infections, it is necessary to strengthen their body’s immune system stimulants before dealing with these infectious agents, and cause decrease in the diseases insusceptible people. It was suggested that garlic supplementation has shown to be effective in patients admitted to ICU, who are highly susceptible to nosocomial infection, and it can be used for the prevention of septicemia and urinary tract infections. However, further research with larger sample size is needed.

Trial registration

The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT207406156480N6.

Funding

Shahrekord University of Medical Sciences financially supported this research.

Epidemiology, associated factors and outcomes of ICU-acquired infections caused by Gram-negative bacteria in critically ill patients: an observational, retrospective study

BACKGROUND

Gram-negative bacteria are increasingly responsible for nosocomial infections, including ICU-acquired infections. Due to high virulence, rate of multi-drug resistance and limited availability of new agents, these infections create cumbersome clinical burdens, making it important to reduce the risk of their occurrence. The aim of the study was to assess epidemiology-related factors and outcomes of Gram-negative, ICU-acquired infections in a cohort of medical-surgical patients.

METHODS

A retrospective survey was conducted on all patients admitted to a mixed ICU from January 2012 to December 2013. 'ICU-acquired infections' were defined as new infections acquired no less than 48 h after ICU admission. Diagnosis was made according to the Centers for Disease Control and Prevention National Healthcare Safety Network (CDC/NHSN) criteria. Differences across patients who did and did not acquire a Gram-negative infection were tested regarding age, sex, body mass index, medical or surgical admission, cardiovascular comorbidities, chronic obstructive pulmonary disease, diabetes, end-stage renal failure, co-existing tumours and prophylactic anti-fungal treatment. Multivariate analysis was used to assess the independency of these associations. Finally, differences in ICU-mortality, ICU-length of stay and duration of mechanical ventilation were tested across patients with and without new, ICU-acquired, Gram-negative infections.

RESULTS

Of 494 patients admitted to the ICU, 46 (9.3 %) acquired an infection 48 or more hours after admittance. In 30/46 patients (65.2 %) the isolated bacterium was Gram-negative. Univariate analysis showed that clinical factors associated with new ICU-acquired Gram-negative infections were medical admission (p < 0.001, 95 % CI 0.59 - 0.29, OR = 0.13), chronic kidney disease (p = 0.018, 95 % CI 1.20 - 7.34, OR = 2.98) and prophylactic antifungal therapy (p < 0.001, 95 % CI 1.91 - 9.79, OR = 4.33). At multivariate analysis, only medical admission and prophylactic antifungal therapy were significantly associated with ICU-acquired Gram-negative infections. Higher ICU-length of stay and longer duration of mechanical ventilation were associated with these infections while ICU-mortality did not significantly differ.

CONCLUSIONS

ICU-acquired Gram-negative infections were common in a cohort of mixed medical-surgical patients. Only medical admission and anti-fungal prophylaxis were found to be independently associated with these infections; they were not found to have a significant effect on ICU-mortality.

Healthcare-associated infections in a Tunisian university hospital: from analysis to action

INTRODUCTION

Our study was conducted, in university hospital center (UHC) Farhat Hached of Sousse (city in Tunisian center-east), within healthcare-associated infections (HAI) epidemiological surveillance (ES) program, based, among others, on HAI regular prevalence surveys. Our objectives are to resituate HAI prevalence rate and to identify their risk factors (RF) in order to adjust, in our hospital, prevention programs.

METHODS

It is a transversal descriptive study, including all patients who had been hospitalized for at least 48 hours, measuring prevalence of HAI a "given day", with only one passage by service. Risk factors were determined using Epiinfo 6.0, by uni-varied analysis, then, logistic regression stepwise descending for the variables whose p.

RESULTS

The study focused on 312 patients. Infected patients prevalence was 12.5% and that of HAI was 14.5%. Infections on peripheral venous catheter (PVC) dominated (42.2%) among all HAI identified. HAI significant RF were neutropenia (p < 10(-4)) for intrinsic factors, and PVC for extrinsic factors (p = 0,003).

CONCLUSION

Predominance of infections on PVC should be subject of specific prevention actions, including retro-information strategy, prospective ES, professional practices evaluation and finally training and increasing awareness of health personnel with hygiene measures. Finally, development of a patient safety culture with personnel ensures best adherence to hygiene measures and HAI prevention.

Does Catheter-Associated Urinary Tract Infection Increase Mortality in Critically Ill Patients?

Objective.

To produce an accurate estimate of the association between catheter-associated urinary tract infection (UTI) and intensive care unit (ICU) and hospital mortality, controlling for major confounding factors.

Design.

Nested case-control study in a multicenter cohort (the OutcomeRea database).

Setting.

Twelve French medical or surgical ICUs.

Methods.

All patients admitted between January 1997 and August 2005 who required the insertion of an indwelling urinary catheter. Patients who developed catheter-associated UTI (ie, case patients) were matched to control patients on the basis of the following criteria: sex, age ( ± 10 years), SAPS (Simplified Acute Physiology Score) II score ( ± 10 points), duration of urinary tract catheterization, and presence or absence of diabetes mellitus. The association of catheter-associated UTI with ICU and hospital mortality was assessed by use of conditional logistic regression.

Results.

Of the 3,281 patients who had an indwelling urinary catheter, 298 (9%) developed at least 1 episode of catheter-associated UTI. The incidence density of catheter-associated UTI was 12.9 infections per 1,000 catheterization-days. Crude ICU mortality rates were higher among patients with catheter-associated UTI, compared with those without catheter-associated UTI (32% vs 25%, P = .02); the same was true for crude hospital mortality rates (43% vs 30%, P>.01). After matching and adjustment, catheter-associated UTI was no longer associated with increased mortality (ICU mortality: odds ratio [OR], 0.846 [95% confidence interval {CI}, 0.659-1.086]; P = .19 and hospital mortality: OR, 0.949 [95% CI, 0.763-1.181]; P = .64).

Conclusion.

After carefully controlling for confounding factors, catheter-associated UTI was not found to be associated with excess mortality among our population of critically ill patients in either the ICU or the hospital.

Impact of nosocomial polymicrobial bloodstream infections on the outcome in critically ill patients

The aims of this study were to compare the clinical and microbiological characteristics from patients with polymicrobial bloodstream infections (BSI) to those from patients with monomicrobial BSI and to determine their influence on the prognosis. A prospective study was conducted on 371 nosocomial BSI in an intensive care unit (ICU). Seventy-five (20.2%) of them were polymicrobial. The mean APACHE II score at the onset of bacteremia in polymicrobial and monomicrobial BSI were 17.7 ± 6.6 and 18.9 ± 7.5, respectively (p=0.228). Severe sepsis and septic shock were present in 68.0% and 50.6% of polymicrobial BSI and in 73.9% and 55.1% of monomicrobial BSI, respectively (p=0.298 and p=0.494, respectively). The length of stay and the length of stay post-infection were significantly longer in patients with polymicrobial BSI. APACHE II score at the onset of BSI, high-risk microorganisms, and septic shock were predictors of related mortality, but polymicrobial BSI and inadequate empirical antimicrobial treatment were not. Our findings suggest that the clinical and microbiological characteristics of polymicrobial BSI are not different from monomicrobial BSI, and polymicrobial BSI do not have any influence on the related mortality. However, they occurred in patients with a longer length of stay in the hospital and were associated with longer stays in the hospital after the episode of BSI.

Burden of endemic health-care-associated infection in developing countries: systematic review and meta-analysis

BACKGROUND

Health-care-associated infection is the most frequent result of unsafe patient care worldwide, but few data are available from the developing world. We aimed to assess the epidemiology of endemic health-care-associated infection in developing countries.

METHODS

We searched electronic databases and reference lists of relevant papers for articles published 1995-2008. Studies containing full or partial data from developing countries related to infection prevalence or incidence-including overall health-care-associated infection and major infection sites, and their microbiological cause-were selected. We classified studies as low-quality or high-quality according to predefined criteria. Data were pooled for analysis.

FINDINGS

Of 271 selected articles, 220 were included in the final analysis. Limited data were retrieved from some regions and many countries were not represented. 118 (54%) studies were low quality. In general, infection frequencies reported in high-quality studies were greater than those from low-quality studies. Prevalence of health-care-associated infection (pooled prevalence in high-quality studies, 15·5 per 100 patients [95% CI 12·6-18·9]) was much higher than proportions reported from Europe and the USA. Pooled overall health-care-associated infection density in adult intensive-care units was 47·9 per 1000 patient-days (95% CI 36·7-59·1), at least three times as high as densities reported from the USA. Surgical-site infection was the leading infection in hospitals (pooled cumulative incidence 5·6 per 100 surgical procedures), strikingly higher than proportions recorded in developed countries. Gram-negative bacilli represented the most common nosocomial isolates. Apart from meticillin resistance, noted in 158 of 290 (54%) Staphylococcus aureus isolates (in eight studies), very few articles reported antimicrobial resistance.

INTERPRETATION

The burden of health-care-associated infection in developing countries is high. Our findings indicate a need to improve surveillance and infection-control practices.

FUNDING

World Health Organization.

[Contact precautions in intensive care units: facilitating and inhibiting factors for professionals' adherence]

The objective of this study was to identify facilitating and limiting factors for professionals' compliance with contact precautions in an intensive care unit of a general hospital. This cross-sectional study was performed from May to October 2007, using a semi-structured questionnaire for data collection. Participants were 102 professionals, as follows: nursing technician (54.9%), nurse (12.7%), preceptor physician (10.8%), apprentice physiotherapist (8.8%), preceptor physiotherapist (7.8%) and resident physician (4.9%). The limiting factors for compliance with hand cleansing were forgetting, lack of knowledge, distance from sink, skin irritation, and lack of materials. The use of scrubs presented the most difficulty (45%) because they were not available at the shower box, were inappropriately stored, and due to the heat and collective use. Glove use was the practice most easily conducted in everyday practice. Results show the need to implement precaution measures to minimize the dissemination of resistant microorganisms.

Intensive care unit professionals' knowledge and behavior related to the adoption of contact precautions

This study aimed to assess the knowledge and behavior of professionals working in Intensive Care Units (ICU) related to the adoption of contact precautions for the control of hospital infections (HI). This cross-sectional study used a semi-structured questionnaire to collect data. Descriptive and multivariate analyses were carried out, including logistic regression and decision tree using CHAID algorithm. A total of 102 professionals participated in the study, of whom 36.3% presented appropriate knowledge and 51% appropriate behavior in relation to HI control measures. Nursing professionals had almost four times more chance (OR = 3.58, CI 1.48-8.68) of presenting appropriate behavior than the remaining professionals. The multivariate analysis did not reveal variables associated with knowledge. No statistically significant association was found between knowledge and behavior (p = 0.196). These results suggest the need to implement educational activities so as to permit a balance between theory and professionals' practice concerning HI preventive measures, aiming to improve knowledge and behavior.

The transmission of nosocomial pathogens in an intensive care unit: a space-time clustering and structural equation modelling approach

We investigated the incidence of cases of nosocomial pathogens and risk factors in an intensive treatment unit ward to determine if the number of cases is dependent on location of patients and the colonization/infection history of the ward. A clustering approach method was developed to investigate the patterns of spread of cases through time for five microorganisms [methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter spp., Klebsiella spp., Candida spp., and Pseudomonas aeruginosa] using hospital microbiological monitoring data and ward records of patient-bed use. Cases of colonization/infection by MRSA, Candida and Pseudomonas were clustered in beds and through time while cases of Klebsiella and Acinetobacter were not. We used structural equation modelling to analyse interacting risk factors and the potential pathways of transmission in the ward. Prior nurse contact with colonized/infected patients, mediated by the number of patient-bed movements, were important predictors for all cases, except for those of Pseudomonas. General health and invasive surgery were significant predictors of cases of Candida and Klebsiella. We suggest that isolation and bed movement as a strategy to manage MRSA infections is likely to impact upon the incidence of cases of other opportunist pathogens.

Hydrocortisone therapy for patients with septic shock

BACKGROUND

Hydrocortisone is widely used in patients with septic shock even though a survival benefit has been reported only in patients who remained hypotensive after fluid and vasopressor resuscitation and whose plasma cortisol levels did not rise appropriately after the administration of corticotropin.

METHODS

In this multicenter, randomized, double-blind, placebo-controlled trial, we assigned 251 patients to receive 50 mg of intravenous hydrocortisone and 248 patients to receive placebo every 6 hours for 5 days; the dose was then tapered during a 6-day period. At 28 days, the primary outcome was death among patients who did not have a response to a corticotropin test.

RESULTS

Of the 499 patients in the study, 233 (46.7%) did not have a response to corticotropin (125 in the hydrocortisone group and 108 in the placebo group). At 28 days, there was no significant difference in mortality between patients in the two study groups who did not have a response to corticotropin (39.2% in the hydrocortisone group and 36.1% in the placebo group, P=0.69) or between those who had a response to corticotropin (28.8% in the hydrocortisone group and 28.7% in the placebo group, P=1.00). At 28 days, 86 of 251 patients in the hydrocortisone group (34.3%) and 78 of 248 patients in the placebo group (31.5%) had died (P=0.51). In the hydrocortisone group, shock was reversed more quickly than in the placebo group. However, there were more episodes of superinfection, including new sepsis and septic shock.

CONCLUSIONS

Hydrocortisone did not improve survival or reversal of shock in patients with septic shock, either overall or in patients who did not have a response to corticotropin, although hydrocortisone hastened reversal of shock in patients in whom shock was reversed. (ClinicalTrials.gov number, NCT00147004.)

Combined measurement of procalcitonin and soluble TREM-1 in the diagnosis of nosocomial sepsis

This prospective, non-interventional study was conducted in a medical adult intensive care unit to determine the usefulness of procalcitonin (PCT) and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) determinations in the diagnosis of nosocomial sepsis. Serum PCT and bronchoalveolar lavage fluid sTREM-1 concentrations were measured in 50 critically ill patients suffering from nosocomial sepsis. Ventilator-associated pneumonia (VAP) was diagnosed in 31 patients and extrapulmonary sepsis in 19. Increase serum PCT concentration (>0.15 ng/ml) was found in 44 (88%) patients and was higher in those suffering from a non-pulmonary sepsis. The concomitant BAL sTREM-1 determination correctly classified pulmonary (VAP) versus non-pulmonary origin in 41 out of 44 cases (93%). Even when PCT concentration remained low, sTREM-1 assessment allowed for the detection of the sepsis (VAP) in 50% of cases. Both PCT and sTREM-1 concentrations were low in only 3 patients (6%) in whom sepsis could have been missed if only diagnosed by the measurement of these 2 biomarkers. We therefore concluded that the combined measurement of serum PCT and BAL sTREM-1 concentrations could be of interest in detecting the presence of a nosocomial sepsis and in discriminating VAP versus extrapulmonary infection.

Acinetobacter infections: a growing threat for critically ill patients

There has been increasing concern regarding the rise of Acinetobacter infections in critically ill patients. We extracted information regarding the relative frequency of Acinetobacter pneumonia and bacteraemia in intensive-care-unit (ICU) patients and the antimicrobial resistance of Acinetobacter isolates from studies identified in electronic databases. Acinetobacter infections most frequently involve the respiratory tract of intubated patients and Acinetobacter pneumonia has been more common in critically ill patients in Asian (range 4-44%) and European (0-35%) hospitals than in United States hospitals (6-11%). There is also a gradient in Europe regarding the proportion of ICU-acquired pneumonias caused by Acinetobacter with low numbers in Scandinavia, and gradually rising in Central and Southern Europe. A higher proportion of Acinetobacter isolates were resistant to aminoglycosides and piperacillin/tazobactam in Asian and European countries than in the United States. The data suggest that Acinetobacter infections are a growing threat affecting a considerable proportion of critically ill patients, especially in Asia and Europe.

Intensive care acquired infection is an independent risk factor for hospital mortality: a prospective cohort study

Introduction

The aim of this study was to elucidate the impact of intensive care unit (ICU)-acquired infection on hospital mortality.

Methods

Patients with a longer than 48 hour stay in a mixed 10 bed ICU in a tertiary-level teaching hospital were prospectively enrolled between May 2002 and June 2003. Risk factors for hospital mortality were analyzed with a logistic regression model.

Results

Of 335 patients, 80 developed ICU-acquired infection. Among the patients with ICU-acquired infections, hospital mortality was always higher, regardless of whether or not the patients had had infection on admission (infection on admission group (IAG), 35.6% versus 17%, p = 0.008; and no-IAG, 25.7% versus 6.1%, p = 0.023). In IAG (n = 251), hospital stay was also longer in the presence of ICU-acquired infection (median 31 versus 16 days, p < 0.001), whereas in no-IAG (n = 84), hospital stay was almost identical with and without the presence of ICU-acquired infection (18 versus 17 days). In univariate analysis, the significant risk factors for hospital mortality were: Acute Physiology and Chronic Health Evaluation (APACHE) II score >20, sequential organ failure assessment (SOFA) score >8, ICU-acquired infection, age ≥ 65, community-acquired pneumonia, malignancy or immunosuppressive medication, and ICU length of stay >5 days. In multivariate logistic regression analysis, ICU-acquired infection remained an independent risk factor for hospital mortality after adjustment for APACHE II score and age (odds ratio (OR) 4.0 (95% confidence interval (CI): 2.0–7.9)) and SOFA score and age (OR 2.7 (95% CI: 2.9–7.6)).

Conclusion

ICU-acquired infection was an independent risk factor for hospital mortality even after adjustment for the APACHE II or SOFA scores and age.

Epidemiology of intensive care unit (ICU)-acquired infections in a 14-month prospective cohort study in a single mixed Scandinavian university hospital ICU

BACKGROUND

Our aim was to evaluate the epidemiology of intensive care unit (ICU)-acquired infections in a prospective cohort study.

METHODS

Patients with longer than a 48-h stay in an adult mixed medical-surgical ICU in a tertiary level teaching hospital were included. The incidence (per cent) and incidence density (per 1000 patient days) of ICU-acquired infections and the device-associated infection rates per 1000 device days were analysed prospectively in a 14-month study.

RESULTS

Eighty (23.9%) of 335 patients, whose ICU stay was longer than 48 h, acquired a total of 107 infections (1.3 per patient) during their ICU stay, with an infection rate of 48 per 1000 patient days. The most common infections were ventilator-associated pneumonia (VAP) [33.8% (18.8 per 1000 respiratory days)], other lower respiratory tract infections (LRTIs) (20%) and sinusitis (13.8%). The rate of central catheter-related (CRI) or primary bloodstream infections was 6.3% (2.2 per 1000 central venous catheter days), and the rate of urinary tract infections was 1.3% (0.5 per 1000 urinary catheter days). The first ICU infection was observed in 58.8% (47/80) of cases within 6 days after admission. The median time from admission to the diagnosis of an ICU-acquired infection was 4 days (25th-75th percentiles, 4.0-6.0) for VAP, 6.0 days (4.5-7.0) for LRTIs and 9.5 days (6.5-13.0) for CRIs.

CONCLUSIONS

The rates of urinary tract infections and bloodstream infections were lower than reported previously, differentiating our results from the classic pattern of ICU-acquired infections, with the exception of the predominance of VAP.

Hospital at home for acute respiratory patients

BACKGROUND

The issue of "hospital at home" (HAH) for acute respiratory patients is one that is still being debated, partly because economic, cultural and health service differences between locations imply that HAH schemes need to be tailored to local situations. The aim of the present study was to analyze the feasibility and effectiveness of HAH for patients with acute respiratory disease at our institution.

METHODS

Of all the patients admitted to our institution via the emergency department during a 34-day subject enrollment period, 25 with diagnoses of respiratory infection, pneumonia, pulmonary insufficiency or exacerbated chronic obstructive pulmonary disease who were living within 25 km of our center and who were willing to receive HAH care were assigned to HAH. Fifty sex-matched controls with the same diagnoses were given conventional hospital care (CHC) as inpatients. The dependent variables evaluated included time to discharge, readmissions within 3 months and deaths within 3 months.

RESULTS

There were no significant differences between the HAH and CHC groups with regard to age, diagnoses, physical and analytical findings, or co-morbidity, or with regard to deaths (HAH 16%, CHC 10%) or readmissions (HAH 17%, CHC 24%). Time to final discharge was significantly shorter for HAH patients (7 days) than for CHC patients (12 days). Some 95% of the HAH patients were satisfied and would choose HAH again.

CONCLUSIONS

HAH seems feasible for appropriately selected acute respiratory disease patients presenting in our emergency department. It frees hospital beds for other patients, its readmission and mortality rates are no higher than for conventional hospitalization, and, in general, it is favorably evaluated by patients.

Factors associated with mortality in critically injured trauma patients who require simultaneous cultures

BACKGROUND

In trauma patients surviving their initial injuries, infectious complications and multiple organ failure represent the major causes of death after the first 72 hours. Critically injured trauma patients frequently have bacteria recoverable simultaneously from multiple culture sites; the clinical significance of this event is unknown. The objective of this study was to identify the association between growth patterns of multiple site cultures and mortality among critically injured trauma patients.

METHODS

We performed a retrospective chart review collecting demographic and medical data on admissions to a state-designated Level I trauma center from April 2000 to December 2002. The inclusion criteria were age >17 years, admission to the trauma intensive care unit (TICU), and simultaneous sampling of blood, sputum, and urine in the setting of fever of undetermined origin or alteration in the white blood cell count. Four mutually exclusive groups were developed according to the number of positive culture sites. We used standard statistical analysis and multivariate logistic regression.

RESULTS

During the study period, 3,402 patients were admitted to the trauma service of whom 124 met the inclusion criteria. Eighty percent of these (99) were male, and the average age was 41 years. The median TICU stay was 17 days. The mortality rate was 24.2% (30 nonsurvivors). The survivors and non-survivors were comparable in injury severity score (ISS), initial base deficit, initial hematocrit, initial blood pressure, and hospital length of stay (p > 0.05), whereas age (p = 0.03), female sex (p = 0.04), and TICU stay (p < 0.01) were higher among non-survivors. More non-survivors showed growth of microorganisms in simultaneous blood, sputum, and urine cultures (p = 0.02). By multivariate analysis, adjusting for age, sex, and TICU length of stay, patients with growth of microorganisms in simultaneous cultures (blood, sputum, and urine) had a 3-fold greater mortality rate (OR, 3.20; 95% CI 1.05, 9.73).

CONCLUSIONS

In this group of patients, growth of bacteria in simultaneous cultures was associated with higher mortality-a factor that may be considered a poor prognostic indicator. This factor requires further studies to explore the relation with survival in critically injured patients.

Cost of intensive care unit-acquired bloodstream infections

Intensive care unit-acquired (ICU-acquired) bloodstream infections (BSI) are an important complication of critical illness. The objective of this study was to quantify the excess length of stay, mortality and cost attributable to ICU-acquired BSI. A matched cohort study was conducted in all adult ICUs in the Calgary Health Region between 1 May 2000 and 30 April 2003. One hundred and forty-four patients with ICU-acquired BSI were matched (1:1) to patients without ICU-acquired BSI. Patients with ICU-acquired BSI had a significantly increased median length of ICU stay {15.5 [interquartile range (IQR) 8-26] days vs 12 [IQR 7-18.5] days, P=0.003} and median costs of hospital care [85,137 dollars (IQR 45,740-131,412 dollars) vs 67,879 dollars (IQR 35,043-115,915 dollars, P=0.02) compared with patients without ICU-acquired BSI. The median excess length of ICU stay was two days and the median cost attributable to ICU-acquired BSI was 12,321 dollars per case. Sixty (42%) of the cases died compared with 37 (26%) of the controls [P=0.002, attributable mortality 16%, 95% confidence interval (CI) 5.9-26.0%]. Patients with ICU-acquired BSI were at increased risk for in-hospital death (odds ratio=2.64, 95%CI 1.40-5.29). Among survivor-matched pairs, the median excess lengths of ICU and hospital stay attributable to development of ICU-acquired BSI were two and 13.5 days, respectively, and the attributable cost due to ICU-acquired BSI was 25,155 dollars per case survivor. Critically ill patients who develop ICU-acquired BSI suffer excess morbidity and mortality, and incur significantly increased healthcare costs. These data support expenditures on infection prevention and control programmes and further research into reducing the impact of these infections.

Epidemiology of intensive care unit-acquired urinary tract infections

PURPOSE OF REVIEW

The development of urinary tract infections in critically ill adult patients is associated with considerable morbidity, prolonged hospitalization, and greater healthcare expenditures. We review the occurrence, microbiology, risk factors for acquisition, and outcomes associated with intensive care unit-acquired urinary tract infections.

RECENT FINDINGS

Reports from several countries indicate that nosocomial urinary tract infections frequently complicate the course of patients admitted to intensive care units. Virtually all patients who develop an intensive care unit-acquired urinary tract infection have indwelling urinary catheters; other factors associated with the development of these infections include increased duration of urinary catheterization, female sex, intensive care unit length of stay, and preceding systemic antimicrobial therapy. The most frequent pathogens include Escherichia coli, Pseudomonas aeruginosa, enterococci, and Candida albicans; both the species distribution and rates of resistance vary considerably among institutions and regions. Secondary bloodstream infections are uncommon. Although acquisition of an intensive care unit-acquired urinary tract infection has been associated with a prolongation of intensive care unit length of stay, higher cost, and a higher crude case fatality rate, they do not appear to independently increase the risk for death.

SUMMARY

Urinary tract infection is a common complication of critical illness that is associated with increased patient morbidity but not mortality. There is a relative paucity of research on nosocomial urinary tract infection specifically acquired in the intensive care unit and further studies are needed to better define the epidemiology and management of these infections.

Outbreaks of Serratia marcescens bacteriuria in a neurosurgical intensive care unit of a tertiary care teaching hospital: a clinical, epidemiologic, and laboratory perspective

BACKGROUND

Serratia marcescens is an aerobic gram-negative bacillus belonging to the family Enterobacteriacea. Infections caused by S marcescens may be difficult to treat because of their resistance to a variety of antibiotics, including beta-lactams and aminoglycosides.

METHODS

This study aimed to (1) identify the risk factors associated with the development of Serratia marcescens bacteriuria in neurosurgical intensive care units (NSICU); (2) genotype the pathogens to determine the source of infection; (3) compare these results with antibiograms; and (4) determine and implement appropriate control measures. A retrospective case-control study of the epidemiologic data, the surveillance of environmental cultures, and the genotyping of strains using arbitrarily primed polymerase chain reaction (AP-PCR) were performed at a 750-bed, tertiary care teaching hospital. Seventy-four bacteriuria patients were compared with 74 age/sex-matched control patients in the NSICU between March 2002 and March 2004. The factors assessed were patient demographics; duration of hospital stay; duration of indwelling catheter use before and during stay in the NSICU; chronic underlying illnesses (diabetes mellitus, cardiovascular disease, malignancy); other sites of infection; history of trauma; exposure to a nasogastric tube; mechanical ventilation; urinary catheterization; central venous catheterization; surgical drainage; tracheostomy; brain or spine surgery; and receipt of total parenteral nutrition (TPN), antimicrobials (beta-lactams, aminoglycosides, quinolones, carbapenems, vancomycins), or steroids.

RESULTS

Patients with S marcescens bacteriuria were more likely to have a longer NSICU stay and other sites of infection. Environmental surveillance showed the handling of urine jugs to be the point source of contamination. Genotyping and antibiograms of 14 patients were the same except for those of 2 patients.

CONCLUSION

The patient-related risk factors were identified, and a rapid identification of the organism was made. Heightened surveillance, infection control measures, and empiric therapy led to improved methods for handling urine jugs, which terminated the outbreak.

Evaluation of risk factors for mortality in intensive care units: a prospective study from a referral hospital in Turkey

BACKGROUND

The aim of the clinical practice is to decrease the mortality rate in intensive care units. Determination of the risk factors for mortality may provide useful guidance for intensive care patients. This study sought to find mortality-related risk factors in intensive care units.

OBJECTIVE

To investigate risk factors for mortality in intensive care units (ICUs).

METHODS

The prospective study was performed from May 2002 to November 2002 in the surgical and medical ICUs of the Ankara Numune Education and Research Hospital. Three hundred thirty-four patients who were followed in the ICUs for at least 48 hours were enrolled in this study. Those patients who died within 48 hours of ICU discharge were included in the mortality analysis.

RESULTS

The overall mortality rate in the ICUs was 46.7%. Among the 334 patients, 104 (31.1%) had ICU-acquired infections. The mortality rate was significantly higher in the patients with nosocomial infections (66.3%) than in the patients without nosocomial infections (37.8%) ( P < .001). The mean age, sex, acute physiology and chronic health evaluation (APACHE) II score, trauma and intraabdominal pathology, nosocomial infection, stay in the medical/surgical ICU, coma, TISS score, use of steroid or chemotherapy, use of antibiotic, and serum urea >50 mg/dL and creatinine >1.2 mg/dL levels were associated with mortality in the univariate analysis. Eight variables were determined as independent risk factors: presence of nosocomial infection (hazard ratio (HR) 0.40; 95% confidence interval (CI), 0.27-0.61), mean age (HR, 1.01; 95% CI, 1.00-1.02), mean APACHE II score (HR, 1.99; 95% CI, 1.50-2.64), mechanical ventilation (HR, 1.98; 95% CI, 1.33-2.95), stay in the medical/surgical ICU (HR, 0.41; 95% CI, 0.27-0.61), enteral nutrition (HR, 0.43; 95% CI, 0.29-0.65), tracheostomy (HR, 0.26; 95% CI, 0.094-0.75), and use of steroid or chemotherapy (HR, 1.61; 95% CI, 1.13-2.29). Nosocomial pneumonia (HR, 0.59; 95% CI, 0.38-0.92) and sepsis (HR, 0.29; 95% CI, 0.16-0.51) were related with mortality.

CONCLUSION

The most important risk factors of mortality were observed as nosocomial infection, older age, high APACHE II score, mechanical ventilation, enteral nutrition, tracheostomy, and use of steroids or chemotherapy.

Intensive-care-unit-acquired bloodstream infections in a regional critically ill population

Bloodstream infection (BSI) is a serious complication of critical illness but it is uncertain whether acquisition of BSI in the intensive care unit (ICU) increases the risk of death. A study was conducted among all Calgary health region (population approximately 1 million) adults admitted to ICUs for 48 h or more during a three-year period to investigate the occurrence, microbiology and risk factors for developing an ICU-acquired BSI and to determine whether these infections independently predict mortality. One hundred and ninety-nine ICU-acquired BSI episodes occurred during 4933 ICU admissions for a cumulative incidence of 4% and an incidence density of 5.4 per 1000 ICU days. The most common isolates were Staphylococcus aureus (18%), coagulase-negative staphylococci (11%), and Enterococcus faecalis (8%); 12% of infections were due to antimicrobial-resistant bacteria. Admission to the regional neurosurgery/trauma ICU [odds ratio (OR) 2.86; 95% confidence interval (CI) 2.10-3.90] and increasing Acute Physiology and Chronic Health Evaluation II (APACHE II) score (OR 1.05 per point, 95% CI 1.03-1.07) were associated with higher risk, whereas a surgical diagnosis (OR 0.69; 95% CI 0.52-0.93) was associated with lower risk of developing ICU-acquired BSI in logistic regression analysis. The crude in-hospital death rate was 45% for patients with ICU-acquired BSI compared with 21% for those without (P < 0.0001) Development of an ICU-acquired BSI was an independent risk factor for death (OR 1.79; 95% CI 1.3-2.5) and increases the risk of dying from critical illness.