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.