Impact of adrenomedullin levels on clinical risk stratification and outcome in subarachnoid haemorrhage

PURPOSE

To use classification tree analysis to identify risk factors for nonsurvival in a neurological patients with subarachnoid haemorrhage (SAH) and to propose a clinical model for predicting of mortality.

METHODS

Prospective study of SAH admitted to a Critical Care Department and Stroke Unit over a 2-year period. Middle region of pro-ADM plasma levels (MR-proADM) was measured in EDTA plasma within the first 24 hours of hospital admission using the automatic immunofluorescence test. A regression tree was made to identify prognostic models for the development of mortality at 90 days.

RESULTS

Ninety patients were included. The mean MR-proADM plasma value in the samples analysed was 0.78 ± 0.41 nmol/L. MR-proADM plasma levels were significantly associated with mortality at 90 days (1.05 ± 0.51 nmol/L vs 0.64 ± 0.25 nmol/L; P < .001). Regression tree analysis provided an algorithm based on the combined use of clinical variables and one biomarker allowing accurate mortality discrimination of three distinct subgroups with high risk of 90-day mortality ranged from 75% to 100% (AUC 0.9; 95% CI 0.83-0.98).

CONCLUSIONS

The study established a model (APACHE II, MR-proADM and Hunt&Hess) to predict fatal outcomes in patients with SAH. The proposed decision-making algorithm may help identify patients with a high risk of mortality.

Invasive fungal infection in crtically ill patients: hurdles and next challenges

A narrative review from a multidisciplinary task force of experts in critical care medicine and clinical mycology was carried out. The multi drug-resistant species Candida auris has emerged simultaneously on several continents, causing hospital outbreaks, especially in critically ill patients. Although there are not enough data to support the routine use of continuous antibiotic prophylaxis in patients subjected to extracorporeal membrane oxygenator, a clear increase of invasive fungal infection (IFI) has been described with the use of this device. Possible IFI treatment failures could be related with suboptimal antifungal concentrations despite dose adjustment. Invasive aspergillosis has become an important life-threating infection in intensive care unit related with new risk factors described. IFI remain important problem in critical patients due to the appearance of new risk factors, new species, and resistance increase. Multidisciplinary packages of measures designed to reduce IFI incidence and improve diagnostics tools may reduce the high mortality associated.

Antibiotic selection in the treatment of acute invasive infections by Pseudomonas aeruginosa: Guidelines by the Spanish Society of Chemotherapy

Pseudomonas aeruginosa is characterized by a notable intrinsic resistance to antibiotics, mainly mediated by the expression of inducible chromosomic β-lactamases and the production of constitutive or inducible efflux pumps. Apart from this intrinsic resistance, P. aeruginosa possess an extraordinary ability to develop resistance to nearly all available antimicrobials through selection of mutations. The progressive increase in resistance rates in P. aeruginosa has led to the emergence of strains which, based on their degree of resistance to common antibiotics, have been defined as multidrug resistant, extended-resistant and panresistant strains. These strains are increasingly disseminated worldwide, progressively complicating the treatment of P. aeruginosa infections. In this scenario, the objective of the present guidelines was to review and update published evidence for the treatment of patients with acute, invasive and severe infections caused by P. aeruginosa. To this end, mechanisms of intrinsic resistance, factors favoring development of resistance during antibiotic exposure, prevalence of resistance in Spain, classical and recently appeared new antibiotics active against P. aeruginosa, pharmacodynamic principles predicting efficacy, clinical experience with monotherapy and combination therapy, and principles for antibiotic treatment were reviewed to elaborate recommendations by the panel of experts for empirical and directed treatment of P. aeruginosa invasive infections.

Intensive care unit patients with lower respiratory tract nosocomial infections: the ENIRRIs project

The clinical course of intensive care unit (ICU) patients may be complicated by a large spectrum of lower respiratory tract infections (LRTI), defined by specific epidemiological, clinical and microbiological aspects.

A European network for ICU-related respiratory infections (ENIRRIs), supported by the European Respiratory Society, has been recently established, with the aim at studying all respiratory tract infective episodes except community-acquired ones. A multicentre, observational study is in progress, enrolling more than 1000 patients fulfilling the clinical, biochemical and radiological findings consistent with a LRTI. This article describes the methodology of this study. A specific interest is the clinical impact of non-ICU-acquired nosocomial pneumonia requiring ICU admission, non-ventilator-associated LRTIs occurring in the ICU, and ventilator-associated tracheobronchitis. The clinical meaning of microbiologically negative infectious episodes and specific details on antibiotic administration modalities, dosages and duration are also highlighted. Recently released guidelines address many unresolved questions which might be answered by such large-scale observational investigations. In light of the paucity of data regarding such topics, new interesting information is expected to be obtained from our network research activities, contributing to optimisation of care for critically ill patients in the ICU.

Methodology for the first European network for ICU-related respiratory infections (ENIRRIs) projecthttp://ow.ly/sud930fU1e7

Impact of colistin plasma levels on the clinical outcome of patients with infections caused by extremely drug-resistant Pseudomonas aeruginosa

BACKGROUND

Colistin has a narrow therapeutic window with nephrotoxicity being the major dose-limiting adverse effect. Currently, the optimal doses and therapeutic plasma levels are unknown.

METHODS

Prospective observational cohort study, including patients infected by colistin-susceptible P. aeruginosa treated with intravenous colistimethate sodium (CMS). Clinical data and colistin plasma levels at steady-state (C_ss) were recorded. The primary and secondary end points were clinical cure and 30-day all-cause mortality.

RESULTS

Ninety-one patients were included. Clinical cure was observed in 72 (79%) patients. The mean (SD) C_ss was 1.49 (1.4) mg/L and 2.42 (1.5) mg/L (p = 0.01) in patients who achieved clinical cure and those who not, respectively. Independent risk factors for clinical failure were male sex (OR 5.88; 95% CI 1.09-31.63), APACHE II score (OR 1.15; 95% CI 1.03-1.27) and nephrotoxicity at the EOT (OR 9.13; 95% CI 95% 2.06-40.5). The 30-day mortality rate was 30.8%. Risk factors for 30-day mortality included the APACHE II score (OR 1.98; 95% CI 1-1.20), the McCabe score (OR 2.49; 95% CI 1.14-5.43) and the presence of nephrotoxicity at the end of treatment (EOT) (OR 3.8; 95% CI 1.26-11.47).

CONCLUSION

In this series of patients with infections caused by XDR P. aeruginosa infections, C_ss is not observed to be related to clinical outcome.

A case-cohort approach for multi-state models in hospital epidemiology

Analysing the determinants and consequences of hospital-acquired infections involves the evaluation of large cohorts. Infected patients in the cohort are often rare for specific pathogens, because most of the patients admitted to the hospital are discharged or die without such an infection. Death and discharge are competing events to acquiring an infection, because these individuals are no longer at risk of getting a hospital-acquired infection. Therefore, the data is best analysed with an extended survival model - the extended illness-death model. A common problem in cohort studies is the costly collection of covariate values. In order to provide efficient use of data from infected as well as uninfected patients, we propose a tailored case-cohort approach for the extended illness-death model. The basic idea of the case-cohort design is to only use a random sample of the full cohort, referred to as subcohort, and all cases, namely the infected patients. Thus, covariate values are only obtained for a small part of the full cohort. The method is based on existing and established methods and is used to perform regression analysis in adapted Cox proportional hazards models. We propose estimation of all cause-specific cumulative hazards and transition probabilities in an extended illness-death model based on case-cohort sampling. As an example, we apply the methodology to infection with a specific pathogen using a large cohort from Spanish hospital data. The obtained results of the case-cohort design are compared with the results in the full cohort to investigate the performance of the proposed method. Copyright © 2016 John Wiley & Sons, Ltd.

Multiple time scales in modeling the incidence of infections acquired in intensive care units

Background

When patients are admitted to an intensive care unit (ICU) their risk of getting an infection will be highly depend on the length of stay at-risk in the ICU. In addition, risk of infection is likely to vary over calendar time as a result of fluctuations in the prevalence of the pathogen on the ward. Hence risk of infection is expected to depend on two time scales (time in ICU and calendar time) as well as competing events (discharge or death) and their spatial location. The purpose of this paper is to develop and apply appropriate statistical models for the risk of ICU-acquired infection accounting for multiple time scales, competing risks and the spatial clustering of the data.

Methods

A multi-center data base from a Spanish surveillance network was used to study the occurrence of an infection due to Methicillin-resistant Staphylococcus aureus (MRSA). The analysis included 84,843 patient admissions between January 2006 and December 2011 from 81 ICUs. Stratified Cox models were used to study multiple time scales while accounting for spatial clustering of the data (patients within ICUs) and for death or discharge as competing events for MRSA infection.

Results

Both time scales, time in ICU and calendar time, are highly associated with the MRSA hazard rate and cumulative risk. When using only one basic time scale, the interpretation and magnitude of several patient-individual risk factors differed. Risk factors concerning the severity of illness were more pronounced when using only calendar time. These differences disappeared when using both time scales simultaneously.

Conclusions

The time-dependent dynamics of infections is complex and should be studied with models allowing for multiple time scales. For patient individual risk-factors we recommend stratified Cox regression models for competing events with ICU time as the basic time scale and calendar time as a covariate. The inclusion of calendar time and stratification by ICU allow to indirectly account for ICU-level effects such as local outbreaks or prevention interventions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-016-0199-y) contains supplementary material, which is available to authorized users.

Risk factors for methicillin-resistant Staphylococcus aureus colonisation or infection in intensive care units and their reliability for predicting MRSA on ICU admission

Predicting methicillin-resistant Staphylococcus aureus (MRSA) in intensive care units (ICUs) avoids inappropriate antimicrobial empirical treatment and enhances infection control. We describe risk factors for colonisation/infection related to MRSA (MRSA-C/I) in critically ill patients once in the ICU and on ICU admission, and search for an easy-to-use predictive model for MRSA colonisation/infection on ICU admission. This multicentre cohort study included 69,894 patients admitted consecutively (stay>24h) in April-June in the five-year period 2006-2010 from 147 Spanish ICUs participating in the National Surveillance Study of Nosocomial Infections in ICUs (ENVIN-HELICS). Data from all patients included were used to identify risk factors for MRSA-C/I during ICU stays, from admission to discharge, using uni- and multivariable analysis (Poisson regression) to check that the sample to be used to develop the predictive models was representative of standard critical care population. To identify risk factors for MRSA-C/I on ICU admission and to develop prediction models, multivariable logistic regression analysis were then performed only on those admitted in 2010 (n=16950, 2/3 for analysis and 1/3 for subsequent validation). We found that, in the period 2006-2010, 1046 patients were MRSA-C/I. Independent risk factors for MRSA-C/I in ICU were: age>65, trauma or medical patient, high APACHE-II score, admitted from a long-term care facility, urinary catheter, previous antibiotic treatment and skin-soft tissue or post-surgical superficial skin infections. Colonisation with several different MDRs significantly increased the risk of MRSA-C/I. Risk factors on ICU admission were: male gender, trauma critical patient, urgent surgery, admitted from other ICUs, hospital ward or long-term facility, immunosuppression and skin-soft tissue infection. Although the best model to identify carriers of MRSA had a good discrimination (AUC-ROC, 0.77; 95% CI, 0.72-0.82), sensitivity was 67% and specificity 76.5%. Including more complex variables did not improve prediction capability. Our conclusion is that clinical-demographic risk factors for colonisation/infection related to MRSA should not be used to accurately identify patients who would benefit from empirical anti-MRSA treatment or from specific preventive measures. Independent risk factors for MRSA colonisation/infection during ICU stay and on ICU admission are described. The latter should be considered in future studies for MRSA prediction.

A full competing risk analysis of hospital-acquired infections can easily be performed by a case-cohort approach

OBJECTIVES

We provide a case-cohort approach and show that a full competing risk analysis is feasible even in a reduced data set. Competing events for hospital-acquired infections are death or discharge from the hospital because they preclude the observation of such infections.

STUDY DESIGN AND SETTING

Using surveillance data of 6,568 patient admissions (full cohort) from two Spanish intensive care units, we propose a case-cohort approach which uses only data from a random sample of the full cohort and all infected patients (the cases). We combine established methodology to study following measures: event-specific as well as subdistribution hazard ratios for all three events (infection, death, and discharge), cumulative hazards as well as incidence functions by risk factor, and also for all three events.

RESULTS

Compared with the values from the full cohort, all measures are well approximated with the case-cohort design. For the event of interest (infection), event-specific and subdistribution hazards can be estimated with the full efficiency of the case-cohort design. So, standard errors are only slightly increased, whereas the precision of estimated hazards of the competing events is inflated according to the size of the subcohort.

CONCLUSION

The case-cohort design provides an appropriate sampling design for studying hospital-acquired infections in a reduced data set. Potential effects of risk factors on the competing events (death and discharge) can be evaluated.

Analysis of Clinical Cohort Data Using Nested Case-control and Case-cohort Sampling Designs. A Powerful and Economical Tool

BACKGROUND

Sampling from a large cohort in order to derive a subsample that would be sufficient for statistical analysis is a frequently used method for handling large data sets in epidemiological studies with limited resources for exposure measurement. For clinical studies however, when interest is in the influence of a potential risk factor, cohort studies are often the first choice with all individuals entering the analysis.

OBJECTIVES

Our aim is to close the gap between epidemiological and clinical studies with respect to design and power considerations. Schoenfeld's formula for the number of events required for a Cox' proportional hazards model is fundamental. Our objective is to compare the power of analyzing the full cohort and the power of a nested case-control and a case-cohort design.

METHODS

We compare formulas for power for sampling designs and cohort studies. In our data example we simultaneously apply a nested case-control design with a varying number of controls matched to each case, a case cohort design with varying subcohort size, a random subsample and a full cohort analysis. For each design we calculate the standard error for estimated regression coefficients and the mean number of distinct persons, for whom covariate information is required.

RESULTS

The formula for the power of a nested case-control design and the power of a case-cohort design is directly connected to the power of a cohort study using the well known Schoenfeld formula. The loss in precision of parameter estimates is relatively small compared to the saving in resources.

CONCLUSIONS

Nested case-control and case-cohort studies, but not random subsamples yield an attractive alternative for analyzing clinical studies in the situation of a low event rate. Power calculations can be conducted straightforwardly to quantify the loss of power compared to the savings in the num-ber of patients using a sampling design instead of analyzing the full cohort.

Multilevel competing risk models to evaluate the risk of nosocomial infection

Introduction

Risk factor analyses for nosocomial infections (NIs) are complex. First, due to competing events for NI, the association between risk factors of NI as measured using hazard rates may not coincide with the association using cumulative probability (risk). Second, patients from the same intensive care unit (ICU) who share the same environmental exposure are likely to be more similar with regard to risk factors predisposing to a NI than patients from different ICUs. We aimed to develop an analytical approach to account for both features and to use it to evaluate associations between patient- and ICU-level characteristics with both rates of NI and competing risks and with the cumulative probability of infection.

Methods

We considered a multicenter database of 159 intensive care units containing 109,216 admissions (813,739 admission-days) from the Spanish HELICS-ENVIN ICU network. We analyzed the data using two models: an etiologic model (rate based) and a predictive model (risk based). In both models, random effects (shared frailties) were introduced to assess heterogeneity. Death and discharge without NI are treated as competing events for NI.

Results

There was a large heterogeneity across ICUs in NI hazard rates, which remained after accounting for multilevel risk factors, meaning that there are remaining unobserved ICU-specific factors that influence NI occurrence. Heterogeneity across ICUs in terms of cumulative probability of NI was even more pronounced. Several risk factors had markedly different associations in the rate-based and risk-based models. For some, the associations differed in magnitude. For example, high Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were associated with modest increases in the rate of nosocomial bacteremia, but large increases in the risk. Others differed in sign, for example respiratory vs cardiovascular diagnostic categories were associated with a reduced rate of nosocomial bacteremia, but an increased risk.

Conclusions

A combination of competing risks and multilevel models is required to understand direct and indirect risk factors for NI and distinguish patient-level from ICU-level factors.

Epidemiological study of Clostridium difficile infection in critical patients admitted to the Intensive Care Unit

Data on the epidemiology of infections caused by Clostridium difficile (CDI) in critically ill patients are scarce and center on studies with a limited time framework and/or epidemic outbreaks.

OBJECTIVE

To describe the characteristics and risk factors of critically ill patients admitted to the ICU with CDI, as well as the treatments used for the control of such infections.

MATERIAL AND METHODS

A retrospective study was made of patients included in the ENVIN-ICU registry with CDI in 2012. Patients were followed up to 72 h after discharge from the ICU. A case report form was used to record the following data: demographic variables, risk factors related to CDI, treatment and outcome. Infections were classified as community-acquired, nosocomial out-ICU and nosocomial in-ICU, according to the day on which Clostridium difficile isolates were obtained. Infection rates as episodes per 10,000 days of ICU stay are presented. The global in-ICU and hospital mortality rates were calculated.

RESULTS

Sixty-eight episodes of CDI in 33 out of a total of 173 ICUs participating in the registry were recorded (19.1%) (2.1 episodes per 10,000 days of ICU stay). Forty-five patients were men (66.2%), with a mean (SD) age of 63.4 (16.4) years, a mean APACHE II score on ICU admission of 19.9 (7.4), and an underlying medical condition in 44 (64.7%). Sixty-two patients (91.2%) presented more than 3 liquid depositions/day, 40 (58.8%) in association with severe sepsis or septic shock. Community-acquired infection occurred in 13 patients (19.1%), nosocomial out-ICU infection in 13 (19.1%), and in-ICU infection in 42 (61.8%). Risk factors included age>64 years in 39 cases (57.4%), previous hospital admission (3 months) in 32 (45.6%), use of antimicrobials (previous 7 days) in 57 (83.8%), enteral nutrition in 23 (33.8%), and the use of H2 inhibitors in 39 (57.4%). Initial combined treatment was administered to 18 patients (26.5%). Metronidazole was used in 60 (88.2%) and vancomycin in 31 (45.6%). The in-ICU mortality rate was 25.0% (n=17), with a hospital mortality 27.9% (n=19).

CONCLUSIONS

The rate of ICD in ICU patients is low, the infection affects severely ill patients, and is associated with high mortality. The presence of CDI is a marker of poor prognosis.

Safety and pharmacokinetics of intravenous zanamivir treatment in hospitalized adults with influenza: an open-label, multicenter, single-arm, phase II study

Background. Intravenous zanamivir is a neuraminidase inhibitor suitable for treatment of hospitalized patients with severe influenza.

Methods. Patients were treated with intravenous zanamivir 600 mg twice daily, adjusted for renal impairment, for up to 10 days. Primary outcomes included adverse events (AEs), and clinical/laboratory parameters. Pharmacokinetics, viral load, and disease course were also assessed.

Results. One hundred thirty patients received intravenous zanamivir (median, 5 days; range, 1–11) a median of 4.5 days (range, 1–7) after onset of influenza; 83% required intensive care. The most common influenza type/subtype was A/H1N1pdm09 (71%). AEs and serious AEs were reported in 85% and 34% of patients, respectively; serious AEs included bacterial pulmonary infections (8%), respiratory failure (7%), sepsis or septic shock (5%), and cardiogenic shock (5%). No drug-related trends in safety parameters were identified. Protocol-defined liver events were observed in 13% of patients. The 14- and 28-day all-cause mortality rates were 13% and 17%. No fatalities were considered zanamivir related. Pharmacokinetic data showed dose adjustments for renal impairment yielded similar zanamivir exposures. Ninety-three patients, positive at baseline for influenza by quantitative polymerase chain reaction, showed a median decrease in viral load of 1.42 log₁₀ copies/mL after 2 days of treatment.

Conclusions. Safety, pharmacokinetic and clinical outcome data support further investigation of intravenous zanamivir.

Clinical Trials Registration NCT01014988.

Cost-Effectiveness Analysis of the Treatment of Ventilator-Associated Pneumonia with Linezolid or Vancomycin in Spain

The aim of this study was to assess the cost-effectiveness of linezolid (LIN) versus vancomycin (VAN) for the treatment of ventilator-associated pneumonia (VAP) using a decision model analysis from the National Health System perspective. Patients and participants comprising four subgroups were analyzed: all, Gram-positive (GP), Staphylococcus aureus (SA), methicillin-resistant SA (MRSA). The treatments were LIN 600 mg i.v., every 12 hours, 10 days and VAN 1,000 mg i.v., every 12 hours 10 days. The primary outcome was the incremental cost-effectiveness of LIN in terms of cost per added quality-adjusted life year (QALY) gained. The secondary outcome was the marginal cost per year of life saved (LYS) generated by using LIN. Clinical cure and survival rates estimates were derived from a retrospective analysis of two trials comparing LIN with VAN. QALY was based on time-trade off study. Resource use and unit costs (Euros 2003) were obtained from Spanish VAP treatment and health cost databases. The additional QALY and LYS per LIN patients were 0.392; 0.688; 0.606; 1.805 and 0.471; 0.829; 0.729; 2.175 respectively, compared with those of VAN in the patients with VAP (all, GP, SA, and MRSA, respectively). The additional costs for LYS with LIN, as compared to VAN were 1,501.31; 827.63; 955.13 and 289.51 Euros, respectively. The additional cost per QALY with LIN was 1,803.87; 997.25; 1,149.00 and 348.85 Euros, respectively.

CONCLUSIONS

LIN was more cost-effective than VAN in the treatment of VAP in Spain, with an additional cost per QALY/LYS gained below the acceptable threshold in Spain of Euros 30,000 for new therapies.

Differences in pharmacokinetics and pharmacodynamics of colistimethate sodium (CMS) and colistin between three different CMS dosage regimens in a critically ill patient infected by a multidrug-resistant Acinetobacter baumannii

Use of colistin has re-emerged for the treatment of infections caused by multidrug-resistant (MDR) Gram-negative bacteria, but information on its pharmacokinetics and pharmacodynamics is limited, especially in critically ill patients. Recent data from pharmacokinetic/pharmacodynamic (PK/PD) population studies have suggested that this population could benefit from administration of higher than standard doses of colistimethate sodium (CMS), but the relationship between administration of incremental doses of CMS and corresponding PK/PD parameters as well as its efficacy and toxicity have not yet been investigated in a clinical setting. The objective was to study the PK/PD differences of CMS and colistin between three different CMS dosage regimens in the same critically ill patient. A critically ill patient with nosocomial pneumonia caused by a MDR Acinetobacter baumannii received incremental doses of CMS. During administration of the different CMS dosage regimens, CMS and colistin plasma concentrations were determined and PK/PD indexes were calculated. With administration of the highest CMS dose once daily (720 mg every 24h), the peak plasma concentration of CMS and colistin increased to 40.51 mg/L and 1.81 mg/L, respectively, and the AUC0-24/MIC of colistin was 184.41. This dosage regimen was efficacious, and no nephrotoxicity or neurotoxicity was observed. In conclusion, a higher and extended-interval CMS dosage made it possible to increase the exposure of CMS and colistin in a critically ill patient infected by a MDR A. baumannii and allowed a clinical and microbiological optimal response to be achieved without evidence of toxicity.

Epidemiology, diagnosis and treatment of fungal respiratory infections in the critically ill patient

OBJECTIVE

To elaborate practical recommendations based on scientific evidence, when available, or on expert opinions for the diagnosis, treatment and prevention of fungal respiratory infections in the critically ill patient, including solid organ transplant recipients.

METHODS

Twelve experts from two scientific societies (The Spanish Society for Chemotherapy and The Spanish Society of Intensive Care and Coronary Units) reviewed in a meeting held in March 2012 epidemiological issues and risk factors as basis for a document about prevention, diagnosis and treatment of respiratory fungal infections caused by Candida spp., Aspergillus spp or Zygomycetes.

RESULTS

Despite the frequent isolation of Candida spp. from respiratory tract samples, antifungal treatment is not recommended since pneumonia by this fungal species is exceptional in non-neutropenic patients. In the case of Aspergillus spp., approximately 50% isolates from the ICU represent colonization, and the remaining 50% cases are linked to invasive pulmonary aspergillosis (IPA), an infection of high mortality. Main risk factors for invasive disease in the ICU are previous treatment with steroids and chronic obstructive pulmonary disease (COPD). Collection of BAL sample is recommended for culture and galactomannan determination. Voriconazole and liposomal amphotericin B have the indication as primary therapy while caspofungin has the indication as salvage therapy. Although there is no solid data supporting scientific evidence, the group of experts recommends combination therapy in the critically ill patient with sepsis or severe respiratory failure. Zygomycetes cause respiratory infection mainly in neutropenic patients, and liposomal amphotericin B is the elective therapy.

CONCLUSIONS

Presence of fungi in respiratory samples from critically ill patients drives to different diagnostic and clinical management approaches. IPA is the most frequent infection and with high mortality.

Device-associated infection rates in Adult Intensive Care Units in Catalonia: VINCat Program findings

Hospital-acquired infections are a leading cause of morbidity and mortality, especially in the intensive care unit (ICU). Surveillance of device-associated infections plays a major role in infection control programs. In 2006, the Surveillance Program of Nosocomial Infections in Catalonia (VINCat Program) was started, with the major aim of reducing infection rates through a process of active monitoring. The study period comprised calendar years 2008 (with 21 ICUs participating), 2009 (with 21 ICUs participating), and 2010 (with 28 ICUs participating). Each participating hospital was required to have an infection control team made up of at least one physician, an infection surveillance nurse, and a microbiology laboratory. Hospitals were classified into three groups according to their size. Central venous catheter-associated bloodstream infection (CVC-BSI) and ventilator-associated pneumonia (VAP) were chosen as the device-associated infections to analyze. Incidence rates of device-associated infections were calculated by dividing the total number of device-associated infection (VAP or CVC-BSI) days by the total number of days use for the relevant device. Mechanical ventilation use ranged from 0.10 to 0.85 days (overall, 0.35), and central venous catheter use ranged from 0.18 to 0.98 days (overall, 0.65). Incidence rates of VAP ranged from 7.2 ± 3.7 to 10.7 ± 9.6 episodes of VAP/1000 ventilator days. Incidence rates of CVC-BSl ranged from 1.9 ± 1.6 to 2.7 ± 2.0 episodes of CVC-associated bloodstream infection/1000 central venous catheter days. The implementation of the VINCat Program allowed monitoring of nosocomial device-associated infections in ICUs in Catalonia and enabled corrective measures in ICUs with increased incidences of device-associated infections.

Impact of liposomal amphotericin B on renal function in critically ill patients with renal function impairment

OBJECTIVE

To assess the tolerability of liposomal amphotericin B (L-AmB) in critically ill patients with elevated serum creatinine concentrations (Cr) (> 1.5 mg/dL) at starting L-AmB therapy.

METHODS

Retrospective, multicenter, comparative study of two cohorts of critically ill patients treated with L-AmB during 3 or more days, the difference between them was the level of Cr at the beginning of treatment. A cutoff value of Cr of 1.5 mg/dL was established. Patients undergoing extrarenal depuration procedures before or 48 hours after starting L-AmB were excluded. The primary endpoint was the difference between Cr values at the end of treatment as compared with Cr at starting L-AmB. Secondary endpoints were treatment-related withdrawals, need of extrarenal depuration techniques, and treatment-related severe adverse events. Demographic data, underlying illness, indication of L-AmB therapy, concomitant risk factors of nephrotoxicity, and vital status at ICU and hospital discharge were recorded.

RESULTS

A total of 122 patients admitted to 26 ICUs (16 with Cr > 1.5 g/dL; 106 with normal Cr levels) were recruited. Main reasons for the use of L-AmB in both groups were the broad spectrum of the drug and the presence of hemodynamic instability. L-AmB was administered as first-line treatment in 68.8% of patients with elevated Cr and in 52.8% with normal Cr. The APACHE II score on ICU admission was 25 in patients with elevated Cr and 17 in those with normal Cr values (p < 0.001). Duration of treatment with L-AmB was 16 and 12 days in patients with elevate and normal Cr values, respectively, with a mean dose of 3.5 vs 3.9 mg/kg/day. The use of concomitant nephrotoxic drugs, mortality rate, and ICU and hospital length of stay were similar in both cohorts. In patients with renal function impairment at the initiation of L-AmB treatment, an absolute decrease of Cf-Ci of 1.08 mg/dL was observed (P < 0.001). A decrease of Cr levels to normal limits was observed in 50% of the patients; in 37.5% of patients there was a decrease but normal levels were not achieved, whereas a Cr increased occurred in only one (6.25%) patient. None of the patients required withdrawal of L-AmB or use of extrarenal depuration procedures. Treatment-related severe adverse events were not reported.

CONCLUSIONS

In critically ill patients with impaired renal function, the impact of L-AmB on renal function was minimal. L-AmB can be used for the treatment of fungal infections in critically ill patients independently of renal function at the initiation of treatment.

Urethral catheter-related urinary infection in critical patients admitted to the ICU. Descriptive data of the ENVIN-UCI study

OBJECTIVE

To describe trends in national catheter-related urinary tract infection (CRUTI) rates, as well as etiologies and multiresistance markers.

DESIGN

An observational, prospective, multicenter voluntary participation study was conducted from 1 April to 30 June in the period between 2005 and 2010.

SETTING

Intensive Care Units (ICUs) that participated in the ENVIN-ICU registry during the study period.

PATIENTS

We included all patients admitted to the participating ICUs and patients with urinary catheter placement for more than 24 hours (78,863 patients).

INTERVENTION

Patient monitoring was continued until discharge from the ICU or up to 60 days.

VARIABLES OF INTEREST

CRUTIs were defined according to the CDC system, and frequency is expressed as incidence density (ID) in relation to the number of urinary catheter-patients days.

RESULTS

A total of 2329 patients (2.95%) developed one or more CRUTI. The ID decreased from 6.69 to 4.18 episodes per 1000 days of urinary catheter between 2005 and 2010 (p<0.001). In relation to the underlying etiology, gramnegative bacilli predominated (55.6 to 61.6%), followed by fungi (18.7 to 25.2%) and grampositive cocci (17.1 to 25.9%). In 2010, ciprofloxacin-resistant E. coli strains (37.1%) increased, as well as imipenem-resistant (36.4%) and ciprofloxacin-resistant (37.1%) strains of P. aeruginosa.

CONCLUSIONS

A decrease was observed in CRUTI rates, maintaining the same etiological distribution and showing increased resistances in gramnegative pathogens, especially E. coli and P. aeruginosa.

[Trends in systemic antifungal use in critically ill patients. Multicenter observational study, 2006-2010]

INTRODUCTION

There are limited data about the use of antifungal agents (AF) in critically ill patients and treatment trends since the inclusion of the new generation AF. The use of these agents may have a significant influence on the development of new resistances.

METHODS

Observational prospective study of the systemic use of AF in patients admitted to Spanish intensive care units (ICU) participating in the ENVIN-HELICS register, from 2006 to 2010. The annual use, the indications that led to that use and, the intra-ICU infections, the AF employment related to the hospital size, and per 1000 patients/day, were compared.

RESULTS

Of the 8240 prescriptions for AF, fluconazole and caspofungin were the most often employed (55% and 19.5%, respectively). An increase in use was observed to the year 2008, with subsequent stabilisation. A decrease in the use of fluconazole and an increase in echinocandins consumption was observed over time. As regards the intra-ICU infections, the AF were ordered empirically in 47.9% of the indications. Fluconazole was more frequently used in medium size hospitals than in the large ones (60.4% versus 53.3%; P=.036) and the opposite occurred in the case of caspofungin (15.8% versus 21.8%; P<.001). Fluconazole was more prematurely employed (median 12 days since ICU admission) and the duration of the therapy was similar to the other AF (median 8 days). The total therapy days were 39.51 per 1000 patient/day, with predominance in fluconazole use (21.48 per 1000 patients/day).

CONCLUSIONS

Fluconazole is the most used antifungal agent in critically ill patients in any of the indications, although a progressive decrease in its use is observed, with a proportional increase in the use of echinocandins.

[Predictive factors for pneumonia in adults infected with the new pandemic A (H1H1) influenza virus]

BACKGROUND

On April 2009 a new A (H1N1) influenza virus was identified with a higher incidence of severe outcome in younger people, most of them with pneumonia. The objective of our study was to identify the predictive risk factors of pneumonia in patients with the new A (H1N1) influenza virus infection.

METHODS

Prospective cohort study of adults infected with the new A (H1N1) influenza virus, admitted in a universitary hospital, from june 2009 to January 2010. Pneumonia was defined as the presence of any pulmonary infiltrate of any distribution with no other evident cause, in the chest radiography. A comparative analysis was made with patients with A (H1N1) influenza without pneumonia.

RESULTS

281 patients with influenza A (H1N1) were treated. Thirty of them (10.6%) had pneumonia and 11 (3.9%) required intensive care. The global mortality was 0.7%. For the comparative analysis, 42 patients with influenza A (H1N1) without pneumonia were analysed (20 hospitalized and 22 nonhospitalised). In the multivariate analysis, obesity (BMI>30), (OR: 3.8; IC 95%: 0.99-15.0), time since symptom onset until hospital admission (OR 1.34; IC 95% 1.04-1.72), serum C reactive protein levels (OR:1.10; IC 95%: 0.98-1.24) and serum IgG2 levels (OR:1.08; IC 95%: 1.0- 1.01), were identified as independent risk factors for pneumonia.

CONCLUSION

Obesity, delay in medical care and higher levels of C reactive protein and IgG2 were predictive factors for pneumonia in adult patients with A (H1N1) influenza infection.

[Daptomycin for the treatment of Gram-positive microorganisms in the critically-ill patient]

INTRODUCTION

Infections caused by multiresistant Gram-positive cocci have increased among critically ill patients admitted to the intensive care unit (ICU). In the last few years, treatment of these infections has changed due to better knowledge of the limitations of glycopeptides and the introduction of novel antimicrobials, such as daptomycin.

OBJECTIVES

To describe the characteristics of daptomycin that justify its administration in critically ill patients and to present data on the use of this antibiotic in patients admitted to Spanish ICUs.

MATERIAL AND METHOD

We reviewed the literature on daptomycin to identify the characteristics that may favor clinical response in critically ill patients. To describe the indications and modalities of use in critically patients, information from the European Cubicin(®) Outcome Registry and Experience (EUCORE) database of Spanish patients admitted to the ICU was employed.

RESULTS

The following favorable conditions were identified: a) scarce systemic response, maintaining high bactericidal activity, b) scarce impact on renal function, c) no requirement for monitoring of plasma levels, d) scarce selection of resistance, and d) excellent tolerability. To assess indications and the use of this agent in the ICU, 122 patients from the EUCORE database were analyzed. The indications were bacteremias (36.2%), complicated infections of the skin and soft tissues (27.6%), and endocarditis (19%). Prominent pathogens were Staphylococcus aureus (26%), S. epidermidis (25%), and other coagulase-negative staphylococci (12%). In 85.7% of patients, treatment was administered as second-line (rescue treatment). In 65 patients (52%), a dose of 6 mg/kg/day was used, with a mean treatment duration of 10.2 days. Overall clinical efficacy was 73.7%. No adverse effects leading to treatment withdrawal were recorded and no increases in creatine phosphokinase (CPK) levels greater than 10-fold the initial values were observed.

CONCLUSIONS

Daptomycin is a novel therapeutic option to be considered in the treatment of severe infections caused by Gram-positive cocci in critically-ill patients.

[Guidelines for the treatment of Invasive Candidiasis and other yeasts. Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC). 2010 Update]

These guidelines are an update of the recommendations of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) that were issued in 2004 (Enferm Infecc Microbiol Clin. 2004, 22:32-9) on the treatment of Invasive Candidiasis and infections produced by other yeasts. This 2010 update includes a comprehensive review of the new drugs that have appeared in recent years, as well as the levels of evidence for recommending them. These guidelines have been developed following the rules of the SEIMC by a working group composed of specialists in infectious diseases, clinical microbiology, critical care medicine, paediatrics and oncology-haematology. It provides a series of general recommendations regarding the management of invasive candidiasis and other yeast infections, as well as specific guidelines for prophylaxis and treatment, which have been divided into four sections: oncology-haematology, solid organ transplantation recipients, critical patients, and paediatric patients.

Impact of early oseltamivir treatment on outcome in critically ill patients with 2009 pandemic influenza A

OBJECTIVES

The impact of oseltamivir on mortality in critically ill patients with 2009 pandemic influenza A (2009 H1N1) is not clear. The main objective of this study was to investigate the relationship between the timing of antiviral administration and intensive care unit (ICU) outcomes.

METHODS

Prospective, observational study of a cohort of ICU patients with confirmed 2009 H1N1 infection. Clinical data, treatment and outcome were compared between patients receiving early treatment (ET) with oseltamivir, initiated within 2 days, and patients administered late treatment (LT), initiated after this timepoint. Multivariate analysis and propensity score were used to determine the effect of oseltamivir on ICU mortality.

RESULTS

Six hundred and fifty-seven patients were enrolled. Four hundred and four (61.5%) patients required mechanical ventilation (MV; mortality 32.6%). Among them, 385 received effective antiviral therapy and were included in the study group. All patients received oseltamivir for a median duration of 10 days (interquartile range 8-14 days). Seventy-nine (20.5%) ET patients were compared with 306 LT patients. The two groups were comparable in terms of main clinical variables. ICU length of stay (22.7 ± 16.7 versus 18.4 ± 14.2 days; P = 0.03), hospital length of stay (34.0 ± 20.3 versus 27.2 ± 18.2 days; P = 0.001) and MV days (17.4 ± 15.2 versus 14.0 ± 12.4; P = 0.04) were higher in the LT group. ICU mortality was also higher in LT (34.3%) than in ET (21.5%; OR = 1.9; 95% CI 1.06-3.41). A multivariate model identified ET (OR = 0.44; 95% CI 0.21-0.87) as an independent variable associated with reduced ICU mortality. These results were confirmed by propensity score analysis (OR = 0.44; 95% CI 0.22-0.90; P < 0.001).

CONCLUSIONS

Our findings suggest that early oseltamivir administration was associated with favourable outcomes among critically ill ventilated patients with 2009 H1N1 virus infection.

[Impact of primary and intravascular catheter-related bacteremia due to coagulase-negative staphylococci in critically ill patients]

OBJECTIVE

To study the impact of coagulase-negative staphylococcal (CNS) primary and intravascular catheter-related bloodstream infection (PBSI/CRBSI) on mortality and morbidity in critically-ill patients.

DESIGN

We performed a double analysis using data from the ENVIN-HELICS registry data (years 1997 to 2008): 1) We studied the clinical characteristics and outcomes of patients with CNS-induced PBSI/CRBSI and compared them with those of patients with PBSI/CRBSI caused by other pathogens; and 2) We analyzed the impact of CNS-induced PBSI/CRBSI using a case-control design (1:4) in patients without other nosocomial infections.

SETTING

167 Spanish Intensive Care Units.

PATIENTS

Patients admitted to ICU for more than 24 hours.

RESULTS

2,252 patients developed PBSI/CRBSI, of which 1,133 were caused by CNS. The associated mortality for PBSI/CRBSI caused by non-CNS pathogens was higher than that of the CNS group (29.8% vs. 25.9%; P=.039) due exclusively to the mortality of patients with candidemia (mortality: 45.9%). In patients without other infections, PBSI/CRBSI caused by CNS (414 patients) is an independent risk factor for a higher than average length of ICU stay (OR: 5.81, 95% CI: 4.31-7.82; P<.001).

CONCLUSION

Crude mortality of patients with CNS-induced BPSI/CRBSI is similar to that of patients with BPSI/CRBSI caused by other bacteria, but lower than that of patients with candidemia. Compared to patients without nosocomial infections, CNS-induced PBSI/CRBSI is associated with a significant increase in length of ICU stay.

Factors associated with adherence to guidelines for the use of tigecycline in a tertiary care hospital

We assessed the adherence to the prescribing hospital protocol for tigecycline and factors associated with noncompliance. A total of 103 patients were included in the study. In 23 (22.3%) patients, tigecycline was not administered according to the protocol, mostly because of the availability of other therapeutic alternatives and prescription for indications that were not included in the guidelines. factors independently associated with nonadherence to the protocol were community-acquired infection (OR, 14.01; 95% CI, 1.54-127.12; P=0.019), and empirical tigecycline treatment (OR, 6.97; 95% CI, 0.88-55.40; P=0.066). penicillin allergy (OR, 0.004; 95% CI, 0.000-0.071; P=0.001) and previous antibiotic treatment (OR, 0.025; 95% CI, 0.003-0.233; P=0.001) were factors associated with adherence to the hospital protocol. A positive time trend between total number of prescriptions and non-compliant prescriptions with the protocol was observed (Spearman's rho coefficient 0.971; P=0.001). Adherence to tigecycline protocol could be improved by focusing on protocols for community-acquired infections, mainly skin and soft tissue infections.

[Experience of micafungin in patients requiring extrarenal depuration]

INTRODUCTION

The use of extrarenal depuration techniques is increasingly frequent in patients admitted to the ICU. The use of these procedures has been related to a decrease in plasma concentrations of several antimicrobials, among which fluconazole. The activity of antifungal agents depends on achievement on adequate concentrations in plasma and at the site of infection. Micafungin is a new antifungal drug recently introduced in our country.

OBJECTIVE

To review the published experience of pharmacokinetic (PK) parameters of micafungin in patients requiring some type of extrarenal depuration procedures during their stay in the ICU.

RESULTS

Three studies with data on PK parameters of micafungin during the use of this drug in continuous venovenous hemodialysis (2 publications) and continuous hemodiafiltration (1 publication) were retrieved. In all of them, minimal variations in the plasma concentration of micafungin at the entry and exit sites of the hemofilter and a negligible or minimal presence of micafungin in the ultrafiltration fluid were demonstrated.

CONCLUSIONS

Adjustment of the doses or the interval between doses of micafungin during the use of extrarenal depuration techniques in critically ill patients admitted to the ICU is not necessary.

Health-care-associated bloodstream infections at admission to the ICU

BACKGROUND

Infections occurring among outpatients having recent contact with the health-care system have been recently classified as health-care-associated infections to distinguish them from hospital- and community-acquired infections. Patients with bloodstream infections (BSIs) were studied to assess health-care-associated infections at admission in the ICU.

METHODS

This work was a multicenter, prospective, observational study of all adult patients with BSI at ICU admission at 27 Spanish hospitals and one Argentine hospital. Cases of BSI were classified as community-acquired BSI (CAB), health-care-associated BSI (HCAB), or hospital-acquired BSI (HAB), and their characteristics were compared.

RESULTS

Of 726 BSIs, 343 (47.2%) were CABs, 252 (34.7%) were HABs, and 131 (18.0%) were HCABs. Potentially antibiotic-resistant pathogens were more frequently isolated in HABs (34.8%) and HCABs (27.6%) than in CABs (10.3%) (P < .001). Logistic regression analysis revealed that HABs (OR, 4.6; 95% CI, 2.9-7.3), HCABs (OR, 3.1; 95% CI, 1.8-5.4), and BSIs of unknown origin (OR, 1.7; 95% CI, 1.0-2.8) were independently associated with the isolation of potentially antibiotic-resistant pathogens. The incidence of inappropriate treatment was significantly higher in HABs (OR, 3.4; 95% CI, 2.1-5.3) and in HCABs (OR, 1.8; 95% CI, 1.0-3.2) than in CABs.

CONCLUSIONS

One in five BSIs diagnosed at ICU admission is health-care-associated. The incidence of potentially drug-resistant pathogens in HCABs is more similar to that of HABs, and they should be treated as such until culture data are available.

[Differences in the use of tigecycline between ICU patients and non-ICU patients]

BACKGROUND

Tigecycline is a new broad spectrum antibiotic that is predominantly used for the treatment of severe infections both in critically ill patients admitted to the ICU and in non-ICU patients with less severe clinical conditions.

OBJECTIVE

To assess differences in the use of tigecycline between ICU patients and non-ICU patients treated with this antibiotics.

MATERIALS AND METHODS

Retrospective, cohort, observational study in which cases were defined as patients who received one or more doses of tigecycline over the first 18 months after approval of the drug in a general hospital. Clinical characteristics, indications, route of administration, clinical response, tolerability and outcome were recorded in the groups of ICU and non-ICU patients. Descriptive data and results of the comparison of both cohorts are presented.

RESULTS

A total of 103 were included in the study, 34(33%) of which received tigecycline during their stay in the ICU. ICU patients compared to non-ICU patients had a higher SAPS II score on admission (39.0 +/- 11.8 vs 26.3 +/- 8.0, p < 0.001) and at the time of starting tigecycline treatment (42.2 +/- 12.6 vs 25.6 +/- 8.2, p < 0.001), were treated with antibiotics for more days (21.4 +/- 30.6 vs 13.6 +/- 30.5 days, p < 0.012) and received a greater number of antibiotic agents concomitantly (85.3% vs 47.8%,p < 0.001), presented a higher selection of emerging bacterial flora (41.2% vs 15.9%, p =0.005), particularly Pseudomonas aeruginosa (20.6%vs 2.9%, p =0.006), higher rate of clinical failure (58.8%vs 21.7%, p < 0.001), longer hospitalization (51.2 +/- 39.4 vs 28.7 +/- 26.3 days, p < 0.001) and higher overall mortality rate (50% vs 14.5%, p < 0.001) and infection-attributed mortality (20.6% vs 7.2%, p =0.047).

CONCLUSIONS

The patient that receives tigecycline in the ICU has a higher severity level and worse clinical outcome than the non-ICU patient treated with this antibiotic. It is necessary to optimize the indications of tigecycline in the ICU to improve the clinical results.

Characteristics of doripenem: a new broad-spectrum antibiotic

Doripenem (S-4661) is a new parenteral antibiotic from the carbapenem class; similarly to imipenem and meropenem, it has a broad-spectrum activity against Gram-positive, Gram-negative, and anaerobic bacteria. It is active against multiresistant Gram-negative bacilli such as extended-spectrum beta-lactamase-producing (ESBL) Gram-negative Enterobacteriaceae and nonfermentative Gram-negative bacilli including some strains of Pseudomonas aeruginosa that are resistant to other carbapenems. Doripenem’s chemical structure is similar to that of meropenem (substitution of one sulfamoxil-aminomethyl chain for the dimethyl-carboxyl chain), and has one 1-beta-methyl chain which provides resistance to dehydropeptidase-I enzyme. The clinical trials conducted so far have focused on the treatment of severe infections such as complicated intra-abdominal infections, complicated urinary tract infections and pyelonephritis, nosocomial pneumonia, and ventilator-associated pneumonia. Given its activity profile and the results from the clinical trials, this antibiotic may be used for empirical treatment of multibacterial infections produced by potentially multiresistant Gram-negative bacilli. In 2007, the US Food and Drug Administration approved the use of doripenem for the treatment of complicated intra-abdominal infections and complicated urinary tract infections. The European Medicines Agency has approved the use of doripenem for the same indications in addition to nosocomial pneumonia regardless of whether it is ventilator-associated or not.

Intensive care adult patients with severe respiratory failure caused by Influenza A (H1N1)v in Spain

INTRODUCTION

Patients with influenza A (H1N1)v infection have developed rapidly progressive lower respiratory tract disease resulting in respiratory failure. We describe the clinical and epidemiologic characteristics of the first 32 persons reported to be admitted to the intensive care unit (ICU) due to influenza A (H1N1)v infection in Spain.

METHODS

We used medical chart reviews to collect data on ICU adult patients reported in a standardized form. Influenza A (H1N1)v infection was confirmed in specimens using real-time reverse transcriptase-polymerase-chain-reaction (RT PCR) assay.

RESULTS

Illness onset of the 32 patients occurred between 23 June and 31 July, 2009. The median age was 36 years (IQR = 31 - 52). Ten (31.2%) were obese, 2 (6.3%) pregnant and 16 (50%) had pre-existing medical complications. Twenty-nine (90.6%) had primary viral pneumonitis, 2 (6.3%) exacerbation of structural respiratory disease and 1 (3.1%) secondary bacterial pneumonia. Twenty-four patients (75.0%) developed multiorgan dysfunction, 7 (21.9%) received renal replacement techniques and 24 (75.0%) required mechanical ventilation. Six patients died within 28 days, with two additional late deaths. Oseltamivir administration delay ranged from 2 to 8 days after illness onset, 31.2% received high-dose (300 mg/day), and treatment duration ranged from 5 to 10 days (mean 8.0 +/- 3.3).

CONCLUSIONS

Over a 5-week period, influenza A (H1N1)v infection led to ICU admission in 32 adult patients, with frequently observed severe hypoxemia and a relatively high case-fatality rate. Clinicians should be aware of pulmonary complications of influenza A (H1N1)v infection, particularly in pregnant and young obese but previously healthy persons.

Use of liposomal amphotericin B in critically ill patients: a retrospective, multicenter, clinical study

The clinical use of liposomal amphotericin B in 179 patients admitted to 30 medical-surgical intensive Care Units (ICUs) treated with this agent in 2006 was analyzed. Invasive fungal infections were proven, probable and possible in 44%, 16%, and 25% of cases, respectively. Fungi isolated were Candida albicans (38%), non-albicans Candida spp. (15%) and Aspergillus spp. (7%). The mean duration of treatment was 15 days (mean dose 3.7 mg/kg/day). The drug was used as rescue treatment after fluconazole or caspofungin in 47% of patients and as first line in 52% with a satisfactory clinical response in 54% of cases (72.6% with proven infection). Microbiological eradication was achieved in 68% of cases. Adverse events occurred in 51 patients but were severe in only 4. The use of liposomal amphotericin B both as first line and rescue treatment and mainly for proven invasive fungal infection was associated with a high rate of satisfactory clinical response.

[Recommendations in the empiric anti-infective agents of intra-abdominal infection]

A significant number of patients with abdominal infection develop advanced stages of infection and mortality is still above 20%. Failure is multifactorial and is associated with an increase of bacterial resistance, inappropriate empirical treatment, a higher comorbidity of patients and poor source control of infection. These guidelines discuss each of these problems and propose measures to avoid the failure based on the best current scientific evidence.

Effectiveness and safety of colistin for the treatment of multidrug-resistant Pseudomonas aeruginosa infections

PURPOSE

To describe the clinical and microbiological outcomes of patients infected with multidrug-resistant Pseudomonas aeruginosa (MDRP) treated with colistin (colistimethate sodium) and the adverse events observed with this treatment.

METHODS

Retrospective study of MDRP infections treated with colistin from 1997 to 2006.

RESULTS

121 episodes were identified. The median daily intravenous dose was 240 mg/day; 28.9% of patients received intravenous and nebulized colistin. Clinical outcome was favorable in ten cases of bacteremia (62.5%, n = 16), 43 cases of bronchial infection (72.9%, n = 59), 13 cases of pneumonia (65%, n = 20), 11 cases of urinary infection (84.6%, n = 13), eight cases of skin and soft tissues (72.7%, n = 11), and in the one case of arthritis and one case of otitis. Eradication was achieved in 31 (34.8%) of the 89 patients with available bacteriologic data. Factors associated with bacteriological failure were smoking, chronic obstructive pulmonary disease (COPD), and previous infection with P. aeruginosa. Nephrotoxicity occurred in ten cases (8.3%), with the associated factors being previous chronic renal insufficiency, diabetes mellitus, and aminoglycoside use. Crude mortality was 16.5%, and related MDRP was 12.4%, and was higher in patients with pneumonia or bacteremia (36.1%) than in other types of infections (8.2%).

CONCLUSIONS

Colistin is a safe option for the treatment of MDRP infections, with acceptable clinical outcomes. However, bacteriological eradication is difficult to achieve, especially in COPD patients.