PAIN MANAGEMENT/CLINICAL POLICY
C
of Adult Patients Presenting to the Emergency Department With
From
Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department with Acute
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Rhonda R. Whitson, RHIA, Staff Liaison, Clinical Policies
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lume , . : October Annals of Emergency Medicine 407
c J. Lavonas, MD
omas W. Lukens, MD, PhD
nna L. Mason, RN, MS, CEN (ENA Representative
2004-2006)
ward Melnick, MD (EMRA Representative 2007-2008)
thony M. Napoli, MD (EMRA Representative 2004-
2006)
Committee and Subcommittees
Approved by the ACEP Board of Directors, June 24,
2008
Supported by the Emergency Nurses Association, July
29, 2008
Policy statements and clinical policies are the official policies of the American College of Emergency
Physicians and, as such, are not subject to the same peer review process as articles appearing in the print
journal. Policy statements and clinical policies of ACEP do not necessarily reflect the policies and beliefs
of Annals of Emergency Medicine and its editors.
96-0644/$-see front matter
pyright © 2008 by the American College of Emergency Physicians.
:10.1016/j.annemergmed.2008.07.001
Headache:
nathan A. Edlow, MD (Chair)
ter D. Panagos, MD
even A. Godwin, MD
mara L. Thomas, MD
att W. Decker, MD
mbers of the American College of Emergency Physicians
dy S. Jagoda, MD (Chair 2003-2006, Co-Chair 2006-
2007)
att W. Decker, MD (Co-Chair 2006-2007, Chair 2007-
2008)
borah B. Diercks, MD
rry M. Diner, MD (Methodologist)
nathan A. Edlow, MD
ncis M. Fesmire, MD
hn T. Finnell, II, MD, MSc (Liaison for Emergency
Medical Informatics Section 2004-2006)
even A. Godwin, MD
rid A. Hahn, MD
hn M. Howell, MD
ical Policies Committee (Oversight Committee):
vorah Nazarian, MD
nMarie Papa, RN, MSN, CEN, FAEN (ENA
Representative 2007-2008)
Richmann, RN, BS, MA(c), CEN (ENA Representative
2006-2007)
ott M. Silvers, MD
ward P. Sloan, MD, MPH
lly E. W. Thiessen, MD (EMRA Representative 2006-
2008)
bert L. Wears, MD, MS (Methodologist)
ephen J. Wolf, MD
erri D. Hobgood, MD (Board Liaison 2004-2006)
vid C. Seaberg, MD, CPE (Board Liaison 2006-2008)
Acute Headache
the American College of Emergency Physicians Clinical Policies Subcommittee (Writing Committee) on Critical
linical Policy: Critical Issues in the Evaluation and Management
[Ann Emerg Med. 2008;52:407-436.]
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Clinical Policy
40
STRACT
This clinical policy from the American College of Emergency
ysicians is an update of a 2002 clinical policy on the
luation and management of adult patients presenting to the
ergency department (ED) with acute, nontraumatic
adache. A writing subcommittee reviewed the literature to
rive evidence-based recommendations to help clinicians
swer the following 5 critical questions: (1) Does a response to
rapy predict the etiology of an acute headache? (2) Which
tients with headache require neuroimaging in the ED? (3)
es lumbar puncture need to be routinely performed on ED
tients being worked up for nontraumatic subarachnoid
morrhage whose noncontrast brain computed tomography
T) scans are interpreted as normal? (4) In which adult
tients with a complaint of headache can a lumbar puncture be
ely performed without a neuroimaging study? (5) Is there a
ed for further emergent diagnostic imaging in the patient
th sudden-onset, severe headache who has negative findings in
th CT and lumbar puncture? Evidence was graded and
ommendations were given based on the strength of the
ilable data in the medical literature.
TRODUCTION
A query of the National Hospital Ambulatory Medical Care
rvey for 1999 to 2001 found that headache accounted for 2.1
llion emergency department (ED) visits (2.2 % of all ED
its). Of the 14% of the patients who underwent imaging,
% received a pathologic diagnosis.1 Emergency physicians
st determine which patients need neuroimaging in the ED
d which can be appropriately deferred and evaluated in the
tpatient setting. Many patients have limited access to care,
ich further complicates this decision process in clinical
ctice, but this variable is not accounted for in most studies.
hen evaluating the data, the outcome measures used in
termining the need for neuroimaging in the ED must also be
nically relevant to practice. For example, diagnosing a brain
or may not require immediate neurosurgery or even
spitalization, yet may clearly direct the disposition and
low-up timing of the patient. This policy is an update of the
02 American College of Emergency Physicians (ACEP)
nical policy on headache.2
In deciding which test to perform, emergency physicians
st assess pretest risk for the condition. Researchers in
tawa, Ontario, conducting an observational study in patients
th severe headache, asked emergency physicians to rate their
mfort level in performing a lumbar puncture without first
taining a head computed tomography (CT) scan, as well as
ir estimates of pretest probability of a subarachnoid
morrhage in these patients.3 Of the 1,070 eligible patients,
7 were prospectively enrolled, with 50 patients having a
nfirmed subarachnoid hemorrhage. Emergency physicians
re either “uncomfortable” or “very uncomfortable” with
8 Annals of Emergency Medicine
.6% of 625 patients. They were “very comfortable” with
rforming a lumbar puncture with a head CT scan in only
.2% of patients with acute headache. Emergency physicians
re better at identifying patients at low risk for subarachnoid
morrhage and less accurate at identifying the high-risk
tients. Emergency physicians’ estimate of the probability of
patient having a subarachnoid hemorrhage revealed a
eiver operating characteristic curve with an area of 0.85 (95%
nfidence interval [CI] 0.80 to 0.91). The sensitivity of clinical
picion was 93% (95% CI 81% to 97%) and specificity was
% (95% CI 45% to 53%) using a pretest probability of 2%
greater as the threshold. Researchers believed that emergency
ysicians discriminate moderately well between headache due
subarachnoid hemorrhage and other causes. However, given
high mortality associated with a missed diagnosis,
ergency physicians are currently unwilling to trust their
gment. There were 3 subarachnoid hemorrhage cases in
ich pretest probability was 2% or lower, which may explain
y many emergency physicians continue to use diagnostic tests
patients with low pretest probability.3
ETHODOLOGY
This clinical policy was created after careful review and
tical analysis of the medical literature. Multiple searches of
EDLINE and the Cochrane database were performed.
ecific key word/phrases used in the searches are identified
der each critical question. To update the 2002 ACEP policy,
ich used literature up to December 1999, all searches were
ited to English-language sources, human studies, adults, and
rs January 2000 to August 2006. Additional articles were
iewed from the bibliography of articles cited and from
blished textbooks and review articles. Subcommittee
mbers supplied articles from their own files, and more recent
icles identified during the expert review process were also
luded.
The reasons for developing clinical policies in emergency
dicine and the approaches used in their development have
en enumerated.4 This policy is a product of the ACEP clinical
licy development process, including expert review, and is
sed on the existing literature; when literature was not
ilable, consensus of emergency physicians was used. Expert
iew comments were received from individual emergency
ysicians and from individual members of the American
adache Society and the Society for Academic Medicine.
eir responses were used to further refine and enhance this
licy; however, their responses do not imply endorsement of
s clinical policy. This document was also reviewed by the
nt Guidelines Committee (JGC) of the American Association
Neurological Surgeons (AANS) and the Congress of
urological Surgeons (CNS), however, this review does not
nstitute an endorsement or approval of the document, its
ntent, or conclusions by the JGC, the AANS, or the CNS.
inical policies are scheduled for revision every 3 years;
Volume , . : October
however, interim reviews are conducted when technology or the
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This policy is not intended to be a complete manual on the
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Clinical Policy
Vo
ctice environment changes significantly.
All articles used in the formulation of this clinical policy were
ded by at least 2 subcommittee members for strength of
dence and classified by the subcommittee members into 3
sses of evidence on the basis of the design of the study, with
sign 1 representing the strongest evidence and design 3
resenting the weakest evidence for therapeutic, diagnostic,
d prognostic clinical reports, respectively (Appendix A).
ticles were then graded on 6 dimensions thought to be most
evant to the development of a clinical guideline: blinded
sus nonblinded outcome assessment, blinded or randomized
ocation, direct or indirect outcome measures (reliability and
idity), biases (eg, selection, detection, transfer), external
idity (ie, generalizability), and sufficient sample size. Articles
eived a final grade (Class I, II, III) on the basis of a
determined formula, taking into account design and quality
study (Appendix B). Articles with fatal flaws were given an
” grade and not used in formulating recommendations in this
licy. Evidence grading was done with respect to the specific
ta being extracted and the specific critical question being
iewed. Thus, the level of evidence for any one study may vary
ording to the question, and it is possible for a single article to
eive different levels of grading as different critical questions
answered. Question-specific level of evidence grading may be
nd in the Evidentiary Table included at the end of this
licy.
Clinical findings and strength of recommendations regarding
tient management were then made according to the following
teria:
Level A recommendations. Generally accepted principles
patient management that reflect a high degree of clinical
tainty (ie, based on strength of evidence Class I or
erwhelming evidence from strength of evidence Class II
dies that directly address all of the issues).
Level B recommendations. Recommendations for patient
nagement that may identify a particular strategy or range of
nagement strategies that reflect moderate clinical certainty
, based on strength of evidence Class II studies that directly
dress the issue, decision analysis that directly addresses the
ue, or strong consensus of strength of evidence Class III
dies).
Level C recommendations. Other strategies for patient
nagement that are based on preliminary, inconclusive, or
nflicting evidence, or in the absence of any published
rature, based on panel consensus.
There are certain circumstances in which the
ommendations stemming from a body of evidence should
t be rated as highly as the individual studies on which they
based. Factors such as heterogeneity of results, uncertainty
out effect magnitude and consequences, strength of prior
liefs, and publication bias, among others, might lead to such a
wngrading of recommendations.
lume , . : October
luation and management of adult patients with acute headache
t rather a focused examination of critical issues that have
ticular relevance to the current practice of emergency medicine.
It is the goal of the Clinical Policies Committee to provide
evidence-based recommendation when the medical literature
vides enough quality information to answer a critical
estion. When the medical literature does not contain enough
ality information to answer a critical question, the members
the Clinical Policies Committee believe that it is equally
portant to alert emergency physicians to this fact.
Recommendations offered in this policy are not intended to
resent the only diagnostic and management options that the
ergency physician should consider. ACEP clearly recognizes
importance of the individual physician’s judgment. Rather,
s guideline defines for the physician those strategies for which
dical literature exists to provide support for answers to the
cial questions addressed in this policy.
Scope of Application. This guideline is intended for
ysicians working in hospital-based EDs.
Inclusion Criteria. This guideline is intended for adult
ients presenting to the ED with acute, nontraumatic headache.
Exclusion Criteria. This guideline is not intended to
dress the care of pediatric patients or the care of patients with
uma-related headaches.
ITICAL QUESTIONS
Does a response to therapy predict the etiology of an
acute headache?
tient Management Recommendations
Level A recommendations. None specified.
Level B recommendations. None specified.
Level C recommendations. Pain response to therapy should
t be used as the sole diagnostic indicator of the underlying
ology of an acute headache.
Key words/phrases for literature searches: thunderclap headache,
te headache, response to therapy, cause or etiology, and
iations and combinations of the key words/phrases.
Because headache is a common complaint, physicians have
ght ways to differentiate the serious life-, limb-, vision-, or
in-threatening etiologies from the more benign ones. Defining
o can be sent home safely without workup beyond medical
tory and physical examination could expedite patient care while
reasing patient cost. Anecdotally, some clinicians have tried to
a favorable response to medications as an indicator that a
ient’s headache is not due to a secondary (serious) etiology. To
ly address this question, it is important to understand the
derlying pathophysiology of headache and the pharmacologic
ionale behind the current concepts in therapy.
Current understanding of headache suggests that there is a
mon pathway for the pain regardless of the underlying etiology.
uch of our understanding about the pathophysiologic
racteristics comes from research on migraine. In essence,
Annals of Emergency Medicine 409
headache can be caused by (1) distention, traction, or dilation of
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Clinical Policy
41
racranial or extracranial arteries; (2) traction or displacement of
ge intracranial veins or the dural envelope; (3) compression,
ction, or inflammation of cranial and spinal nerves; (4) head and
k muscle spasm, inflammation, or trauma; (5) meningeal
tation; (6) raised intracranial pressure; and (7) disturbance of
racerebral serotonergic projections.5
Evidence suggests that headache pain is transmitted by the
geminal nerve from the blood vessels of the pia mater and
ra mater.6 The exact trigger of the pain may be
ltifactorial, but once the trigger occurs, the
geminovascular axons are stimulated, resulting in the onset
pain and release of neurogenic peptides stored in the
erent C fibers innervating cephalic blood vessels. These
oactive neuropeptides then stimulate endothelial cells,
st cells, and platelets, creating an inflammatory cascade
own as “neurogenic inflammation.” Vasodilatation with
hanced permeability of plasma proteins follows with a
rivascular inflammatory reaction.7 “Neurogenic
ammation” within the cephalic tissue is one model that
s been proposed as the pathogenic mechanism of headache.
wever, selective and potent inhibitors of “neurogenic
ammation” have thus far proven ineffective in clinical
als.
Serotonin (5-HT) receptors are the main focus of pain
nagement because they are known to modulate neurogenic
ptide release and vasoconstrict dilated dural vessels.8 The goal
therapy is to prevent or abort the neurogenic inflammation
t occurs as a result of neuropeptide release. Subtypes of the
T1 receptor are believed to be the most important receptors
the final common pathway of headache. Despite many
verse effects, 5-HT is a potent vasoconstrictor, a property that
y be a factor in its ability to treat migraines. Pharmacologic
nts with an affinity for 5-HT receptors are currently the
ferred therapy in acute headache management. Some agents,
h as the triptans, are specific agonists at the 5-HT1 receptor,
ereas other medications, such as dihydroergotamine,
chlorperazine, and metoclopramide, act at a variety of 5-HT
d other aminergic receptors.5,9
There are no prospective randomized controlled trials,
dence from meta-analysis from randomized controlled trials,
well-designed cohort studies to support or refute the practice
using response to therapy in nontraumatic headaches as an
icator of potential underlying pathologic entities. The only
blished data about response to pain medications as an
icator of underlying headache etiology is in Class III
dence in the form of case reports and case series.
Numerous articles have described headaches of varying
ondary (serious) etiologies showing clinical improvement or
olution of pain in response to many different analgesics.
ese conditions include but are not limited to the following:
racerebral hemorrhage/subarachnoid hemorrhage (ibuprofen,
orolac, prochlorperazine),10 viral meningitis/meningeal
cinomatosis (dihydroergotamine and metoclopramide),11
0 Annals of Emergency Medicine
ous thrombosis (sumatriptan and various common
algesics),13 carotid artery dissection (sumatriptan),14,15
arachnoid hemorrhage (sumatriptan),16,17 and cysts of the
um septi pellucidi (indomethacin).18
Which patients with headache require neuroimaging in
the ED?
tient Management Recommendations
Level A recommendations. None specified.
Level B recommendations.
Patients presenting to the ED with headache and new
abnormal findings in a neurologic examination (eg, focal
deficit, altered mental status, altered cognitive function)
should undergo emergent* noncontrast head CT.
Patients presenting with new sudden-onset severe headache
should undergo an emergent* head CT.
HIV-positive patients with a new type of headache should
be considered for an emergent* neuroimaging study.
Level C recommendations. Patients who are older than 50
rs and presenting with new type of headache but with a
rmal neurologic examination should be considered for an
ent† neuroimaging study.
*Emergent studies are those essential for a timely decision
arding potentially life-threatening or severely disabling
tities. †Urgent studies are those that are arranged prior to
charge from the ED (scan appointment is included in the
position) or performed prior to disposition when follow-
cannot be assured. Routine studies are indicated when the
dy is not considered necessary to make a disposition in the
.19
Key words/phrases for literature searches: acute headache,
gnostic imaging, CT scan, MRI, emergency department, and
iations and combinations of the key words/phrases.
The primary focus in obtaining a neuroimaging study in the
is to identify a treatable lesion. Treatable lesions include
ors, vascular malformations, aneurysms, subarachnoid
morrhage, cerebral venous sinus thrombosis, subdural and
idural hemat