Diagnosis of Subarachnoid Hemorrhage in the Emergency Department

1
Diagnosis of Subarachnoid Hemorrhage in the
Emergency Department

• Nathan Maust
• MS IV
• Emergency Medicine Sub-Internship
• May 2006

2
Overview

• Case JM
• Epidemiology
• How to Diagnose
• History Physical
• ED Diagnostic Testing CT and LP
• Misdiagnosis
• Reasons Consequences
• Summary

3
Case JM

• HPI
• 37 yo female with h/o ectopic pregnancy and GERD
  p/w acute onset nausea vomiting, followed by
  severe HA
• HA described as 12/10 and like I was having a
  baby in my head
• Onset at rest
• Severe sharp pain on the L side of the head
• Denies visual disturbance, any focal neurologic
  deficit, or neck pain or stiffness
• No h/o migraine or other chronic HA and has never
  before had a HA nearly this severe
• After 5-10 minutes, pain began to gradually and
  modestly improve w/o treatment pain 5/10 at time
  of interview

4
Case JM

• ROS otherwise negative
• PMH h/o ectopic pregnancy 2001
• Denies HTN, connective tissue disorder
• Meds Allegra D, occasional Benadryl
• NKDA
• Social Denies tobacco, alcohol, and illicits
• Family Denies h/o SAH or any CTD

5
Case JM

• Physical Exam
• VS T 96.2 BP 112/80 P 89 RR 14
• Well-appearing 37 yo female in NAD, AO x 3
• PERRLA
• CN II-XII intact
• No focal neurologic deficit, gait intact
• No nuchal rigidity or meningismus
• Labs
• unremarkable

6
Case JM

• Differential of Consequence for Severe Headache
• Subarachnoid hemorrhage (SAH)
• Meningitis, encephalitis
• Temporal arteritis
• Acute narrow angle closure glaucoma
• Hypertensive emergency
• CO poisoning
• Pseudotumor cerebri
• Central venous/dural sinus thrombosis
• Acute stroke (esp. hemorrhagic)
• Mass lesion (tumor, abscess, intracranial
  hematoma)

7
SAH Epidemiology(Edlow JA, et al. N Engl J Med.
2006 342(1)29-36)

• Incidence of aneurysmal SAH is 6 to 10 per 100k
• HA constitutes 1-2 of ED visits and up to 4 of
  physician office visits
• SAH makes up about 1 of those presenting to the
  ED with HA as primary complaint
• Worst HA of patients life
• Abnormal neuro exam 25 had SAH
• Normal neuro exam 12 had SAH
• Misdiagnosis is common and causes increases in
  MM
• 23 to 53 initial misdiagnosis rate
• Common source of ED malpractice suits

8
SAH Quick Pathology Pathophys

• Causes
• Ruptured aneurysm (75)
• MF, 5th or 6th decade, acute ? BP
• Usually congenital berry aneurysms in Circle of
  Willis
• Polycystic Kidney Dz, Coarctation of Aorta,
  Ehlers-Danlos
• HTN, alcohol, cigarettes, cocaine
• 2-3 are mycotic aneuryms (s/p infective
  endocarditis)
• Intracranial AVM (10)
• MgtF, 2nd to 4th decades
• Source of symptoms
• Rupture of intracranial artery ? ? ICP
• ? distortion of pain-sensitive structures ? HA
• ? decreased cerebral perfusion ? LOC
• ? compression of intracranial structures ? 3rd n.
  palsy,

9
History Findings

• History
• Sentinel/Warning/Thunderclap HA 20 to 50 get a
  distinct, unusual, severe HA that precedes the
  actual HA that causes the pt to seek medical
  attention can come days to weeks earlier
• Nausea/vomiting
• Exertion at time of HA onset
• Depressed consciousness
• Neck stiffness or pain
• Visual changes
• Gait disturbance

10
Physical Findings(Edlow JA, Caplan LR. N Engl J
Med. 2000342(1)29-36)

• Nuchal rigidity
• Diminished level of consciousness
• Papilledema
• Retinal and subhyaloid hemorrhage
• Third nerve palsy
• Sixth nerve palsy
• Bilateral weakness in legs or abulias
• Nystagmus or ataxia
• Aphasia, hemiparesis, or visual neglect

11
Current Treatment Algorithm(Suarez JI, et al. N
Engl J Med. 2006354(4)387-96)

• CT scan without contrast
• If positive, perform CT or cerebral angiography
• If negative, perform Lumbar Puncture
• If abnormal CT or cerebral angiography
• If abnormal but equivocal CT or cerebral
  angiography
• If normal Stop

If aneurysm is found, treat promptly. If
negative, repeat CT angiogram in 1-3 weeks
and image brain, brainstem, and spinal cord.
12
Sensitivity of 5th generation CT
scanners(Boesiger BM, et al. J Emerg Med. 2005
Jul29(1)23-7)

• Retrospective chart review of 177 patients in
  2002 that presented with HA and had CT and LP
  performed to rule out SAH.
• Exclusions trauma within 3 months, age 17, not
  having r/o SAH as reason for LP on chart, recent
  neurosurgery.
• Patients were followed up for a minimum of 3
  months by chart review and/or phone call to
  assess for complications after CT and LP were
  performed
• Sensitivity of CT for SAH 100 (95 CI
  61.0-100)
• Specificity of CT for SAH 99.4 CI 96.8-99.9)

13
Lumbar Puncture(Shah KH, Edlow JA. J Emerg Med.
200223(1)67-74)

• The gold standard for diagnosis of SAH
• 100 sensitive in detected blood in the CSF
• Traumatic tap occurs in 20 of LPs
• Interpretation
• Three tube test should see a decrease in
  traumatic tap vs. steady level of RBCs in true
  SAH
• Xanthochromia 20 in first 6 hr, 65 between 6
  and 12 hr, and 100 after 12 hr
• Elevated opening pressure (gt20 cm H2O) seen in
  60 of cases

14
Case JM

• Head CT
• Normal
• LP results
• Phone call follow-up 14 days s/p discharge.
• Only one instance of mild HA in past two weeks.
• Denies nausea, vomiting, visual disturbance, neck
  stiffness or any other complaints.

15
Incorrect diagnoses in misdiagnosed SAH(Edlow
JA. Emerg Med Clin N Am. 2003 2173-78)

• No dx/HA or unknown cause
• Primary HA disorder (migraine, cluster, tension)
• Meningitis and encephalitis
• Systemic infection (flu, gastroenteritis, viral)
• Stroke or TIA
• Hypertensive crisis
• Cardiovascular diagnosis (r/o MI, arrythmia,
  syncope)
• Sinus-related HA
• Neck problem (cervical disc dz, arthritis)
• Psychiatric dx (alcohol intoxication,
  malingering)
• Trauma-related
• Back pain

8
4
Number of episodes required for diagnosis
according to Int. HA Society
16
Misdiagnosis of SAH(Kowalski RG, et al. JAMA.
2004 Feb 18291(7)866-9)

• Inception cohort of 482 SAH patients admitted to
  Columbia-Presbyterian in NY between 1996 and 2001
• Goal
• determine the association between initial missed
  diagnosis and outcome after SAH
• identify factors associated with misdiagnosis
• Main outcome measures
• Modified Rankin Scale (functional outcome) and
  Sickness Impact Profile (QOL) at 3 and 12 months
  (performed by interview in person or via
  telephone)

17
Misdiagnosis of SAH(Kowalski RG, et al. JAMA.
2004 Feb 18291(7)866-9)

• Results
• Misdiagnosis occurred in 12 (56/482) of patients
• Location of initial misdiagnosis
• ED (43) or a physicians office (32)
• Diagnostic error
• No CT performed (73)
• CT or LP results misinterpreted (16)
• CT done, but LP not performed (7)
• Initial misdiagnosis
• Migraine/tension HA (36)
• No diagnosis (12)
• Viral syndrome (11)

18
Misdiagnosis of SAH(Kowalski RG, et al. JAMA.
2004 Feb 18291(7)866-9)

• Independently associated with misdiagnosis in all
  patients
• Normal mental status
• Small SAH volume
• Right-sided aneurysm location
• Also associated with misdiagnosis in those
  presenting with normal mental status
• Education 12 years
• Nonfluency in English
• Being unmarried

19
Case Report 1(Wasserberg J, Barlow P. BMJ.
1997315(7122)1598-9)

• 58M p/w LOC x 1 minute, then had severe HA and
  hematemesis after awakening
• Initial dx hematemesis
• Admitted to hospital, given IM opiates for pain
• Initial sx attributed to EtOH withdrawal, pt
  treated with diazepam
• HA not improved after 2 days
• SAH was considered, pt booked for elective CT,
  next appt 2 days later
• 1 day before scan, pt became unconscious, had
  fixed, dilated L pupil
• ER CT shows extensive SAH ? tx to NICU ? died
  shortly thereafter

20
Case Report 2(Wasserberg J, Barlow P. BMJ.
1997315(7122)1598-9)

• 17F p/w HA associated with n/v x 1 week
• CT to rule out SAH normal ? reassured, sent home
  (CT later reviewed and confirmed normal)
• 2 days later she is awakened by sudden HA, she
  vomits, and collapses
• In coma on arrival, reacting to pain only
• CT shows SAH, angiogram shows terminal carotid
  artery aneurysm but patient dies before
  completion of angiography

21
Summary

• Always consider SAH in a patient who presents
  with the worst HA of their life
• Avoid certain pitfalls
• The patient with known HA history that presents
  with a new, distinct severe HA
• The patient whose clinical picture is complicated
  by other complaints, intoxication, etc.
• Know how to distinguish traumatic tap from SAH to
  avoid subjecting patients to unnecessary invasive
  diagnostic testing
• Despite advancement in CT scanner technology,
  todays data does not support the thought that CT
  without LP can definitively exclude SAH

22
References

• Boesiger BM, Shiber JR. Subarachnoid hemorrhage
  diagnosis by computed tomography and lumbar
  puncture are fifth generation CT scanners better
  at identifying subarachnoid hemorrhage? J Emerg
  Med. 2005 Jul29(1)23-7.
• Coats TJ, Loffhagen R. Diagnosis of subarachnoid
  haemorrhage following a negative computed
  tomography for acute headache a Bayesian
  analysis. Eur J Emerg Med. 2006 Apr13(2)80-3.
• Edlow JA. Diagnosis of subarachnoid hemorrhage in
  the emergency department. Emerg Med Clin N Am.
  2003 Feb21(1)73-87. Review.
• Edlow JA, Caplan LR. Avoiding pitfalls in the
  diagnosis of subarachnoid hemorrhage. N Engl J
  Med. 2000 Jan 6342(1)29-36.
• Edlow JA, Wyer PC. How good is a negative cranial
  computed tomographic scan result in excluding
  subarachnoid hemorrhage? Ann Emerg Med. November
  200036507-516
• Kowalski BS, et al. Initial misdiagnosis and
  outcome after subarachnoid hemorrhage. JAMA. 2004
  Feb 18291(7)866-9.
• Subarachnoid hemorrhage. Lange Neurology. The
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• Seehusen DA, Reeves MM, Fomin DA. Cerebrospinal
  fluid analysis. Am Fam Physician. 2003 Sep
  1568(6)1103-8.
• Shah KH, Edlow JA. Distinguishing traumatic
  lumbar puncture from true subarachnoid
  hemorrhage. J Emerg Med. 2002 Jul23(1)67-74.
• Suarez JI, Tarr RW, Selman WR. Aneurysmal
  subarachnoid hemorrhage. N Engl J Med. 2006 Jan
  26354(4)387-96. Review.
• Wasserberg J, Barlow P. Lesson of the week.
  Lumbar puncture still has an important role in
  diagnosing subarachnoid haemorrhage. BMJ. 1997
  Dec 13315(7122)1598-9.
• Wood MJ, Dimeski G, Nowitzke AM. CSF
  spectrophotometry in the diagnosis and exclusion
  of spontaneous subarachnoid haemorrhage. J Clin
  Neurosci. 2005 Feb12(2)142-6.