- Email: [email protected]
299 Repeat Lactate Value, Not Lactate Clearance, Best Predicts 24-Hour Mortality in Injured Patients
Research Forum Abstracts then the iCXR diagnostic approach, nowadays considered the standard of care. When the analyses of all patients enrolled will be completed (expected in June 2015), we will able to compare the diagnostic accuracy of the iLUS and iCXR diagnostic protocols in a significantly larger sample of patients.
298
End-Tidal Carbon Dioxide Monitoring and the Possibility of Return of Spontaneous Circulation During Out-ofHospital Cardiac Arrest: A Population-Based Study
Cheng P-L, Su Y-C/Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Chiayi County, Taiwan
Background: End-tidal carbon dioxide (ETCO2) monitoring is recommended as a chest compression performance indicator during cardiac arrest. However, the frequency of use during out-of-hospital cardiac arrest (OHCA) and its benefits have never been evaluated in real clinical situations. Study Objective: We investigated OHCA patients in Taiwan to evaluate the frequency of ETCO2 use and the effects on return of spontaneous circulation (ROSC). Methods: We utilized a sampled National Health Insurance claims database containing one million beneficiaries. All adult beneficiaries older than 18 years presented with OHCA and received chest compression between January 1, 2005 and December 31, 2012 were enrolled. We further identified patients with ETCO2 use and matched each one with twenty patients without ETCO2 use based on their propensity scores. The Logistic regression model was applied to compare the odds ratios (ORs) of ROSC in the matched cohorts. Results: A total of 5041 OHCA patients were enrolled. The frequency of ETCO2 use is increased after 2010 but still is low. After matching, 59 patients with ETCO2 use and 1180 without were selected. The adjusted OR of ROSC is significantly increased (2.89; 95% CI 1.53-5.48). Conclusion: Patients with ETCO2 use may benefit from better chest compression performance which in turn results in higher possibility of ROSC. However, the overall use of ETCO2 is still low despite strong recommendation in the guidelines.
299
Repeat Lactate Value, Not Lactate Clearance, Best Predicts 24-Hour Mortality in Injured Patients
Dezman ZDW, Comer AC, Smith GS, Narayan M, Scalea TM, Hirshon JM/University of Maryland School of Medicine, Baltimore, MD; National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD
Study Objective: Injury is the most common cause of death in people between 1 and 45 years of age. The resuscitation of injured patients is often guided by serial venous lactate measurements. Lactate clearance, calculated as a relative percent change, is the most commonly used method of determining a patient’s response to resuscitative efforts, yet no study has compared the different approaches to interpreting serial lactates. The purpose of this study is to determine the best model for predicting 24hour mortality, using serial lactate values from a large undifferentiated population of injured patients. Methods: The subjects for this single-center retrospective cohort study were patients admitted to the R Adams Cowley Shock Trauma Center directly from the scene of injury between January 2010 and December 2012. All patients underwent resuscitation according to our institutional guidelines, with venous lactate concentrations measured on arrival and again 6 hours later. Documentation of death at 24 hours, lactate levels, and timing of test results was extracted from patient records. All patients in the study had (1) two lactate measurements within 24 hours after admission and (2) an elevated initial lactate level (3.0 mmol/L). Patients were excluded if they were transfers from another facility, died within 15 minutes after arrival, had incomplete records, or did not have an elevated initial lactate level or serial lactate measurements. Serial lactate measurements were used to calculate five models of clearance for each subject: actual value of the repeat level (Lactate2, mmol/ L), absolute clearance (Lactate1‒Lactate2, mmol), relative clearance ([Lactate1‒ Lactate2]/Lactate1, %), absolute rate ([Lactate1‒Lactate2]/[timeLactate1-lactate2], mmol/ hr), and relative rate ([Lactate1‒Lactate2]/[Lactate1 x timeLactate1-Lactate2], %/hr). A receiver operating curve for 24-hour mortality was calculated for each model. We compared the different approaches using the area under these receiver operating curves (AUC). AUCs were compared using Delong’s method (two-tailed, a¼0.05) and the cut-off values that optimized sensitivity and specificity for each model were included.
S108 Annals of Emergency Medicine
Results: A total of 3,395 patients had an elevated lactate level on admission (mean¼5.592.88 mmol/L), followed by a second lactate (mean¼2.552.06 mmol/L). The value of the repeat lactate measurement had the highest AUC (AUC¼0.743, [Table]). This was significantly higher than absolute clearance (P ¼ .005), absolute rate (P < .0001), and relative clearance rate (P < .0001). There was a trend toward significance when compared with relative clearance (P ¼ .193). Table. Comparison of AUCs and Cutoffs of Models Used to Calculate Lactate Clearance Clearance Model Absolute clearance Absolute clearance rate Relative clearance Relative clearance rate Actual value of repeat lactate
AUC
Optimal Cutoff
0.624 0.509 0.688 0.528 0.743
1.7 mmol/L 0.1 mmol/L/hr 31.3% 3.0%/hr 3.8 mmol/L
Conclusions: In this large single-center study of injured patients with serial lactate measurements, the value of the repeated lactate had the greatest ability to predict 24hour mortality. This simpler approach both predicts mortality the best and is easy to interpret.
300
Focused Cardiac Sonography During Resuscitation of Cardiac Arrest Patients in the Emergency Department
Luna AC, Babasa R, Gaerlan FJ/St. Luke’s Medical Center, Quezon City, Philippines
Study Objective: Focused sonography may be considered an extension of the physical examination as it allows accurate and rapid recognition of critical conditions. Multiple studies have shown evidence that focused cardiac sonography is a feasible adjunct to cardiopulmonary resuscitation. This study, which is the first known research on this topic in the Philippines, investigated the utility of cardiac sonography performed by emergency physicians to predict the resuscitation outcomes of cardiac arrest patients. The study likewise aimed to determine the utility of ultrasound to direct the management of patients in cardiac arrest and to determine the possible etiology of the arrest. Methods: This is a prospective cohort study which included a convenience sample of cardiac arrest patients seen in the emergency department during the 11-month study period. These patients underwent focused cardiac sonography through the subxiphoid view at the end of each 2-minute cycle during resuscitation. The presence of cardiac activity as well as the possible etiology of the arrest was also noted. End points analyzed as possible predictors of resuscitation included patients’ clinical profile, pre hospital transit time, presenting cardiac rhythm, cardiac activity on sonography, and length of emergency department (ED) resuscitation. Data were then analyzed through MEDCALC and SPSS. Results: A total of 53 patients were included in the study. The results showed that cardiac activity when correlated to return of spontaneous circulation, 24-hour survival and survival to hospital discharge has a sensitivity of 59.1, 66.7 and 50, respectively while the specificity was 64.5, 59.1, and 54.9 accordingly. The negative predictive value for all clinical outcomes was higher than the positive predictive value suggesting that the absence of cardiac activity is a poor prognosticating factor. Among the other patient factors analyzed, number of arrests and transit time were the only variables significantly associated with survival. No possible etiology of the arrest was seen in all 53 patients. Nineteen patients were found to be in PEA but with presence of cardiac activity on ultrasound. Three of these 19 patients were given Atropine and inotropes and all 3 patients achieved return of spontaneous circulation. Conclusion: Although there was no possible etiology of the arrest seen in all patients, this data is important to narrow the differential diagnosis. In addition, the use of inotropes, as the results showed, may be considered in patients found to be in pseudo PEA. Although, the absence of cardiac activity is associated with a poor outcome of resuscitation, it is important that other patient factors are considered. Ultimately, the management of each cardiac arrest patient is unique and dependent on the emergency physician’s clinical judgment.
Volume 66, no. 4s : October 2015
298
End-Tidal Carbon Dioxide Monitoring and the Possibility of Return of Spontaneous Circulation During Out-ofHospital Cardiac Arrest: A Population-Based Study
Cheng P-L, Su Y-C/Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Chiayi County, Taiwan
Background: End-tidal carbon dioxide (ETCO2) monitoring is recommended as a chest compression performance indicator during cardiac arrest. However, the frequency of use during out-of-hospital cardiac arrest (OHCA) and its benefits have never been evaluated in real clinical situations. Study Objective: We investigated OHCA patients in Taiwan to evaluate the frequency of ETCO2 use and the effects on return of spontaneous circulation (ROSC). Methods: We utilized a sampled National Health Insurance claims database containing one million beneficiaries. All adult beneficiaries older than 18 years presented with OHCA and received chest compression between January 1, 2005 and December 31, 2012 were enrolled. We further identified patients with ETCO2 use and matched each one with twenty patients without ETCO2 use based on their propensity scores. The Logistic regression model was applied to compare the odds ratios (ORs) of ROSC in the matched cohorts. Results: A total of 5041 OHCA patients were enrolled. The frequency of ETCO2 use is increased after 2010 but still is low. After matching, 59 patients with ETCO2 use and 1180 without were selected. The adjusted OR of ROSC is significantly increased (2.89; 95% CI 1.53-5.48). Conclusion: Patients with ETCO2 use may benefit from better chest compression performance which in turn results in higher possibility of ROSC. However, the overall use of ETCO2 is still low despite strong recommendation in the guidelines.
299
Repeat Lactate Value, Not Lactate Clearance, Best Predicts 24-Hour Mortality in Injured Patients
Dezman ZDW, Comer AC, Smith GS, Narayan M, Scalea TM, Hirshon JM/University of Maryland School of Medicine, Baltimore, MD; National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD
Study Objective: Injury is the most common cause of death in people between 1 and 45 years of age. The resuscitation of injured patients is often guided by serial venous lactate measurements. Lactate clearance, calculated as a relative percent change, is the most commonly used method of determining a patient’s response to resuscitative efforts, yet no study has compared the different approaches to interpreting serial lactates. The purpose of this study is to determine the best model for predicting 24hour mortality, using serial lactate values from a large undifferentiated population of injured patients. Methods: The subjects for this single-center retrospective cohort study were patients admitted to the R Adams Cowley Shock Trauma Center directly from the scene of injury between January 2010 and December 2012. All patients underwent resuscitation according to our institutional guidelines, with venous lactate concentrations measured on arrival and again 6 hours later. Documentation of death at 24 hours, lactate levels, and timing of test results was extracted from patient records. All patients in the study had (1) two lactate measurements within 24 hours after admission and (2) an elevated initial lactate level (3.0 mmol/L). Patients were excluded if they were transfers from another facility, died within 15 minutes after arrival, had incomplete records, or did not have an elevated initial lactate level or serial lactate measurements. Serial lactate measurements were used to calculate five models of clearance for each subject: actual value of the repeat level (Lactate2, mmol/ L), absolute clearance (Lactate1‒Lactate2, mmol), relative clearance ([Lactate1‒ Lactate2]/Lactate1, %), absolute rate ([Lactate1‒Lactate2]/[timeLactate1-lactate2], mmol/ hr), and relative rate ([Lactate1‒Lactate2]/[Lactate1 x timeLactate1-Lactate2], %/hr). A receiver operating curve for 24-hour mortality was calculated for each model. We compared the different approaches using the area under these receiver operating curves (AUC). AUCs were compared using Delong’s method (two-tailed, a¼0.05) and the cut-off values that optimized sensitivity and specificity for each model were included.
S108 Annals of Emergency Medicine
Results: A total of 3,395 patients had an elevated lactate level on admission (mean¼5.592.88 mmol/L), followed by a second lactate (mean¼2.552.06 mmol/L). The value of the repeat lactate measurement had the highest AUC (AUC¼0.743, [Table]). This was significantly higher than absolute clearance (P ¼ .005), absolute rate (P < .0001), and relative clearance rate (P < .0001). There was a trend toward significance when compared with relative clearance (P ¼ .193). Table. Comparison of AUCs and Cutoffs of Models Used to Calculate Lactate Clearance Clearance Model Absolute clearance Absolute clearance rate Relative clearance Relative clearance rate Actual value of repeat lactate
AUC
Optimal Cutoff
0.624 0.509 0.688 0.528 0.743
1.7 mmol/L 0.1 mmol/L/hr 31.3% 3.0%/hr 3.8 mmol/L
Conclusions: In this large single-center study of injured patients with serial lactate measurements, the value of the repeated lactate had the greatest ability to predict 24hour mortality. This simpler approach both predicts mortality the best and is easy to interpret.
300
Focused Cardiac Sonography During Resuscitation of Cardiac Arrest Patients in the Emergency Department
Luna AC, Babasa R, Gaerlan FJ/St. Luke’s Medical Center, Quezon City, Philippines
Study Objective: Focused sonography may be considered an extension of the physical examination as it allows accurate and rapid recognition of critical conditions. Multiple studies have shown evidence that focused cardiac sonography is a feasible adjunct to cardiopulmonary resuscitation. This study, which is the first known research on this topic in the Philippines, investigated the utility of cardiac sonography performed by emergency physicians to predict the resuscitation outcomes of cardiac arrest patients. The study likewise aimed to determine the utility of ultrasound to direct the management of patients in cardiac arrest and to determine the possible etiology of the arrest. Methods: This is a prospective cohort study which included a convenience sample of cardiac arrest patients seen in the emergency department during the 11-month study period. These patients underwent focused cardiac sonography through the subxiphoid view at the end of each 2-minute cycle during resuscitation. The presence of cardiac activity as well as the possible etiology of the arrest was also noted. End points analyzed as possible predictors of resuscitation included patients’ clinical profile, pre hospital transit time, presenting cardiac rhythm, cardiac activity on sonography, and length of emergency department (ED) resuscitation. Data were then analyzed through MEDCALC and SPSS. Results: A total of 53 patients were included in the study. The results showed that cardiac activity when correlated to return of spontaneous circulation, 24-hour survival and survival to hospital discharge has a sensitivity of 59.1, 66.7 and 50, respectively while the specificity was 64.5, 59.1, and 54.9 accordingly. The negative predictive value for all clinical outcomes was higher than the positive predictive value suggesting that the absence of cardiac activity is a poor prognosticating factor. Among the other patient factors analyzed, number of arrests and transit time were the only variables significantly associated with survival. No possible etiology of the arrest was seen in all 53 patients. Nineteen patients were found to be in PEA but with presence of cardiac activity on ultrasound. Three of these 19 patients were given Atropine and inotropes and all 3 patients achieved return of spontaneous circulation. Conclusion: Although there was no possible etiology of the arrest seen in all patients, this data is important to narrow the differential diagnosis. In addition, the use of inotropes, as the results showed, may be considered in patients found to be in pseudo PEA. Although, the absence of cardiac activity is associated with a poor outcome of resuscitation, it is important that other patient factors are considered. Ultimately, the management of each cardiac arrest patient is unique and dependent on the emergency physician’s clinical judgment.
Volume 66, no. 4s : October 2015