Causes and predictors of nonresponse to treatment of intensive care unit–acquired pneumonia*

Systemic and bronchoalveolar cytokines as predictors of in-hospital mortality in severe community-acquired pneumonia

OBJECTIVES

The aim of this study was to determine whether cytokine expression (interleukin [IL]-1beta, IL-6, IL-8, IL-10, and tumor necrosis factor [TNF]-alpha), C-reactive protein, and endotoxins on the first day of intensive care unit (ICU) admission are associated with hospital mortality in severe community-acquired pneumonia (CAP).

DESIGN

This was a prospective study with bronchoalveolar lavage (BAL) and blood sampling.

SETTING

This study was carried out in a 44-bed medical ICU of a 1700-bed university hospital.

PATIENTS

Participants included 112 mechanically ventilated patients with severe CAP.

INTERVENTIONS

Serum and BAL fluid IL-1beta, IL-6, IL-8, IL-10, TNF-alpha, C-reactive protein, and endotoxins on the first day of ICU admission were obtained.

MEASUREMENTS AND MAIN RESULTS

The concentrations of TNF-alpha in BALF and IL-6, IL-8, IL-10, and TNF-alpha in serum were higher in nonsurvivors than in survivor patients with CAP. Of these 112 patients with severe CAP (39%), 44 developed acute respiratory distress syndrome (ARDS); these patients seemed to have higher serum IL-6, IL-8, and IL-10 levels than did the non-ARDS group. Furthermore, in the ARDS population, we found that the endotoxin levels in the BAL fluid were higher in the survival than in the nonsurvival group and BAL fluid concentrations of IL-6, IL-8, and IL-1beta and sera levels of IL-6 and IL-10 were lower in the survival than in the nonsurvival group, and they were associated with a high negative predictive value.

CONCLUSIONS

Serum and BAL fluid levels of the studied cytokines on admission may provide valuable prognostic information for patients with severe CAP.

Hospital-acquired pneumonia: pathophysiology, diagnosis, and treatment

Hospital-acquired pneumonia (HAP) is one of the most common causes of nosocomial infection, morbidity, and mortality in hospitalized patients. Many patient- and disease-specific factors contribute to the pathophysiology of HAP, particularly in the surgical population. Risk-factor modification and inpatient prevention strategies can have a significant impact on the incidence of HAP. While the best diagnostic strategy remains a subject of some debate, prompt and appropriate antimicrobial therapy in patients suspected of having HAP has been shown to significantly decrease mortality. Because the pathogens responsible for HAP are frequently more virulent and have greater resistance to commonly used antimicrobials than other pathogens, clinicians must have knowledge of the resistance patterns at their institutions to choose appropriate therapy.

Defining, treating and preventing hospital acquired pneumonia: European perspective

INTRODUCTION

Many controversies still remain in the management of hospital acquired pneumonia (HAP), and ventilation-acquired pneumonia (VAP), Three European Societies, European Respiratory Society (ERS), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and European Society of Intensive Care Medicine (ESICM), were interested in producing a document on HAP and VAP with European perspective.

MATERIALS AND METHODS

The scientific committees from each Society designated one chairman; Antoni Torres (ERS), Harmut Lode (ESCMID) and Jean Carlet (ESICM). The chairmen of this Task Force suggested names from each Society to be a member of the panel. They also choose controversial topics on the field and others that were not covered by the last IDSA/ATS guidelines. Each topic was assigned to a pair of members to be reviewed and written. Finally, the panel defined 20 consensual points that were circulated several times among the members of the panel until total agreement was reached. A combination of evidences and clinical-based medicine was used to reach these consensus.

CONCLUSION

This manuscript reviews in depth several controversial or new topics in HAP and VAP. In addition 20 consensual points are presented. This manuscript may be useful for the development of future guidelines and to stimulate clinical research by lying out what is currently accepted and what is unknown or controversial.

Risk factors for treatment failure in patients with ventilator-associated pneumonia receiving appropriate antibiotic therapy

PURPOSE

The aim of this study was to investigate modifiable risk factors and predictors for treatment failure (TF) in patients with ventilator-associated pneumonia (VAP) receiving appropriate antibiotic therapy.

MATERIALS AND METHODS

An observational cohort study performed in an intensive care unit (ICU) of a University hospital. Eighty-nine patients with VAP were enrolled in the study consecutively. Treatment failure was defined as lack of clinical and microbiological response to therapy within 2 weeks. Potential risk factors for TF, related with patients, microorganisms, and ICU therapies, were evaluated.

RESULTS

Mean age was 72 +/- 13 years. Fifty-three of the patients had TF. Patients with TF were older, had more comorbidities, higher admission and Acute Physiology and Chronic Health Evaluation Score (APACHE II)-VAP scores, lower daily carbohydrate intake, and lymphocyte number below 1000/mm(3) than the treatment success group. Transfusions, bacteremia, infection with multidrug-resistant microorganisms, initial bacterial load (CFU/mL), and steroid therapy were similar across the groups. Comorbidity (odds ratio [OR], 4.4; 95% CI, 1.2-16.8; P = .030), VAP-APACHE II scores above 16 (OR, 6.4; 95% CI, 2.1-18.6; P = .001), daily carbohydrate intake below 190 g/d (OR, 3; 95% CI,1.1-8.6; P = .038), lymphocyte number below 1000/mm3 (OR, 4.1; 95% CI, 1.3-12.9; P = .014) were independent predictors for TF.

CONCLUSIONS

Patients with comorbidities, who are severely ill and lymphocytopenic at the time of VAP diagnosis, are at high risk for TF.

Risk factors affecting in-hospital mortality in patients with nosocomial infections

BACKGROUND/PURPOSE

Nosocomial infection (NI)-associated death is an important issue for both patients and clinicians, and is of emerging importance in public health. This study investigated the factors associated with in-hospital deaths among patients with NI.

METHODS

Between July 1, 2002 and June 30, 2003, a total of 1574 patients with NI at National Taiwan University Hospital were enrolled to investigate the factors associated with fatal outcome. Host factors, hospital services, surgical and medical interventions, microbial factors, infection sites, and the treatment and complications of NI were analyzed retrospectively.

RESULTS

During the study period, 554 of the 1574 patients died (mortality rate, 28.3%). NI was directly involved in 80.5% of them (n = 446), and over two-thirds (67.9%) of deaths occurred within 2 weeks of NI onset. Sixteen variables were statistically implicated as independent factors significantly associated with mortality. Host factors included higher disease severity (p < 0.0001), liver cirrhosis (p < 0.0001), solid tumors (p < 0.0001), chronic lung disease (p = 0.003), and congestive heart failure (p = 0.005). Hospital and interventional factors included intensive care hospitalization (p = 0.002), longer hospitalization before NI onset (p = 0.004), hemodialysis (p = 0.0003), arterial-line insertion (p < 0.0001), urinary catheterization (p < 0.0001), and central venous catheterization (p = 0.001). Blood stream infections (p < 0.0001), NI due to Candida (p < 0.0001), and multiple (> or = 2) episodes of NI (p < 0.0001) were significant risk factors for death, as were occurrence of NI-associated septic shock (p < 0.0001) and disseminated intravascular coagulation (p < 0.0001). No significant associations of mortality with age, sex, species of bacteria, multi-antibiotic resistant bacteria, regimen for initial treatment, or multiple antibiotic therapy were evident.

CONCLUSION

Measures that prevent the occurrence of NI, such as improving the immunity status of the host, removal of catheters as soon as possible, and implementing an infection control program, could reduce the risk of in-hospital deaths attributable to NI.

Predictive value of serial measurements of sTREM-1 in the treatment response of patients with community-acquired pneumonia

BACKGROUND/PURPOSE

To evaluate the roles of plasma sTREM-1 (soluble triggering receptor expressed on myeloid cells-1) and C-reactive protein (CRP) in predicting treatment response in patients with community-acquired pneumonia (CAP).

METHODS

Patients with CAP were enrolled prospectively at a medical center in central Taiwan from September 1, 2004 to July 31, 2005. They were treated according to the guidelines proposed by the American Thoracic Society. Patients were noted as nonresponsive to initial treatment if they had one of the following: persistent fever for more than 3 days, progression on chest radiograph, switching to other antibiotics, or need of mechanical ventilation and/or chest tube drainage.

RESULTS

Fifty-eight patients (43 males/15 females; mean age, 67 +/- 21 years) with CAP were enrolled. Twelve (12/58, 21%) were nonresponsive. In the response group, CRP was reduced up to 58% from day 1 to day 3 (from 18.8 to 7.8 mg/dL), whereas sTREM-1 was reduced by only 15% (from 32.8 to 28.1 pg/mL). In the nonresponse group, CRP still declined 20% (from 22.2 to 17.7 mg/dL), whereas sTREM-1 was persistently high (from 61.7 to 63.7 pg/mL). Using multivariate logistic regression analysis, both CRP (p = 0.006) and sTREM-1 (p = 0.046) on day 3 predicted treatment response significantly, but CRP on day 3 had stronger statistic power.

CONCLUSION

Both CRP and sTREM-1 on day 3 could be useful in predicting nonresponsive CAP patients. Differential trends between sTREM-1 and CRP in nonresponsive CAP suggest that sTREM-1 could be an adjuvant biomarker to CRP in predicting CAP patients without response to empiric treatment.

Early evolution of arterial oxygenation in severe community-acquired pneumonia: a prospective observational study

PURPOSE

Acute respiratory failure requiring mechanical ventilation in severe community-acquired pneumonia has been shown to be a significant negative prognostic factor. We analyzed the early evolution of the Pao(2)/Fio(2) ratio and evaluated its clinical value as an outcome predictor.

MATERIALS AND METHODS

This is a prospective study conducted in a tertiary referral hospital. In 62 adult patients requiring early mechanical ventilation due to severe community-acquired pneumonia, we measured serial changes in Pao(2)/Fio(2) ratio and other clinical variables within the first 48 hours of mechanical ventilation and compared the difference between survivors and nonsurvivors.

RESULTS

The initial Pao(2)/Fio(2) ratio was lower in nonsurvivors (n = 27) than in survivors (n = 35) (158.0 +/- 55.8 vs 117.9 +/- 50.6, P = .025). Over the next 48 hours, the ratio increased significantly in survivors but not in nonsurvivors (analysis of variance, P < .001). An increase in Pao(2)/Fio(2) ratio greater than 56 mm Hg had a sensitivity of 75% and a specificity of 81% of survival. A definite causative pathogen was identified in 36 patients (58%) and the 3 most commonly isolated pathogens were Streptococcus pneumoniae, Staphylococcus aureus, and Klebsiella pneumoniae. Ten patients received inadequate initial empirical antimicrobial therapy, in which the Pao(2)/Fio(2) ratio change was significantly less than those who were adequately treated (analysis of variance, P < .001). Mortality was much higher (86% [6/7]) in patients who received inadequate antibiotics and where Pao(2)/Fio(2) ratio change was less than 56 mm Hg. On multivariate analysis, trend changes in Pao(2)/Fio(2) ratio over 48 hours, shock, and Acute Physiology and Chronic Health Evaluation II score were documented to be independent predictors of mortality.

CONCLUSIONS

A progressive improvement of Pao(2)/Fio(2) ratio during the first 48 hours of mechanical ventilation indicates favorable outcome. Serial measurement of this ratio should be considered in decision making for therapeutic strategy.

Early predictors for infection recurrence and death in patients with ventilator-associated pneumonia

OBJECTIVE

Early recognition of predictors of unfavorable evolution of ventilator-associated pneumonia (VAP) might prompt therapeutic measures that might improve outcome. The objective of this study was to describe resolution of VAP variables and to determine early predictors of VAP recurrence and death.

DESIGN AND SETTING

Description of the natural course of VAP resolution and multivariable analyses of predictors of VAP recurrence and death by day 28 after VAP onset based on the 401 patients included in the PNEUMA trial, a multiple-center, randomized study comparing 8 vs. 15 days of antibiotics for microbiologically proven VAP. Every patient included in that trial had received appropriate empirical antibiotics.

MEASUREMENTS AND MAIN RESULTS

By day 28 after VAP onset, 27% of patients had VAP recurrence and 18% had died. On day 8 after VAP onset, predictors of VAP recurrence included intensive care unit admission Simplified Acute Physiology Score II (odds ratio [OR], 1.02), radiologic score (OR, 1.17), temperature (OR, 1.34), nonfermenting Gram-negative bacilli (OR, 2.00) or methicillin-resistant Staphylococcus aureus (OR, 2.50) as pathogens responsible for VAP, and mechanical ventilation dependency (OR, 2.08). Day 8 predictors of 28-day death were age (OR, 1.06), female sex (OR, 2.30), Sepsis-Related Organ Failure Assessment score (OR, 1.26), and nonfermenting Gram-negative bacilli (OR, 2.83) as pathogens responsible for VAP. However, the duration of antimicrobial therapy (8 vs. 15 days) was not associated with any of the studied adverse outcomes.

CONCLUSIONS

For patients benefiting from appropriate empirical antibiotics for VAP, early predictors of infection recurrence or death included demographic characteristics, such as age or female sex, disease severity at VAP onset, nonfermenting Gram-negative bacilli or methicillin-resistant S. aureus as VAP-causative pathogens, prolonged mechanical ventilation dependency, persistent fever, and severity of lung injury. Future studies should attempt to determine whether specific diagnostic or therapeutic strategies could markedly improve VAP outcomes when early criteria for treatment failure are present.

De-escalation in lower respiratory tract infections

PURPOSE OF REVIEW

The present article reviews recent data on the de-escalation of empirical antibiotic treatment on pneumonia, with special attention to newer strategies aimed at increasing adequacy and minimizing resistance emergence risks in ventilator-associated pneumonia.

RECENT FINDINGS

A de-escalation strategy is feasible in a large proportion of patients with pneumonia, and at least two reports have associated de-escalation with a significantly better survival. Combined with other strategies, such as using biomarkers (e.g. C-reactive protein or procalcitonin), antibiotic heterogeneity, adherence to local microbiological flora, objective clinical criteria of non-response and of clinical ventilator-associated pneumonia resolution, they contribute to rationalizing and individualizing antimicrobial therapy.

SUMMARY

A patient-based approach with prompt adequate empirical therapy, using broad-spectrum antibiotics based on reliable local microbiological data with streamlining as soon as microbiological data become available, allow outcomes to be improved and the emergence of resistance to be minimized.

[Follow-up criteria for community acquired pneumonias and acute exacerbations of chronic obstructive pulmonary disease]

The follow-up of Community Acquired Pneumonias (CAP) and Acute Exacerbations of Chronic Obstructive Pulmonary Diseases (AECOPD) differs with the setting of care, but overall calls upon the same investigations as the initial evaluations. In the event of initial ambulatory care, the evaluation is carried out primarily on clinical data, at the 2 or 3rd day for the CAP, at the 2nd to 5th day for the AECOPD. In the event of unfavourable evolution, or from the start in the most severe cases, the follow-up is carried out in hospital; clinical evaluation is readily daily, and all the more frequent that the clinical condition is worrying because of the severity or risk factors. The investigations will be limited to those initially abnormal in the event of favourable evolution; on the contrary, unfavourable evolution can justify new investigations which depend on clinical characteristics. Remotely, i.e. 4 to 8 weeks later, must be checked the return at the baseline clinical state, a chest X-ray (CAP), spirometry and arterial blood gas (AECOPD), even bronchoscopy and thoracic CT-scan.

[Assessment of patients with poor resolution of HAP]

Emphasis in VAP management is now shifting to the effectiveness of antibiotic therapy and its effect on subsequent mortality. As many as 62% of patients with VAP meet a set of objective criteria for failure to respond. The predominant microorganisms associated with failure of therapy are Pseudomonas aeruginosa and methicillin-resistant S. aureus (MRSA). Multiple causes of failure to respond in VAP exist: compromised host immunity, occult antibiotic resistance, inadequate antibiotic dosing, and concomitant or subsequent superinfections. The diagnosis of antibiotic failure and distinguishing failure from superinfection or noninfectious mimics is difficult because clinical criteria alone are inadequate. Microbiologic response is accurate only if quantitative cultures are used. Biochemical markers may be more accurate than clinical but still don't discriminate between causes. The appropriate diagnostic strategy and treatment algorithms have not been fully addressed and more research is clearly needed.

Associated inflammatory response in pneumonia: role of adjunctive therapy with glucocorticoids

PURPOSE OF REVIEW

This article reviews the potential use of glucocorticoids as adjunctive therapy in the management of patients with severe bacterial pneumonia or pulmonary infections of other etiologies.

RECENT FINDINGS

The importance of an adequate assessment of the inflammatory process and the appearance of inflammatory markers that correlate with the severity of pneumonia is underlined. A recent randomized clinical trial indicates that adjunctive treatment of severe community-acquired pneumonia with glucocorticoids reduces complications and improves survival. The role of glucocorticoids in other lung infections is also reviewed. The design of new compounds with similar anti-inflammatory properties to classical glucocorticoids but with significantly fewer side effects constitutes a specific challenge for the near future.

SUMMARY

Although adjunctive treatment with glucocorticoids in severe pneumonia is probably indicated, further randomized clinical trials are urgently needed to confirm the preliminary positive results. In this regard, a proper evaluation of the inflammatory response is likely to be essential for the accurate selection of the target population.

[Management of ventilator acquired pneumonia]

Ventilator-associated pneumonia occurs in the evolution of 8 to 70% of patients in the Intensive Care Unit. It is the main site of nosocomial infection for mechanically ventilated patients. Nosocomial pneumonia represents an important cause of morbidity and mortality, despite progresses in antibiotic prescription, use of intensive care and prevention. This review is based on the ATS guidelines, and reviews epidemiology, diagnosis and treatment of ventilator-acquired pneumonia, in non-immunocompromised adults.

Risk and prognostic factors of ventilator-associated pneumonia in trauma patients

OBJECTIVE

To assess the risk and prognostic factors of ventilator-associated pneumonia in trauma patients, with an emphasis on the inflammatory response.

DESIGN

Case-control study.

SETTING

Trauma intensive care unit.

PATIENTS

Of 190 consecutive mechanically ventilated patients, those with microbiologically confirmed pneumonia (n = 62) were matched with 62 controls without pneumonia.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Clinical, microbiological, and outcome variables were recorded. Cytokines were measured in serum and blind bronchoalveolar lavage specimens at onset of pneumonia. Multivariate analyses of risk and prognostic factors for ventilator-associated pneumonia were done. Increased severity of head and neck injury (odds ratio, 11.9; p < .001) was the only independent predictor of pneumonia. Among patients with pneumonia, serum levels of interleukin-6 (p = .019) and interleukin-8 (p = .036) at onset of pneumonia were higher in nonresponders to treatment. Moreover, serum levels of tumor necrosis factor-alpha (p = .028) and interleukin-6 (p = .007) at onset of pneumonia were higher in nonsurvivors. Mortality in the intensive care unit was 23% in cases and controls. Nonresponse to antimicrobial treatment (odds ratio, 22.2; p = .001) and the use of hyperventilation (p = .021) were independent predictors of mortality in the intensive care unit for patients with pneumonia.

CONCLUSIONS

Severe head and neck trauma is strongly associated with ventilator-associated pneumonia. A higher inflammatory response is associated with nonresponse to treatment and mortality among patients with pneumonia. Although pneumonia did not influence mortality, nonresponse to treatment independently predicted mortality among these patients.

Etiology and cytokine expression in patients requiring mechanical ventilation due to severe community-acquired pneumonia

BACKGROUND

The relationship between bacterial etiology and serum cytokine levels in patients with severe community-acquired pneumonia (CAP) without response to initial empiric treatment remains unclear. This study investigated the bacterial etiology, outcomes, and bronchoalveolar and systemic cytokines (interleukin [IL]-1beta, IL-8, IL-10) in these patients.

METHODS

This hospital-based study enrolled 47 consecutive patients without response to initial empiric treatment and requiring mechanical ventilation due to severe CAP between July 1, 2000 and October 31, 2001, in a respiratory intensive care unit of a 1200-bed teaching hospital in central Taiwan. Bronchoalveolar lavage (BAL) was performed within 3 days after hospitalization. BAL fluid was processed for quantitative bacterial cultures. Blood samples were taken just before BAL, and the levels of both BAL and serum cytokines were measured.

RESULTS

The most common pathogens isolated were Pseudomonas aeruginosa (22.5%) and Klebsiella pneumoniae (25%). Patients with a K. pneumoniae isolate (n = 10) had significantly higher levels of IL-1beta in BAL fluid and significantly higher levels of IL-10 in serum and BAL fluid than patients with other etiologies. Non-survivors had higher levels of serum IL-8 (p = 0.001), serum IL-10 (p < 0.001) and BAL IL-10 (p = 0.039) than survivors. Marked increases in local and systemic cytokine expression (IL-8 and IL-10) were noted in rapidly fatal cases.

CONCLUSION

P. aeruginosa and K. pneumoniae are the most common causes of CAP requiring mechanical ventilation in Taiwan. Cytokine patterns in the BAL fluid and serum of patients with severe CAP due to K. pneumoniae showed significant elevations compared to other pathogens. Bronchoalveolar and systemic cytokine levels (especially IL-10) predicted mortality. These findings suggest the need for a clinical trial to determine how immunomodulating therapy might affect cytokine profiles and clinical outcome.

Bronchial colonization and postoperative respiratory infections in patients undergoing lung cancer surgery

STUDY OBJECTIVES

To evaluate the risk factors associated with postoperative respiratory infection in patients undergoing lung cancer surgery, with special emphasis on the perioperative pattern of airway colonization.

DESIGN

Prospective cohort study.

SETTING

Department of Pneumology and Thoracic Surgery of a tertiary hospital.

PATIENTS

Seventy-eight consecutive patients undergoing lung cancer surgery were evaluated. Patients were followed up until hospital discharge or death.

INTERVENTIONS

Fiberoptic bronchoscopies with bilateral protected specimen brush or bronchial aspirates were performed during anesthesia prior to the initiation of the surgical procedure.

RESULTS

Sixty-five patients (83%) had perioperative bronchial colonization by either potentially pathogenic microorganisms (PPMs) [28 patients, 36%] or non-potentially pathogenic microorganisms (56 patients, 72%). The 24 patients (31%) with a postoperative respiratory infection (pneumonia, purulent tracheobronchitis, or pleural empyema) had significantly higher perioperative bronchial colonization by PPMs (15 patients [63%] vs 13 patients [24%], p = 0.003) and a higher bacterial index (mean +/- SD, 3.6 +/- 3.3 vs 0.9 +/- 1.4; p = 0.003), compared to patients without infection. The agreement between pathogens found in perioperative evaluation and during postoperative infection was total in 5 patients (21%), partial in 5 patients (21%), and no concordance in 14 patients (58%). In the multivariate analysis, the presence of perioperative airway colonization by a PPM (odds ratio [OR], 6.9; p = 0.001) and a higher postoperative pain score (OR, 4.1; p = 0.014) were independent predictors of postoperative respiratory infection.

CONCLUSION

Adequate control of postoperative pain, as well as the conditions that potentially cause airway colonization by PPMs, could be beneficial in preventing postoperative respiratory infections after lung cancer surgery.

Impact of ventilator-associated pneumonia on outcome in patients with COPD

PURPOSES

The aim of this study was to determine the impact of ventilator-associated pneumonia (VAP) on outcome in patients with COPD.

METHODS

Prospective, observational, case-control study conducted in a 30-bed ICU during a 5-year period. All COPD patients who required intubation and mechanical ventilation (MV) for > 48 h were eligible. VAP diagnosis was based on clinical, radiographic, and quantitative microbiologic criteria. Patients with unconfirmed VAP were excluded, as well as patients with ventilator-associated tracheobronchitis without subsequent VAP. Matching (1:1) criteria included MV duration before VAP occurrence, age +/- 5 years, simplified acute physiology score II on ICU admission +/- 5, and ICU admission category. Variables associated with ICU mortality were determined using univariate and multivariate analyses.

RESULTS

A total of 1,241 patients were eligible; 181 patients (14%) were excluded, including 133 patients for VAT and 48 patients for unconfirmed VAP. VAP developed in 77 patients (6%), and all were successfully matched. Pseudomonas aeruginosa was the most frequently isolated bacteria (31%). ICU mortality rate (64% vs 28%), duration of MV (24 +/- 15 d vs 13 +/- 11 d [+/- SD]), and ICU stay (26 +/- 17 d vs 15 +/- 13 d) were significantly (< 0.001) higher in case patients than in control patients. VAP was the only variable independently associated with ICU mortality (odds ratio [OR], 7.7; 95% confidence interval [CI], 3.2 to 18.6; p < 0.001). In VAP patients who received corticosteroids during their ICU stay compared with those who did not receive corticosteroids, mortality rate (50% vs 82%; OR, 1.8; 95% CI, 1.2 to 2.7; p = 0.002), duration of MV (21 +/- 14 d vs 27 +/- 16 d, p = 0.043), and ICU stay (22 +/- 16 d vs 31 +/- 18 d, p = 0.006) were significantly lower.

CONCLUSION

VAP is associated with increased mortality rates and longer duration of MV and ICU stay in COPD patients.

Clinical resolution in patients with suspicion of ventilator-associated pneumonia: A cohort study comparing patients with and without acute respiratory distress syndrome*

OBJECTIVES

To determine the pattern of resolution of classic infectious and respiratory variables in patients with ventilator-associated pneumonia (VAP) and appropriate empirical therapy, depending on the presence of acute respiratory distress syndrome (ARDS). A secondary objective was to identify clinical variables that might be useful for monitoring response to therapy.

DESIGN

Prospective, observational cohort study.

SETTING

Medical-surgical intensive care unit.

PATIENTS

Seventy-five episodes of VAP without ARDS were identified and compared with 20 episodes with ARDS at VAP onset. Six episodes were excluded due to in vitro resistance to the initial antibiotic choice and six due to death in the first 72 hrs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Resolution of fever, Pao2/Fio2 >250 mm Hg, and white blood cell count in episodes of VAP were present in 73.3%, 74.7%, and 53.3% of patients after 3 days of therapy. Indeed, >50% of episodes with the absence of ARDS presented resolution of fever and Pao2/Fio2 >250 within the first day of therapy. In contrast, resolution of radiologic opacities and clearance of secretions (median of 14 and 6 days of resolution) were late events. In patients with ARDS, resolution of fever remained the earliest variable. However, similar to Pao2/Fio2 250 and white blood cell count, fever showed a significantly worse pattern after 3 days of therapy: 45%, 15% and 25%, respectively. Radiologic resolution was an extremely poor indicator, being present in only 10% of ARDS patients after 15 days of follow-up. Failure to improve after 48 hrs of therapy was documented in 65% of ARDS patients and 14.7% of controls (p < .05).

CONCLUSIONS

Measures of oxygenation and core temperature can help physicians to individualize and shorten the duration of antibiotic therapy in VAP episodes. ARDS patients with VAP take twice as long to resolve fever, whereas hypoxemia should be ignored in defining resolution in this subset.

De-escalation therapy in ventilator-associated pneumonia

OBJECTIVE

To evaluate de-escalation of antibiotic therapy in patients with ventilator-associated pneumonia.

DESIGN

Prospective observational study during a 43-month period.

SETTING

Medical-surgical intensive care unit.

PATIENTS

One hundred and fifteen patients admitted to the intensive care unit with clinical diagnosis of ventilator-associated pneumonia. All the episodes of ventilator-associated pneumonia received initial broad-spectrum coverage followed by reevaluation according to clinical response and microbiology. Quantitative cultures obtained by bronchoscopic examination or tracheal aspirates were used to modify therapy.

INTERVENTIONS

: None.

MEASUREMENTS AND MAIN RESULTS

One hundred and twenty-one episodes of ventilator-associated pneumonia were diagnosed. Change of therapy was documented in 56.2%, including de-escalation (the most frequent cause) in 31.4% (increasing to 38% if isolates were sensitive). Overall intensive care unit mortality rate was 32.2%. Inappropriate antibiotic therapy was identified in 9% of cases and was associated with 14.4% excess intensive care unit mortality. Quantitative tracheal aspirates and bronchoscopic samples (58 protected specimen brush and three bronchoalveolar lavage) were associated with 32.7% and 29.5% intensive care unit mortality and 29.3% and 34.4% de-escalation rate. De-escalation was lower (p < .05) in the presence of nonfermenting Gram-negative bacillus (2.7% vs. 49.3%) and in the presence of late-onset pneumonia (12.5% vs. 40.7%). When the pathogen remained unknown, half of the patients died and de-escalation was not performed.

CONCLUSION

De-escalation was the most important cause of antibiotic modification, being more feasible in early-onset pneumonia and less frequent in the presence of nonfermenting Gram-negative bacillus. The impact of quantitative tracheal aspirates or bronchoscopic techniques was comparable in terms of mortality.

Respiratory nosocomial infections in the medical intensive care unit

Intensive care unit (ICU)-acquired lower respiratory tract infections include acute tracheobronchitis and hospital-acquired and ventilator-associated pneumonia (VAP). Nosocomial pneumonia is the second most common hospital-acquired infection and the leading cause of death in hospital-acquired infections. The mortality rate in VAP ranges from 24% to 76% in several studies. ICU ventilated patients with VAP have a 2- to 10-fold higher risk of death than patients without it. Early oropharyngeal colonization is pivotal in the etiopathogenesis of VAP. The knowledge of risk factors for VAP is important in developing effective preventive programs. Once the physician decides to treat a suspected episode of ICU-acquired pneumonia, some issues should be kept on mind: first, the adequacy of the initial empiric antibiotic therapy; second, the modification of initial inadequate therapy according to microbiological results; third, the benefit of combination therapy; and finally, the duration of the antimicrobial treatment. Additionally, a protocolized work-up to identify the causes of non-response to treatment is mandatory. All these issues are discussed in depth in this article.

Procalcitonin kinetics as a prognostic marker of ventilator-associated pneumonia

We investigated the value of procalcitonin kinetics as a prognostic marker during ventilator-associated pneumonia (VAP). This prospective, observational study was conducted in a medical intensive care unit in a university hospital. All consecutive patients with microbiologically proven VAP who survived 3 days after its diagnosis were included and grouped according to clinical outcome: favorable or unfavorable, defined as death, VAP recurrence, or extrapulmonary infection requiring antibiotics before Day 28. Serum procalcitonin levels were measured on Days 1, 3, and 7 for all patients. Among the 63 patients included, 38 had unfavorable outcomes. On Day 1, they were more critically ill than patients with a favorable outcome. Serum procalcitonin levels decreased during the clinical course of VAP but were significantly higher from Day 1 to Day 7 in patients with unfavorable outcomes. Multivariate analyses retained serum procalcitonin levels on Days 1, 3, and 7 as strong predictors of unfavorable outcome. Based on these data, procalcitonin could be a prognostic marker of outcome during VAP.