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D. R. Korenstein and L. Schimming
Table 1. (Continued )
Ease Frequency Clinical Summaries of Single
of of Quality Topic Systematic Systematic Study Individual
Resource Use Updates1Ratings Summaries Reviews Reviews Summaries Studies Comments
Dynamed ☺ Daily Systematic A single search box,
left side-bar and
http://www.ebscohost. collapsible sections
com/dynamed provide easy
navigation. Outline
format.
Epocrates Essentials Daily Some Search by keywords.
Use horizontal menu
http://online. at the top of page to
epocrates.com select each topic
section.
eMedicine Quarterly None Browse by specialty
or search using
http://www. keywords. Must
imedicine.com scroll through entire
topic; no way to
select a section.
Paragraph format.
(Continued)
p
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On the Fly: Using Electronic Resources to Enhance Evidence-based Practice
Table 1. (Continued)
Ease Frequency Clinical Summaries of Single
of of Quality Topic Systematic Systematic Study Individual
Resource Use Updates1Ratings Summaries Reviews Reviews Summaries Studies Comments
National Guideline Daily Some Difficult to use. No
Clearinghouse way to rank or sort
guidelines.
http://www.
guideline.gov
Essential Evidence Daily Systematic Search by keywords or
Plus browse frequently
searched topics. Use
http://www. table of contents to
essentialevidence select each section.
plus.com Outline format.
First Consult Daily Some Browse alphabetically
or search by
http://www. keyword. Scroll
mdconsult.com through entire
document or use
left side-bar to
select a section.
Outline format.
PIER Quarterly Systematic Browse by topic type
or enter keywords
http://pier. in combination with
acponline.com a drop-down menu.
Outline format.
https://avxhm.se/blogs/hill0
Answering Questions
Resources to Answer Background Questions
In general, background questions are answered by evidence-based topic
summaries, which incorporate several different types of resources. First,
guidelines can be extremely helpful in directing care, but are only as reliable as their methodology. When reading guidelines, clinicians should
look for the following:
• A transparent development process.
• Lack of bias or conflicts of interest among the committee members or
in the umbrella organization.
• Quality ratings of the evidence.
• Strength ratings for the recommendations themselves.
One US-based electronic resource is dedicated to presenting guidelines.
The National Guideline Clearinghouse (NGC) is produced by the Agency
for Healthcare Research and Quality (AHRQ), the US Department of
Health and Human Services, the American Medical Association and the
American Association of Health Plans-Health Insurance Association of
America. It is a comprehensive database of practice guidelines, and is quite
complete, although the included guidelines are of varying quality and there
are no ratings of the quality of the evidence.
The second type of resource to answer background questions is a collection of topic summaries, such as a textbook. When considering topic
summaries, clinicians should look for an explicit process for inclusion of
evidence and complete referencing (Table 1). Many textbooks will
provide links to relevant guidelines. Some useful resources include:
Clinical Evidence. Produced by the BMJ Group, Clinical Evidence
produces evidence summaries which include levels of effectiveness and
provides links to relevant guidelines.
Dynamed. Dynamed performs daily systematic literature surveillance to
incorporate new evidence, and presents the date of most recent update to
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D. R. Korenstein and L. Schimming
each topic and the content that was updated. Evidence quality is provided
for each recommendation and the site is quite user-friendly.
eMedicine. eMedicine provides clinical topic summaries in a traditional text-
book format and does not systematically grade evidence in support of recommendations. It can be accessed via its own interface or through the TRIP
database (described under Resources to Answer Foreground Questions).
Epocrates Essentials. Epocrates Essentials contains disease summaries
written by the BMJ Group and includes evidence grades for most recommendations. It contains a well-known and widely utilized database of drug
information.
Essential Evidence Plus. Essential Evidence Plus is made up of topic
summaries, with key bullet points provided. It contains consistent strength
of evidence ratings, but the interface is less sophisticated and more difficult to navigate than some other resources. There is a PDA option.
First Consult. Integrated with MDConsult, First Consult is an online
textbook which provides inconsistent evidence grading, and evidence
grades are not incorporated into the main text.
PIER. The Physician’s Information and Education Resource (PIER) is
produced by the American College of Physicians (ACP) and is updated
quarterly. It contains clinical recommendations for many diseases, and
provides standardized evidence ratings.
UpToDate. UpToDate is a well-written and user-friendly online textbook.
It is well-referenced, but crafted much like a traditional textbook, with no
explicit process for evidence selection. Age of chapters is variable and
evidence quality ratings are available for a very small number of topic
reviews. References are linked to abstracts and full text articles.
Resources to Answer Foreground Questions
Foreground questions are usually best answered by systematic reviews
of individual studies or in summaries of those systematic reviews. The
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optimal database in which to begin searching for answers to these types of
questions is determined by the specific question. For questions with a
large amount of relevant data, it is best to first look for summaries of systematic reviews, or for systematic reviews themselves. For more obscure
issues which are less well studied, it may be better to begin with single
study summaries or even individual studies themselves. Useful resources
for answering foreground questions include:
ACP Journal Club: ACP Journal Club is published by the ACP as part of
the Annals of Internal Medicine, and is available free on-line to ACP
members. It contains summaries of relevant high-quality original articles,
including systematic reviews.
The Cochrane Database of Systematic Reviews (CDSR): CDSR contains
systematic reviews completed by the Cochrane Review groups. These
reviews are very complete and of uniformly outstanding quality and concern only issues of treatment and screening. A brief summary of the
findings is provided on a first page. CDSR can be searched simultaneously with DARE (described below) within the Cochrane Library.
The Database of Abstracts of Reviews and Effects (DARE): DARE is
published by the Cochrane Collaboration and contains summaries of systematic reviews (regarding diagnosis, treatment or screening) from a
variety of sources which have been assessed for quality. It can be searched
simultaneously with CDSR within the Cochrane Library.
PubMed Clinical Queries: PubMed is the Medline interface provided by
the US National Library of Medicine and is available free on the Internet
(although many links to full text articles require subscriptions). One of its
features, “Clinical Queries,” is a useful tool for finding individual highquality articles. Clinical Queries performs one simultaneous search in three
clinical research areas: “Clinical Study Categories,” “Systematic Reviews”
and “Medical Genetics.” The user enters search terms in a central search
box and selects the “Clinical Study Category” (therapy, diagnosis, prognosis). The search engine adds additional words to the search, resulting in the
selection of high quality articles of the chosen type. For example, when
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D. R. Korenstein and L. Schimming
“therapy” is selected, the system adds the words “randomized controlled
trial” to the search. At the same time PubMed utilizes the same terms to
simultaneously identify systematic reviews and medical genetics results,
displayed in separate columns. Clinical Queries allows the user to find a
variety of foreground studies using a single search and can be an excellent
starting point when searching for individual articles.
TRIP Database: The TRIP Database provides searches of multiple free-
access databases simultaneously, including a textbook (eMedicine) and
foreground resources (the Cochrane Library and ACP Journal Club). Its
results will vary in quality based on the source, but it allows the user to
perform the search in multiple databases at once to maximize yield.
Summary
In summary, there are many useful resources to help hospitalists become
expert evidence-based practitioners. Table 1 provides a summary of the
resources discussed in this chapter. With a little practice any clinician can
become an expert. Mastering the evidence is possible and even fun if you
use the right tools.
References
1. Kalra A, Fisher R, Axelrod P. (2010) Decreased length of stay and
cumulative hospitalized days despite increased patient admissions and
readmissions in an area of urban poverty. JGIM 25. published online
April 29.
2. Fry A, Shay D, Holman R, Curns A, Anderson L. (2005) Trends in
hospitalizations for pneumonia among persons aged 65 years or older
in the United States, 1988–2002. JAMA 294: 2712–2719.
3. Oliveri R, Gluud C, Wille-Jorgensen P. (2004) Hospital doctors’ self-
rated skills in and use of evidence-based medicine — A questionnaire
survey. J Eval in Clin Pract 10: 219–226.
4. DiCenso A, Bayley L, Haynes RB. (2009) Accessing preappraised evi-
dence: Fine-tuning the 5S model into a 6S model. ACP J Club 151: 2–3.
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41
The Physical Exam: An Evidence
Based Approach to Common
Abnormal Findings
James K. Stulman,* Catherine Bigelow*
and Susan Kahane*
Key Pearls
• A postural pulse increment of ≥ 30/min is the most predictive vital
sign for detecting hypovolemia.
• The presence of apical-carotid delay is highly confirmatory in patients
with suspected aortic stenosis. Increased murmur intensity with
transient arterial occlusion confirms both mitral regurgitation and
aortic insufficiency.
• The presence of a fluid wave and shifting dullness helps rule-in ascites.
• The abdominojugular reflex has a low sensitivity but high specificity
for diagnosing congestive heart failure.
• The presence of dullness to percussion and decreased vocal tactile
fremitus are useful in detecting the presence of a pleural effusion.
Introduction
This goal of this chapter is to identify components of the physical exam
which are most useful for ruling-in and ruling-out specific medical conditions. We do not attempt a complete head-to-toe review but focus on
4
Chapter
*Mount Sinai School of Medicine, New York, NY, USA.
https://avxhm.se/blogs/hill0
abnormalities that are commonly found among hospitalized patients
and areas where strong evidence is available. The discussion focuses on
the accuracy of common physical maneuvers and how best to perform
them.
The Clinical Exam as Diagnostic Test
Clinicians frequently discuss the sensitivity or specificity when describing
the accuracy of a physical exam maneuver. These terms, however, apply
only when we already know if the patient does or does not have the target
disorder.
The mathematical expression, likelihood ratio, combines sensitivity
and specificity into a single function and can be utilized in diagnostic reasoning before we know if the disorder is present or absent. The likelihood
ratio for a positive test result (LR+) = sensitivity/ 1- specificity. Similarly,
the likelihood ratio for a negative test result (LR-) = 1-sensitivity/specificity. We will use the likelihood ratio as an expression of the clinical utility of a physical exam maneuver.
Physical exam maneuvers associated with likelihood ratios of > 5.0 or
< 0.2 are generally the most clinically useful.
Assessing Volume Status
Hypovolemia is defined as an abnormal decrease in blood volume.
Physical exam findings may help detect and assess the degree of hypovolemia in patients with hemorrhage, GI fluid loss, diuresis, or dehydration. The clinical reference standard for detecting hypovolemia is a
combination of laboratory findings (e.g. BUN/creatinine ratio, fractional
excretion of sodium) and the response to hydration.
Acute Blood Loss
Hematocrit correlates poorly with degree of blood loss because a fall in
hematocrit is often delayed 24–72 hours.
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J. K. Stulman, C. Bigelow and S. Kahane
A postural pulse increment of ≥30/min or the inability of the patient
to stand for vital signs because of dizziness are the most useful physical
exam findings. After moderate blood loss (450–650 ml), only 20% of
patients demonstrate these findings (sensitivity 20%; specificity 98%).
Sensitivity increases to 97% after large blood loss (630–1150 mL). If a
patient sits rather than stands from supine, the sensitivity of a 30/min
pulse increment decreases significantly. Sensitivity may also be lower in
elderly patients or those taking as medications such as beta-blockers.
Postural hypotension has little additional predictive value for moderate
blood loss after excluding those unable to stand for vital signs (LR+ 1).
Supine hypotension is a specific but insensitive measure of blood loss, as
is supine tachycardia. Bradycardia occurs frequently after significant blood
loss.
A complaint of postural dizziness, not severe enough to prevent standing, and accompanied by a pulse increment < 30/min, has little predictive
value.
Non-Blood Loss Causes of Hypovolemia
Severe postural dizziness or a 30/min postural pulse increase is predictive
of non-blood loss causes of hypovolemia. A dry axilla has an LR+ of 8.
A moist axilla decreases the probability of hypovolemia only slightly (LR−
0.6). Confusion, extremity weakness, non-fluent speech, dry mucous membranes, dry tongue, furrowed tongue, and sunken eyes are useful in
combinations but the isolated presence of any has an LR+ near 1.
How to Perform Postural Vital Signs
Accuracy is the highest when vital signs are measured with patient supine
and then standing. Wait 2 minutes before measuring supine vital signs and
1 minute before measuring standing vital signs. Accuracy is also increased
by counting pulse for 30 seconds and doubling, compared with counting
for 15 seconds.
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The Physical Exam: An Evidence Based Approach to Common Abnormal Findings
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