The utility of head computed tomography in the emergency department evaluation of syncope

Neuroimaging for differential diagnosis of transient neurological attacks

BACKGROUND

Rapid yet comprehensive neuroimaging protocols are required for patients with suspected acute stroke. However, stroke mimics can account for approximately one in five clinically diagnosed acute ischemic strokes and the rate of thrombolyzed mimics can be as high as 17%. Therefore, to accurately determine the diagnosis and differentiate mimics from true transient ischemic attacks, acute ischemic stroke is a challenge to every clinician.

DISCUSSION

Medical history and neurological examination, noncontract head computed tomography, and routine magnetic resonance imaging play important roles in the assessment and management of patients with transient neurological attacks in the emergency department. This review attempts to summarize how neuroimaging can be utilized to help differentiate the most common mimics from transient ischemic attack and acute ischemic stroke.

CONCLUSION

Although imaging can help direct critical triage decisions for intravenous thrombolysis or endovascular therapy, more detailed medical history and neurological examination are crucial for making a prompt and accurate diagnosis for transient neurological attack patients.

ACR Appropriateness Criteria® Syncope

Syncope and presyncope lead to well over one million emergency room visits in the United States each year. Elucidating the cause of syncope or presyncope, which are grouped together given similar etiologies and outcomes, can be exceedingly difficult given the diverse etiologies. This becomes more challenging as some causes, such as vasovagal syncope, are relatively innocuous while others, such as cardiac-related syncope, carry a significant increased risk of death. While the mainstay of syncope and presyncope assessment is a detailed history and physical examination, imaging can play a role in certain situations. In patients where a cardiovascular etiology is suspected based on the appropriate history, physical examination, and ECG findings, resting transthoracic echocardiography is usually considered appropriate for the initial imaging. While no imaging studies are considered usually appropriate when there is a low probability of cardiac or neurologic pathology, chest radiography may be appropriate in certain clinical situations. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The Yield of Computed Tomography of the Head Among Patients Presenting With Syncope: A Systematic Review

BACKGROUND

Overuse of head computed tomography (CT) for syncope has been reported. However, there is no literature synthesis on this overuse. We undertook a systematic review to determine the use and yield of head CT and risk factors for serious intracranial conditions among syncope patients.

METHODS

We searched Embase, Medline, and Cochrane databases from inception until June 2017. Studies including adult syncope patients with part or all of patients undergoing CT head were included. We excluded case reports, reviews, letters, and pediatric studies. Two independent reviewers screened the articles and collected data on CT head use, diagnostic yield (proportion with acute hemorrhage, tumors or infarct), and risk of bias. We report pooled percentages, I² , and Cochran's Q-test.

RESULTS

Seventeen articles with 3,361 syncope patients were included. In eight ED studies (n = 1,669), 54.4% (95% confidence interval [CI] = 34.9%-73.2%) received head CT with a 3.8% (95% CI = 2.6%-5.1%) diagnostic yield and considerable heterogeneity. In six in-hospital studies (n = 1,289), 44.8% (95% CI = 26.4%-64.1%) received head CT with a 1.2% (95% CI = 0.5%-2.2%) yield and no heterogeneity. In two articles, all patients had CT (yield 2.3%) and the third enrolled patients ≥ 65 years old (yield 7.7%). Abnormal neurologic findings, age ≥ 65 years, trauma, warfarin use, and seizure/stroke history were identified as risk factors. The quality of all articles referenced was strong.

CONCLUSION

More than half of patients with syncope underwent CT head with a diagnostic yield of 1.1% to 3.8%. A future large prospective study is needed to develop a robust risk tool.

Value of Head CT Scan in the Emergency Department in Patients with Vertigo without Focal Neurological Abnormalities

BACKGROUND:

Vertigo is a common symptom and reason for admission to the emergency department (ED).

AIM:

This research aimed to determine the incidence of clinically significant findings on computed tomography (CT) in patients with vertigo without focal neurological abnormalities in the ED.

MATERIAL AND METHODS:

The results of the native CT scans in the ED were retrospectively analysed. Exclusion criteria included: focal neurological abnormalities, underlying malignancy, brain metastasis, previous brain operation, headache, fever, nausea, vomiting, head trauma, coagulopathy. As a clinically significant finding, we took into an account tumour, haemorrhage and acute ischemic lesion. 72 patients fulfilled the set criteria, present vertigo, without focal neurological abnormalities. Out of 72 patients with a median age of 62 (23-87) years old, 54% of the patients were female, and 46% were male.

RESULTS:

Normal CT findings were found in 44 patients (61.1%), 28 patients (38.9%) had pathological findings, out of that number 23 (31.9%) findings were clinically irrelevant and 5 (6.9%) were clinically significant. Out of the 5 clinically significant findings, tumour process was found in 3 (4.2%) patients, haemorrhage was found in 1 (1.4%) patient, and the ischemic lesion was found in 1 (1.4%) patient. Additional evaluation of five clinically significant findings showed a change of initial diagnosis in one case, but the significance of the finding remained the same.

CONCLUSION:

Our study demonstrates a low diagnostic yield of head CT examination with 6.9% of clinically significant findings in patients with vertigo without focal neurological abnormalities.

Predictor variables of abnormal imaging findings of syncope in the emergency department

BACKGROUND

This study aimed to describe the pathological findings and to analyze clinical predictors of abnormal imaging findings in patients presenting to the emergency department (ED) with syncope.

METHODS

The database was retrospectively reviewed for all patients who underwent cranial computed tomography (CT) or magnetic resonance imaging (MRI), having the symptom of syncope. Patients were included only if they were from the emergency department and excluded if were under 18 years of age, had known recent intracranial pathology, known brain tumor, or having a history of trauma. The primary outcome was assumed as abnormal head CT or MRI including intracranial hemorrhage, acute or subacute stroke, and newly diagnosed brain mass. Univariate and multivariate logistic regression analysis was utilized to determine the association between clinical variables and any significant pathology in either CT or MR scan.

RESULTS

Total of 1230 syncope (717 men and 513 women; range, 18-92 years; mean, 54.5 years) as presenting symptoms were identified in patients receiving either cranial CT or MR scan in the ED. Abnormal findings related to the syncope were observed in 47 (3.8%) patients. The following predictor variables were found to be significantly correlated with acutely abnormal head CT and MRI: a focal neurologic deficit, history of malignancy, hypertension, and age greater than 60 years.

CONCLUSIONS

Our data offer that the identification of predictor variables has a potential to decrease the routine use of head CT and MRI in patients admitting to the ED with syncope.

A Population-Based Cohort Study Evaluating Outcomes and Costs for Syncope Presentations to the Emergency Department

OBJECTIVES

This study sought to examine outcomes and costs of patients with syncope admitted and discharged from the emergency department (ED).

BACKGROUND

ED visits for syncope are common, yet the impact on health care utilization is relatively unknown.

METHODS

A total of 51,831 consecutive patients presented to the ED with a primary diagnosis of syncope (International Classification of Diseases-9 code 780.2 and International Classification of Diseases-10 code R55) in Alberta, Canada from 2006 to 2014. Outcomes included 30-day syncope ED and hospital readmissions; 30-day and 1-year mortality; and annual inpatient, outpatient, physician, and drug costs, cumulative.

RESULTS

Of adults presenting to the ED, 6.6% were hospitalized and discharged with a primary diagnosis of syncope (Cohort 1), 8.7% were hospitalized and discharged with a primary diagnosis other than syncope (Cohort 2), and 84.7% were discharged home with a syncope diagnosis (Cohort 3). The 30-day ED revisits for syncope varied from 1.2% (Cohort 2) to 2.4% (Cohort 1) (p < 0.001), and readmission rates were <1% among cohorts. Short- and long-term mortality rates were highest for Cohort 2 and lowest for Cohort 3 (30-day mortality: Cohort 1 of 1.2%, Cohort 2 of 5.2%, Cohort 3 of 0.4%; p < 0.001) (1-year mortality: Cohort 1 of 9.2%, Cohort 2 of 17.7%, Cohort 3 of 3.0%; p < 0.001). Total cost of syncope presentations was $530.6 million (Cohort 1: $75.3 million; $29,519/patient, Cohort 2: $138.1 million; $42,042/patient, Cohort 3: $317.3 million; $9,963/patient; p<0.001).

CONCLUSIONS

Most patients with syncope presenting to the ED were discharged and had a favorable prognosis but overall costs were high compared with patients hospitalized. Further research is needed for cost-saving strategies across all cohorts.

Vascular Causes of Syncope: An Emergency Medicine Review

BACKGROUND

Syncope is a common emergency department (ED) complaint, accounting for 2% of visits annually. A wide variety of etiologies can result in syncope, and vascular causes may be deadly.

OBJECTIVE

This review evaluates vascular causes of syncope and their evaluation and management in the ED.

DISCUSSION

Syncope is defined by a brief loss of consciousness with loss of postural tone and complete, spontaneous recovery without medical intervention. Causes include cardiac, vasovagal, orthostatic, neurologic, medication-related, and idiopathic, and most cases of syncope will not receive a specific diagnosis pertaining to the cause. Emergency physicians are most concerned with life-threatening causes such as dysrhythmia and obstruction, and electrocardiogram is a primary means of evaluation. However, vascular etiologies can result in patient morbidity and mortality. These conditions include pulmonary embolism, subclavian steal, aortic dissection, cerebrovascular disease, intracerebral hemorrhage, carotid/vertebral dissection, and abdominal aortic aneurysm. A focused history and physical examination can assist emergency physicians in determining the need for further testing and management.

CONCLUSIONS

Syncope is common and may be the result of a deadly condition. The emergency physician, through history and physical examination, can determine the need for further evaluation and resuscitation of these patients, with consideration of vascular etiologies of syncope.

Knowledge translation of the American College of Emergency Physicians' clinical policy on syncope using computerized clinical decision support

Aims

To influence physician practice behavior after implementation of a computerized clinical decision support system (CDSS) based upon the recommendations from the 2007 ACEP Clinical Policy on Syncope.

Methods

This was a pre-post intervention with a prospective cohort and retrospective controls. We conducted a medical chart review of consecutive adult patients with syncope. A computerized CDSS prompting physicians to explain their decision-making regarding imaging and admission in syncope patients based upon ACEP Clinical Policy recommendations was embedded into the emergency department information system (EDIS). The medical records of 410 consecutive adult patients presenting with syncope were reviewed prior to implementation, and 301 records were reviewed after implementation. Primary outcomes were physician practice behavior demonstrated by admission rate and rate of head computed tomography (CT) imaging before and after implementation.

Results

There was a significant difference in admission rate pre- and post-intervention (68.1% vs. 60.5% respectively, p = 0.036). There was no significant difference in the head CT imaging rate pre- and post-intervention (39.8% vs. 43.2%, p = 0.358). There were seven physicians who saw ten or more patients during the pre- and post-intervention. Subset analysis of these seven physicians’ practice behavior revealed a slight significant difference in the admission rate pre- and post-intervention (74.3% vs. 63.9%, p = 0.0495) and no significant difference in the head CT scan rate pre- and post-intervention (42.9% vs. 45.4%, p = 0.660).

Conclusions

The introduction of an evidence-based CDSS based upon ACEP Clinical Policy recommendations on syncope correlated with a change in physician practice behavior in an urban academic emergency department. This change suggests emergency medicine clinical practice guideline recommendations can be incorporated into the physician workflow of an EDIS to enhance the quality of practice.