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392 The Use of Lactate Levels to Distinguish Grand Mal Seizures From Syncope in Patients Presenting With Loss of Consciousness
Research Forum Abstracts populations, clinician judgment in ordering the test, levels of comfort with interpretation of the test on the part of reading radiologists, evolution of the actual scanning procedure itself, or a combination of these or other factors.
391
What Is the Value of a Chest Radiography in the Emergency Department Evaluation of SIRS Without Respiratory Abnormalities? A Retrospective Review
Ryles A, Lalani F, Kochert E, Stahlman B/York Hospital, York, PA
Background: Systemic Inflammatory Response Syndrome (SIRS) criteria are used to classify and initiate care for patients with presumed infection. However, SIRS is also present with noninfectious causes such as burns, pancreatitis and hemorrhage. More often, SIRS implies sepsis. Since pneumonia is the most common source of sepsis, chest radiography (CXR) are routinely obtained in the evaluation of patients with SIRS, whether or not they demonstrate respiratory abnormalities (RA). Evidence is lacking that demonstrates the utility of ordering CXRs for patients who present with SIRS criteria but have no respiratory abnormalities. Study Objectives: Our objective is to determine the prevalence of pneumonia and the predictive properties of CXR in the evaluation of SIRS for patients with and without respiratory abnormalities. We hypothesize that patients who present to the emergency department (ED) with SIRS criteria and no RA have a lower prevalence of pneumonia and, therefore, do not require a CXR on initial work-up. Methods: In an institutional review board-approved retrospective chart review conducted in a community ED, consecutive patients with CXR in the ED in December 2010 were identified by billing codes. Patients with 2 or more SIRS criteria were included. Patients were excluded with age less than 18, known pneumonia at presentation, chronic abnormal CXR, or DNR/comfort care only. A standardized data collection sheet was used. Subjects were stratified by the presence or absence of RAs, defined a priori as dyspnea, cough, chest pain, hypoxia (Sats ⬍90% on RA), tachypnea (RR⬎20), or focal lung findings on exam. The hospital discharge diagnosis was used as the gold standard to determine the presence or absence of pneumonia. Radiology interpretation of CXRs as a new infiltrate, opacity, or effusion was considered to be a positive test result. All other interpretations were considered negative test results. Descriptive statistics and Fisher’s exact test were used. Results: 2152 CXRs were obtained in the ED in December 2010. 1053 (49%) of the patients tested with CXR in the ED during the study period were screened, and 193 met inclusion/exclusion criteria. Out of these, 39 (20.2%) had no RAs while 154 had at least one. Pneumonia was diagnosed in 14.9% (95%CI 9.9-21.8%) and 0% (95%CI 0-11.2%) in those with and without respiratory abnormalities, respectively (p⫽0.005). History and physical exam to assess for RAs had a sensitivity of 100% (95% CI 82-100%) and a specificity of 23% (95% CI 17-30%) for the diagnosis of pneumonia. The sensitivity and specificity of CXR in this ED population of patients with SIRS is 65% (95% CI 43-83%) and 86% (95% CI 80-91%), respectively. Of the 39 patients with no RAs, there were 2 CXRs that were false positives for pneumonia and 37 CXRs that were true negatives. No patients in this group were ultimately diagnosed with a pneumonia. Conclusion: The prevalence of pneumonia is low in patients with SIRS without respiratory abnormalities in the ED. History and physical exam outperformed CXR in the ability to predict pneumonia in this population. Chest radiography may not be routinely indicated in the ED evaluation of patients with SIRS and no respiratory abnormalities.
392
The Use of Lactate Levels to Distinguish Grand Mal Seizures From Syncope in Patients Presenting With Loss of Consciousness
Gallagher MR, Hughes M, Betten D, Felton B, Hibbs N, Glynn T/Sparrow Hospital/Michigan State University, Lansing, MI; McLaren Greater Lansing/Michigan State University, Lansing, MI
Study Objectives: Properly diagnosing the cause of loss of consciousness is a critical action in the emergency department (ED) and directly impacts a patient’s treatment plan. Transient lactic acidosis is described by Orringer, et al with patients experiencing seizure activity in the ED. The purpose of this study is to evaluate the effectiveness of a serum lactate level in distinguishing a diagnosis of generalized seizure from other forms of loss of consciousness as well as the time frame which it is applicable. Methods: Patients presenting to Sparrow hospital and McLaren Greater Lansing hospital EDs with a clear diagnosis of generalized seizure or syncope were prospectively enrolled in this institutional review board approved study from
S138 Annals of Emergency Medicine
February-April 2012. Patients were diagnosed, treated and enrolled by an emergency physician. A routine serum lactate level was drawn on patients as soon as possible. Charts were reviewed retrospectively for further data collection and eligibility. Patients were eligible if they had a clear discharge diagnosis and had no other identifiable cause of lactic acidosis. Ineligible patients did not have a consensus diagnosis, could not consent, or had another potential source of lactic acidosis present. The Student T-test was used to evaluate individual lactate levels and the Chi-square test used to analyze a lactate level greater than 2.0mmol/L as a positive test result. Time was a dependent variable in this study. Results: Initial enrollment included 57 patients with 12 excluded due to undetermined final diagnosis. This resulted in a final enrollment of 23 patients with generalized seizure and 22 with syncope. The mean lactate level for seizure versus syncope was statistically significant when drawn within 1.5 hours of the event (4.08 versus 1.67, p⫽0.038) and was insignificant afterwards. Patients with seizure were more likely to have a positive lactate test (⬎2.0 mmol/L) if serum was drawn within 1.5 hours (p⫽0.030) with an odds ratio of 3.4. Nearly 90% of all patients with a lactate ⬎3.5mmol/L had a discharge diagnosis of seizure. No patients with seizure had a lactate ⬎2 mmol/L if drawn after 3 hours. Conclusions: A lactate level drawn soon after the episode of loss of consciousness has predictive value in distinguishing a generalized seizure from syncope in select populations. A higher lactate level is associated with a higher likelihood of seizure activity. Serum lactate appears to peak instantaneously after a seizure and rapidly clears, making it ineffective as a test after 1.5 hours. The test could be used to help diagnose patients in the future with undifferentiated loss of consciousness.
393
Stroke Onset: How Accurate Are Last Known Well Times Obtained Out-of-Hospital
Craig SL, Sanossian N, Starkman S, Liebeskind D, Hamilton S, Stratton S, Koenig W, Pratt F, Saver JL, FAST-MAG Enrolling Physicians and Coordinators/ UCLA, Los Angeles, CA; USC Medical Center, Los Angeles, CA; UCLA Medical Center, Los Angeles, CA; Bracket Data Analysis, San Francisco, CA; Orange County EMS, Tustin, CA; Los Angeles EMS, Santa Fe Springs, CA; Los Angeles EMS, Los Angeles, CA
Study Objective: Several aspects of out-of-hospital stroke care are guided by determination of the last known well time (LKWT), including performance of pre-arrival notification and direct routing to designated stroke receiving hospitals. The accuracy of out-of-hospital-determined LKWT has not been prospectively studied. Method: Los Angeles and Orange County EMS System paramedics screen for stroke using the modified Los Angeles Out-of-hospital Stroke Screen (mLAPSS) which includes LKWT. Patients with LKWT ⬍2 hours are eligible for routing to the nearest Primary Stroke Center (PSC) with bypass of non-PSC and eligible for enrollment in the NIH Field Administration of Stroke Therapy - Magnesium (FASTMAG) study. FAST-MAG is a phase 3 clinical trial of out-of-hospital magnesium sulfate versus placebo initiated ⬍2 hours from symptom onset in acute stroke being performed in 42 emergency medical service systems and 59 receiving hospitals throughout Los Angeles and Orange Counties. We tested the sensitivity and specificity of LKWT obtained in the out-of-hospital setting by paramedics and phone-enrolling physicians compared to the final LKWT obtained after ED arrival. Excellent agreement was defined as within 15 minutes and good agreement as within 30 minutes. Results: Among 1398 consecutive subjects enrolled from 1/2005-12/2011, mean age 69 (⫾14) years old, and 42% were women. Agreement between out-of-hospital and ED-determined LKWT was excellent (within 15 minute range) in 1225/1398 (87.8%) and good or excellent (within 30 minutes) in 1295/1398 (92.8%). In 1346 subjects, the ED-determined LKWT was confirmed ⬍2 hours. The performance of out-of-hospital obtained LKWT ⱕ 2 hours in predicting final ED-determined LKWT ⱕ 2 hours was sensitivity 99% and specificity 97%. Information sources establishing the out-of-hospital LKWT were: the patient in 51%, family members in 46%, and other individuals in 2%. Accuracy of out-of-hospital LKWT did not vary with informant source, accuracy to 15 minutes (p⫽0.305) and 30 minutes (p⫽0.230). Conclusion: In acute stroke patients, last known well times obtained in the outof-hospital setting in a field treatment trial show good concordance with final EDdetermined LKWTs and highly sensitive and specific in identifying patients with symptom onset within the ⱕ 2 hour window for routing to designated Stroke Centers.
Volume , . : October
391
What Is the Value of a Chest Radiography in the Emergency Department Evaluation of SIRS Without Respiratory Abnormalities? A Retrospective Review
Ryles A, Lalani F, Kochert E, Stahlman B/York Hospital, York, PA
Background: Systemic Inflammatory Response Syndrome (SIRS) criteria are used to classify and initiate care for patients with presumed infection. However, SIRS is also present with noninfectious causes such as burns, pancreatitis and hemorrhage. More often, SIRS implies sepsis. Since pneumonia is the most common source of sepsis, chest radiography (CXR) are routinely obtained in the evaluation of patients with SIRS, whether or not they demonstrate respiratory abnormalities (RA). Evidence is lacking that demonstrates the utility of ordering CXRs for patients who present with SIRS criteria but have no respiratory abnormalities. Study Objectives: Our objective is to determine the prevalence of pneumonia and the predictive properties of CXR in the evaluation of SIRS for patients with and without respiratory abnormalities. We hypothesize that patients who present to the emergency department (ED) with SIRS criteria and no RA have a lower prevalence of pneumonia and, therefore, do not require a CXR on initial work-up. Methods: In an institutional review board-approved retrospective chart review conducted in a community ED, consecutive patients with CXR in the ED in December 2010 were identified by billing codes. Patients with 2 or more SIRS criteria were included. Patients were excluded with age less than 18, known pneumonia at presentation, chronic abnormal CXR, or DNR/comfort care only. A standardized data collection sheet was used. Subjects were stratified by the presence or absence of RAs, defined a priori as dyspnea, cough, chest pain, hypoxia (Sats ⬍90% on RA), tachypnea (RR⬎20), or focal lung findings on exam. The hospital discharge diagnosis was used as the gold standard to determine the presence or absence of pneumonia. Radiology interpretation of CXRs as a new infiltrate, opacity, or effusion was considered to be a positive test result. All other interpretations were considered negative test results. Descriptive statistics and Fisher’s exact test were used. Results: 2152 CXRs were obtained in the ED in December 2010. 1053 (49%) of the patients tested with CXR in the ED during the study period were screened, and 193 met inclusion/exclusion criteria. Out of these, 39 (20.2%) had no RAs while 154 had at least one. Pneumonia was diagnosed in 14.9% (95%CI 9.9-21.8%) and 0% (95%CI 0-11.2%) in those with and without respiratory abnormalities, respectively (p⫽0.005). History and physical exam to assess for RAs had a sensitivity of 100% (95% CI 82-100%) and a specificity of 23% (95% CI 17-30%) for the diagnosis of pneumonia. The sensitivity and specificity of CXR in this ED population of patients with SIRS is 65% (95% CI 43-83%) and 86% (95% CI 80-91%), respectively. Of the 39 patients with no RAs, there were 2 CXRs that were false positives for pneumonia and 37 CXRs that were true negatives. No patients in this group were ultimately diagnosed with a pneumonia. Conclusion: The prevalence of pneumonia is low in patients with SIRS without respiratory abnormalities in the ED. History and physical exam outperformed CXR in the ability to predict pneumonia in this population. Chest radiography may not be routinely indicated in the ED evaluation of patients with SIRS and no respiratory abnormalities.
392
The Use of Lactate Levels to Distinguish Grand Mal Seizures From Syncope in Patients Presenting With Loss of Consciousness
Gallagher MR, Hughes M, Betten D, Felton B, Hibbs N, Glynn T/Sparrow Hospital/Michigan State University, Lansing, MI; McLaren Greater Lansing/Michigan State University, Lansing, MI
Study Objectives: Properly diagnosing the cause of loss of consciousness is a critical action in the emergency department (ED) and directly impacts a patient’s treatment plan. Transient lactic acidosis is described by Orringer, et al with patients experiencing seizure activity in the ED. The purpose of this study is to evaluate the effectiveness of a serum lactate level in distinguishing a diagnosis of generalized seizure from other forms of loss of consciousness as well as the time frame which it is applicable. Methods: Patients presenting to Sparrow hospital and McLaren Greater Lansing hospital EDs with a clear diagnosis of generalized seizure or syncope were prospectively enrolled in this institutional review board approved study from
S138 Annals of Emergency Medicine
February-April 2012. Patients were diagnosed, treated and enrolled by an emergency physician. A routine serum lactate level was drawn on patients as soon as possible. Charts were reviewed retrospectively for further data collection and eligibility. Patients were eligible if they had a clear discharge diagnosis and had no other identifiable cause of lactic acidosis. Ineligible patients did not have a consensus diagnosis, could not consent, or had another potential source of lactic acidosis present. The Student T-test was used to evaluate individual lactate levels and the Chi-square test used to analyze a lactate level greater than 2.0mmol/L as a positive test result. Time was a dependent variable in this study. Results: Initial enrollment included 57 patients with 12 excluded due to undetermined final diagnosis. This resulted in a final enrollment of 23 patients with generalized seizure and 22 with syncope. The mean lactate level for seizure versus syncope was statistically significant when drawn within 1.5 hours of the event (4.08 versus 1.67, p⫽0.038) and was insignificant afterwards. Patients with seizure were more likely to have a positive lactate test (⬎2.0 mmol/L) if serum was drawn within 1.5 hours (p⫽0.030) with an odds ratio of 3.4. Nearly 90% of all patients with a lactate ⬎3.5mmol/L had a discharge diagnosis of seizure. No patients with seizure had a lactate ⬎2 mmol/L if drawn after 3 hours. Conclusions: A lactate level drawn soon after the episode of loss of consciousness has predictive value in distinguishing a generalized seizure from syncope in select populations. A higher lactate level is associated with a higher likelihood of seizure activity. Serum lactate appears to peak instantaneously after a seizure and rapidly clears, making it ineffective as a test after 1.5 hours. The test could be used to help diagnose patients in the future with undifferentiated loss of consciousness.
393
Stroke Onset: How Accurate Are Last Known Well Times Obtained Out-of-Hospital
Craig SL, Sanossian N, Starkman S, Liebeskind D, Hamilton S, Stratton S, Koenig W, Pratt F, Saver JL, FAST-MAG Enrolling Physicians and Coordinators/ UCLA, Los Angeles, CA; USC Medical Center, Los Angeles, CA; UCLA Medical Center, Los Angeles, CA; Bracket Data Analysis, San Francisco, CA; Orange County EMS, Tustin, CA; Los Angeles EMS, Santa Fe Springs, CA; Los Angeles EMS, Los Angeles, CA
Study Objective: Several aspects of out-of-hospital stroke care are guided by determination of the last known well time (LKWT), including performance of pre-arrival notification and direct routing to designated stroke receiving hospitals. The accuracy of out-of-hospital-determined LKWT has not been prospectively studied. Method: Los Angeles and Orange County EMS System paramedics screen for stroke using the modified Los Angeles Out-of-hospital Stroke Screen (mLAPSS) which includes LKWT. Patients with LKWT ⬍2 hours are eligible for routing to the nearest Primary Stroke Center (PSC) with bypass of non-PSC and eligible for enrollment in the NIH Field Administration of Stroke Therapy - Magnesium (FASTMAG) study. FAST-MAG is a phase 3 clinical trial of out-of-hospital magnesium sulfate versus placebo initiated ⬍2 hours from symptom onset in acute stroke being performed in 42 emergency medical service systems and 59 receiving hospitals throughout Los Angeles and Orange Counties. We tested the sensitivity and specificity of LKWT obtained in the out-of-hospital setting by paramedics and phone-enrolling physicians compared to the final LKWT obtained after ED arrival. Excellent agreement was defined as within 15 minutes and good agreement as within 30 minutes. Results: Among 1398 consecutive subjects enrolled from 1/2005-12/2011, mean age 69 (⫾14) years old, and 42% were women. Agreement between out-of-hospital and ED-determined LKWT was excellent (within 15 minute range) in 1225/1398 (87.8%) and good or excellent (within 30 minutes) in 1295/1398 (92.8%). In 1346 subjects, the ED-determined LKWT was confirmed ⬍2 hours. The performance of out-of-hospital obtained LKWT ⱕ 2 hours in predicting final ED-determined LKWT ⱕ 2 hours was sensitivity 99% and specificity 97%. Information sources establishing the out-of-hospital LKWT were: the patient in 51%, family members in 46%, and other individuals in 2%. Accuracy of out-of-hospital LKWT did not vary with informant source, accuracy to 15 minutes (p⫽0.305) and 30 minutes (p⫽0.230). Conclusion: In acute stroke patients, last known well times obtained in the outof-hospital setting in a field treatment trial show good concordance with final EDdetermined LKWTs and highly sensitive and specific in identifying patients with symptom onset within the ⱕ 2 hour window for routing to designated Stroke Centers.
Volume , . : October