Selective use of blood cultures in emergency department pneumonia patients

Our objectives were to identify factors associated with positive blood cultures and to evaluate blood culture use in the management of hospitalized pneumonia patients to limit their use. A retrospective chart review was conducted at a community teaching hospital. Emergency Department patients with an admission diagnosis of pneumonia during calendar years 2001-2002 were included. Patients younger than age 18 years and those with a non-pneumonia discharge diagnosis were excluded. Of 684 eligible patients, 23 (3.4%) had true positive blood cultures. All organisms were sensitive to empiric antibiotics. Three risk factors were associated with positive blood cultures: oxygen saturation < 90%, serum sodium < 130 and respiratory rate > 30 breaths/min. No patient had antibiotic coverage broadened based on blood culture results. Positive blood culture rates were low and did not affect the clinical management of pneumonia patients. We recommend eliminating blood cultures in community-acquired pneumonia (CAP) patients, but obtaining blood cultures in patients at risk for multi-drug resistant pathogens, such as health-care-associated pneumonia (HCAP) patients.     

Weekly E-mail Reminders Influence Emergency Physician Behavior: A Case Study Using the Joint Commission and Centers for Medicare and Medicaid Services Pneumonia Guidelines

Objectives:  Improving physician compliance with evidence-based guidelines is challenging. The authors wanted to determine if weekly e-mail reminders to emergency department (ED) staff increase compliance with Joint Commission and the Centers for Medicare and Medicaid Services (CMS) community-acquired pneumonia quality measures.
Methods:  One nurse administrator reviewed records on a weekly basis for all adult patients admitted to the hospital from the ED with a working diagnosis of pneumonia. An e-mail was then sent to all ED staff indicating the percentage of patients with antibiotic timing less than 4 hours from arrival. The names of individuals who administered antibiotics in less than 1 hour were highlighted. This study compared the time to antibiotics for 11 months before and 11 months after commencing this intervention.
Results:  There were 281 patients in the control cohort, and 37 met exclusion criteria, leaving 244 for analysis. There were 342 patients in the intervention cohort, and 40 met exclusion criteria, leaving 302 for analysis. The median time from arrival to chest radiograph order decreased significantly from 61 to 47 minutes (p < 0.001). The median time interval from chest radiograph order to antibiotic administration did not change significantly (92 to 88 minutes, p = 0.294). The overall median time from arrival to antibiotic administration decreased significantly from 162 to 146 minutes (p = 0.018). The percentage of patients with antibiotic administration within 4 hours increased from 77.5% to 86.1% (p = 0.009).
Conclusions:  Weekly e-mail reminders listing performance on antibiotic administration recommendations are associated with increased compliance with a clinical guideline.     

Usefulness of initial blood cultures in patients admitted with pneumonia from an emergency department in Japan

Guidelines recommend obtaining blood cultures for all patients admitted with pneumonia. However, recent American studies have reported the low impact of these cultures on antibiotic therapy. Our aim was to investigate the incidence of bacteremia and change of therapy in admitted pneumonia patients from whom blood cultures were obtained in the emergency department (ED). A retrospective, observational, cohort study was conducted on consecutive patients (age ≥12 years) with pneumonia hospitalized through the ED between January 1 and December 31, 2006, in an urban teaching hospital in Japan. Data were collected on antibiotic sensitivities, empirical antibiotics, and changes of antibiotic management. Blood cultures were classified as positive, negative, or contaminant, based on previously established criteria. Out of 164 consecutive cases, blood cultures were positive in 6 patients (3.7%; 95% confidence interval [CI], 0.8%–6.6%), contaminated in 6 (3.7%), and negative in 152 (92.7%). Of the 6 bacteremic patients, 2 cases were likely to have been caused by concomitant diseases. Blood culture results altered therapy for 4 patients (2.4% of 164; 95% CI, 0.7%–6.1%), of whom 2 patients (1.2%; 95% CI, 0.1%–4.3%) had their coverage narrowed, 1 patient (0.6%; 95% CI, 0.0%–3.4%) had coverage broadened, and 1 patient had altered therapy before the drug sensitivities were reported. Considering cost and workload, the overall total annual cost was €758 631 (€107 = 1 $US in June 2008). Blood cultures could identify organisms in only a few patients with pneumonia and rarely altered antibiotic management even in patients with positive cultures. It may not be necessary to obtain blood cultures for patients admitted with pneumonia.     

Would Earlier Microbe Identification Alter Antibiotic Therapy in Bacteremic Emergency Department Patients?

Background

Although debate exists about the treatment of sepsis, few disagree about the benefits of early, appropriately targeted antibiotic administration.

Study Objectives

To determine the appropriateness of empiric antimicrobial therapy and the extent to which therapy would be altered if the causative organism for sepsis was known at the time of administration.

Methods

This was a retrospective cohort study, conducted in an academic Emergency Department (ED), on consecutive positive blood cultures between November 1, 2008 and February 1, 2009. Blood cultures and the appropriateness of administered antimicrobial therapy were evaluated. Therapy choices were categorized based on whether or not a physician, complying with antimicrobial guidelines, would have made changes to empiric antibiotic therapy had the causative organism initially been known.

Results

There were 90 positive blood cultures obtained from 84 patients. Of these, 21.1% (n = 19) were considered contaminants. The final categorization of empiric antibiotics given in the ED for the remaining blood culture results were: 1) therapy would be changed to narrower-spectrum antibiotics (n = 34, 55.7%); 2) therapy would be changed because the organism was not covered (n = 13, 21.3%); and 3) therapy would remain the same (n = 14, 23.0%). There was 90.2% inter-rater agreement for these classifications (p < 0.0001), with a kappa of 0.84. Polymerase chain reaction analysis had a statistically significant advantage (p < 0.0001) over Infectious Disease Society of America protocols in facilitating accurate antimicrobial therapies.

Conclusion

This study confirms the need for more rapid and accurate laboratory methods for bloodstream pathogen identification.     

Ofloxacin versus standard therapy in treatment of community-acquired pneumonia requiring hospitalization. Pneumonia Study Group.

Community-acquired pneumonia occurs 3 to 4 million times per year in the United States, accounting for about 500,000 hospitalizations annually. Empiric treatment is usually instituted because of a lack of early organism-specific diagnostic tests. This study compared empiric therapy with ofloxacin to standard antibiotic regimens (usually a beta-lactam with or without a macrolide) for patients hospitalized for community-acquired pneumonia. Therapy was administered to 298 patients (146 receiving ofloxacin and 152 receiving standard therapy); 227 patients (ofloxacin, 109; standard treatment, 118) were evaluable for treatment efficacy. The most common pyogenic respiratory pathogens were Haemophilus influenzae (30 isolates) and Streptococcus pneumoniae (24 isolates). There was evidence of infection with either Mycoplasma pneumoniae (38 patients), Chlamydia pneumoniae (40 patients), or a Legionella sp. (8 patients) in a total of 79 patients (35%). The clinical success rates were similar in both groups among evaluable patients (92%, ofloxacin; 87%, standard therapy) and among patients with atypical respiratory pathogens (88%, ofloxacin; 81%, standard therapy). The mean numbers (+/- the standard deviations) of intravenous doses of antibiotics were 7.5 +/- 8.0 in the ofloxacin group and 18.4 +/- 18.5 in the standard therapy group (P < 0.001); the mean number of oral doses of ofloxacin per patient was 19.7 +/- 11.2, compared with 30.2 +/- 16.0 oral antibiotic doses in the standard therapy group (P < 0.001). All treatments were well tolerated and associated with no significant clinical or laboratory abnormalities. The findings of this study indicate that ofloxacin is active against traditional bacterial pathogens as well as the major atypical respiratory pathogens. When given as monotherapy for the empiric treatment of community-acquired pneumonia, ofloxacin is as effective as standard antimicrobial therapy.     

Utility of Urine and Blood Cultures in Pyelonephritis

Objective: To determine how often the results of urine and blood cultures led to changes in antibiotic therapy for patients discharged from the hospital with the diagnosis of pyelonephritis.
Methods: A retrospective chart review was performed of consecutively admitted patients, 10–90 years old, with an ICD-9 discharge diagnosis of acute pyelonephritis. All patients were admitted to a university-based, tertiary care center and a large HMO medical center from 1993 to 1994. The association of urine and blood culture results with a change in antibiotic therapy was assessed.
Results: Of the 194 patients who met inclusion criteria, 189 (97%) had urine cultures obtained at the time of admission and 139 (71%) had blood cultures obtained. Ampicillin, gentamicin, or both were given as initial antibiotics 81% of the time, and isolated organisms from urine or blood were sensitive to the empiric antibiotics 95% of the time. Most (171/189; 90%) urine cultures were positive, but only 9 (5%) of these led to a change in antibiotic therapy. 80% of the urinary pathogens were Escherichia coli , 5% Enterococcus, 5% Proteus, and 4% Klebsiella. Only 40 (29%) of the 139 blood cultures were positive; none prompted a change in antibiotics. There were no cases in which blood and urine cultures grew different pathogens.
Conclusions: Urine cultures are useful in directing antibiotic therapy in patients with the discharge diagnosis of acute pyelonephritis and support a change in therapy in 5% of cases. Among the patients in this study, blood culture results did not lead to changes in antibiotic therapy. These findings warrant prospective, mul-ticenter evaluation.     

Antimicrobial selection for hospitalized patients with presumed community-acquired pneumonia: a survey of nonteaching US community hospitals

OBJECTIVE: To describe and evaluate empiric antimicrobial regimens chosen for hospitalized patients with presumed community-acquired pneumonia (CAP) in US hospitals, including compliance with the American Thoracic Society (ATS) guidelines. Secondary outcomes included length of stay (LOS) and mortality associated with the choice of therapy. METHODS: A nonrandomized, prospective, observational study was performed in 72 nonteaching hospitals affiliated with a national group purchasing organization. Patients with an admission diagnosis of physician-presumed CAP and an X-ray taken within 72 hours of admission were eligible for the study. Demographic, antibiotic selection, and outcomes data were collected prospectively from patient charts. RESULTS: 3035 patients were enrolled; 2963 were eligible for analysis. Compliance with the ATS guidelines was 81% in patients with nonsevere CAP. The most common antibiotic regimen used for empiric treatment was ceftriaxone alone or in combination with a macrolide (42%). The overall mortality rate was 5.5%. The addition of a macrolide to either a second- or third-generation cephalosporin or a beta-lactam/beta-lactamase inhibitor was associated with decreased mortality and reduced LOS. CONCLUSIONS: Most hospitalized patients with CAP receive antimicrobial therapy consistent with the ATS guidelines. The addition of a macrolide may be associated with improved patient outcomes.     

Effects of a Pneumonia Clinical Pathway on Time to Antibiotic Treatment, Length of Stay, and Mortality

OBJECTIVES: A clinical pathway standardizing management for patients with an admission diagnosis of pneumonia was initiated after a previous study found delayed time to initial antibiotic administration, a longer length of stay, and higher mortality rate for the authors' patients as compared with those in a "benchmark" hospital. The current study was undertaken to determine whether implementation of the clinical pathway resulted in statistically significant decreases for these measures, both in the initial year following pathway implementation and two years later. METHODS: A retrospective chart review was completed for three cohorts of pneumonia patients admitted via the ED: 1) three months immediately prior to pathway implementation, 2) 10-12 months after implementation of the pathway, and 3) 34-36 months after implementation of the pathway. Four standard antibiotic regimens were used following pathway implementation: community-acquired, community-acquired penicillin-allergic, nursing home-acquired, and nursing home-acquired penicillin-allergic. Demographics, medical history, presentation signs and symptoms, process of care, and outcome data were abstracted from each patient's medical record. RESULTS: The mean time to antibiotic administration decreased from 315 minutes prepathway to approximately 175 minutes during the first postpathway period and 171 minutes at three years (ANOVA, p < 0.0001). The percentage of patients who received antibiotics in the ED increased from 58% prepathway to 94% during the first postpathway period and 97% at three years (chi square, p < 0.0001). Length of stay decreased from 9.7 prepathway to 8.9 days during the first postpathway period and 6.4 days at three years (ANOVA, p < 0.0001). There was no significant change of in-hospital mortality (9.6% prepathway to 5.2% and 4.9%) in the two respective periods. CONCLUSIONS: This study demonstrates that implementation of a pneumonia clinical pathway for the management of hospitalized patients admitted via the ED decreases the time to initial antibiotic treatment and increases the proportion of patients initially treated with antibiotics in the ED. These effects were evident in the first year following pathway implementation and sustained at the three-year study interval.     

De-escalation therapy in ventilator-associated pneumonia

PURPOSE OF REVIEW: To describe the use of a 'de-escalation' strategy to deliver appropriate empiric therapy for ventilator-associated pneumonia, without the overuse of antibiotics. RECENT FINDINGS: Initial empiric therapy can be appropriate in 80-90% of ventilator-associated pneumonia patients, if it is selected on the basis of local microbiologic data or individual patient surveillance cultures. Following initial empiric therapy, de-escalation means using microbiologic and clinical data to change from an initial broad-spectrum, multidrug empiric therapy regimen to a therapy with fewer antibiotics and agents of narrower spectrum. In spite of early success with this approach there is an opportunity to de-escalate more often, particularly in patients with negative pretherapy cultures, and in those whose cultures show multidrug-resistant organisms, including Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. In addition, it is possible to reduce the total duration of therapy, particularly when the initial therapy is accurate. When de-escalation has been employed, it has led to less antibiotic usage, shorter durations of therapy, fewer episodes of secondary pneumonia and reduced mortality, without increasing the frequency of antibiotic resistance. SUMMARY: De-escalation is a promising strategy for optimizing the responsible use of antibiotics while allowing the delivery of prompt and appropriate empiric therapy of ventilator-associated pneumonia.     

The impact of empiric antimicrobial therapy with a beta-lactam and fluoroquinolone on mortality for patients hospitalized with severe pneumonia

ABSTRACT : INTRODUCTION : National clinical practice guidelines have recommended specific empiric antimicrobial regimes for patients with severe community-acquired pneumonia. However, evidence confirming improved mortality with many of these regimes is lacking. Our aim was to determine the association between the empiric use of a beta-lactam with fluoroquinolone, compared with other recommended antimicrobial therapies, and mortality in patients hospitalized with severe community-acquired pneumonia. METHODS : A retrospective observational study was conducted at two tertiary teaching hospitals. Eligible subjects were admitted with a diagnosis of community-acquired pneumonia and had a chest X-ray and a discharge ICD-9 diagnosis consistent with this. Subjects were excluded if they received 'comfort measures only' during the admission, had been transferred from another acute care hospital, did not meet criteria for severe pneumonia, or were treated with non-guideline-concordant antibiotics. A multivariable logistic regression model was used to assess the association between 30-day mortality and the use of a beta-lactam antibiotic with a fluoroquinolone compared with other guideline-concordant therapies, after adjustment for potential confounders including a propensity score. RESULTS : Data were abstracted on 172 subjects at the two hospitals. The mean age was 63.5 years (SD 15.0). The population was 88% male; 91% were admitted through the emergency department and 62% were admitted to the intensive care unit within the first 24 hours after admission. Mortality was 19.8% at 30 days. After adjustment for potential confounders the use of a beta-lactam with a fluoroquinolone (odds ratio 2.71, 95% confidence interval 1.2 to 6.1) was associated with increased mortality. CONCLUSION : The use of initial empiric antimicrobial therapy with a beta-lactam and a fluoroquinolone was associated with increased short-term mortality for patients with severe pneumonia in comparison with other guideline-concordant antimicrobial regimes. Further research is needed to determine the range of appropriate empiric antimicrobial therapies for patients with severe community-acquired pneumonia.     

Systematic Delays in Antibiotic Administration in the Emergency Department for Adult Patients Admitted with Pneumonia

Objectives: The authors sought to determine the contribution of delays in care on time to antibiotics for patients admitted from the emergency department (ED) with pneumonia and to identify patients at risk for delayed antibiotics.
Methods: This was a retrospective cohort study of patients admitted to the Hospital of the University of Pennsylvania (HUP) and to Pennsylvania Presbyterian Hospital (Presbyterian) with an admission diagnosis of pneumonia in 2004.
Results: A total of 393 patients were included. Ninety percent had antibiotics documented as given in the ED. Eighty-three (43%) of 209 at HUP and 104 (64%) of 161 patients at Presbyterian received antibiotics within four hours. Patients who received antibiotics more than four hours after ED arrival experienced longer waits for radiograph orders (HUP, 54 min [95% confidence interval {CI} = 33 to 76 min]; Presbyterian, 43 min [95% CI = 29 to 58 min]), for radiograph performance (HUP, 21 min [95% CI = 4 to 39 min], Presbyterian, 24 min [95% CI = 8 to 47 min]), for antibiotic orders (HUP, 56 min [95% CI = 38 to 95 min]; Presbyterian, 67 min [95% CI = 33 to 103 min]), and for antibiotic administration (HUP, 28 min [95% CI = 17 to 39 min]; Presbyterian, 30 min [95% CI = 21 to 38 min]). Patients with lower severity scores (p = 0.005) and patients with nonclassic clinical presentations for pneumonia were at increased risk for delayed antibiotics (odds ratio, 2.2; 95% CI = 1.1 to 4.4).
Conclusions: Antibiotic delays for patients admitted with pneumonia occur across multiple care processes. Less severely ill patients and patients with nonclassic presentations are at higher risk for delayed antibiotic administration. Hospitals should consider performing a similar analysis to evaluate hospital-specific and patient-specific care delays.     

A Simulation Study Reveals Lack of Pharmacokinetic/Pharmacodynamic Target Attainment in De-escalated Antibiotic Therapy in Critically Ill Patients

De-escalation of empirical antibiotic therapy is often included in antimicrobial stewardship programs in critically ill patients, but differences in target attainment when antibiotics are switched are rarely considered. The primary objective of this study was to compare the fractional target attainments of contemporary dosing of empirical broad-spectrum β-lactam antibiotics and narrower-spectrum antibiotics for a number pathogens for which de-escalation may be considered. The secondary objective was to determine whether alternative dosing strategies improve target attainment. We performed a simulation study using published population pharmacokinetic (PK) studies in critically ill patients for a number of broad-spectrum β-lactam antibiotics and narrower-spectrum antibiotics. Simulations were undertaken using a data set obtained from critically ill patients with sepsis without absolute renal failure (n = 49). The probability of target attainment of antibiotic therapy for different microorganisms for which de-escalation was applied was analyzed. EUCAST MIC distribution data were used to calculate fractional target attainment. The probability that therapeutic exposure will be achieved was lower for the narrower-spectrum antibiotics with conventional dosing than for the broad-spectrum alternatives and could drastically be improved with higher dosages and different modes of administrations. For a selection of microorganisms, the probability that therapeutic exposure will be achieved was overall lower for the narrower-spectrum antibiotics using conventional dosing than for the broad-spectrum antibiotics.     

Ampicillin versus cefamandole as initial therapy for community-acquired pneumonia.

One hundred seven patients with community-acquired pneumonia thought to be of bacterial etiology by the admitting physician but whose initial sputum Gram stain was inadequate to direct specific therapy were randomized to receive either intravenous ampicillin or cefamandole as empiric therapy. Patients were excluded if the initial sputum Gram stain was highly suggestive of infection with Streptococcus pneumoniae, Staphylococcus aureus, or an enteric gram-negative bacillus. The two study groups had comparable demographic and presenting clinical features. The mean age of the patients evaluable for determination of clinical efficacy was 69 years, and greater than 75% had at least one serious underlying medical disorder. In the 90 evaluable patients, there were 11 therapeutic failures (12%), including 5 deaths (5%). Cefamandole, a broad-spectrum antibiotic, was not more efficacious than ampicillin in producing a satisfactory clinical response or in shortening the duration of parenteral therapy. Patients received an average of only 4 days of intravenous antibiotics before changeover to oral therapy and were hospitalized for a mean of 7 days. No patient experienced a relapse of pneumonia following successful completion of parenteral drug therapy. We conclude that cefamandole is not a more effective agent than ampicillin for empiric therapy of community-acquired bacterial pneumonia of uncertain etiology.     

Peritoneal fluid cultures rarely alter management in patients with ascites

Study objective: The objective of this study is to determine if the peritoneal fluid culture results in the ascites patient being evaluated for spontaneous bacterial peritonitis (SBP) in the Emergency Department (ED) are used by the inpatient physician to appropriately alter empiric antibiotic treatment. Methods: We performed a retrospective study of all ascitic fluid samples sent from the ED between January 1, 2002 and December 31, 2004. Exclusion criteria included peritoneal fluid samples sent from peritoneal dialysis patients and those undergoing diagnostic peritoneal lavage for trauma. Medical records were examined to determine culture results, initial antibiotic choices, and subsequent changes in antibiotics by the inpatient physician in response to the culture results. The primary outcome measure was the percentage of cases in which ED peritoneal fluid culture results caused inpatient physicians to appropriately change antibiotic coverage. Results: There were 201 ascitic fluid samples, of which 7 (3.5%; 95% confidence interval [CI] 1.4%–7.0%) had a pathogen identified. Of these, only 1 (0.5%; 95% CI .01%–2.4%) resulted in an appropriate change in empiric antibiotic therapy. Although there were additional opportunities for appropriately using the culture results to change the antibiotic coverage in 2 (1%; 95% CI 0.1%–3.6%) patients, coverage was not changed. In fact, it was changed inappropriately in these 2 patients, and in an additional patient on appropriate empiric therapy. Conclusions: The yield from ascitic fluid cultures was low, and when positive, did not appropriately change management according to microbiologic criteria.     

ED antibiotic use for acute respiratory illnesses since pneumonia performance measure inception

Objective

The study aimed to determine if emergency department (ED)–administered antibiotics for patients discharged home with nonpneumonia acute respiratory tract infections (ARIs) have increased since national pneumonia performance measure implementation, including antibiotic administration within 4 hours of arrival.

Methods

Design: Time series analysis. Setting: Six university and 7 Veterans Administration EDs participating in the Improving Antibiotic Use for Acute Care Treatment (IMPAACT) trial (randomized educational intervention to reduce antibiotics for bronchitis). Participants: Randomly selected adult (age >18 years) ED visits for acute cough, diagnosed with nonpneumonia ARIs, discharged home during winters (November-February) of 2003 to 2007. Main outcome: Time trend in ED-administered antibiotics, adjusted for patient demographics, comorbidities, vital signs, ED length of stay, IMPAACT intervention status, geographic region, Veterans Administration/university setting, and site and provider level clustering.

Results

Six thousand four hundred seventy-six met study criteria. Three hundred ninety-four (6.1%) received ED-administered antibiotics. Emergency department–administered antibiotics did not increase across the study period among all IMPAACT sites (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.76-1.01) after adjusting for age, congestive heart failure history, temperature higher than 100°F, heart rate more than 100, blood cultures obtained, diagnoses, and ED length of stay. The ED-administered antibiotic rate decreased at IMPAACT intervention (OR, 0.80; 95% CI, 0.69-0.93) but not nonintervention sites (OR, 1.04; 95% CI, 0.91-1.19). Adjusted proportions receiving ED-administered antibiotics were 6.1% (95% CI, 2.7%-13.2%) for 2003 to 2004; 4.8% (95% CI, 2.2%-10.0%) for 2004 to 2005; 4.6% (95% CI, 2.7%-7.8%) for 2005 to 2006; and 4.2% (95% CI, 2.2%-8.0%) for 2006 to 2007.

Conclusions

Emergency department–administered antibiotics did not increase for patients with acute cough discharged home with nonpneumonia ARIs since pneumonia antibiotic timing performance measure implementation in these academic EDs.     

Nosocomial pneumonia. Diagnostic and therapeutic considerations

Many patients with presumed nosocomial pneumonia probably have infiltrates on the chest radiograph, fever, and leukocytosis resulting from noninfectious causes. Because of the high mortality and morbidity associated with nosocomial pneumonias, however, most clinicians treat such patients with a 2-week empiric trial of antibiotics. Before therapy is initiated, the clinician should rule out other causes of pulmonary infiltrates, fever, and leukocytosis that mimic a nosocomial pneumonia (e.g., pre-existing interstitial lung disease, primary or metastatic lung carcinomas, pulmonary emboli, pulmonary drug reactions, pulmonary hemorrhage, collagen vascular disease affecting the lungs, or congestive heart failure). If these disorders can be eliminated from diagnostic consideration, a 2-week trial of empiric monotherapy is indicated. The clinician should treat cases of presumed nosocomial pneumonia as if P. aeruginosa were the pathogen. Although P. aeruginosa is not the most common cause of nosocomial pneumonia, it is the most virulent pulmonary pathogen associated with nosocomial pneumonia. Coverage directed against P. aeruginosa is effective against all other aerobic gram-negative bacillary pathogens causing hospital-acquired pneumonia. The clinician should select an antibiotic for empiric monotherapy that is highly effective against P. aeruginosa, has a good side-effect profile, has a low resistance potential, and is relatively inexpensive in terms of its cost to the institution. The preferred agents for empiric monotherapy for nosocomial pneumonia are cefepime, meropenem, and piperacillin. Single organisms are responsible for nosocomial pneumonia, not multiple pathogens. S. aureus rarely, if ever, causes nosocomial pneumonia but is mentioned frequently in studies based on cultures of respiratory tract secretions. S. aureus, unless accompanied by a necrotizing pneumonia with rapid cavitation within 72 hours, in the sputum indicates colonization rather than infection and should not be addressed therapeutically. Antibiotics associated with a high resistance potential should not be used as monotherapy or included in combination therapy regimens (i.e., ceftazidime, ciprofloxacin, imipenem, or gentamicin). Combination therapy is more expensive than monotherapy and is indicated only when P. aeruginosa is extremely likely, based on its characteristic clinical presentation, or is proved by tissue biopsy. Therapy should not be based on respiratory secretion cultures regardless of technique. Optimal combination regimens include cefepime or meropenem plus levofloxacin or piperacillin or aztreonam or amikacin. Nosocomial pneumonias usually are treated for 14 days. Lack of radiographic or clinical response to appropriate empiric nosocomial pneumonia monotherapy after 14 days suggests an alternate diagnosis. In these patients, a tissue biopsy specimen should be obtained to determine the cause of the persistence of pulmonary infiltrates unresponsive to appropriate antimicrobial therapy.     

Impact of an emergency medicine pharmacist on empiric antibiotic prescribing for pneumonia and intra-abdominal infections

Purpose

It is critical to engage ED providers in antimicrobial stewardship programs (ASP). Emergency medicine pharmacists (EMPs) play an important role in ASP by working with providers to choose empiric antimicrobials. This study aimed to determine the impact of an EMP on appropriate empiric antibiotic prescribing for community-acquired pneumonia (CAP) and intra-abdominal infections (CA-IAI).

Désescalade de l’antibiothérapie en réanimation

Successful treatment of severe infections in the intensive care unit (ICU) often requires broad-spectrum empiric therapy, while attempting to control the source of infection. However, this liberal antibiotic strategy may be associated with adverse effects on the patients as well as on the overall microbial ecology of the unit. This “antibiotic dilemma” may be solved by early de-escalation of antibiotic therapy, which allows reducing the overall antibiotic exposure of ICU patients by shortening the duration of therapy (including early stop when infection is not confirmed), switching from combined to single therapy, and/or substituting broad-spectrum agent with narrower-spectrum regimen. The opportunity for de-escalation varies across series from 20% to 50%, depending on the empiric antibiotic policy and the epidemiological context. Adapting the antibiotic regimen, possible as early as 24 h after obtaining the first results from adequate samples, is mandatory at 48–72 h, once full microbiological results are obtained. Subsequently, the intensivist must reassess daily the continued need for antibiotics, just like sedation is reassessed daily in mechanically ventilated patients. Several studies have confirmed that early deescalation is safe, and recent evidence suggests that it may even be associated with improved outcome of patients.     

Selection of an empiric antibiotic regimen for hospital-acquired pneumonia using a unit and culture-type specific antibiogram

The objective of this retrospective study was to determine the optimal initial antibiotic regimen for hospital-acquired pneumonia using the frequency and sensitivity of Gram negative microorganisms found in sputum cultures. An antibiogram was constructed and compared with the hospital intensive care unit (ICU) antibiogram. The results yielded 191 microorganisms. The study-generated antibiogram showed that the highest percent susceptible antibiotics for all Gram-negative microorganisms were imipenem (75%) and amikacin (84%). Considering only Pseudomonas aeruginosa, the study-generated antibiogram and the hospital ICU antibiogram showed similar results, piperacillin and amikacin (86% and 82%, respectively, vs 91% and 85%, P = nonsignificant for both). The optimal empiric antibiotic regimen in the surgical ICU is different if directed against all possible microorganisms as opposed to the most prevalent microorganism P aeruginosa. Determining initial empiric antibiotic therapy using an ICU and culture-type specific antibiogram would result in a greater likelihood that more patients would receive adequate initial antibiotic therapy.