When is it safe to rule out subarachnoid hemorrhage without CT and lumbar puncture?
Date First Published:
October 21, 2012
Last Updated:
November 13, 2012
Report by:
Daniel Goh, Medical Student (Yong Loo Lin School of Medicine, National University of Singapore)
Three-Part Question:
In [an adult presenting with acute headache to the emergency department], [how effective are patient histories and physical findings] in [ruling out subarachnoid hemorrhage]?
Clinical Scenario:
A 26 year old man attends the emergency department with a first-time headache of moderate to severe intensity, with no clinical course of vomiting. It is however of a sudden onset. Neurological examination was unremarkable. He has no history of trauma and has no relevant previous medical history. You wonder if it would be safe to rule out sub-arachnoid hemorrhage without an emergent CT scan.
Search Strategy:
Medline 1950 to 10/12 via PubMed
Search Details:
headache[Title/Abstract] AND subarachnoid[Title/Abstract] AND (\\\"humans\\\"[MeSH Terms] AND English[lang])
Outcome:
883 Results
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Atraumatic headache in US emergency departments: recent trends in CT/MRI utilisation and factors associated with severe intracranial pathology Gilbert JW, Johnson KM, Larkin GL, Moore CL. 2012 USA | 15,062 atraumatic headache-related ED visits identified using preassigned reason-for-visit codes. | Retrospective study to (1) estimate recent trends in CT/MRI utilisation among patients seeking emergency care for atraumatic headache in the USA. (2) to identify factors associated with a diagnosis of significant intracranial pathology (ICP) in these patients. | Factors significantly associated with ICP diagnosis (odds ratio) | >50 years (7.26), arrival by ambulance (3.66), triage immediacy <15 min (6.04), systolic blood pressure > 160 mm Hg (2.34) or diastolic blood pressure more than 100 mm Hg (1.98) / disturbance in sensation (6.04), vision (3.02), speech (10.54) or motor function (11.67) including neurological weakness (8.46) | Dataset reliant on accuracy of patient record. Missing diagnoses, coding bias. Lack of follow-up to track diagnoses or investigations after initial ED evaluation. |
| Factors not significantly associated (odds ratio) | dizziness (1.85), heart rate <60 or >100 (1.70), convulsions/seizures (1.12), nausea (0.95), neck stiffness (0.44), vomiting (1.42), male gender (1.56), non-Hispanic white (1.49) | ||||
| Correlation between ED symptoms and clinical outcomes in the patient with aneurysmal subarachnoid hemorrhage. Adkins K, Crago E, Kuo CW, Horowitz M, Sherwood P. 2012 USA | 193 adult aSAH patients | Retrospective review of the (1) presenting historical features in patients with aneurysmal subarachnoid hemorrhage to the emergency department, (2) whether presentation predicts length of stay or death | SAH Presentation | headache 160 (82.9%), nausea 83 (43%), stiff neck 53 (27.5%). No significant neurological deficits ost patients in this analysis arrived at the emergency department without significant neurologic deficits: GCS 15 (55%) and HH score<3 36 (39%) | Bias in severity of injury due to inclusion criteria. Subjective symptom reporting from variety of sources. |
| High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: prospective cohort study. Perry JJ, Stiell IG, Sivilotti ML, Bullard MJ, Lee JS, Eisenhauer M, Symington C, Mortensen M, Sutherland J, Lesiuk H, Wells GA. 2010 Canada | 1999 alert patients aged ≥16 who presented to an emergency department with a chief complaint of non-traumatic headache peaking within an hour or of syncope associated with a headache were included. 130 were eventually diagnosed with subarachnoid hemorrhage. | Prospective multicentre cohort study at university affiliated tertiary care teaching hospitals. Univariate analyses of 26 potential predicting variables. Subsequently multivariate models via recursive partitioning to predict for subarachnoid hemorrhage. | Rule 1 | Age>40, complaint of neck pain or stiffness, onset with exertion, witnessed LOC. Sensitivity 100%, Specificity 28.4%, Negative Predictive Value 100%, Investigation Rate 73.5% | Potentially missing a third of patients in enrollment. |
| Rule 2 | Age>45, arrived by ambulance, vomiting at least once, diastolic BP at least 100 mmHg. Sensitivity 100%, Specificity 36.5%, Negative Predictive Value 100%, Investigation Rate 65.8% | ||||
| Rule 3: | Age 45-55, arrived by ambulance, complaint of neck pain or stiffness, diastolic BP at least 160 mmHg. Sensitivity 100%, Specificity 38.8%, Negative Predictive Value 100%, Investigation Rate 63.7% | ||||
| Risk stratification of non-traumatic headache in the emergency department. Grimaldi D, Nonino F, Cevoli S, Vandelli A, D Amico R, Cortelli P. 2009 Italy | 256 patients presenting to ED for non-traumatic headaches. | Prospective study: patient assigned to 1 out 4 scenarios. Scenario 1 aims to include headache associated with SAH or other causes of thunderclap headache with the following features: acute onset (thunderclap headache), OR with neurological signs, OR with vomiting OR syncope at the onset of headache. | SAH Diagnosis | All assigned to Scenario 1 accurately | Limited sample size with high drop-out rate (18%) Reproducibility of diagnostic algorithm untested |
| Clinical lessons and risk factors from 403 fatal cases of subarachnoid haemorrhage. Gambhir S, O Grady G, Koelmeyer T. 2009 New Zealand | 403 autopsied cases of fatal subarachnoid haemorrhage. | Retrospective review to (i) compare the fatal case population to local unselected data; (ii) examine the aetiology and risk factors that contribute to fatality from SAH in our community; and (iii) determine the clinical factors that might help reduce misdiagnosis. | SAH Presentation | >females (67%), sedentary at onset (39% asleep), involved in significant physical exertion (6%), found dead or collapsed (69%), complaint of headache (27%), atypical primary symptoms (4%), warning headaches (38%), posterior circulation aneurysms 25%, left ventricular hypertrophy (45%), prominent fatty metamorphosis of liver (16%) | Lack of multivariate analysis to establish significance. |
| Warning signs and symptoms of subarachnoid hemorrhage. Togha M, Sahraian MA, Khorram M, Khashayar P. 2009 Iran | 28 cases of spontaneous SAH. | Prospective analysis. History obtained from patient when possible, or if necessary, by family member or associate. Evaluation of the quality and frequency of warning symptoms in patients admitted with spontaneous SAH. | SAH Presentation | sudden pulsatile severe onset (64.3%), transient loss of consciousness (42.8%), difficulty in walking (21.4%), hemiparesis (14.2%), ocular signs (14.2%) and seizure (3.6%) | Multivariate analysis was not performed. Small sample size, descriptive in character Severity of SAH outcomes not calculated. |
| Breakdown of Symptoms | bilateral headache (63%), nausea (41%), not relieved by analgesia (10.7%), headache as sole warning symptom (11%), headache in association with other neurologic signs and symptoms (53.6%), various neurological signs and symptoms but no headache (35.7%) | ||||
| SAH Risk Factors | hypertension (39.3%), smoking (32.1%) | ||||
| Acute headache: a prospective diagnostic work-up of patients admitted to a general hospital. Bø SH, Davidsen EM, Gulbrandsen P, Dietrichs E. 2008 Norway | 433 ED adult patients seen in Norway 1998–2002 | 72 (16%) with SAH. Parameters: sex, age, state at ictus, maximum pain intensity, nausea, vomiting, photophobia | SAH Presentation | Higher mean age; otherwise considerable overlap between diagnostic groups regarding headache characteristics | |
| Attitudes and judgment of emergency physicians in the management of patients with acute headache. Perry JJ, Stiell IG, Wells GA, Mortensen M, Lesiuk H, Sivilotti M, Kapur A. 2005 Canada | 747 patients, including 50 (6.7%) with SAHs | Prospective cohort assessing emergency physicians in: 1) pretest accuracy for predicting SAH, 2) comfort with not ordering either CT or LP in patients with acute headache, and 3) comfort with not ordering head CT before performing LP in patients with acute headache. |
Clinical suspicion of SAH (pretest probability) | Sensitivity 93%, specificity 49% | Inclusion criteria allowed less severe headaches to be enrolled by including headaches with slower onset (up to 1 hour) |
| Physician confidence in clinical judgement | Uncomfortable or very uncomfortable with not ordering any tests for 75.4% of patients when in reality 6.7% had SAH | ||||
| Initial misdiagnosis and outcome after subarachnoid hemorrhage. Kowalski RG, Claassen J, Kreiter KT, Bates JE, Ostapkovich ND, Connolly ES, Mayer SA. 2004 USA | Inception cohort of 482 SAH patients admitted to a tertiary care urban hospital between August 1996 and August 2001. Of which, 12% were misdiagnosed. | Prospective analysis. Identifying independent predictors of misdiagnosis with forward stepwise logistic regression. | Factors associated with misdiagnosis | lower education (less than 12 years), smaller hemorrhages, nonfluency in English, being unmarried | Hospital-based study: may not fully capture all SAH misdiagnosis, no data on misdiagnosed patients with good outcomes |
| Clinical presentation of patients with subarachnoid haemorrhage at a local emergency department. Seet CM. 1999 Singapore | 61 patients with diagnosis of SAH confirmed by CT, LP or cerebral angiogram. | Retrospective study | SAH Risk Factors | History of hypertension: 30 (49%) | Uncaptured or unrecorded physical findings or historical features |
| SAH Presentation | headache (70%), vomiting (61%), giddiness (30%), unconsciousness (28%), syncope (26%), fits (20%) | ||||
| SAH Physical Findings | elevated blood pressure (34%), neck stiffness (21%), focal weakness (13%), fever (8%), preretinal haemorrhages (2%) | ||||
| Headache characteristics in subarachnoid haemorrhage and benign thunderclap headache. Linn FH, Rinkel GJ, Algra A, van Gijn J. 1998 The Netherlands | 102 adult patients referred by GP for acute severe headeache suggestive of aneurysmal subarachnoid hemorrhage (ASAH). ASAH was diagnosed in 42 patients (41%), perimesencephalic hemorrhages (PMH) 23 (23%), and benign thunderclap headache 37 (36%). | Prospective study. Comparison was made between groups by means of relative risks (RRs), or mean differences, at 95% CI. Headache characteristics were also compared. | Headache onset (RR: ASAH vs BTH) | Almost instantaneous 50% (RR 0.7), 1-5 minutes 19% (1.0), exertion 50% (2.3) | Deliberate exclusions of patients with acute severe headache not caused by ASAH, BTH or PMH. |
| SAH presentation | Transient loss or clouding of consciousness 26% (RR 1.6), transient focal symptoms 33% (RR 1.5), female sex 57% (1.6), nausea 76% (1.0), vomiting 69% (1.6) | ||||
| Acute headache of recent onset and subarachnoid hemorrhage: a prospective study. Lledo A, Calandre L, Martinez-Menendez B, Perez-Sempere A, Portera-Sanchez A. 1994 Spain | 27 patients with acute severe headache of recent onset in ED | Prospective cohort. | SAH presentation | bilateral, very intense and involving the occipital region. | |
| Warning signs in subarachnoid hemorrhage: a cooperative study. Bassi P, Bandera R, Loiero M, Tognoni G, Mangoni A. 1991 Italy | 364 patients with intracranial aneurysms confirmed by angiography and reliable clinical history. | Retrospective survey of subarachnoid hemorrhage cases, with comparison of clinical features. | Correct First Diagnosis of SAH (Group A - 78) | headache (97.4%), nausea or vomiting (70.5%), dizziness (14.1%), loss of consciousness (33.3%), transient motor deficit (7.7%), headache only (14.1%), | Potential selection bias Loss of data due to lack of records |
| Diagnosed only at a second episode of SAH (Group B: 74) | headache (98.6%), nausea or vomiting (51.3%), dizziness (20.3%), loss of consciousness (12.2%)*, transient motor deficit (2.7%), headache only (32.4%), | ||||
| Recognition of subarachnoid hemorrhage. Fontanarosa PB. 1989 USA | 109 patients presenting to ED with proven nontraumatic, spontaneous subarachnoid hemorrhage (SAH), | Retrospective review of clinical presentation, diagnostic modalities used, and accuracy of diagnosis. | SAH Presentation | Headache (74%), nausea or vomiting (77%), loss of consciousness (53%), nonexertional activities (57%) vs exertional activites (21%), neurologic findings (64%: mainly altered LOC), nuchal rigidity (35%). | Absent or inadequate documentation of useful data due to retrospective nature design. |
| Delayed diagnosis | Delayed diagnosis in 16 patients (15%), majority of whom had headaches and normal neurologic examinations | ||||
| Pitfalls in the recognition of subarachnoid hemorrhage. Adams HP Jr, Jergenson DD, Kassell NF, Sahs AL. 1980 USA | 182 patients admitted for treatment of SAH reviewed. Focus was on 41 patients with delayed diagnosis of SAH. | Retrospective review of the 41 patients misdiagnosed initially. | SAH Presentation (in the misdiagnosed 41 cases) | headache (85%), nausea (44%), vomiting (34%), brief loss of consciousness (32%), neck stiffness (15%), confusion (12%) | Inherent flaws of retrospective study: missing data |
| Misdiagnoses (in the 41 cases) | systemic infection (24%), migraine headache (20%0, hypertensive crisis (7%), neck trouble (10%), brain tumor (7%), aseptic meningitis (7%), sinusitis (7%) |
Author Commentary:
In patients presenting with an acute history of headache, the emergency physician is often wary of missing a diagnosis of subarachnoid hemorrhage (SAH). Such associated morbidity and legal consequences may engender the fear of discharging these patients without further investigative studies – despite additional costs and complications associated with computed tomography (CT) and lumbar puncture (LP). Use of CT/LP in the emergent setting has thus increased significantly despite the incidence of SAH having remained relatively constant. Publications till date have suggested a potential role of evidence-based clinical criteria that recommend high-risk patients for further investigations. Such criteria should be based on account of patient history and physical findings, with faultless sensitivity in picking up SAH.
Only one of the studies has developed clinical rules based on multivariate models that predict for SAH. The other studies review cohort of patients to consider the clinical features of SAH – age, neck stiffness, vomiting, arrival by ambulance, etc – while attempting to qualify them. Another study prospectively assigns patients with non-traumatic headaches into 1 of 4 scenarios for further management, but this was limited by a small sample size.
Only one of the studies has developed clinical rules based on multivariate models that predict for SAH. The other studies review cohort of patients to consider the clinical features of SAH – age, neck stiffness, vomiting, arrival by ambulance, etc – while attempting to qualify them. Another study prospectively assigns patients with non-traumatic headaches into 1 of 4 scenarios for further management, but this was limited by a small sample size.
Bottom Line:
History-taking and physical examination will reveal clinical features that are significantly associated with subarachnoid hemorrhage. Each feature by itself does not predict for SAH, but when used in combination, can yield clinical rules with 100% sensitivity and 100% negative predictive value for SAH.
References:
- Gilbert JW, Johnson KM, Larkin GL, Moore CL.. Atraumatic headache in US emergency departments: recent trends in CT/MRI utilisation and factors associated with severe intracranial pathology
- Adkins K, Crago E, Kuo CW, Horowitz M, Sherwood P.. Correlation between ED symptoms and clinical outcomes in the patient with aneurysmal subarachnoid hemorrhage.
- Perry JJ, Stiell IG, Sivilotti ML, Bullard MJ, Lee JS, Eisenhauer M, Symington C, Mortensen M, Sutherland J, Lesiuk H, Wells GA.. High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: prospective cohort study.
- Grimaldi D, Nonino F, Cevoli S, Vandelli A, D Amico R, Cortelli P.. Risk stratification of non-traumatic headache in the emergency department.
- Gambhir S, O Grady G, Koelmeyer T.. Clinical lessons and risk factors from 403 fatal cases of subarachnoid haemorrhage.
- Togha M, Sahraian MA, Khorram M, Khashayar P.. Warning signs and symptoms of subarachnoid hemorrhage.
- Bø SH, Davidsen EM, Gulbrandsen P, Dietrichs E.. Acute headache: a prospective diagnostic work-up of patients admitted to a general hospital.
- Perry JJ, Stiell IG, Wells GA, Mortensen M, Lesiuk H, Sivilotti M, Kapur A.. Attitudes and judgment of emergency physicians in the management of patients with acute headache.
- Kowalski RG, Claassen J, Kreiter KT, Bates JE, Ostapkovich ND, Connolly ES, Mayer SA.. Initial misdiagnosis and outcome after subarachnoid hemorrhage.
- Seet CM.. Clinical presentation of patients with subarachnoid haemorrhage at a local emergency department.
- Linn FH, Rinkel GJ, Algra A, van Gijn J.. Headache characteristics in subarachnoid haemorrhage and benign thunderclap headache.
- Lledo A, Calandre L, Martinez-Menendez B, Perez-Sempere A, Portera-Sanchez A.. Acute headache of recent onset and subarachnoid hemorrhage: a prospective study.
- Bassi P, Bandera R, Loiero M, Tognoni G, Mangoni A.. Warning signs in subarachnoid hemorrhage: a cooperative study.
- Fontanarosa PB.. Recognition of subarachnoid hemorrhage.
- Adams HP Jr, Jergenson DD, Kassell NF, Sahs AL.. Pitfalls in the recognition of subarachnoid hemorrhage.