Antibiotic therapy of ventilator-associated pneumonia--a reappraisal of rationale in the era of bacterial resistance

A survey on infection management practices in Italian ICUs

Introduction

An online survey was conducted to characterize current infection management practices in Italian intensive care units (ICUs), including the antibacterial and antifungal drug regimens prescribed for various types of infections.

Methods

During February and March 2011, all 450 ICUs in public hospitals in Italy were invited to take part in an online survey. The questionnaire focused on ICU characteristics, methods used to prevent, diagnose, and treat infections, and antimicrobials prescribing policies. The frequency of each reported practice was calculated as a percentage of the total number of units answering the question. The overall response rate to the questionnaire was 38.8% (175 of the 450 ICUs contacted) with homogeneous distribution across the country and in terms of unit type.

Results

Eighty-eight percent of the responding facilities performed periodical surveillance cultures on all patients. In 71% of patients, cultures were also collected on admission. Endotracheal/bronchial aspirates were the most frequently cultured specimens at both time points. Two-thirds of the responding units had never performed screening cultures for methicillin-resistant Staphylococcus aureus. Around 67% of the ICUs reported the use of antimicrobial de-escalation strategies during the treatment phase. In general, the use of empirical antimicrobial drug regimens was appropriate. Although the rationale for the choice was not always clearly documented, the use of a combination therapy was preferred over antibiotic monotherapy. The preferred first-line agents for invasive candidiasis were fluconazole and an echinocandin (64% and 25%, respectively). Two-thirds of the ICUs monitored vancomycin serum levels and administered it by continuous infusion in 86% of cases. For certain antibiotics, reported doses were too low to ensure effective treatment of severe infections in critically ill patients; conversely, inappropriately high doses were administered for certain antifungal drugs.

Conclusions

Although infection control policies and management practices are generally appropriate in Italian ICUs, certain aspects, such as the extensive use of multidrug empirical regimens and the inappropriate antimicrobial dosing, deserve careful management and closer investigation.

Prognosis and risk factors of early onset pneumonia in ventilated patients with Guillain–Barré syndrome

OBJECTIVE

Invasive mechanical ventilation is required in 30% of patients with Guillain-Barré syndrome (GBS) and is associated with pneumonia and increased mortality. Our objective was to determine the incidence, characteristics, outcomes, and risk factors of pneumonia in GBS patients receiving mechanical ventilation.

DESIGN AND SETTING

Study of a prospective database in an intensive care unit of a university hospital.

PATIENTS

The study included 81 patients who required intubation for GBS. Neurological findings, vital capacity, and signs of respiratory distress were recorded at admission and at intubation. A score predicting the risk of intubation (0-4) was calculated for each patient. Pneumonia was diagnosed based on predefined criteria and retrospectively confirmed by two observers. Early-onset pneumonia was defined as pneumonia diagnosed within 5 days after intubation.

MEASUREMENTS AND RESULTS

Mean vital capacity was 57 +/- 22% of predicted at admission and 33 +/- 11% at intubation. Pneumonia developed in 63 patients (78%), including 48 with early-onset pneumonia. Bacteria were consistent with aspiration. Of the 63 patients with pneumonia 11 (18%) had septic shock, 6 (10%) had acute respiratory distress syndrome, and 9 (14%) died. In the univariate analysis milder weakness, a lower risk of intubation (score < 2), and time from admission to intubation longer than 2 days were associated with early-onset pneumonia. Time from admission to intubation was the only independent predictor in the multivariate logistic regression model.

CONCLUSIONS

Early-onset pneumonia is a common and severe complication that is related to aspiration in patients with GBS. Delaying intubation may increase the risk of early-onset pneumonia.

Comparative impact of guidelines, clinical data, and decision support on prescribing decisions: an interactive web experiment with simulated cases

OBJECTIVE

The aim of this study was to compare the clinical impact of computerized decision support with and without electronic access to clinical guidelines and laboratory data on antibiotic prescribing decisions.

DESIGN

A crossover trial was conducted of four levels of computerized decision support-no support, antibiotic guidelines, laboratory reports, and laboratory reports plus a decision support system (DSS), randomly allocated to eight simulated clinical cases accessed by the Web.

MEASUREMENTS

Rate of intervention adoption was measured by frequency of accessing information support, cost of use was measured by time taken to complete each case, and effectiveness of decision was measured by correctness of and self-reported confidence in individual prescribing decisions. Clinical impact score was measured by adoption rate and decision effectiveness.

RESULTS

Thirty-one intensive care and infectious disease specialist physicians (ICPs and IDPs) participated in the study. Ventilator-associated pneumonia treatment guidelines were used in 24 (39%) of the 62 case scenarios for which they were available, microbiology reports in 36 (58%), and the DSS in 37 (60%). The use of all forms of information support did not affect clinicians' confidence in their decisions. Their use of the DSS plus microbiology report improved the agreement of decisions with those of an expert panel from 65% to 97% (p=0.0002), or to 67% (p=0.002) when antibiotic guidelines only were accessed. Significantly fewer IDPs than ICPs accessed information support in making treatment decisions. On average, it took 245 seconds to make a decision using the DSS compared with 113 seconds for unaided prescribing (p<0.001). The DSS plus microbiology reports had the highest clinical impact score (0.58), greater than that of electronic guidelines (0.26) and electronic laboratory reports (0.45).

CONCLUSION

When used, computer-based decision support significantly improved decision quality. In measuring the impact of decision support systems, both their effectiveness in improving decisions and their likely rate of adoption in the clinical environment need to be considered. Clinicians chose to use antibiotic guidelines for one third and microbiology reports or the DSS for about two thirds of cases when they were available to assist their prescribing decisions.

Nosocomial pneumonia: emerging concepts in diagnosis, management, and prophylaxis

Nosocomial pneumonia is a dynamic disease with multiple etiologic agents and a changing natural history. The highest attack rates and mortality occur in patients with ventilator-associated pneumonia. Diagnosis of nosocomial pneumonia is often made by clinical criteria that are sensitive but lack specificity. The use of quantitative endotracheal aspirates or bronchoscopy with bronchoalveolar lavage and protected specimen brush clearly improve diagnostic specificity and outcome in patients who are mechanically ventilated. The rapid spread of multidrug-resistant, spp, and has made initial empiric therapy more difficult. Management principles include the use of techniques for more accurate diagnosis and early antimicrobial therapy with appropriate agents along with careful analysis of culture results, clinical response, and potential complications of pneumonia and therapy. Strategies for prophylaxis are of critical importance for risk reduction, improvement in patient outcome, and reduction of hospital costs.