Novel pneumonia score based on a machine learning model for predicting mortality in pneumonia patients on admission to the intensive care unit

BACKGROUND

Scores for predicting the long-term mortality of severe pneumonia are lacking. The purpose of this study is to use machine learning methods to develop new pneumonia scores to predict the 1-year mortality and hospital mortality of pneumonia patients on admission to the intensive care unit (ICU).

METHODS

The study population was screened from the MIMIC-IV and eICU databases. The main outcomes evaluated were 1-year mortality and hospital mortality in the MIMIC-IV database and hospital mortality in the eICU database. From the full data set, we separated patients diagnosed with community-acquired pneumonia (CAP) and ventilator-associated pneumonia (VAP) for subgroup analysis. We used common shallow machine learning algorithms, including logistic regression, decision tree, random forest, multilayer perceptron and XGBoost.

RESULTS

The full data set of the MIMIC-IV database contained 4697 patients, while that of the eICU database contained 13760 patients. We defined a new pneumonia score, the "Integrated CCI-APS", using a multivariate logistic regression model including six variables: metastatic solid tumor, Charlson Comorbidity Index, readmission, congestive heart failure, age, and Acute Physiology Score III. The area under the curve (AUC) and accuracy of the integrated CCI-APS were assessed in three data sets (full, CAP, and VAP) using both the test set derived from the MIMIC-IV database and the external validation set derived from the eICU database. The AUC value ranges in predicting 1-year and hospital mortality were 0.784-0.797 and 0.691-0.780, respectively, and the corresponding accuracy ranges were 0.723-0.725 and 0.641-0.718, respectively.

CONCLUSIONS

The main contribution of this study was a benchmark for using machine learning models to build pneumonia scores. Based on the idea of integrated learning, we propose a new integrated CCI-APS score for severe pneumonia. In the prediction of 1-year mortality and hospital mortality, our new pneumonia score outperformed the existing score.

The NUTRIC Score as a Tool to Predict Mortality and Increased Resource Utilization in Intensive Care Patients with Sepsis

The Nutrition Risk in Critically Ill score (NUTRIC) is an important nutritional risk assessment instrument for patients in the intensive care unit (ICU). The purpose of this study was to evaluate the power of the score to predict mortality in patients treated for sepsis and to forecast increased resource utilization and nursing workload in the ICU. The NUTRIC score predicted mortality (AUC 0.833, p < 0.001) with the optimal cut-off value of 6 points. Among patients with a score ≥ 6 on ICU admission, the 28-day mortality was 61%, and 10% with a score < 6 (p < 0.001). In addition, a NUTRIC score of ≥6 was associated with a more intense use of ICU resources, as evidenced by a higher proportion of patients requiring vasopressor infusion (98 vs. 82%), mechanical ventilation (99 vs. 87%), renal replacement therapy (54 vs. 26%), steroids (68 vs. 31%), and blood products (60 vs. 43%); the nursing workload was also significantly higher in this group. In conclusion, the NUTRIC score obtained at admission to the ICU provided a good discriminative value for mortality and makes it possible to identify patients who will ultimately require intense use of ICU resources and an associated increase in the nursing workload during treatment.

Biogenic nanosilver-fabricated endotracheal tube to prevent microbial colonization in a veterinary hospital

COVID-19 patients have often required prolonged endotracheal intubation, increasing the risk of developing ventilator-associated pneumonia (VAP). A preventive strategy is proposed based on an endotracheal tube (ETT) modified by the in situ deposition of eucalyptus-mediated synthesized silver nanoparticles (AgNPs). The surfaces of the modified ETT were embedded with AgNPs of approximately 28 nm and presented a nanoscale roughness. Energy dispersive X-ray spectroscopy confirmed the presence of silver on and inside the coated ETT, which exhibited excellent antimicrobial activity against Gram-positive and Gram-negative bacteria, and fungi, including multidrug-resistant clinical isolates. Inhibition of planktonic growth and microbial adhesion ranged from 99 to 99.999% without cytotoxic effects on mammalian cells. Kinetic studies showed that microbial adhesion to the coated surface was inhibited within 2 h. Cell viability in biofilms supplemented with human tracheal mucus was reduced by up to 95%. In a porcine VAP model, the AgNPs-coated ETT prevented adhesion of Pseudomonas aeruginosa and completely inhibited bacterial invasion of lung tissue. The potential antimicrobial efficacy and safety of the coated ETT were established in a randomized control trial involving 47 veterinary patients. The microbial burden was significantly lower on the surface of the AgNPs-coated ETT than on the uncoated ETT (p < 0.05). KEY POINTS: • Endotracheal tube surfaces were modified by coating with green-synthesized AgNPs • P. aeruginosa burden of endotracheal tube and lung was reduced in a porcine model • Effective antimicrobial activity and safety was demonstrated in a clinical trial.

Early prediction of ventilator-associated pneumonia in critical care patients: a machine learning model

Background

This study was performed to develop and validate machine learning models for early detection of ventilator-associated pneumonia (VAP) 24 h before diagnosis, so that VAP patients can receive early intervention and reduce the occurrence of complications.

Patients and methods

This study was based on the MIMIC-III dataset, which was a retrospective cohort. The random forest algorithm was applied to construct a base classifier, and the area under the receiver operating characteristic curve (AUC), sensitivity and specificity of the prediction model were evaluated. Furthermore, We also compare the performance of Clinical Pulmonary Infection Score (CPIS)-based model (threshold value ≥ 3) using the same training and test data sets.

Results

In total, 38,515 ventilation sessions occurred in 61,532 ICU admissions. VAP occurred in 212 of these sessions. We incorporated 42 VAP risk factors at admission and routinely measured the vital characteristics and laboratory results. Five-fold cross-validation was performed to evaluate the model performance, and the model achieved an AUC of 84% in the validation, 74% sensitivity and 71% specificity 24 h after intubation. The AUC of our VAP machine learning model is nearly 25% higher than the CPIS model, and the sensitivity and specificity were also improved by almost 14% and 15%, respectively.

Conclusions

We developed and internally validated an automated model for VAP prediction using the MIMIC-III cohort. The VAP prediction model achieved high performance based on its AUC, sensitivity and specificity, and its performance was superior to that of the CPIS model. External validation and prospective interventional or outcome studies using this prediction model are envisioned as future work.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02031-w.

Investigating patient outcomes and healthcare costs associated with ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia is the most frequent infection seen in intensive care units. Of those patients with an endotracheal tube, many will develop ventilator-associated pneumonia within 48 hours of being mechanically ventilated. There are many issues related to mechanical ventilation including costs, patient outcomes and the amount of suffering patients experience during the process.

AIM

To determine the relationship between development of ventilator-associated pneumonia and patient outcomes and costs, including length of stay on mechanical ventilation, in intensive care units (ICU) and in hospital, and mortality rates and to compare results between ventilator-associated pneumonia and non-ventilator-associated pneumonia groups.

METHOD

Cross-sectional, observational design. A convenience sample of 151 patients on mechanical ventilation (101 with ventilator-associated pneumonia and 50 with non-ventilator-associated pneumonia) were recruited from ICUs in two public hospitals in Jordan. APACHE-II scores, SOFA scores and clinical pulmonary infection scores (CPIS) were assessed.

RESULTS

The incidence rate of ventilator-associated pneumonia was 50.9/1000 mechanical ventilation days and the cumulative incidence rate was 66.9% among patients on mechanical ventilation. The mean score of hospital length of stay and CPIS was significantly higher in the ventilator-associated pneumonia than the non-ventilator-associated pneumonia group. Higher disease severity and higher organ failure scores increase the risk of mortality in patients with ventilator-associated pneumonia.

CONCLUSION

A high ventilator-associated pneumonia incidence rate is associated with increased mechanical ventilation, ICU and hospital length of stays, higher mortality and attributed costs. There is a need for continuing education and training for ICU staff to reduce ventilator-associated pneumonia incidence in ICUs.

Clinical Implication of Candida Score in Multidrug-Resistant Pneumonia with Airway Candida Colonization

Background

The growth of Candida in respiratory secretions is usually considered colonization, and antifungal therapy is rarely required. The role of Candida colonization in the progression of bacterial pneumonia remains controversial. The aim of this study was to identify the clinical implication of Candida score by analyzinge the relationship with multidrug-resistant (MDR) pneumonia and prognosis in patients with airway Candida colonization.

Materials and Methods

This study was a retrospective review of patients with airway Candida colonization by bronchial washing or bronchoalveolar lavage. The Candida score was calculated according to the four factors (severe sepsis, surgery at baseline, total parenteral nutrition, and multifocal Candida colonization). Pneumonia related mortality or hopeless discharge expecting death was defined as a poor outcome.

Results

A total of 148 patients were enrolled in the study. In a multivariate analysis model, Candida score was identified as an independent predictor of poor outcomes (odds ratio 2.23; 95% confidential interval 1.57 – 3.17; P <0.001) in pneumonia patients with airway Candida colonization. With a Candida score of three or higher compared with low score group, it was associated with bacterial pneumonia, especially methicillin-resistant Staphylococcus aureus (MRSA) infection (0.0% vs. 15.2%, P = 0.004). In addition, patients with a high Candida score had a longer hospital stay (13 vs. 38 days, P <0.001), longer duration of intensive care (7 vs. 18 days, P <0.001), and higher pneumonia-related mortality (0.0% vs. 45.5%, P <0.001) as compared to the low Candida score group. The Candida score showed a positive correlation with other pneumonia severity scales such as CURB-65 (Confusion, Urea, Respiratory rate, Blood pressure, and age ≥65 years) (r = 0.461, P <0.001), Pneumonia Severity Index (r = 0.397, P <0.001), and predisposition, insult, response, and organ dysfunction (PIRO) score (r = 0.425, P <0.001).

Conclusion

This study revealed that Candida is no longer a bystander of airway colonization, and that it affects the progression of bacterial pneumonia, including multidrug-resistant pathogens, particularly MRSA infection. Also Candida score can be used to predict the prognosis of patients with pneumonia.

COVID-PIRO (Predisposition, Insult, Response, Organ Dysfunction) Score: A Reliable Predictor of Outcomes in COVID-19 Patients Admitted in Intensive Care Unit

Introduction

To measure the severity of sepsis and pneumonia in adult patients with coronavirus disease 2019 (COVID-19), the PIRO model (predisposition, insult, response, organ dysfunction) was adopted as a scoring system. In this study, the PIRO model was modified to classify the severity of pneumonia in adults and predict mortality risk infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), admitted to a tertiary intensive care unit (ICU) in central rural India.

Method

This prospective, observational study was conducted in the Department of Medicine, in rural medical college at Wardha, Maharashtra, India from May 2020 to May 2021. Patients with reverse transcription-polymerase chain reaction (RT-PCR) positive for COVID-19 and whose age was more than 18 years admitted in the intensive care unit were included in the study.

Results

A total of 240 patients were included in the analysis having mean age of 60.27 ± 15.3 years. Number of deaths were 115 out of 240 (48.3%). Mean ICU stay was 9.09 ± 6.34 days. PIRO score ≤14.5 had a mortality rate of 1.25% as compared to the group having PIRO>14.5 which had mortality of 27.5%, with a cure rate of 26.25% and 5% respectively in both groups (p = 0.0001).

Conclusion

COVID-PIRO modified PIRO score was a highly sensitive and specific model in predicting in-hospital mortality but it is moderately sensitive in predicting ICU stay.

Validation of the Predisposition Infection Response Organ (PIRO) dysfunction score for the prognostic stratification of patients with sepsis in the Emergency Department

OBJECTIVE

There are many different methods for computing the Predisposition Infection Response Organ (PIRO) dysfunction score. We compared three PIRO methods (PIRO1 (Howell), PIRO2 (Rubulotta) and PIRO3 (Rathour)) for the stratification of mortality and high level of care admission in septic patients arriving at the Emergency Department (ED) of an Italian Hospital.

DESIGN, SETTING AND PARTICIPANTS

We prospectively collected clinical data of 470 patients admitted due to infection in the ED to compute PIRO according to three different methods. We tested PIRO variables for the prediction of mortality in the univariate analysis. Calculation and comparison were made of the area under the receiver operating curve (AUC) for the three PIRO methods, SOFA and qSOFA.

RESULTS

Most of the variables included in PIRO were related to mortality in the univariate analysis. Increased PIRO scores were related to higher mortality. In relation to mortality, PIRO 1 performed better than PIRO2 at 30 d ((AUC 0.77 (0.716-0.824) vs. AUC 0.699 (0.64-0.758) (p=0.03) and similarly at 60 d (AUC 0.767 (0.715-0.819) vs AUC 0.709 (0.656-0.763)(p=0.55)); PIRO1 performed similarly to PIRO3 (AUC 0.765 (0.71-0.82) at 30 d, AUC 0.754 (0.701-0.806) at 60 d, p=ns). Both PIRO1 and PIRO3 were as good as SOFA referred to mortality (AUC 0.758 (0.699, 0.816) at 30 d vs. AUC 0.738 (0.681, 0.795) at 60 d; p=ns). For high level of care admission, PIRO proved inferior to SOFA.

CONCLUSIONS

We support the use of PIRO1, which combines ease of use and the best performance referred to mortality over the short term. PIRO2 proved to be less accurate and more complex to use, suffering from missing microbiological data in the ED setting.

Predicting ventilator-associated pneumonia with machine learning

Ventilator-associated pneumonia (VAP) is the most common and fatal nosocomial infection in intensive care units (ICUs). Existing methods for identifying VAP display low accuracy, and their use may delay antimicrobial therapy. VAP diagnostics derived from machine learning (ML) methods that utilize electronic health record (EHR) data have not yet been explored. The objective of this study is to compare the performance of a variety of ML models trained to predict whether VAP will be diagnosed during the patient stay.A retrospective study examined data from 6126 adult ICU encounters lasting at least 48 hours following the initiation of mechanical ventilation. The gold standard was the presence of a diagnostic code for VAP. Five different ML models were trained to predict VAP 48 hours after initiation of mechanical ventilation. Model performance was evaluated with regard to the area under the receiver operating characteristic (AUROC) curve on a 20% hold-out test set. Feature importance was measured in terms of Shapley values.The highest performing model achieved an AUROC value of 0.854. The most important features for the best-performing model were the length of time on mechanical ventilation, the presence of antibiotics, sputum test frequency, and the most recent Glasgow Coma Scale assessment.Supervised ML using patient EHR data is promising for VAP diagnosis and warrants further validation. This tool has the potential to aid the timely diagnosis of VAP.

Derivation and Validation of a Novel Severity Scoring System for Pneumonia at Intensive Care Unit Admission

BACKGROUND

Severity stratification scores developed in intensive care units (ICUs) are used in interventional studies to identify the most critically ill. Studies that evaluate accuracy of these scores in ICU patients admitted with pneumonia are lacking. This study aims to determine performance of severity scores as predictors of mortality in critically ill patients admitted with pneumonia.

METHODS

Prospective cohort study in a general ICU in Brazil. ICU severity scores (Simplified Acute Physiology Score 3 [SAPS 3] and Sepsis-Related Organ Failure Assessment [qSOFA]), prognostic scores of pneumonia (CURB-65 [confusion, urea, respiratory rate, blood pressure, age] and CRB-65 [confusion, respiratory rate, blood pressure, age]), and clinical and epidemiological variables in the first 6 hours of hospitalization were analyzed.

RESULTS

Two hundred patients were included between 2015 and 2018, with a median age of 81 years (interquartile range, 67-90 years) and female predominance (52%), primarily admitted from the emergency department (65%) with community-acquired pneumonia (CAP, 80.5%). SAPS 3, CURB-65, CRB-65,and qSOFA all exhibited poor performance in predicting mortality. Multivariate regression identified variables independently associated with mortality that were used to develop a novel pneumonia-specific ICU severity score (Pneumonia Shock score) that outperformed SAPS 3, CURB-65, and CRB-65. The Shock score was validated in an external multicenter cohort of critically ill patients admitted with CAP.

CONCLUSIONS

We created a parsimonious score that accurately identifies patients with pneumonia at highest risk of ICU death. These findings are critical to accurately stratify patients with severe pneumonia in therapeutic trials that aim to reduce mortality.

Validation of the Predisposition Infection Response Organ (PIRO) dysfunction score for the prognostic stratification of patients with sepsis in the Emergency Department

OBJECTIVE

There are many different methods for computing the Predisposition Infection Response Organ (PIRO) dysfunction score. We compared three PIRO methods (PIRO1 (Howell), PIRO2 (Rubulotta) and PIRO3 (Rathour)) for the stratification of mortality and high level of care admission in septic patients arriving at the Emergency Department (ED) of an Italian Hospital.

DESIGN, SETTING AND PARTICIPANTS

We prospectively collected clinical data of 470 patients admitted due to infection in the ED to compute PIRO according to three different methods. We tested PIRO variables for the prediction of mortality in the univariate analysis. Calculation and comparison were made of the area under the receiver operating curve (AUC) for the three PIRO methods, SOFA and qSOFA.

RESULTS

Most of the variables included in PIRO were related to mortality in the univariate analysis. Increased PIRO scores were related to higher mortality. In relation to mortality, PIRO 1 performed better than PIRO2 at 30 d ((AUC 0.77 (0.716-0.824) vs. AUC 0.699 (0.64-0.758) (p=0.03) and similarly at 60 d (AUC 0.767 (0.715-0.819) vs AUC 0.709 (0.656-0.763)(p=0.55)); PIRO1 performed similarly to PIRO3 (AUC 0.765 (0.71-0.82) at 30 d, AUC 0.754 (0.701-0.806) at 60 d, p=ns). Both PIRO1 and PIRO3 were as good as SOFA referred to mortality (AUC 0.758 (0.699, 0.816) at 30 d vs. AUC 0.738 (0.681, 0.795) at 60 d; p=ns). For high level of care admission, PIRO proved inferior to SOFA.

CONCLUSIONS

We support the use of PIRO1, which combines ease of use and the best performance referred to mortality over the short term. PIRO2 proved to be less accurate and more complex to use, suffering from missing microbiological data in the ED setting.

Biomarker-guided antibiotic stewardship in suspected ventilator-associated pneumonia (VAPrapid2): a randomised controlled trial and process evaluation

BACKGROUND

Ventilator-associated pneumonia is the most common intensive care unit (ICU)-acquired infection, yet accurate diagnosis remains difficult, leading to overuse of antibiotics. Low concentrations of IL-1β and IL-8 in bronchoalveolar lavage fluid have been validated as effective markers for exclusion of ventilator-associated pneumonia. The VAPrapid2 trial aimed to determine whether measurement of bronchoalveolar lavage fluid IL-1β and IL-8 could effectively and safely improve antibiotic stewardship in patients with clinically suspected ventilator-associated pneumonia.

METHODS

VAPrapid2 was a multicentre, randomised controlled trial in patients admitted to 24 ICUs from 17 National Health Service hospital trusts across England, Scotland, and Northern Ireland. Patients were screened for eligibility and included if they were 18 years or older, intubated and mechanically ventilated for at least 48 h, and had suspected ventilator-associated pneumonia. Patients were randomly assigned (1:1) to biomarker-guided recommendation on antibiotics (intervention group) or routine use of antibiotics (control group) using a web-based randomisation service hosted by Newcastle Clinical Trials Unit. Patients were randomised using randomly permuted blocks of size four and six and stratified by site, with allocation concealment. Clinicians were masked to patient assignment for an initial period until biomarker results were reported. Bronchoalveolar lavage was done in all patients, with concentrations of IL-1β and IL-8 rapidly determined in bronchoalveolar lavage fluid from patients randomised to the biomarker-based antibiotic recommendation group. If concentrations were below a previously validated cutoff, clinicians were advised that ventilator-associated pneumonia was unlikely and to consider discontinuing antibiotics. Patients in the routine use of antibiotics group received antibiotics according to usual practice at sites. Microbiology was done on bronchoalveolar lavage fluid from all patients and ventilator-associated pneumonia was confirmed by at least 104 colony forming units per mL of bronchoalveolar lavage fluid. The primary outcome was the distribution of antibiotic-free days in the 7 days following bronchoalveolar lavage. Data were analysed on an intention-to-treat basis, with an additional per-protocol analysis that excluded patients randomly assigned to the intervention group who defaulted to routine use of antibiotics because of failure to return an adequate biomarker result. An embedded process evaluation assessed factors influencing trial adoption, recruitment, and decision making. This study is registered with ISRCTN, ISRCTN65937227, and ClinicalTrials.gov, NCT01972425.

FINDINGS

Between Nov 6, 2013, and Sept 13, 2016, 360 patients were screened for inclusion in the study. 146 patients were ineligible, leaving 214 who were recruited to the study. Four patients were excluded before randomisation, meaning that 210 patients were randomly assigned to biomarker-guided recommendation on antibiotics (n=104) or routine use of antibiotics (n=106). One patient in the biomarker-guided recommendation group was withdrawn by the clinical team before bronchoscopy and so was excluded from the intention-to-treat analysis. We found no significant difference in the primary outcome of the distribution of antibiotic-free days in the 7 days following bronchoalveolar lavage in the intention-to-treat analysis (p=0·58). Bronchoalveolar lavage was associated with a small and transient increase in oxygen requirements. Established prescribing practices, reluctance for bronchoalveolar lavage, and dependence on a chain of trial-related procedures emerged as factors that impaired trial processes.

INTERPRETATION

Antibiotic use remains high in patients with suspected ventilator-associated pneumonia. Antibiotic stewardship was not improved by a rapid, highly sensitive rule-out test. Prescribing culture, rather than poor test performance, might explain this absence of effect.

FUNDING

UK Department of Health and the Wellcome Trust.

Epidemiology of ICU-acquired pneumonia

PURPOSE OF REVIEW

Review of the epidemiology of ICU-acquired pneumonia, including both ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP) in nonventilated ICU patients, with critical review of the most recent literature in this setting.

RECENT FINDINGS

The incidence of ICU-acquired pneumonia, mainly VAP has decrease significantly in recent years possibly due to the generalized implementation of preventive bundles. However, the exact incidence of VAP is difficult to establish due to the diagnostic limitations and the methods employed to report rates. Incidence rates greatly vary based on the studied populations. Data in the literature strongly support the relevance of intubation, not ventilatory support, in the development of HAP in ICU patients, but also that the incidence of HAP in nonintubated patients is not negligible. Despite the fact of a high crude mortality associated with the development of VAP, the overall attributable mortality of this complication was estimated in 13%, with higher mortality rates in surgical patients and those with mid-range severity scores at admission. Mortality is consistently greatest in patients with HAP who require intubation, slightly less in VAP, and least for nonventilated HAP. The economic burden of ICU acquired pneumonia, particularly VAP, is important. The increased costs are mainly related to the longer periods of ventilatory assistance and ICU and hospital stays required by these patients. However, the different impact of VAP on economic burden among countries is largely dependent on the different costs associated with heath care.

SUMMARY

VAP has significant impact on mortality mainly in surgical patients and those with mid-range severity scores at admission. The economic burden on ICU-acquired pneumonia depends mainly on the increased length of stay of these patients.

Monocyte Chemoattractant Protein-1, a Possible Biomarker of Multiorgan Failure and Mortality in Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) leads to increased patients’ mortality and medical expenditure. Monocyte chemoattractant protein-1 (MCP-1) plays a role in the pathogenesis of lung inflammation and infection. Therefore, the plasma concentration of MCP-1 was assessed and correlated with the clinical course in VAP patients. This retrospective observational study recruited 45 healthy volunteers, 12 non-VAP subjects, and 30 VAP patients. The diagnostic criteria for VAP were based on the American Thoracic Society guidelines, and the level of plasma MCP-1 was determined by ELISA. Plasma MCP-1 concentration was significantly elevated in the acute stage in VAP patients when compared with the control (p < 0.0001) and non-VAP patient groups (p = 0.0006). Subsequently, it was remarkably decreased following antibiotic treatment. Moreover, plasma MCP-1 concentration was positively correlated with indices of pulmonary dysfunction, including the lung injury score (p = 0.02) and the oxygenation index (p = 0.02). When patients with VAP developed adult respiratory distress syndrome (ARDS), their plasma MCP-1 concentrations were significantly higher than those of patients who did not develop ARDS (p = 0.04). Moreover, plasma MCP-1 concentration was highly correlated with organ failure scores, including simplified acute physiology score II (SAPS II, p < 0.0001), sequential organ failure assessment score (SOFA, p < 0.0001), organ dysfunctions and/or infection (ODIN, p < 0.0001), predisposition, insult response and organ dysfunction (PIRO, p = 0.005), and immunodeficiency, blood pressure, multilobular infiltrates on chest radiograph, platelets and hospitalization 10 days before onset of VAP (IBMP-10, p = 0.004). Our results demonstrate that plasma MCP-1 is an excellent marker for recognizing VAP when the cut-off level is set to 347.18 ng/mL (area under the curve (AUC) = 0.936, 95% CI = 0.863–0.977). In conclusion, MCP-1 not only could be a biological marker related to pulmonary dysfunction, organ failure, and mortality in patients with VAP, but also could be used for early recognition of VAP.

Development and validation of a new score for predicting functional outcome of neurocritically ill patients: The INCNS score

Aims

To develop and validate a novel score for prediction of 3‐month functional outcome in neurocritically ill patients.

Methods

The development of the novel score was based on two widely used scores for general critical illnesses (Acute Physiology and Chronic Health Evaluation II, APACHE II; Simplified Acute Physiology Score II, SAPS II) and consideration of the characteristics of neurocritical illness. Data from consecutive patients admitted to neurological ICU (N‐ICU) between January 2013 and June 2016 were used for the validation. The modified Rankin Scale (mRS) was used to evaluate 3‐month functional outcomes. APACHE II scores, SAPS II scores, and our novel scores at 24 hours and 72 hours in N‐ICU were obtained. We compared the prognostic performance of our score with APACHE II and SAPS II.

Results

We developed a 44‐point scoring system named the INCNS score, and it includes 19 items which were categorized into five parts: inflammation (I), nutrition (N), consciousness (C), neurological function (N), and systemic function (S). We validated the INCNS score with a cohort of 941 N‐ICU patients. The 72‐hours INCNS score achieved an area under the receiver operating characteristic curve (AUC) of 0.828 (95% CI: 0.802‐0.854), and the 24‐hours INCNS score achieved an AUC of 0.788 (95% CI: 0.759‐0.817). The INCNS score exhibited significantly better discriminative and prognostic performance than APACHE II and SAPS II at both 24 hours and 72 hours in N‐ICU.

Conclusion

We developed an INCNS score with superior predictive power for functional outcome of neurocritically ill patients.

Comparison of severity score models based on different sepsis definitions to predict in-hospital mortality among sepsis patients in the Intensive Care Unit

OBJECTIVE

A comparison is made of the accuracy between severity models, based on different sepsis definitions (systemic inflammatory response syndrome (SIRS), predisposition, insult, response, organ dysfunction (PIRO), and sequential organ failure assessment (SOFA) concepts), in predicting outcomes among sepsis patients.

DESIGN

A retrospective study was carried out.

SETTING

The study was conducted in the Intensive Care Unit (ICU) of a university teaching hospital.

PATIENTS

Septic patients admitted to the ICU during 2007-2016.

MAIN VARIABLES OF INTEREST

The primary outcome was in-hospital mortality, with ICU mortality being the secondary outcome.

RESULTS

A total of 2152 septic patient were identified, with ICU and in-hospital mortality rates of 33.3% and 45.9%, respectively. The Moreno PIRO (AUC, 95%CI) (0.835; 0.818-0.852) showed the highest discriminating capacity, followed by SOFA (0.828; 0.811-0.846), qSOFA (0.792; 0.775-0.809), Rubulotta PIRO (0.708; 0.687-0.730), Howell PIRO (0.706; 0.685-0.728) and SIRS (0.578; 0.556-0.600). The AUC of the SOFA score was comparable to that of the Moreno PIRO (p=0.43), though the AUCs of both of these scores were significantly higher than those of the other scores (p<0.001 for all other comparisons). However, the SOFA score showed the best discriminating capacity in predicting ICU mortality (0.838; 0.820-0.855), followed by Moreno PIRO (0.804; 0.785-0.823) and qSOFA (0.787; 0.770-0.805). The accuracy of the qSOFA in predicting ICU mortality was comparable to that of the Moreno PIRO score (p=0.15).

CONCLUSION

The SOFA score and Moreno PIRO score showed the best accuracy in predicting in-hospital mortality among septic patients admitted to the ICU.

The relationship between ventilator-associated pneumonia and chronic obstructive pulmonary disease: what is the current evidence?

Chronic obstructive pulmonary disease (COPD) affects approximately 65 million people from which > 25% will require intensive care unit (ICU) admission. Ventilator-associated pneumonia (VAP) is the commonest ICU infection and results in increased morbidity/mortality and costs. The literature on the interaction between COPD and VAP is scarce and controversial. The project aimed to search the literature in order to address the following: (i) Is COPD a risk factor for VAP development? (ii) Does COPD impact the outcome of patients with VAP? (iii) Does VAP development impact the outcome of COPD patients? (iv) Does COPD impact the aetiology of VAP? Current evidence on the topic is controversial. Regarding the impact of VAP on COPD patients, the majority of the existing limited number of studies suggests that VAP development results in higher mortality and longer duration of mechanical ventilation and ICU stay. Also, the majority of the studies exploring the impact of COPD on VAP outcomes suggest that COPD is independently associated with a decrease in survival, although the number of such studies is limited. Regarding the aetiology, Pseudomonas aeruginosa is the most frequent pathogen in VAP patients with COPD. Noteworthy, one study suggests that P. aeruginosa is higher in COPD patients even in the early-onset VAP subgroup. This manuscript provides a comprehensive overview of the available literature on the interaction between COPD and VAP, highlighting the differences and limitations that may have led to controversial results, and it may act as a platform for further research with important clinical implications.

Acinetobacter etiology respiratory tract infections associated with mechanical ventilation: what impacts on the prognosis? A retrospective cohort study

INTRODUCTION

Acinetobacter species treatment often represents a challenge. The main objective of this study is identify predictors of ICU mortality in patients submitted to mechanical ventilation (MV).

MATERIALS AND METHODS

Retrospective cohort study. Patients with MV > 48 h who developed a respiratory tract positive culture for Acinetobacter were included, and distinguished among colonized, ventilator-associated pneumonia (VAP) or ventilator-associated tracheobronchitis (VAT) patients. Primary outcome was ICU mortality.

RESULTS

153 patients were in MV and presented positive culture for Acinetobacter calcoaceticus-baumanii complex, 70 of them with VAP, 59 with VAT and 24 patients were colonized. The factors related to ICU mortality were VAP (OR 2.2, 95% CI 1.1-4.5) and shock at the time of diagnosis (OR 4.8, 95% CI 1.8-2.3). In multivariate analysis, only SOFA score at the time of diagnosis (OR 1.06, 95% CI 1.03-1.09) was related with ICU mortality. A paired-matched analysis was performed to assess effect of dual therapy on outcomes, and no effect was found in terms of clinical cure, ICU or hospital mortality or duration of antimicrobial therapy.

CONCLUSIONS

Previous comorbidities and degree of associated organic injury seem to be more important factors in the prognosis than double antibiotic therapy in patients with Acinetobacter-related respiratory infection.

Getting the invite list right: a discussion of sepsis severity scoring systems in severe complicated intra-abdominal sepsis and randomized trial inclusion criteria

Background

Severe complicated intra-abdominal sepsis (SCIAS) is a worldwide challenge with increasing incidence. Open abdomen management with enhanced clearance of fluid and biomediators from the peritoneum is a potential therapy requiring prospective evaluation. Given the complexity of powering multi-center trials, it is essential to recruit an inception cohort sick enough to benefit from the intervention; otherwise, no effect of a potentially beneficial therapy may be apparent. An evaluation of abilities of recognized predictive systems to recognize SCIAS patients was conducted using an existing intra-abdominal sepsis (IAS) database.

Methods

All consecutive adult patients with a diffuse secondary peritonitis between 2012 and 2013 were collected from a quaternary care hospital in Finland, excluding appendicitis/cholecystitis. From this retrospectively collected database, a target population (93) of those with either ICU admission or mortality were selected. The performance metrics of the Third Consensus Definitions for Sepsis and Septic Shock based on both SOFA and quick SOFA, the World Society of Emergency Surgery Sepsis Severity Score (WSESSSS), the APACHE II score, Manheim Peritonitis Index (MPI), and the Calgary Predisposition, Infection, Response, and Organ dysfunction (CPIRO) score were all tested for their discriminant ability to identify this subgroup with SCIAS and to predict mortality.

Results

Predictive systems with an area under-the-receiving-operating characteristic (AUC) curve > 0.8 included SOFA, Sepsis-3 definitions, APACHE II, WSESSSS, and CPIRO scores with the overall best for CPIRO. The highest identification rates were SOFA score ≥ 2 (78.4%), followed by the WSESSSS score ≥ 8 (73.1%), SOFA ≥ 3 (75.2%), and APACHE II ≥ 14 (68.8%) identification. Combining the Sepsis-3 septic-shock definition and WSESSS ≥ 8 increased detection to 80%. Including CPIRO score ≥ 3 increased this to 82.8% (Sensitivity-SN; 83% Specificity-SP; 74%. Comparatively, SOFA ≥ 4 and WSESSSS ≥ 8 with or without septic-shock had 83.9% detection (SN; 84%, SP; 75%, 25% mortality).

Conclusions

No one scoring system behaves perfectly, and all are largely dominated by organ dysfunction. Utilizing combinations of SOFA, CPIRO, and WSESSSS scores in addition to the Sepsis-3 septic shock definition appears to offer the widest "inclusion-criteria" to recognize patients with a high chance of mortality and ICU admission.

Trial registration

https://clinicaltrials.gov/ct2/show/NCT03163095; Registered on May 22, 2017.

Comparison of the Nosocomial Pneumonia Mortality Prediction (NPMP) model with standard mortality prediction tools

BACKGROUND

Severity or mortality prediction of nosocomial pneumonia could aid in the effective triage of patients and assisting physicians.

AIM

To compare various severity assessment scoring systems for predicting intensive care unit (ICU) mortality in nosocomial pneumonia patients.

METHODS

A prospective cohort study was conducted in a tertiary care university-affiliated hospital in Manipal, India. One hundred patients with nosocomial pneumonia, admitted in the ICUs who developed pneumonia after >48h of admission, were included. The Nosocomial Pneumonia Mortality Prediction (NPMP) model, developed in our hospital, was compared with Acute Physiology and Chronic Health Evaluation II (APACHE II), Mortality Probability Model II (MPM₇₂ II), Simplified Acute Physiology Score II (SAPS II), Multiple Organ Dysfunction Score (MODS), Sequential Organ Failure Assessment (SOFA), Clinical Pulmonary Infection Score (CPIS), Ventilator-Associated Pneumonia Predisposition, Insult, Response, Organ dysfunction (VAP-PIRO). Data and clinical variables were collected on the day of pneumonia diagnosis. The outcome for the study was ICU mortality. The sensitivity and specificity of the various scoring systems was analysed by plotting receiver operating characteristic (ROC) curves and computing the area under the curve for each of the mortality predicting tools.

FINDINGS

NPMP, APACHE II, SAPS II, MPM₇₂ II, SOFA, and VAP-PIRO were found to have similar and acceptable discrimination power as assessed by the area under the ROC curve. The AUC values for the above scores ranged from 0.735 to 0.762. CPIS and MODS showed least discrimination.

CONCLUSION

NPMP is a specific tool to predict mortality in nosocomial pneumonia and is comparable to other standard scores.

Infections in intensive care unit adult patients harboring multidrug-resistant Pseudomonas aeruginosa: implications for prevention and therapy

The purpose of this paper was to report the burden and characteristics of infection by multidrug-resistant Pseudomonas aeruginosa (MDR-PA) in clinical samples from intensive care unit (ICU) adults, and to identify predictors. This was a retrospective observational study at four medical-surgical ICUs. The case cohort comprised adults with documented isolation of an MDR-PA strain from a clinical specimen during ICU stay. Multivariate analysis was performed to identify predictors for MDR-PA infection. During the study period, 5667 patients were admitted to the ICU and P. aeruginosa was isolated in 504 (8.8%). MDR-PA was identified in 142 clinical samples from 104 patients (20.6%); 62 (43.6%) of these samples appeared to be true infections. One hundred and eighteen (83.1%) isolates were susceptible only to amikacin and colistin, and 13 (9.2%) were susceptible only to colistin. Overall, the MIC₅₀ to meropenem was 16 μg/mL and the MIC₉₀ was >32 μg/mL, with 60.4% of respiratory samples being MIC >32 μg/mL to meropenem. Independent predictors for MDR-PA infection were fever/hypothermia [odds ratio (OR) 9.09], recent antipseudomonal cephalosporin therapy (OR 6.31), vasopressors at infection onset (OR 4.40), and PIRO (predisposition, infection, response, and organ dysfunction) score >2 (OR 2.06). This study provides novel information that may be of use for the clinical management of patients harboring MDR-PA and for the control of the spread of this organism.

Risk prediction models for mortality in patients with ventilator-associated pneumonia: A systematic review and meta-analysis

PURPOSE

Ventilator-associated pneumonia (VAP) is a common and serious complication in patients requiring mechanical ventilation in the intensive care unit. The aims of this study were to identify models used to predict mortality in VAP patients and to assess their prognostic accuracy.

METHODS

The PubMed and EMBASE were searched in February 2016. We included studies in English that evaluated models' ability to predict the risk of mortality in patients with VAP. The reported mortality with the longest follow-up was used in the meta-analysis. Prognostic accuracy was measured with the area under the receiver operator characteristic curve (AUC).

RESULTS

We identified 19 articles studying 7 different models' ability to predict mortality in VAP patients. The models were Acute Physiology and Chronic Health Evaluation (APACHE) II (9 studies, n = 1398); Clinical Pulmonary Infection Score (4 studies, n = 303); "Immunodeficiency, Blood pressure, Multilobular infiltrates on chest radiograph, Platelets and hospitalization 10 days before onset of VAP" (3 studies, n = 406); "VAP Predisposition, Insult Response and Organ dysfunction" (2 studies, n = 589); Sequential Organ Failure Assessment (7 studies, n = 1019); Simplified Acute Physiology Score II (6 studies, n = 1043); and APACHE III (1 study, n = 198). APACHE II had the highest pooled AUC (95% confidence intervals), 0.72 (0.64-0.80), and CPIS had the lowest pooled AUC, 0.64 (0.55-0.72).

CONCLUSION

We identified 7 models that have been evaluated for their ability to predict mortality in patients with VAP. The models had nearly equal predictive accuracies, although some models are more complex and time consuming.

PIRO concept: staging of sepsis

Introduction:

Sepsis is common presenting illness to the emergency services and one of the leading causes of hospital mortality. Researchers and clinicians have realized that the systemic inflammatory response syndrome concept for defining sepsis is less useful and lacks specificity. The predisposition, infection (or insult), response and organ dysfunction (PIRO) staging of sepsis similar to malignant diseases (TNM staging) might give better information.

Materials and Methods:

A prospective observational study was conducted in emergency medical services attached to medicine department of a tertiary care hospital in Northern India. Patients with age 18 years or more with proven sepsis were included in the first 24 hours of the diagnosis. Two hundred patients were recruited. Multivariate logistic regression analysis was done to assess the factors that predicted in-hospital mortality.

Results:

Two hundred patients with proven sepsis, admitted to the emergency medical services were analysed. Male preponderance was noted (M: F ratio = 1.6:1). Mean age of study cohort was 50.50 ± 16.30 years. Out of 200 patients, 116 (58%) had in-hospital mortality. In multivariate logistic regression analysis, the factors independently associated with in-hospital mortality for predisposition component of PIRO staging were age >70 years, chronic obstructive pulmonary disease, chronic liver disease, cancer and presence of foley's catheter; for infection/insult were pneumonia, urinary tract infection and meningitis/encephalitis; for response variable were tachypnea (respiratory rate >20/minute) and bandemia (band >5%). Organ dysfunction variables associated with hospital mortality were systolic blood pressure <90mm Hg, prolonged activated partial thromboplastin time, raised serum creatinine, partial pressure of oxygen in arterial blood/fraction of inspired oxygen (PaO₂/FiO₂) ratio <300, decreased urine output in first two hours of emergency presentation and Glasgow coma scale ≤9. Each of the components of PIRO had good predictive capability for in-hospital mortality but the total score was more accurate than the individual score and increasing PIRO score was associated with higher in-hospital mortality. The area under receiver operating characteristic curve for cumulative PIRO staging system as a predictor of in-hospital mortality was 0.94.

Conclusion:

This study finds PIRO staging as an important tool to stratify and prognosticate hospitalised patients with sepsis at a tertiary care center. The simplicity of score makes it more practical to be used in busy emergencies as it is based on four easily assessable components.

Impact of COPD in the outcome of ICU-acquired pneumonia with and without previous intubation

BACKGROUND

COPD seems related to poor outcome in patients with ventilator-associated pneumonia (VAP). However, many patients in the ICU with COPD do not require intubation but can also develop pneumonia in the ICU. We, therefore, compared the characteristics and outcomes of patients with ICU-acquired pneumonia (ICUAP) with and without underlying COPD.

METHODS

We prospectively assessed the characteristics, microbiology, systemic inflammatory response, and survival of 279 consecutive patients with ICUAP clustered according to underlying COPD or not. The primary end point was 90-day survival.

RESULTS

Seventy-one patients (25%) had COPD. The proportion of VAP was less frequent in patients with COPD: 30 (42%) compared with 126 (61%) in patients without COPD (P = .011). Patients with COPD were older; were more frequently men, smokers, and alcohol abusers; and more frequently had previous use of noninvasive ventilation. The rate of microbiologic diagnosis was similar between groups, with a higher rate of Aspergillus species and a lower rate of Enterobacteriaceae in patients with COPD. We found lower levels of IL-6 and IL-8 in patients with COPD without previous intubation. The 90-day mortality was higher in patients with COPD (40 [57%] vs 74 [37%] in patients without COPD, P = .003). Among others, COPD was independently associated with decreased 90-day survival in the overall population (adjusted hazard ratio, 1.94; 95% CI, 1.11-3.40; P = .020); this association was observed only in patients with VAP but not in those without previous intubation.

CONCLUSIONS

COPD was independently associated with decreased 90-day survival in patients with VAP but not in those without previous intubation.

Prognostic factors associated with mortality of drug-resistant Acinetobacter baumannii ventilator-associated pneumonia

Background

Ventilator-associated pneumonia (VAP) caused by drug-resistant Acinetobacter baumannii is associated with high mortality in critically ill patients. We identified the prognostic factors of 30-day mortality in patients with VAP caused by drug-resistant A. baumannii and compared survival outcomes among multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) A. baumannii VAP.

Methods

A retrospective cohort study was conducted in the Medical Intensive Care Unit at Chiang Mai University Hospital, Thailand. All adult patients diagnosed with A. baumannii VAP between 2005 and 2011 were eligible. Univariable and multivariable Cox’s proportional hazards regression were performed to identify the prognostic factors of 30-day mortality.

Results

A total of 337 patients with microbiologically confirmed A. baumannii VAP were included. The proportion of drug-sensitive (DS), MDR, XDR, and PDR A. baumannii were 9.8%, 21.4%, 65.3%, and 3.6%, respectively. The 30-day mortality rates were 21.2%, 31.9%, 56.8%, and 66.7%, respectively. The independent prognostic factors were SOFA score >5 (hazard ratio (HR) = 3.33, 95% confidence interval (CI) 1.94–5.72, P < 0.001), presence of septic shock (HR = 2.66, 95% CI 1.71–4.12, P < 0.001), Simplified Acute Physiology Score (SAPS) II >45 (HR = 1.58, 95% CI 1.01–2.46, P = 0.045), and inappropriate initial antibiotic treatment (HR = 1.53, 95% CI 1.08–2.20, P = 0.016).

Conclusions

Drug-resistant A. baumannii, particularly XDR and PDR, was associated with a high mortality rate. Septic shock, high SAPS II, high SOFA score, and inappropriate initial antibiotic treatment were independent prognostic factors for 30-day mortality.

A comparison of APACHE II and CPIS scores for the prediction of 30-day mortality in patients with ventilator-associated pneumonia

OBJECTIVE

The aim of this study was to compare the Acute Physiology and Chronic Health Evaluation II (APACHE II) score and the Clinical Pulmonary Infection Score (CPIS) for the prediction of 30-day mortality in patients with ventilator-associated pneumonia (VAP).

METHODS

A single-center, prospective cohort study design was employed between January 1, 2010 and January 1, 2014. APACHE II and CPIS scores were determined on the day of VAP diagnosis. Discrimination was tested using receiver-operating characteristic (ROC) curves and the areas under the curve (AUC). Calibration was tested using the Hosmer-Lemeshow statistic.

RESULTS

Of 135 patients with VAP, 39 died; the 30-day mortality was 28.9%. APACHE II and CPIS scores were significantly higher in non-survivors compared to survivors (23.1±4.8 vs. 16.7±4.6, p<0.001; 6.8±1.3 vs. 6.2±1.3, p=0.016). APACHE II had excellent discrimination for predicting 30-day mortality in patients with VAP, with AUC 0.808 (95% confidence interval (CI) 0.704-0.912, p<0.001). However, the CPIS score did not have discrimination power for predicting mortality, with AUC 0.612 (95% CI 0.485-0.739, p=0.083). The Hosmer-Lemeshow statistic showed good goodness-of-fit for observed 30-day mortality and APACHE II expected mortality (Chi-square=1.099, p=0.785). However, CPIS expected 30-day mortality did not fit the observed mortality (Chi-square=6.72, p=0.004).

CONCLUSIONS

These data suggest that APACHE II is useful for predicting 30-day mortality in patients with VAP, but that the CPIS does not have good discrimination and calibration for predicting mortality.

Respiratory infections in patients undergoing mechanical ventilation

Lower respiratory tract infections in mechanically ventilated patients are a frequent cause of antibiotic treatment in intensive-care units. These infections present as severe sepsis or septic shock with respiratory dysfunction in intubated patients. Purulent respiratory secretions are needed for diagnosis, but distinguishing between pneumonia and tracheobronchitis is not easy. Both presentations are associated with longlasting mechanical ventilation and extended intensive-care unit stay, providing a rationale for antibiotic treatment initiation. Differentiation of colonisers from true pathogens is difficult, and microbiological data show Staphylococcus aureus and Pseudomonas aeruginosa to be of great concern because of clinical outcomes and therapeutic challenges. Key management issues include identification of the pathogen, choice of initial empirical antibiotic, and decisions with regard to the resolution pattern.

The PIRO (predisposition, insult, response, organ dysfunction) model: toward a staging system for acute illness

Multimodal therapy for diseases like cancer has only become practicable following the development of staging systems like the TNM (tumor, nodes, metastases) system. Staging enables the identification of subgroups of patients with a disease who not only have a differing prognosis, but who are also more likely to benefit from a specific therapeutic modality. Critically ill patients represent a highly heterogeneous population for whom multiple therapeutic options are potentially available, each carrying not only the potential for differential benefit, but also the potential for differential harm. The PIRO system (predisposition, insult, response, organ dysfunction) is a template proposal for a staging system for acute illness that incorporates assessment of pre-morbid baseline susceptibility (predisposition), the specific disorder responsible for acute illness (insult), the response of the host to that insult, and the resulting degree of organ dysfunction. However the creation of a valid, robust, and clinically useful system presents significant challenges arising from the complexity of the disease state, the lack of a clear phenotype, the confounding influence of the effects of therapy and of cultural and socio-economic factors, and the relatively low profile of acute illness with clinicians and the general public. This review summarizes the rationale for such a model of illness stratification and the results of preliminary cohort studies testing the concept. It further proposes two strategies for building a staging system, recognizing that this will be a demanding undertaking that will require decades of work.

Predisposition, insult/infection, response and organ dysfunction (PIRO): a pilot clinical staging system for hospital mortality in patients with infection

PURPOSE

To develop a clinical staging system based on the PIRO concept (Predisposition, Infection, RESPONSE and Organ dysfunction) for hospitalized patients with infection.

METHODS

One year prospective cohort study of all hospitalized patients with infection (n = 1035), admitted into a large tertiary care, university hospital. Variables associated with hospital mortality were selected using logistic regressions. Based on the regression coefficients, a score for each PIRO component was developed and a classification tree was used to stratify patients into four stages of increased risk of hospital mortality. The final clinical staging system was then validated using an independent cohort (n = 186).

RESULTS

Factors significantly associated with hospital mortality were • for Predisposition: age, sex, previous antibiotic therapy, chronic hepatic disease, chronic hematologic disease, cancer, atherosclerosis and a Karnofsky index<70; • for Insult/Infection: type of infection • for

RESPONSE

abnormal temperature, tachypnea, hyperglycemia and severity of infection and • for Organ dysfunction: hypotension and SOFA score≥1. The area under the ROC curve (CI95%) for the combined PIRO model as a predictor for mortality was 0.85 (0.82-0.88). Based on the scores for each of the PIRO components and on the cut-offs estimated from the classification tree, patients were stratified into four stages of increased mortality rates: stage I: ≤5%, stage II: 6-20%, stage III: 21-50% and stage IV: >50%. Finally, this new clinical staging system was studied in a validation cohort, which provided similar results (0%, 9%, 31% and 67%, in each stage, respectively).

CONCLUSIONS

Based on the PIRO concept, a new clinical staging system was developed for hospitalized patients with infection, allowing stratification into four stages of increased mortality, using the different scores obtained in Predisposition, RESPONSE, Infection and Organ dysfunction. The proposed system will likely help to define inclusion criteria in clinical trials as well as tailoring individual management plans for patients with infection.

Potentially resistant microorganisms in intubated patients with hospital-acquired pneumonia: the interaction of ecology, shock and risk factors

PURPOSE

As per 2005 American Thoracic Society and Infectious Disease Society of America (ATS/IDSA) guidelines for managing hospital-acquired pneumonia, patients with early-onset pneumonia and without risk factors do not need to be treated for potentially resistant microorganisms (PRM).

METHODS

This was a secondary analysis of a prospective, observational, cohort, multicentre study conducted in 27 ICUs from nine European countries.

RESULTS

From a total of 689 patients with nosocomial pneumonia who required mechanical ventilation, 485 patients with confirmed etiology and antibiotic susceptibility were further analysed. Of these patients, 152 (31.3 %) were allocated to group 1 with early-onset pneumonia and no risk factors for PRM acquisition, and 333 (68.7 %) were classified into group 2 with early-onset pneumonia with risk factors for PRM or late-onset pneumonia. Group 2 patients were older and had more chronic renal failure and more severe illness (SAPS II score, 44.6 ± 16.5 vs. 47.4 ± 17.8, p = 0.04) than group 1 patients. Trauma patients were more frequent and surgical patients less frequent in group 1 than in group 2 (p < 0.01). In group 1, 77 patients (50.7 %) had PRM in spite of the absence of classic risk factors recognised by the current guidelines. A logistic regression analysis identified that presence of severe sepsis/septic shock (OR = 3.7, 95 % CI 1.5-8.9) and pneumonia developed in centres with greater than 25 % prevalence of PRM (OR = 11.3, 95 % CI 2.1-59.3) were independently associated with PRM in group 1 patients.

CONCLUSIONS

In patients admitted to ICUs with a prevalence of PRM greater than 25 % or with severe sepsis/septic shock, empiric therapy for group 1 nosocomial pneumonia requiring mechanical ventilation should also include agents likely to be effective for PRM pathogens.

The predisposition, infection, response and organ failure (Piro) sepsis classification system: results of hospital mortality using a novel concept and methodological approach

Introduction

PIRO is a conceptual classification system in which a number of demographic, clinical, biological and laboratory variables are used to stratify patients with sepsis in categories with different outcomes, including mortality rates.

Objectives

To identify variables to be included in each component of PIRO aiming to improve the hospital mortality prediction.

Methods

Patients were selected from the Portuguese ICU-admitted community-acquired sepsis study (SACiUCI). Variables concerning the R and O component included repeated measurements along the first five days in ICU stay. The trends of these variables were summarized as the initial value at day 1 (D1) and the slope of the tendency during the five days, using a linear mixed model. Logistic regression models were built to assess the best set of covariates that predicted hospital mortality.

Results

A total of 891 patients (age 60±17 years, 64% men, 38% hospital mortality) were studied. Factors significantly associated with mortality for P component were gender, age, chronic liver failure, chronic renal failure and metastatic cancer; for I component were positive blood cultures, guideline concordant antibiotic therapy and health-care associated sepsis; for R component were C-reactive protein slope, D1 heart rate, heart rate slope, D1 neutrophils and neutrophils slope; for O component were D1 serum lactate, serum lactate slope, D1 SOFA and SOFA slope. The relative weight of each component of PIRO was calculated. The combination of these four results into a single-value predictor of hospital mortality presented an AUC-ROC 0.84 (IC_95%:0.81–0.87) and a test of goodness-of-fit (Hosmer and Lemeshow) of p = 0.368.

Conclusions

We identified specific variables associated with each of the four components of PIRO, including biomarkers and a dynamic view of the patient daily clinical course. This novel approach to PIRO concept and overall score can be a better predictor of mortality for patients with community-acquired sepsis admitted to ICUs.

DALI: Defining Antibiotic Levels in Intensive care unit patients: a multi-centre point of prevalence study to determine whether contemporary antibiotic dosing for critically ill patients is therapeutic

Background

The clinical effects of varying pharmacokinetic exposures of antibiotics (antibacterials and antifungals) on outcome in infected critically ill patients are poorly described. A large-scale multi-centre study (DALI Study) is currently underway describing the clinical outcomes of patients achieving pre-defined antibiotic exposures. This report describes the protocol.

Methods

DALI will recruit over 500 patients administered a wide range of either beta-lactam or glycopeptide antibiotics or triazole or echinocandin antifungals in a pharmacokinetic point-prevalence study. It is anticipated that over 60 European intensive care units (ICUs) will participate. The primary aim will be to determine whether contemporary antibiotic dosing for critically ill patients achieves plasma concentrations associated with maximal activity. Secondary aims will compare antibiotic pharmacokinetic exposures with patient outcome and will describe the population pharmacokinetics of the antibiotics included. Various subgroup analyses will be conducted to determine patient groups that may be at risk of very low or very high concentrations of antibiotics.

Discussion

The DALI study should inform clinicians of the potential clinical advantages of achieving certain antibiotic pharmacokinetic exposures in infected critically ill patients.

Performance of the PIRO score for predicting mortality in patients with ventilator-associated pneumonia

The ventilator-associated pneumonia (VAP) PIRO score is a new scoring system based on the PIRO concept. The aim of this study was to validate the PIRO score against the Acute Physiology and Chronic Health Evaluation (APACHE) II and VAP APACHE II in an independent group of VAP patients. Areas under the receiver operating characteristic curves were compared to determine the tests' abilities to predict intensive care unit and 28-day mortality. Variables associated with intensive care unit mortality were evaluated. One hundred and forty-eight intensive care unit patients who met radiographic and clinical criteria for VAP were included. The area under the receiver operating characteristic curves for predicting intensive care unit mortality with the PIRO, APACHE II and VAP APACHE II scores were 0.605 (P=0.03), 0.631 (P=0.01) and 0.724 (P <0.0001), respectively. Areas under the receiver operating characteristic curve for predicting 28-day mortality were 0.614 (P=0.01) for PIRO, 0.633 (P=0.01) for APACHE II and 0.697 (P=0.002) for VAP APACHE II. No differences in area under the receiver operating characteristic curve between scores were found at either endpoint. Variables independently associated with intensive care unit mortality were bacteraemia (adjusted odds ratio 7.16, 95% confidence interval 1.19 to 42.98, P=0.03) and APACHE II (1.06, 1.01 to 1.11, P=0.006). VAP PIRO score was not a good predictor of intensive care unit and 28-day mortality. The low sensitivity and specificity of VAP PIRO score preclude its use clinically.

Attributable mortality of ventilator-associated pneumonia

PURPOSE OF REVIEW

To critically discuss the attributable mortality of ventilator-associated pneumonia (VAP) and potential sources of variation.

RECENT FINDINGS

The review will cover the available estimates (0-50%). It will also explore the source of variation because of definition of VAP (being lower if inaccurate), case-mix issues (being lower for trauma patients), the severity of underlying illnesses (being maximal when the severity of underlying illness is intermediate), and on the characteristics and the severity of the VAP episode. Another important source of variation is the use of poorly appropriate statistical models (estimates biased by lead time bias and competing events). New extensions of survival models which take into account the time dependence of VAP occurrence and competing risks allow less biased estimation as compared with traditional models.

SUMMARY

Attributable mortality of VAP is about 6%. Accurate diagnostic methods are key to properly estimating it. Traditional statistical models should no longer be used to estimate it. Prevention efforts targeted on patients with intermediate severity may result in the most important outcome benefits.

Ventilator-associated pneumonia with or without toothbrushing: a randomized controlled trial

Certain guidelines for the prevention of ventilator-associated pneumonia (VAP) recommend oral care with chlorhexidine, but none refer to the use of a toothbrush for oral hygiene. The role of toothbrush use has received scant attention. Thus, the objective of this study was to compare the incidence of VAP in critical care patients receiving oral care with and without manual brushing of the teeth. This was a randomized clinical trial developed in a 24-bed medical-surgical intensive care unit (ICU). Patients undergoing invasive mechanical ventilation for than 24 h were included. Patients were randomly assigned to receive oral care with or without toothbrushing. All patients received oral care with 0.12 % chlorhexidine digluconate. Tracheal aspirate samples were obtained during endotracheal intubation, then twice a week, and, finally, on extubation. There were no significant differences between the two groups of patients in the baseline characteristics. We found no statistically significant differences between the groups regarding the incidence of VAP (21 of 217 [9.7 %] with toothbrushing vs. 24 of 219 [11.0 %] without toothbrushing; odds ratio [OR] = 0.87, 95 % confidence interval [CI] = 0.469-1.615; p = 0.75). Adding manual toothbrushing to chlorhexidine oral care does not help to prevent VAP in critical care patients on mechanical ventilation.

Comparison of Predisposition, Insult/Infection, Response, and Organ dysfunction, Acute Physiology And Chronic Health Evaluation II, and Mortality in Emergency Department Sepsis in patients meeting criteria for early goal-directed therapy and the severe sepsis resuscitation bundle

PURPOSE

The aim of the study was to examine the performance of the Predisposition, Insult/Infection, Response, and Organ dysfunction (PIRO) model compared with the Acute Physiology and Chronic Health Evaluation (APACHE) II and Mortality in Emergency Department Sepsis (MEDS) scoring systems in predicting in-hospital mortality for patients presenting to the emergency department (ED) with severe sepsis or septic shock.

MATERIALS AND METHODS

This study was an analysis of a prospectively maintained registry including adult patients with severe sepsis or septic shock meeting criteria for early goal-directed therapy and the severe sepsis resuscitation bundle over a 6-year period. The registry contains data on patient demographics, sepsis category, vital signs, laboratory values, ED length of stay, hospital length of stay, physiologic scores, and outcome status. The discrimination and calibration characteristics of PIRO, APACHE II, and MEDS were analyzed.

RESULTS

Five-hundred forty-one patients with age 63.5 ± 18.5 years were enrolled, 61.9% in septic shock, 46.9% blood-culture positive, and 31.8% in-hospital mortality. Median (25th and 75th percentile) PIRO, APACHE II, and MEDS scores were 6 (5 and 8), 28 (22 and 34), and 12 (9 and 15), with predicted mortalities of 48.5% (40.1 and 63.9), 66.0% (42.0 and 83.0), and 16.0% (9.0 and 39.0), respectively. The area under the receiver operating characteristic curves for PIRO was 0.71 (95% confidence interval, 0.66-0.75); APACHE II, 0.71 (0.66-0.76); and MEDS, 0.63 (0.60-0.70). The standardized mortality ratio was 0.70 (0.08-1.41), 0.70 (-0.46 to 1.80), and 4.00 (-8.53 to 16.62), respectively. Actual mortality significantly increased with increasing PIRO score in patients with APACHE II 25 or more (P < .01).

CONCLUSIONS

The PIRO, APACHE II, and MEDS have variable abilities to early discriminate and estimate in-hospital mortality of patients presenting to the ED meeting criteria for early goal-directed therapy and the severe sepsis resuscitation bundle. The PIRO may provide additional risk stratification in patients with APACHE II 25 or more. More studies are required to evaluate the clinical applicability of PIRO in high-risk patients with severe sepsis and septic shock.