Management of Acinetobacter baumannii Reviewed CME



Management of Acinetobacter baumannii Reviewed CME

News Author: Laurie Barclay, MD

CME Author: Laurie Barclay, MD

Complete author affiliations and disclosures, and other CME information, are available at the end of this activity.

Release Date: November 19, 2008; Valid for credit through November 19, 2009

Credits Available

Physicians - maximum of 0.25 AMA PRA Category 1 Credit(s)™ for physicians;

Family Physicians - up to 0.25 AAFP Prescribed credit(s) for physicians

All other healthcare professionals completing continuing education credit for this activity will be issued a certificate of participation.

Physicians should only claim credit commensurate with the extent of their participation in the activity.

[pic]

To participate in this internet activity: (1) review the target audience, learning objectives, and author disclosures; (2) study the education content; (3) take the post-test and/or complete the evaluation; (4) view/print certificate View details.

Learning Objectives

Upon completion of this activity, participants will be able to:

1. Describe characteristics of and general control measures for Acinetobacter baumannii infection.

2. Describe antibiotic treatment of Acinetobacter baumannii infection.

Authors and Disclosures

Laurie Barclay, MD

Disclosure: Laurie Barclay, MD, has disclosed no relevant financial relationships.

Brande Nicole Martin

Disclosure: Brande Nicole Martin has disclosed no relevant financial information.

November 19, 2008 — Current strategies for control and treatment of Acinetobacter baumannii, an antimicrobial drug-resistant infection that occurs in many critically ill hospitalized patients, are reviewed in the December issue of Lancet Infectious Diseases.

"The reported incidence of A baumannii infections has substantially increased during the past decades," write Drosos E. Karageorgopoulos, MD, and Matthew E. Falagas, MD, from the Alfa Institute of Biomedical Sciences in Athens, Greece. "This increase could be attributed to a rise in the proportion of the susceptible population as a result of advancements in medical support of critically ill and frail patients. A substantial increase in the rates of antibiotic resistance of A baumannii has also been documented during the past decades."

Environmental sources of A baumannii include soil and foods such as vegetables, meat, and fish. In healthy humans, skin colonization may occur at a low density and for a short time, but colonization of the throat, nares, and intestinal tract is rare.

Infections with A baumannii most often occur in critically ill hospitalized patients, especially those with advanced age, serious underlying diseases, immunosuppression, major trauma, or burn injuries. Other risk factors are invasive procedures, indwelling catheters, mechanical ventilatory support, extended hospital stay, and previous antibiotic administration.

Major clinical syndromes caused by A baumannii infections include pneumonia; bacteremia; surgical site infection; skin and soft tissue infection; urinary tract infection; secondary meningitis, particularly in patients with ventricular draining tubes; and peritonitis in patients undergoing peritoneal dialysis.

Community-acquired A baumannii pneumonia, which is typically severe, occurs primarily in southeast Asia and tropical Australia in patients with underlying chronic obstructive pulmonary disease, renal failure, diabetes mellitus, or heavy consumption of tobacco or alcohol. Wound infections may also occur in patients who have experienced mass destruction or war conflicts.

Institutional outbreaks of antimicrobial drug–resistant A baumannii are posing an increasing threat to public health, with the often complex epidemiology of these outbreaks hindering adequate infection control.

Potential common sources of the outbreak may include contaminated environmental sites and medical equipment as well as healthcare personnel with skin colonization. Implementing specific control measures can be facilitated by identifying potential common sources of an outbreak with surveillance cultures and epidemiologic typing studies.

To contain an outbreak of A baumannii, appropriate administrative guidance and support, as well as strict compliance with a series of infection control techniques, are required. These include environmental cleaning, adequately sterilizing reusable medical equipment, practicing effective hand hygiene, and using contact precautions.

Ventilator-associated pneumonia, bloodstream infections, and other infections with A baumannii mandate effective antibiotic treatment. Currently available antimicrobial classes and agents potentially effective against A baumannii include sulbactam; antipseudomonal penicillins, cephalosporins, and carbapenems; monobactams, aminoglycosides, fluoroquinolones, tetracyclines, glycylcyclines, and polymyxins.

High and increasing resistance rates of A baumannii to many of these agents limit the choice of appropriate antimicrobial therapy. Microbiological surveillance trials have reported rates of multidrug resistance in A baumannii of approximately 30%, but there are geographic differences in resistance patterns.

Frequently encountered mechanisms of antimicrobial resistance of this bacterium include production of β lactamases, efflux pumps, reduced permeability of the outer membrane, mutations in antibiotic targets (eg, for quinolones), and production of enzymes inactivating aminoglycosides.

Knowledge concerning the efficacy of various therapeutic options is primarily derived from retrospective studies or from small, nonrandomized, prospective studies. Although carbapenems have long been considered to be first-line therapeutic agents of choice, resistance rates in some areas have dramatically increased.

Serious A baumannii infections have previously responded to sulbactam, but the efficacy of this drug is decreasing against carbapenem-resistant isolates. Clinical data, mostly derived from small-sized studies showing favorable clinical outcomes, indicate reliable antimicrobial activity of polymyxins against extensively drug-resistant isolates of A baumannii and reduce earlier concerns regarding toxicity.

Preclinical evidence suggests that minocycline, and especially its derivative, tigecycline, are highly effective against A baumannii. However, clinical trials are lacking. Further research is therefore needed to elucidate several issues regarding the best therapeutic options for multidrug-resistant A baumannii infections.

"The role of A baumannii as a pathogen causing serious infections in critically ill patients has become increasingly clear," Drs. Karageorgopoulos and Falagas conclude. "Measures to address specific modes of transmission identified during an outbreak and strict adherence to a variety of infection control measures are typically required for the containment of an outbreak. Treatment options against multidrug-resistant A baumannii infections seem to be limited."

Dr. Falagas has received speaker fees from Wyeth, AstraZeneca, Merck, Cipla, and Grunenthal. Dr. Karageorgopoulos has disclosed no relevant financial relationships.

Lancet Infect Dis. 2008;8:751-762.

Learning Objectives for This Educational Activity

Upon completion of this activity, participants will be able to:

1. Describe characteristics of and general control measures for Acinetobacter baumannii infection.

2. Describe antibiotic treatment of Acinetobacter baumannii infection.

Clinical Context

Infections with A baumannii are on the rise, especially in hospital settings in critically ill patients, in part attributed to the ability of this organism to cause outbreaks. Acinetobacter species may survive for 1 to 5 months on dry, inanimate surfaces, and A baumannii has several mechanisms enhancing its ability to colonize patients or equipment used in medical care.

One of the most important factors allowing persistence of Acinetobacter infections in healthcare settings is resistance to antimicrobial agents. Although several classes of antibiotics are potentially effective against A baumannii, increasing multidrug resistance is a growing problem.

Study Highlights

• A baumannii infections usually occur in critically ill hospitalized patients.

• Risk factors include advanced age, serious underlying diseases, immunosuppression, major trauma, burn injuries, invasive procedures, indwelling catheters, mechanical ventilation, prolonged hospital stay, and recent antibiotic use.

• Clinical syndromes include pneumonia; bacteremia; and infections of surgical sites, skin and soft tissue, and the urinary tract.

• Secondary meningitis may occur in patients with ventricular draining tubes.

• Patients undergoing peritoneal dialysis may acquire A baumannii peritonitis.

• Institutional outbreaks of antimicrobial drug–resistant A baumannii pose a growing threat to public health. These outbreaks usually stem from contaminated environmental sites and medical equipment, or healthcare personnel with skin colonization.

• Surveillance cultures and epidemiologic typing studies can help identify potential common sources and institute appropriate control measures.

• Useful infection-control techniques include environmental cleaning, adequately sterilizing reusable medical equipment, effective hand hygiene, and contact precautions.

• Currently available antimicrobials potentially effective against A baumannii include sulbactam; antipseudomonal penicillins, cephalosporins, and carbapenems; monobactams; aminoglycosides; fluoroquinolones; tetracyclines; glycylcyclines; and polymyxins.

• Resistance rates of A baumannii to many of these agents are high (approximately 30%) and are increasing, limiting effective treatment options.

• Carbapenems were initially thought to be therapeutic agents of choice for A baumannii, but resistance rates in some areas have dramatically increased.

• Because of resistance, sulbactam is not as effective against A baumannii as it had been, according to previous research studies.

• Polymyxins appear to be effective against extensively drug-resistant isolates of A baumannii and are not as toxic as previously thought.

• Preclinical evidence suggests that minocycline and tigecycline are highly effective against A baumannii, but clinical trials are lacking.

• Further research is therefore needed to determine the best therapeutic options for multidrug-resistant A baumannii infections.

• Combining carbapenems with other antimicrobial agents may help overcome carbapenem resistance.

• In vitro, imipenem plus sulbactam have shown synergistic activity, but clinical usefulness in patients infected with carbapenem-resistant A baumannii is not well established.

Pearls for Practice

• A baumannii infections usually occur in critically ill hospitalized patients with patient-related and treatment-related risk factors. Institutional outbreaks of antimicrobial drug–resistant A baumannii, usually arising from contaminated environmental sites and medical equipment, or healthcare personnel with skin colonization, are increasingly common.

• Currently available antimicrobials potentially effective against A baumannii include sulbactam; antipseudomonal penicillins, cephalosporins, and carbapenems; monobactams; aminoglycosides; fluoroquinolones; tetracyclines; glycylcyclines; and polymyxins. However, resistance rates of A baumannii to many of these agents are high and are increasing, limiting effective treatment options.

Principio del formulario

 

|  |

|According to the review by Karageorgopoulos and Falagas, which of the following statements about A baumannii infections in |

|healthcare settings is not correct? |

| |

|[pic] |

|Secondary meningitis may occur in patients with ventricular draining tubes |

| |

| |

| |

|[pic] |

|Risk factors include advanced age, serious underlying diseases, and immunosuppression |

| |

| |

| |

|[pic] |

|Contaminated food is the usual source for institutional outbreaks |

| |

| |

| |

|[pic] |

|Useful infection-control techniques include environmental cleaning, adequately sterilizing reusable medical equipment, |

|effective hand hygiene, and contact precautions |

| |

| |

| |

| |

|According to the review by Karageorgopoulos and Falagas, which of the following statements about antibiotic treatment of A |

|baumannii infections is correct? |

| |

|[pic] |

|Resistance to carbapenems is infrequent |

| |

| |

| |

|[pic] |

|Severe toxicity precludes polymixin use |

| |

| |

| |

|[pic] |

|Large numbers of clinical trials support use of minocycline and tigecycline |

| |

| |

| |

|[pic] |

|Further research is needed to determine the best therapeutic options for multidrug-resistant A baumannii infections |

| |

| |

| |

Final del formulario

Instructions for Participation and Credit

There are no fees for participating in or receiving credit for this online educational activity. For information on applicability and acceptance of continuing education credit for this activity, please consult your professional licensing board.

This activity is designed to be completed within the time designated on the title page; physicians should claim only those credits that reflect the time actually spent in the activity. To successfully earn credit, participants must complete the activity online during the valid credit period that is noted on the title page.

FOLLOW THESE STEPS TO EARN CME/CE CREDIT*:

1. Read the target audience, learning objectives, and author disclosures.

2. Study the educational content online or printed out.

3. Online, choose the best answer to each test question. To receive a certificate, you must receive a passing score as designated at the top of the test. Medscape encourages you to complete the Activity Evaluation to provide feedback for future programming.

You may now view or print the certificate from your CME/CE Tracker. You may print the certificate but you cannot alter it. Credits will be tallied in your CME/CE Tracker and archived for 5 years; at any point within this time period you can print out the tally as well as the certificates by accessing "Edit Your Profile" at the top of your Medscape homepage.

*The credit that you receive is based on your user profile.

Target Audience

This article is intended for infectious disease specialists, intensivists, public health specialists, and other specialists who care for patients with Acinetobacter baumannii infection.

Goal

The goal of this activity is to provide medical news to primary care clinicians and other healthcare professionals in order to enhance patient care.

Accreditation Statements

For Physicians

[pic]

Medscape, LLC is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

Medscape, LLC designates this educational activity for a maximum of 0.25 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity. Medscape Medical News has been reviewed and is acceptable for up to 350 Prescribed credits by the American Academy of Family Physicians. AAFP accreditation begins 09/01/08. Term of approval is for 1 year from this date. This activity is approved for 0.25 Prescribed credits. Credit may be claimed for 1 year from the date of this activity.

Note: Total credit is subject to change based on topic selection and article length.

[pic]

AAFP Accreditation Questions

[pic]

For questions regarding the content of this activity, contact the accredited provider for this CME/CE activity: CME@. For technical assistance, contact CME@.

[pic]

Authors and Disclosures

As an organization accredited by the ACCME, Medscape, LLC requires everyone who is in a position to control the content of an education activity to disclose all relevant financial relationships with any commercial interest. The ACCME defines "relevant financial relationships" as financial relationships in any amount, occurring within the past 12 months, including financial relationships of a spouse or life partner, that could create a conflict of interest.

Medscape, LLC encourages Authors to identify investigational products or off-label uses of products regulated by the US Food and Drug Administration, at first mention and where appropriate in the content.

News Author

Laurie Barclay, MD

is a freelance reviewer and writer for Medscape.

Disclosure: Laurie Barclay, MD, has disclosed no relevant financial relationships.

CME Author

Laurie Barclay, MD

is a freelance reviewer and writer for Medscape.

Disclosure: Laurie Barclay, MD, has disclosed no relevant financial relationships.

Brande Nicole Martin

is the News CME editor for Medscape Medical News.

Disclosure: Brande Nicole Martin has disclosed no relevant financial information.

Medscape Medical News 2008. ©2008 Medscape

Legal Disclaimer

The material presented here does not necessarily reflect the views of Medscape or companies that support educational programming on . These materials may discuss therapeutic products that have not been approved by the US Food and Drug Administration and off-label uses of approved products. A qualified healthcare professional should be consulted before using any therapeutic product discussed. Readers should verify all information and data before treating patients or employing any therapies described in this educational activity.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download