Treatment failures in patients with ventilator-associated pneumonia

Clinical practice guidelines for hospital-acquired pneumonia and ventilator-associated pneumonia in adults

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are important causes of morbidity and mortality, with mortality rates approaching 62%. HAP and VAP are the second most common cause of nosocomial infection overall, but are the most common cause documented in the intensive care unit setting. In addition, HAP and VAP produce the highest mortality associated with nosocomial infection. As a result, evidence-based guidelines were prepared detailing the epidemiology, microbial etiology, risk factors and clinical manifestations of HAP and VAP. Furthermore, an approach based on the available data, expert opinion and current practice for the provision of care within the Canadian health care system was used to determine risk stratification schemas to enable appropriate diagnosis, antimicrobial management and nonantimicrobial management of HAP and VAP. Finally, prevention and risk-reduction strategies to reduce the risk of acquiring these infections were collated. Future initiatives to enhance more rapid diagnosis and to effect better treatment for resistant pathogens are necessary to reduce morbidity and improve survival.

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.

Safety and efficacy of colistin in Acinetobacter and Pseudomonas infections: a prospective cohort study

OBJECTIVE

To assess renal dysfunction and outcome in patients treated exclusively with colistin vs. other antibiotics.

DESIGN AND SETTING

Prospective cohort study in a mixed ICU in a university-affiliated hospital.

PATIENTS

185 patients infected with Acinetobacter baumannii and Pseudomonas aeruginosa after an ICU stay longer than 48 h: 55 in the colistin group and 130 in the noncolistin group, similar in age, APACHE II, medical status, and SOFA score.

MEASUREMENTS AND RESULTS

We recorded data on epidemiology and severity of illness, site of infection, renal function before and after treatment, clinical cure, and mortality. Clinical cure was defined as simultaneous normalization of central temperature (< or = 38 degrees), leukocyte count (< or = 10,000/mm3), and PaO2/FIO2 ratio (>187). Before treatment creatinine was 0.9+/-0.2 in the colistin group and 0.9+/-0.1 in the noncolistin group; after treatment the value was 1.0+/-0.3 in both groups. The most frequent infection was ventilator-associated pneumonia: 53% vs. 66% in colistin and noncolistin groups, respectively, Acinetobacter was the cause in 65% and 60% and Pseudomonas in 35% and 53%. In the noncolistin group 81% of patients were treated with carbapenems. Inadequate empirical antimicrobial treatment was more frequent in the colistin group (100% vs. 8%), but there were no differences in the frequency of clinical cure on day 6 of treatment (15% and 17%) or in mortality (29% and 24%).

CONCLUSIONS

Colistin appears to be as safe and as effective as other antimicrobials for treatment of sepsis caused by Acinetobacter and Pseudomonas in critically ill patients.

Effect of ventilator-associated tracheobronchitis on outcome in patients without chronic respiratory failure: a case-control study

Introduction

Our objective was to determine the effect of ventilator-associated tracheobronchitis (VAT) on outcome in patients without chronic respiratory failure.

Methods

This was a retrospective observational matched study, conducted in a 30-bed intensive care unit (ICU). All immunocompetent, nontrauma, ventilated patients without chronic respiratory failure admitted over a 6.5-year period were included. Data were collected prospectively. Patients with nosocomial pneumonia, either before or after VAT, were excluded. Only first episodes of VAT occurring more than 48 hours after initiation of mechanical ventilation were studied. Six criteria were used to match cases with controls, including duration of mechanical ventilation before VAT. Cases were compared with controls using McNemar's test and Wilcoxon signed-rank test for qualitative and quantitative variables, respectively. Variables associated with a duration of mechanical ventilation longer than median were identified using univariate and multivariate analyses.

Results

Using the six criteria, it was possible to match 55 (87%) of the VAT patients (cases) with non-VAT patients (controls). Pseudomonas aeruginosa was the most frequently isolated bacteria (34%). Although mortality rates were similar between cases and controls (29% versus 36%; P = 0.29), the median duration of mechanical ventilation (17 days [range 3–95 days] versus 8 [3–61 days]; P < 0.001) and ICU stay (24 days [range 5–95 days] versus 12 [4–74] days; P < 0.001) were longer in cases than in controls. Renal failure (odds ratio [OR] = 4.9, 95% confidence interval [CI] = 1.6–14.6; P = 0.004), tracheostomy (OR = 4, 95% CI = 1.1–14.5; P = 0.032), and VAT (OR = 3.5, 95% CI = 1.5–8.3; P = 0.004) were independently associated with duration of mechanical ventilation longer than median.

Conclusion

VAT is associated with longer durations of mechanical ventilation and ICU stay in patients not suffering from chronic respiratory failure.