Risk of Multidrug-Resistant Pathogens in Severe Community-Acquired Pneumonia

Severe community-acquired pneumonia (SCAP) is difficult to treat when caused by difficult-to-treat (DTR) pathogens because of limited treatment options and poorer clinical outcomes. Over time, several predictive scoring systems based on risk factors for infection with multidrug resistant pathogens have been developed. We reviewed the available tools for identifying DTR pathogens as the cause of SCAP, both predictive scoring systems and rapid diagnostic methods, to develop management strategies aimed at early identification of DTR pathogens, reducing broad-spectrum antibiotic use and improving clinical outcomes. The scoring systems reviewed show considerable heterogeneity among them at the level of the region studied, the definition of risk factors, as well as which DTR pathogens are the target pathogens. The models described have shown limited effectiveness in reducing inappropriate antibiotic treatment or improving patient outcomes by themselves. However, predictive models could serve as a first step in identifying DTR pathogen infections as part of a larger detection algorithm. Rapid diagnostic tools, such as multiplex polymerase chain reaction, would be useful for the rapid identification of pneumonia-causing pathogens and their resistance mechanisms. In resource-limited settings, rapid tests should be limited to patients at high risk of developing SCAP due to DTR pathogens. We propose an integrative algorithm based on the different scores, taking into account local epidemiological data, where ideally each center should have an antimicrobial stewardship program.

Association between early cumulative fluid balance and successful liberation from invasive ventilation in COVID-19 ARDS patients — insights from the PRoVENT-COVID study: a national, multicenter, observational cohort analysis

Background

Increasing evidence indicates the potential benefits of restricted fluid management in critically ill patients. Evidence lacks on the optimal fluid management strategy for invasively ventilated COVID-19 patients. We hypothesized that the cumulative fluid balance would affect the successful liberation of invasive ventilation in COVID-19 patients with acute respiratory distress syndrome (ARDS).

Methods

We analyzed data from the multicenter observational ‘PRactice of VENTilation in COVID-19 patients’ study. Patients with confirmed COVID-19 and ARDS who required invasive ventilation during the first 3 months of the international outbreak (March 1, 2020, to June 2020) across 22 hospitals in the Netherlands were included. The primary outcome was successful liberation of invasive ventilation, modeled as a function of day 3 cumulative fluid balance using Cox proportional hazards models, using the crude and the adjusted association. Sensitivity analyses without missing data and modeling ARDS severity were performed.

Results

Among 650 patients, three groups were identified. Patients in the higher, intermediate, and lower groups had a median cumulative fluid balance of 1.98 L (1.27–7.72 L), 0.78 L (0.26–1.27 L), and − 0.35 L (− 6.52–0.26 L), respectively. Higher day 3 cumulative fluid balance was significantly associated with a lower probability of successful ventilation liberation (adjusted hazard ratio 0.86, 95% CI 0.77–0.95, P = 0.0047). Sensitivity analyses showed similar results.

Conclusions

In a cohort of invasively ventilated patients with COVID-19 and ARDS, a higher cumulative fluid balance was associated with a longer ventilation duration, indicating that restricted fluid management in these patients may be beneficial.

Trial registration Clinicaltrials.gov (NCT04346342); Date of registration: April 15, 2020.

Graphical abstract

The impact of pre-existing chronic heart failure on the intensive care treatment and outcome of old intensive care patients suffering from COVID-19

Background

Patients suffering from COVID-19 with pre-existing chronic heart failure (CHF) are considered to have a significant risk regarding morbidity and mortality. Similarly, older patients on the intensive care unit (ICU) constitute another vulnerable subgroup. This study investigated the association between pre-existing CHF and clinical practice in critically ill older ICU patients with COVID-19.

Methods

Patients with severe COVID-19 and who were ≥70 years old were recruited from this prospective multicenter international study. Patients' treatment, follow-up, and pre-existing heart failure data were collected during ICU stay. Univariate and multivariate logistic regression analyses examined the association between pre-existing heart failure and the primary endpoint of 30-day mortality.

Results

The study included 3,917 patients, with 407 patients (17%) evidencing pre-existing CHF. These patients were older (77±5 versus 76±5, p<0.001) and more frail (Clinical Frailty Scale 4±2 versus 3±2, p<0.0001). The other comorbidities were also significantly more common in CHF patients. Before hospital admission, CHF patients suffered fewer days from symptoms (5 days (3–8) versus 7 days (4–10), p<0.001), but there was no difference in the days in the hospital before ICU admission (2 days (1–5) versus 2 (1–5) days, p=0.21). At ICU admission, disease severity assessed by SOFA scores was significantly higher in CHF patients (7±3 versus 5±3). During ICU-stay, intubation, mechanical ventilation, and tracheostomy occurred significantly more often in patients without CHF (63% versus 69%, p=0.017; and 13% versus 18%, p=0.002, respectively). In contrast, there was no difference regarding non-invasive ventilation (28% versus 27%, p=0.20), and the need for vasoactive drugs (66% versus 64, p=0.30). Regarding the limitation of life-sustaining therapy, therapy was significantly more often withheld (32% versus 25%, p=0.001) but not withdrawn (18% versus 17%, p=0.21) in CHF patients. Length of ICU stay was significantly shorter in CHF patients (166 (72–336) hours versus 260 hours (120–528), p<0.001). CHF patients had significantly higher ICU- (52% versus 46%, p=0.007), 30-day mortality (60% vs. 48%, p<0.001; OR 1.87, 95% CI 1.5–2.3) and 3-month mortality (69% vs. 56%, p<0.001). In the univariate regression analysis, having pre-existing CHF was significantly associated with 30-day mortality (OR 1.89, 95% CI 1.5–2.3; p<0.001), but after adjusting for confounders (SOFA, age, gender, frailty), heart failure was not independently associated any more (aOR 1.2, 95% CI 0.5–1.5; p=0.137).

Conclusion

In critically ill old COVID-19 patients, pre-existing chronic heart failure is associated with significantly increased short- and long-term mortality, but heart failure is not independently associated with increased 30-day mortality when adjusted for confounders.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): This study was endorsed by the ESICM. Free support for running the electronic database and was granted from the dep. of Epidemiology, University of Aarhus, Denmark. The support of the study in France by a grant from “Fondation Assistance Publique-Hôpitaux de Paris pour la recherche” is greatly appreciated. In Norway, the study was supported by a grant from the Health Region West. In addition, the study was supported by a grant from the European Open Science Cloud (EOSC). EOSCsecretariat.eu has received funding from the European Union's Horizon Programme call H2020-INFRAEOSC-05-2018-2019, grant agreement number 831644. This work was supported by the Forschungskommission of the Medical Faculty of the Heinrich-Heine-University Düsseldorf, No. 2018-32 to GW and No. 2020-21 to RRB for a Clinician Scientist Track.

Mesenchymal stem/stromal cell-based therapies for severe viral pneumonia: therapeutic potential and challenges

Severe viral pneumonia is a significant cause of morbidity and mortality globally, whether due to outbreaks of endemic viruses, periodic viral epidemics, or the rarer but devastating global viral pandemics. While limited anti-viral therapies exist, there is a paucity of direct therapies to directly attenuate viral pneumonia-induced lung injury, and management therefore remains largely supportive. Mesenchymal stromal/stem cells (MSCs) are receiving considerable attention as a cytotherapeutic for viral pneumonia. Several properties of MSCs position them as a promising therapeutic strategy for viral pneumonia-induced lung injury as demonstrated in pre-clinical studies in relevant models. More recently, early phase clinical studies have demonstrated a reassuring safety profile of these cells. These investigations have taken on an added importance and urgency during the COVID-19 pandemic, with multiple trials in progress across the globe. In parallel with clinical translation, strategies are being investigated to enhance the therapeutic potential of these cells in vivo, with different MSC tissue sources, specific cellular products including cell-free options, and strategies to ‘licence’ or ‘pre-activate’ these cells, all being explored. This review will assess the therapeutic potential of MSC-based therapies for severe viral pneumonia. It will describe the aetiology and epidemiology of severe viral pneumonia, describe current therapeutic approaches, and examine the data suggesting therapeutic potential of MSCs for severe viral pneumonia in pre-clinical and clinical studies. The challenges and opportunities for MSC-based therapies will then be considered.

Interhospital Sepsis Code in Catalonia (Spain): Territorial model for initial care of patients with sepsis

Sepsis is a syndromic entity with high prevalence and mortality. The management of sepsis is standardized and exhibits time-dependent efficiency. However, the management of patients with sepsis is complex. The heterogeneity of the forms of presentation can make it difficult to detect and manage such cases, in the same way as differences in training, professional competences or the availability of health resources. The Advisory Commission for Patient Care with Sepsis (CAAPAS), comprising 7 scientific societies, the Emergency Medical System (SEM) and the Catalan Health Service (CatSalut), have developed the Interhospital Sepsis Code (CSI) in Catalonia (Spain). The general objective of the CSI is to increase awareness, promote early detection and facilitate initial care and interhospital coordination to attend septic patients in a homogeneous manner throughout Catalonia.

Impact of goal directed basic echocardiography on diagnostic and therapeutic management in an ICU of cardiac surgery

OBJECTIVE

Few studies have evaluated the impact in diagnosis and therapeutic management of basic transthoracic echocardiography in postoperated cardiac surgery. The aim of our study was to evaluate the impact of basic transthoracic echocardiography in the management of this kind of patients.

DESIGN

Over an 18-month period, we prospectively studied all patients admitted to a university hospital Intensive Care Unit following heart surgery. We evaluated clinically all of them to establish a diagnosis and an initial treatment. We performed basic transthoracic echocardiography for a diagnosis evaluation that was compared with clinical diagnosis. If they differed, we assessed to change treatment and evaluate the therapeutic response. We performed a descriptive analysis.

RESULTS

We included 136 patients and performed 203 echocardiographies. Transthoracic echocardiography differed of initial diagnosis in 101 (49.8%) echocardiographies. In 56 of these echocardiographies (55.44%), we could give an alternative diagnosis with a change in the treatment in 30patients (53,6%). We found clinical improvement in 26 patients (86.76%) in the following 30-60minutes.

CONCLUSIONS

Basic transthoracic echocardiography is useful in diagnostic and therapeutic management of postoperative cardiac surgery patients. We could not confirm the clinical diagnosis in half of the performed echocardiographies. In most patients in whom we observe a change in the diagnosis due to echocardiography, we observed a clinical improvement after changing the treatment.

Evaluation of intensivist basic training in transthoracic echocardiography in the postoperative period of heart surgery

BACKGROUND

Transthoracic echocardiography can significantly change the management of many critical patients, and is being incorporated into many Intensive Care Units (ICU). Very few studies have examined the feasibility and impact of intensivists performing basic transthoracic echocardiography upon the management of critical patients after cardiac surgery. The present study therefore evaluates the quality of acquisition and accuracy of intensivist interpretation of basic transthoracic echocardiograms in the postoperative period of heart surgery.

METHODS

Over an 8-month period we prospectively studied 148 patients within 24h after admission to a university hospital ICU following heart surgery. We performed basic transthoracic echocardiography to evaluate ventricular function, pericardial effusion, hypovolemia and mitral regurgitation. Cohen's Kappa was used to compare transthoracic echocardiograms obtained by intensivists with basic versus advanced training. Concordance on image acquisition and interpretation was evaluated.

RESULTS

We analyzed data of adequate transthoracic echocardiograms in 148 patients (92.5%). Apical four-chamber view and advanced trainees obtained better quality images. Concordance was good for right and left ventricular function (kappa=0.7±0.14 and 0.87±0.05, respectively), and moderate for the remaining parameters. Interpretation concordance between basic and advanced training intensivists was good (kappa=0.73±0.05).

CONCLUSIONS

Intensivists with basic training in echocardiography are capable of performing and interpreting echocardiograms in most patients during the postoperative period of heart surgery.

Identification and validation of distinct biological phenotypes in patients with acute respiratory distress syndrome by cluster analysis

RATIONALE

We hypothesised that patients with acute respiratory distress syndrome (ARDS) can be clustered based on concentrations of plasma biomarkers and that the thereby identified biological phenotypes are associated with mortality.

METHODS

Consecutive patients with ARDS were included in this prospective observational cohort study. Cluster analysis of 20 biomarkers of inflammation, coagulation and endothelial activation provided the phenotypes in a training cohort, not taking any outcome data into account. Logistic regression with backward selection was used to select the most predictive biomarkers, and these predicted phenotypes were validated in a separate cohort. Multivariable logistic regression was used to quantify the independent association with mortality.

RESULTS

Two phenotypes were identified in 454 patients, which we named 'uninflamed' (N=218) and 'reactive' (N=236). A selection of four biomarkers (interleukin-6, interferon gamma, angiopoietin 1/2 and plasminogen activator inhibitor-1) could be used to accurately predict the phenotype in the training cohort (area under the receiver operating characteristics curve: 0.98, 95% CI 0.97 to 0.99). Mortality rates were 15.6% and 36.4% (p<0.001) in the training cohort and 13.6% and 37.5% (p<0.001) in the validation cohort (N=207). The 'reactive phenotype' was independent from confounders associated with intensive care unit mortality (training cohort: OR 1.13, 95% CI 1.04 to 1.23; validation cohort: OR 1.18, 95% CI 1.06 to 1.31).

CONCLUSIONS

Patients with ARDS can be clustered into two biological phenotypes, with different mortality rates. Four biomarkers can be used to predict the phenotype with high accuracy. The phenotypes were very similar to those found in cohorts derived from randomised controlled trials, and these results may improve patient selection for future clinical trials targeting host response in patients with ARDS.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

A new experimental model of acid- and endotoxin-induced acute lung injury in rats

The majority of the animal models of acute lung injury (ALI) are focused on the acute phase. This limits the studies of the mechanisms involved in later phases and the effects of long-term treatments. Thus the goal of this study was to develop an experimental ALI model of aspiration pneumonia, in which diffuse alveolar damage continues for 72 h. Rats were intratracheally instilled with one dose of HCl (0.1 mol/l) followed by another instillation of one dose of LPS (0, 10, 20, 30, or 40 μg/g body weight) 2 h later, which models aspiration of gastric contents that progresses to secondary lung injury from bacteria or bacterial products. The rats were euthanized at 24, 48, and 72 h after the last instillation. The results showed that HCl and LPS at all doses caused activation of inflammatory responses, increased protein permeability and apoptosis, and induced mild hypoxemia in rat lungs at 24 h postinstillation. However, this lung damage was present at 72 h only in rats receiving HCl and LPS at the doses of 30 and 40 μg/g body wt. Mortality (∼50%) occurred in the first 48 h and only in the rats treated with HCl and LPS at the highest dose (40 μg/g body wt). In conclusion, intratracheal instillation of HCl followed by LPS at the dose of 30 μg/g body wt results in severe diffuse alveolar damage that continues at least 72 h. This rat model of aspiration pneumonia-induced ALI will be useful for testing long-term effects of new therapeutic strategies in ALI.

Evolution over a 15-year period of the clinical characteristics and outcomes of critically ill patients with severe community-acquired pneumonia

OBJECTIVES

To study the characteristics and outcomes of patients in the ICU with severe community-acquired pneumonia (SCAP) over a 15-year surveillance period.

METHODS

We conducted a retrospective cohort study of episodes of SCAP, and assessed the epidemiology, etiology, treatment and outcomes of patients admitted to the ICU, comparing three periods (1999-2003, 2004-2008 and 2009-2013).

RESULTS

A total of 458 patients were diagnosed with SCAP. The overall cumulative incidence was 37.4 episodes/1000 admissions, with a progressive increase over the three periods (P<0.001). Patients fulfilling the two major IDSA/ATS criteria at admission increased from 64.2% in the first period to 82.5% in the last period (P=0.005). Streptococcus pneumoniae was the prevalent pathogen. The incidence of bacteremia was 23.1%, and a progressive significant reduction in overall incidence was observed over the three periods (P=0.02). Globally, 91% of the patients received appropriate empiric antibiotic treatment, increasing from 78.3% in the first period to 97.7% in the last period (P<0.001). Combination antibiotic therapy (betalactam+macrolide or fluoroquinolone) increased significantly from the first period (61%) to the last period (81.3%) (P<0.001). Global ICU mortality was 25.1%, and decreased over the three periods (P=0.001).

CONCLUSIONS

Despite a progressively higher incidence and severity of SCAP in our ICU, crude ICU mortality decreased by 18%. The increased use of combined antibiotic therapy and the decreasing rates of bacteremia were associated to improved patient prognosis.

Bioreactance is not reliable for estimating cardiac output and the effects of passive leg raising in critically ill patients

BACKGROUND

Bioreactance estimates cardiac output in a non-invasive way. We evaluated the ability of a bioreactance device (NICOM®) to estimate cardiac index (CI) and to track relative changes induced by volume expansion.

METHODS

In 48 critically ill patients, we measured CI estimated by the NICOM® device (CINicom) and by transpulmonary thermodilution (CItd, PiCCO2™ device) before and after a 500 ml saline infusion. Before volume expansion, we performed a passive leg raising (PLR) test and measured the changes it induced in CINicom and in pulse contour analysis-derived CI.

RESULTS

Considering the values recorded before PLR and before and after volume expansion (n=144), the bias (lower and upper limits of agreement) between CItd and CINicom was 0.9 (-2.2 to 4.1) litre min(-1) m(-2). The percentage error was 82%. There was no significant correlation between the changes in CItd and CINicom induced by volume expansion (P=0.24). An increase in CI estimated by pulse contour analysis >9% during the PLR test predicted fluid responsiveness with a sensitivity of 84% (95% confidence interval 60-97%) and a specificity of 97% (95% confidence interval 82-100%). The area under the receiver operating characteristic curve constructed to test the ability of the PLR-induced changes in CINicom in predicting fluid responsiveness did not differ significantly from 0.5 (P=0.77).

CONCLUSIONS

The NICOM® device cannot accurately estimate the cardiac output in critically ill patients. Moreover, it could not predict fluid responsiveness through the PLR test.

Macrolide-based regimens in absence of bacterial co-infection in critically ill H1N1 patients with primary viral pneumonia

PURPOSE

To determine whether macrolide-based treatment is associated with mortality in critically ill H1N1 patients with primary viral pneumonia.

METHODS

Secondary analysis of a prospective, observational, multicenter study conducted across 148 Intensive Care Units (ICU) in Spain.

RESULTS

Primary viral pneumonia was present in 733 ICU patients with pandemic influenza A (H1N1) virus infection with severe respiratory failure. Macrolide-based treatment was administered to 190 (25.9 %) patients. Patients who received macrolides had chronic obstructive pulmonary disease more often, lower severity on admission (APACHE II score on ICU admission (13.1 ± 6.8 vs. 14.4 ± 7.4 points, p < 0.05), and multiple organ dysfunction syndrome less often (23.4 vs. 30.1 %, p < 0.05). Length of ICU stay in survivors was not significantly different in patients who received macrolides compared to patients who did not (10 (IQR 4-20) vs. 10 (IQR 5-20), p = 0.9). ICU mortality was 24.1 % (n = 177). Patients with macrolide-based treatment had lower ICU mortality in the univariate analysis (19.2 vs. 28.1 %, p = 0.02); however, a propensity score analysis showed no effect of macrolide-based treatment on ICU mortality (OR = 0.87; 95 % CI 0.55-1.37, p = 0.5). Moreover, the sensitivity analysis revealed very similar results (OR = 0.91; 95 % CI 0.58-1.44, p = 0.7). A separate analysis of patients under mechanical ventilation yielded similar results (OR = 0.77; 95 % CI 0.44-1.35, p = 0.4).

CONCLUSION

Our results suggest that macrolide-based treatment was not associated with improved survival in critically ill H1N1 patients with primary viral pneumonia.

[Current status of fibreoptic bronchoscopy in intensive care medicine]

Flexible bronchoscopy (FB) has been of great help in the management of critically ill patients. Its safety and usefulness in the hands of experienced professionals, with the required measures of caution, has resulted in the increasingly widespread use of the technique even in unstable critical patients subjected to mechanical ventilation and with high oxygen demands. The Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC), through its Acute Respiratory Failure (GT-IRA) and Infectious Diseases (GT-EI) Work Groups, aims to promote knowledge and standards of quality in the use of FB among all specialists in Intensive Care Medicine. Through an expert committee, the SEMICYUC has established the objective of accrediting such training, with the preparation of a curriculum and definition of those Units qualified for providing training in the different techniques and levels. The accreditation process seeks to stimulate good learning practice and quality in training. Both specialists in Intensive Care Medicine and other specialists, and the patients, will benefit from the commitment and control afforded by such accreditation, and from the learning and training which the mentioned process entails.

Renal replacement therapy in the critical patient: treatment variation over time

OBJECTIVES

To analyze the evolution of patients subjected to renal replacement therapy (RRT), and to determine risk factors associated with mortality and the recovery of renal function.

DESIGN

A prospective, observational study of critically ill patients.

SETTING

Clinical-surgical Intensive Care Unit (ICU) of Sabadell Hospital (Spain).

PATIENTS

Inclusion of all patients treated in our Unit due to acute renal failure (ARF) requiring RRT.

PRIMARY VARIABLES OF INTEREST

We recorded epidemiological data, severity using the APACHE II score, days of the technique, ICU mortality, and renal function recovery. The study period was divided into 2 parts: part 1 (2000-2004) and part 2 (2005-2009). The 2 periods were compared using the Student t-test for continuous variables and the chi-squared test for categorical variables. Multiple regression analysis was performed to determine the risk factors for mortality and recovery of renal function.

RESULTS

A total of 304 patients were treated. Sepsis was the main etiology of ARF (61%), involving principally respiratory and abdominal foci. In the second period the convective technique and community-acquired ARF were far more prevalent than in the first period. There were fewer days of therapy in the second period (19.7 versus 12.3 days; P=.015). Total ICU mortality was 52.3%, with a decrease in the last period (61.9% to 45.5%: P=.003). The risk factors associated to mortality were creatinine upon admission (odds ratio [OR] 0.77; 95% confidence interval [95%CI] 0.61-0.97) and treatment with IHD alone (OR 0.37, 95%CI 0.16-0.87). Survivors had normal renal function at ICU discharge in 56.7% of the cases in the second period, vs in 72.9% in the first period, with more patients subjected to IHD in the second period (10.4% versus 26.8%). The factors related to the recovery of renal function were creatinine upon admission (OR 1.98, 95%CI 1.12-3.48), acute renal failure (OR 0.11, 95%CI 0.04-0.34) and treatment with continuous techniques (OR 0.18, 95%CI 0.03-0.85).

CONCLUSIONS

Mortality among critically ill patients subjected to RRT has improved in recent years.

Differential time to positivity of blood cultures: a valid method for diagnosing catheter-related bloodstream infections in the intensive care unit

PURPOSE

The validation in critical patients with short-term catheters of a method for diagnosing catheter-related bloodstream infection (CR-BSI), based on the differential time to positivity (DTP) of blood cultures.

METHODS

Patients suspected of having CR-BSI were included. Two peripheral vein blood cultures and a catheter hub blood culture were simultaneously carried out. The responsible catheter was removed and tip cultured. Times to positivity of all blood cultures were automatically registered. CR-BSI was diagnosed when all the cultures were positive for the same microorganism and DTP≥120 min. This diagnosis was compared with the one obtained using the standard method.

RESULTS

226 cases suspected of CR-BSI were analyzed during a 20-month period. A total of 19 removed catheters were associated with CR-BSI. Seven cases of polymicrobial cultures (4 with CR-BSI) were discarded from the final analysis due to the impossibility of determining the time to positivity for each individual microorganism. Using the DTP method, 12 out of 15 CR-BSI cases were diagnosed (sensitivity 80%, specificity 99%, PPV 92%, NPV 98%). In a ROC curve, we found a cut-off value of 17.7 h in positivity of hub blood cultures that may be useful for diagnosing CR-BSI.

CONCLUSION

DTP can be a valid method for CR-BSI diagnosis in critically ill patients, avoiding unnecessary catheter withdrawal.

Effectiveness of treatments for severe sepsis: data from the bundle implementation programs

In severe sepsis, several studies, a recent meta--analysis and studies evaluating multifaceted strategies for quality improvement, have shown that bundled care can improve survival. Here, the effectiveness of treatments for severe sepsis included in the bundles was analyzed. Despite the observational design of the studies, possible biases are minimized using propensity scores and other adjustments. The results of are very consistent: early sepsis recognition with the administration of broad-spectrum antibiotics in all patients and specific treatments for patients in shock, such as activated protein C, or those on mechanical ventilation play a role in improving sepsis outcome. Hospitals should recognize this new evidence and design strategies to guarantee bundled care for severe sepsis.

[Dendritic cells in sepsis: an approach to post-infectious immunosuppression]

Dendritic cells (DCs) play a decisive role in the immune system, especially in the initial events that determine coordination between the innate and adaptive response. Moreover, they are antigen-presenting cells which, through contact with T cells, determine the type of immune responses towards inflammatory or anti-inflammatory. Currently, the hypothesis that attributes importance to the development of a post-infectious immunosuppression in the prognosis of the septic patient is growing stronger. It has been possible to verify the role played by these cells in this type of immunosuppression by the significant decrease in the number of DCs and by the dysfunctions in the functional capacity that include, on the one hand, the abnormal cytokine production and, on the other hand, the alterations in communication between the DCs and T cells that constitute an essential immunological fact. Further research into the knowledge regarding the DCs, in the context of severe infection, may help to consolidate some encouraging data that indicate these cells as: 1) an effective tool for monitoring the acute infection, 2) a discriminatory variable that may help determine the risk of nosocomial infection and 3) in a longer term, a treatment target that would restore the immunological abnormalities that occur in sepsis.

[Role of coagulation in acute pulmonary lesion physiopathology. Parallelism with sepsis]

Acute respiratory distress syndrome and acute lung injury for a part of a devastating syndrome characterized by acute onset, hypoxemia and bilateral infiltrates in the chest x-ray with absence of heart failure signs. Acute lung injury is the response of the lung to a local or systemic aggression, resulting in local inflammation and coagulation disorders, this leading to increased inflammatory pulmonary edema. Acute lung injury/acute respiratory distress syndrome are associated with increased procoagulant and reduced fibrinolytic activities mainly in alveoli and interstitial spaces in the lung. Fibrin deposits, which are the hallmark of early phase acute lung injury, stimulate fibroblast aggregation and collagen secretion, participating to the constitution of pulmonary fibrosis. The only clinical intervention found to have a significant impact on mortality in acute respiratory distress syndrome, despite the significant pro - gress in the understanding of the disease made over the past 10 years, is the use of low tidal volume ventilation. In severe sepsis, only recombinant human activated protein C administration has demonstrated a mortality reduction, together with faster improvement in respiratory dysfunction and shorter duration of mechanical ventilation. Future clinical trials should consider the potential benefit of anticoagulants administrated systemically or locally in the lungs to determine the role of anticoagulants in the treatment of acute pulmonary injury/acute respiratory distress syndrome.

Daily assessment of severity of illness and mortality prediction for individual patients

OBJECTIVE

To refine the prognosis of critically ill patients using a statistical model that incorporates the daily probabilities of hospital mortality during the first week of stay in the intensive care unit (ICU).

DESIGN

Prospective inception cohort.

SETTING

Fifteen adult medical and surgical ICUs in Spain.

PATIENTS

A total of 1,441 patients aged > or =18 yrs who were consecutively admitted from April 1, 1995, through July 31, 1995.

INTERVENTIONS

Prospective data collection during the stay of the patient in the ICU. Data collected included vital status at hospital discharge as well as all variables necessary for computing the Mortality Probability Models II system at admission and during the first 7 days of stay in the ICU.

MEASUREMENTS AND MAIN RESULTS

Four logistic regression models were obtained. These models contained survival status at hospital discharge as a dependent variable and the following explanatory variables: (model 1) only the probability of dying at admission; (model 2) only the probability of dying during the current day; (model 3) the probability of dying at admission and during the current day; and (model 4) the probabilities of dying at admission and during the previous and current days. Models were evaluated using the Hosmer-Lemeshow statistic and the area under the receiver operating characteristic curve. For survivor and nonsurvivor patients, mortality probabilities obtained using the aforementioned models were compared using linear regression and the paired Student's t-test. Although severity at admission was a statistically significant variable, models 2 and 3 produced almost the same probabilities of hospital mortality, as shown with the linear regression and paired Student's t-test results.

CONCLUSIONS

To have an accurate measurement of the prognosis, it is necessary to update the severity measure. The best estimate of hospital mortality was the probability of death on the current day. Severity at admission and at previous days did not improve the assessment of prognosis.

Performance of the Mortality Probability Models in assessing severity of illness during the first week in the intensive care unit

OBJECTIVE

To extend the Mortality Probability Models (MPM) II severity system to time periods between 4 and 7 days after admission to the intensive care unit (ICU).

DESIGN

Prospective inception cohort.

SETTING

Fifteen adult medical and surgical ICUs in Spain.

PATIENTS

A total of 1,441 patients aged > or =18 yrs consecutively admitted from April 1, 1995 through July 31, 1995.

INTERVENTIONS

Prospective data collection during the stay of the patient in the ICU. Data collected included demographic information, length-of-stay and vital status at both ICU and hospital discharge, as well as all variables necessary for computing the MPM II system at admission and during the first 7 days of stay in the ICU MEASUREMENTS AND MAIN RESULTS: Calibration and discrimination of the four existing MPM II models (MPM0, MPM24, MPM48, and MPM72) were assessed in the study database. The MPM II system overestimated the mortality of patients with probabilities of death > or =0.4. The MPM24 model was customized. Models for time periods between 48 hrs and 7 days (MPM48 to MPMd7) were obtained using the same strategy that was used to develop the original MPM48 and the MPM72 models. The variable coefficients of the MPM24 model were kept fixed and the constant terms of the MPM48 to MPMd7 models were estimated by logistic regression. The constant term stabilized after the fourth day of admission and it was similar to the constant term of the MPM72 model. The customized MPM72 performed very well for days 4 to 7 after admission to the ICU.

CONCLUSIONS

If the patient's condition stays the same day after day, the probability of dying in the hospital increases until 72 hrs, and then stabilizes. A severity measure that performs well at 72 hrs can be a useful tool for measuring severity at later time periods.

Interobserver variability of the measurement of the mortality probability models (MPM II) in the assessment of severity of illness

OBJECTIVE

To assess the interobserver variability of the measurement of the MPM II system.

DESIGN

Random sample of an inception cohort.

SETTING

Fifteen adult medical and surgical intensive care units (ICUs) in Spain.

PATIENTS

A 5% random sample (n = 119) of 2332 patients consecutively admitted in the ICU, aged 18 years or older.

INTERVENTIONS

Prospective data collection during the stay of the patient in the ICU. Repeated data collection, after the patient's hospital discharge.

MEASUREMENTS AND MAIN RESULTS

Demographic information, length-of-stay and vital status at both ICU and hospital discharge, as well as all variables necessary for computing the MPM II system were measured. Interobserver variability for categorical variables was measured computing the kappa index. For interval variables the interobserver variability was assessed by the intraclass correlation coefficient, the paired t-test, and linear regression. In the MPM II0 index, the variables coma, heart rate, systolic blood pressure, chronic renal insufficiency, metastatic neoplasm, acute renal failure, cardiac dysrhythmia and cardiopulmonary resuscitation, showed moderate or low levels of agreement. In the MPM II24 index, the variables coma or deep stupor, PaO2 and prothrombin time showed low or moderate interobserver agreement. Agreement for the MPM II probability of death was high, although the external observer obtained a lower estimation than the hospital observer.

CONCLUSIONS

The MPM II severity system showed a high level of stability when used in groups of patients. Nevertheless, the observed variability in some variables means that it should be used with caution for individual patients.

Effect of acute moderate changes in PaCO2 on global hemodynamics and gastric perfusion

OBJECTIVE

To describe global hemodynamics and splanchnic perfusion changes in response to acute modifications in Paco2 in hemodynamically stable patients.

DESIGN

Prospective, randomized crossover study.

SETTING

Medical-surgical intensive care unit at a community hospital (400,000 inhabitants).

PATIENTS

Ten critically ill patients who were sedated, paralyzed, and mechanically ventilated.

INTERVENTIONS

Hypercapnia and hypocapnia were obtained by increasing and reducing instrumental deadspace in random order. After each intervention, patients returned to the basal condition. Each period lasted 80 min: 20 min to achieve stable Paco2 and 60 min for tonometer equilibration. In each period, global hemodynamic variables and tonometric data were collected. The periods were compared using analysis of variance.

MEASUREMENTS AND MAIN RESULTS

Acute hypercapnia (Paco2 from 40+/-3 to 52+/-3 torr, p<.05) increased cardiac index (3.43+/-0.37 vs. 3.97+/-0.43 mL/min/m2, p<.05), heart rate (95+/-6 vs. 105+/-3 beats/min, p<.05), and mean pulmonary artery pressure (21+/-1 vs. 24+/-1 mm Hg, p<.05) and reduced systemic vascular resistance (992+/-98 vs. 813+/-93 dyne x sec/ cm5, p<.05) and oxygen extraction ratio (27+/-3% vs. 22+/-2%, p<.05). Standardized intramucosal Pco2 increased from 49+/-2 to 61+/-3 torr (p<.05) with an associated decrease in calculated intramucosal pH ([pHi] 7.35+/-0.03 vs. 7.25+/-0.02, p<.05), but the gastro-arterial Pco2 gradient (deltaPco2) did not change. Acute hypocapnia (Paco2 from 41+/-3 to 34+/-3 torr, p<.05; pH 7.41+/-0.01 to 7.47+/-0.02, p<.05) induced slight increments in systemic vascular resistance (995+/-117 vs. 1088 +/- 160 dyne x sec/cm5, p<.05) and oxygen extraction ratio (28+/-2% vs. 30+/-2%, p<.05). Standardized intramucosal Pco2 decreased (50+/-4 vs. 44+/-3 torr, p<.05), pHi increased (7.33+/-0.03 vs. 7.36+/-0.02; p<.05), but deltaPco2 did not change.

CONCLUSIONS

In this small group of stable patients, moderate acute variations in Paco2 had a significant effect on global hemodynamics, but splanchnic perfusion, assessed by deltaPco2, did not change. In these conditions, the use of pHi to evaluate gastric perfusion appears unreliable.

Inhaled nitric oxide does not improve cardiac or pulmonary function in patients with an exacerbation of chronic obstructive pulmonary disease

OBJECTIVE

To determine whether inhaled nitric oxide (NO) improves right ventricular function in mechanically ventilated patients with severe chronic obstructive pulmonary disease (COPD).

DESIGN

Open, prospective, controlled trial.

SETTING

General intensive care unit of a community hospital.

PATIENTS

Twelve patients with acute respiratory failure caused by acute exacerbation of COPD requiring mechanical ventilation.

INTERVENTIONS

Insertion of a pulmonary artery catheter modified with a rapid response thermistor and a radial arterial catheter. Nitric oxide was then administered to the patient via a T piece placed between the Y piece of the ventilator and the endotracheal tube.

MEASUREMENTS AND MAIN RESULTS

Hemodynamic and gasometric variables were recorded before NO inhalation, during administration of inhaled NO (20 ppm, 20 mins), and 20 mins after NO discontinuation. Inhaled NO reduced pulmonary artery pressure from 26 +/- 6 to 22 +/- 5 mm Hg (p = .0004), but arterial oxygenation, cardiac output, and right ventricular ejection fraction remained unmodified (41% +/- 9% vs. 41% +/- 8%; not significant). Calculated pulmonary vascular resistance decreased from 453 +/- 233 to 348 +/- 108 dyne x sec/cm5 x m2 (p = .02), and right ventricular volumes did not change. Subsequently, right ventricular end-systolic pressure/volume ratio decreased from 0.52 +/- 0.22 to 0.44 +/- 0.19 mm Hg/mL/m2 (p = .01). No significant correlation was observed between the changes of pulmonary artery pressure (or pulmonary vascular resistance) and changes of right ventricular ejection fraction.

CONCLUSION

Inhalation of NO does not seem to improve either right ventricular function or arterial oxygenation in patients with acute respiratory failure caused by acute exacerbation of COPD.

[Quality of life and mortality of patients in intensive care. Indices of quality of life]

INTRODUCTION

At present there is no single practical standardized scale for measuring quality of life (QL). Any proposal should include the patient's physical impairment, level of independence, and subjective perception of happiness. We combined three previously published scales to define a quality of life index (QLI) that we propose as a standard quantitative instrument. The applicability and usefulness of QLI for the measurement of the level of deterioration of patients after admission to an intensive care unit (ICU) was examined. We prospectively evaluated QL before patient admission to determine if it influences mortality, as well as long-term changes in the QL and the factors conditioning te deterioration of patients released from the UCI as evaluated by QL indicators.

MATERIAL AND METHODS

To calculate QLI, we combined the Karnofsky scale, daily life activities index, and the perception of quality of life scale. The resulting percentage (QLI) was used to evaluate 536 patients after admission to the ICU and 6 and 12 months after release. QLI was compared with the severity of disease (Apache II), probability of death (MPM), diagnostic group, and socioeconomic variables.

RESULTS

Using multivariate methods, four significant variables related with mortality were identified: Apache II--MPM, duration of the stay in the unit, age, and QLI. Our analysis of long-term deterioration showed that advanced age, high QLI before admission, and the patient's diagnostic group explained the degree of deterioration.

DISCUSSION

QLI was a useful instrument for obtaining a quantitative estimate of the QL of critically ill patients.

Hemodynamic profile in severe ARDS: results of the European Collaborative ARDS Study

OBJECTIVE

Although the acute respiratory distress syndrome (ARDS) was identified as long as 30 years ago, potential therapeutic objectives have been defined from small series rather than large trials. Moreover, relationships between ARDS and hemodynamics are unclear. The European Collaborative ARDS Study was designed to identify factors influencing the pathogenesis, severity, and prognosis of ARDS. Analysis of the hemodynamic profiles collected during this study and of their contribution to the above-mentioned facets of ARDS is the focus of the present report.

DESIGN

Prospective clinical study.

SETTING

38 European intensive care units (ICUs).

PATIENTS AND METHODS

We collected 2758 sets of data from 586 patients, including baseline data, data on proven or suspected causes of ARDS differentiating direct and nondirect lung injury, and data on baseline status including multiple organ dysfunction (MOD) with differentiation of primary ARDS from ARDS secondary to severe systemic disorders. Events during follow-up were also recorded, including whether the acute respiratory failure did or did not improve after 24 h (groups A and B, respectively). When available, hemodynamic data were recorded at enrollment (day 0), on days 1-3, 7, 14, and 21, and at discharge or at the time of death in the ICU.

RESULTS

Although the rate of pre-existing disease and the nature and rate of complications varied widely among etiologic categories, differences in the hemodynamic profile occurred only between primary and secondary ARDS. Both at inclusion and during the course of the illness, variables that were used to investigate Va/Q mismatch [arterial oxygen tension (PaO2, arterial oxygen saturation, right-to-left shunt, and the PaO2/fractional inspired oxygen (FIO2) ratio] predicted survival. High pulmonary artery pressure (PAP) and low systemic artery pressure (SAP) were also related to the prognosis. In the logistic regression model including hemodynamic and oxygen-related variables, however, the only independent predictors of survival were the ratio of right over left ventricular stroke work (RVSW/LVSW) and the PaO2/FIO2 ratio at admission. On day 2, the best prognostic model included: age [odds ratio (OR) = 1.04, p = 0.0004], opportunistic pneumonia as the cause of ARDS (OR = 3.2, p = 0.03), existence of MOD (OR = 1.9, p = 0.03), PaO2/FIO2 (OR = 0.96, p = 0.005), and RVSW/LVSW (OR = 25, p = 0.02). A high RVSW/LVSW ratio, high systolic PAP, low diastolic SAP, and low PaO2/FIO2, and increased right atrial pressure were negative prognostic indicators during follow-up.

CONCLUSION

In addition to the cause of ARDS and the early time-course of lung function, a high systolic PAP and a low diastolic SAP were strong independent indicators of survival.

The American-European Consensus Conference on ARDS, part 2: Ventilatory, pharmacologic, supportive therapy, study design strategies, and issues related to recovery and remodeling. Acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) continues as a contributor to the morbidity and mortality of patients in intensive care units throughout the world, imparting tremendous human and financial costs. During the last 10 years there has been a decline in ARDS mortality without a clear explanation. The American-European Consensus Committee on ARDS was formed to re-evaluate the standards for the ICU care of patients with acute lung injury (ALI), with regard to ventilatory strategies, the more promising pharmacologic agents, and the definition and quantification of pathologic features of ALI that require resolution. It was felt that the definition of strategies for the clinical design and coordination of studies between centers and continents was becoming increasingly important to facilitate the study of various new therapies for ARDS.