2006_11_01_archive

Background Resources for October 2006 Case

Table 1 of our current case lists several medical concepts which are

central to our clinical question. This post is intended to explain why

each concept is important, how to assess the quality and relevance of

background information sources, and to provide links to freely

available resources may be useful for acquiring background knowledge

on these topics. You may also wish to consult textbooks, databases, or

other subscription items available at your own library.

The Question:

What is the evidence basis for the use of intravenous colistin for

multi-drug resistant Acinetobacter infections in the adult,

non-neutropenic, critical care population?

How to Evaluate Online Resources:

Medical Library Association: A User's Guide to Finding and

Evaluating Health Information on the Web

MedlinePlus: Guide to Healthy Web Surfing

National Center for Complementary and Alternative Medicine: 10

Things To Know About Evaluating Medical Resources on the Web

National Cancer Institute: How To Evaluate Health Information on the

Internet: Questions and Answers

U.S. Food and Drug Administration: How to Evaluate Health

Information on the Internet

The Concepts:

Respiratory Failure

The patient was admitted to the ICU with respiratory failure; this

informs you that the patient is currently unable to breathe on his

own, resulting in the use of mechanical ventilation and leading to the

development of ventilator-associated pneumonia (VAP).

eMedicine: Respiratory Failure

The Merck Manuals Online Medical Library, Home Edition: Respiratory

Failure

MeSH Database: Respiratory Insufficiency

Ventilator-Associated Pneumonia

The patient is showing signs of VAP, which is why the cultures

(brochoscopy and bronchoalveolar lavage) were conducted, leading to

the identification of the Acinetobacter species in this patient.

CDC: Ventilator-Associated Pneumonia

MeSH Database: Pneumonia, Bacterial; Respiration, Artificial;

Ventilators, Mechanical

Acinetobacter

This is the organism identified as causing the patient's pneumonia,

and you've been asked to find evidence on drugs to treat this specific

type of infection.

CDC: Drug Resistant Acinetobacter Infections in Healthcare Settings

eMedicine: Acinetobacter

MeSH Database: Acinetobacter

Chronic Liver Failure with Hepatic Encephalopathy

This is the other condition (in addition to respiratory failure) for

which the patient was admitted to the ICU. It may or may not turn out

to have an impact on the drug regimen the patient receives, but helps

you understand the overall clinical picture for this patient. Hepatic

encephalopathy is the underlying cause of the patient's respiratory

failure, as it leads to decreased mental status which in turn causes

respiratory dysfunction and the inability of the patient to protect

his own airway. The resources listed below address hepatic

encephalopathy, but we don't know the cause or type of the chronic

liver failure.

MedlinePlus Medical Encyclopedia: Hepatic encephalopathy

eMedicine: Encephalopathy, Hepatic

MeSH Database: Hepatic Encephalopathy; Liver Failure

Bronchoscopy

The patient underwent bronchoscopy when signs of VAP developed.

Bronchoscopy is a fairly common procedure, so it will help you in the

future to understand this term.

MedlinePlus Medical Encyclopedia: Bronchoscopy

UpToDate Patient Information: Fiberoptic Bronchoscopy

MeSH Database: Bronchoscopy

Bronchoalveolar Lavage

The procedure is used with bronchoscopy to identify the infectious

organism affecting a patient. "Lavage" essentially means "to wash,"

and has its origin in the Latin lavare - the lungs are washed with

fluid, which is then suctioned back up for culturing and diagnostic

purposes.

MeSH Database: Bronchoalveolar Lavage

Wikipedia: Bronchoalveolar Lavage - Normally, you might want to

consult other, more authoritative background resources before checking

Wikipedia, but there is very little basic information on this

procedure online. In this case, reading the Wikipedia entry can give

you a basic idea of what bronchoalveolar lavage consists of.

Antibiotic Sensitivity/Susceptibility Testing

This type of testing is used to determine which agents will be

effective against an infectious organism. It is how doctors know what

the "right" antibiotic is to use for an infection.

Lab Tests Online: Susceptibility Testing

MeSH Database: Microbial Sensitivity Tests

Colistin

Colistin is an antimicrobial (or antibacterial) drug, and the

clinicians would like to know if it has been proven effective against

Acinetobacter infection. A search of free resources does not turn up

much of anything on this drug. However, through further investigation,

we find that Colistimethate is a derivative of Colistin, and

information is available on that.

MeSH Database: Colistin