Impact of early coronary angiography on the survival to discharge after out-of-hospital cardiac arrest

OBJECTIVE: Acute myocardial infarction is a major cause of out-of-hospital cardiac arrest (OHCA). Coronary angiography (CAG) enables diagnostic confirmation of coronary artery disease and subsequent revascularization, which might improve the prognosis of OHCA survivors. Non-randomized data has shown a favorable impact of CAG on prognosis for this population. However, the optimal timing of CAG has been debated. METHODS: The clinical outcomes of 607 OHCA patients registered in CAPTURES (Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiologic Surveillance), a nationwide multicenter registry performed in 27 hospitals, were analyzed. Early CAG was defined as CAG performed within 24 hours of emergency department admission. The primary outcome was survival to discharge, with neurologically favorable status defined by cerebral performance category scores ≤2. RESULTS: Compared to patients without CAG (n=469), patients who underwent early CAG (n=138) were younger, more likely to be male, and more likely to have received bystander cardiopulmonary resuscitation, pre-hospital defibrillation, and revascularization (P<0.01 for all). Analysis of 115 propensity score-matched pairs showed that early CAG is associated with a 2.3-fold increase in survival to discharge with neurologically favorable status (P<0.001, all). Survival to discharge increased consistently according to the time interval between emergency department visit and CAG (P<0.05). CONCLUSION: Early CAG of OHCA patients was associated with better survival and favorable neurologic outcomes at discharge. However, there was no clear time threshold for CAG that predicted survival to discharge.

Developing and Application of a Novel Triage Tag

PURPOSE: Triage tags help prioritize the treatment for disaster patients based on the severity of the illness and help distribute limited resources during a time of disaster. In this study, we developed a novel triage tag and evaluated its feasibility during a hospital-based disaster drill. METHODS: For the first stage, we developed a new triage tag. The most commonly used triage tags (Medical Emergency Triage-TAG and SMART tag) were analyzed. We reassembled their advantages and invented a novel triage tag (NT tag). The second stage involved an evaluation of the quality of NT tag. The NT tag was used in a hospital-based disaster drill held in a single center with 22 mock patients. After the drill, hospital staffs were asked to complete a questionnaire which included visibility, comprehensibility, and ease of use with respect to the new NT tag. A five-category Likert scale was used to quantify the answer. RESULTS: The NT tag was successfully developed considering 6 quality indexes: visibility, expandability, flexibility, solidity, space, and fixity. Forty-two out of ninety (46.7%) subjects answered the questionnaire. Approximately 21% of participants had previous disaster drill experience and 33% had previous education of the SMART triage system. The visibility scale of the severity category was on average 3.3 (standard deviation (SD): 1.0), the comprehensiveness of the severity category was 3.6 (SD:0.9), the ease to understand patient information was 2.2-4.2, the ease to follow up symptoms and vital signs was 2.3-4.1. Eighty and percent of participants preferred to use the NT tag in a future disaster situation or disaster drill. CONCLUSION: We successfully developed a novel triage tag. The NT tag showed moderate feasibility.

Emergency Department Workers' Perceptions of Effectiveness and Reported Compliance of Infection Control Measures after Middle East Respiratory Syndrome Outbreaks

PURPOSE: Middle East respiratory syndrome (MERS) outbreaks occurred in Korea during the year 2015, with the involvement of 186 patients in a relatively short period of time. The epidemiological pattern in South Korea was hospital-associated. Infection control plans for all hospitals were implemented to stop the spread of and to protect the healthcare workers from MERS infection. Such enhanced guidelines for infection control measures might affect healthcare workers. The purpose of this study was to determine the changes of tertiary emergency department healthcare workers' perception and compliance to hand hygiene and personal protective equipment (PPE) before and after the MERS outbreak. METHODS: A written questionnaire was administered to members in the emergency department at Samsung Medical Center. Participants were asked to rate the combined overall effectiveness of hand hygiene and PPE and to report their compliance on a 5-point scale. This survey was conducted between 11th and 26th of September 2015. RESULTS: The total number of participants was 123. Perception of effectiveness before and after the MERS outbreak was improved on hand hygiene, N-95 masks, gowns, eye protection, and gloves, except surgical masks (3.65 vs. 3.68, p=0.714). Respondents showed a statistically higher compliance with hand washing and PPE. Compliance with hand hygiene and PPE showed a dependency on their patients' symptoms; symptoms of fever or fever with upper respiratory symptoms were reported with statistically increased compliance, with the exception of surgical masks. CONCLUSION: Infection control measures except surgical masks were perceived to be more effective post the MERS outbreaks. The emergency department's workers reported increased compliance on hand hygiene and PPE, except surgical masks.

A Survey of Emergency Department Health Care Provider on Awareness of Elder Abuse

PURPOSE: The population of senior citizens is rapidly growing in Korea, and this would inevitably result in the increase of elder abuse. This study was designed to survey healthcare providers in the emergency department, who may have a high probability of coming into contact with abused senior citizens, on the awareness of elder abuse, and to evaluate the level of legal knowledge and standard of education amongst these care providers. METHODS: This study was a descriptive, cross-sectional survey research and was made for doctors and nurses with at least a one-year experience working in an emergency department at a university hospital in Seoul. A total of 142 participants were included for analysis. RESULTS: Approximately 69.7% (n=99) of participants were relatively well aware of the obligation to report an elder abuse case. However, only 17.6% (n=25) of participants were aware of the method to file a report. Moreover, only 8.0% (n=11) of participants knew the provisions on punishing for not reporting. Only 15% (n=22) of participants received proper education relating to elder abuse after getting hired. Participants who received the education after getting hired have a better knowledge about elder abuse than those who did not receive the education (p=0.001). Participants who watch press reports about elder abuse showed to have better legal knowledge than those who do not watch such reports (p=0.012). CONCLUSION: With regard to participants' level of awareness of the severity according to the type of abuse, physical abuse was seen as the most serious (4.22), followed by neglect (3.52), abandonment (3.18), emotional abuse (2.66), sexual abuse (2.61), and financial abuse (2.27).

The Change of Surface Temperature in Healing Process of Wound and Burn in Porcine Model

PURPOSE: The goal of wound managements are to prevent further tissue injury during dressing changes, and absorb the excessive exudates, provide moist condition, reduce the infection. But the usual dressing methods have several limitations to serve the information about wound surface environment. Moist, pressure, temperature, pH are the important factors that give us the information about the healing process phase, speed of healing, & the risk of infection. METHODS: We made full thickness wounds & burn on porcine model, then assessed the surface temperature intermittently until repithelialization were completed, and size measurement were done with Image Pro Plus 6.0. RESULTS: In wound areas, the surface temperature was lowest at post operation #1 day, then slightly increased till POD #21 days, and again down slope curvature. In burn area, the surface temperature was highest at POD #1 day, then slightly decreased till POD # 21 days, and more fall curvature. Modern sensing technology along with wireless radio frequency communication technology is posed to make significant advances in wound management. Our result will be a basic data for the future researches about the surface temperature monitor to detect the early infection and the intervention to modulate the surface temperature to increase the rate of epithelialization. CONCLUSION: The result of the correlation between the surface temperature and area reduction have weak or moderate negative Pearson correlation coefficient.

Part 1. The update process and highlights: 2015 Korean Guidelines for Cardiopulmonary Resuscitation

No abstract available.

Part 2. Adult basic life support: 2015 Korean Guidelines for Cardiopulmonary Resuscitation

No abstract available.

Upper airway obstruction resulting from acute mucosal injury induced by direct ingestion of sodium picosulfate/magnesium citrate powder

A 59-year-old man presented to the emergency department with a chief complaint of sore throat after swallowing sodium picosulfate/magnesium citrate powder for bowel preparation, without first dissolving it in water. The initial evaluation showed significant mucosal injury involving the oral cavity, pharynx, and epiglottis. Endotracheal intubation was performed for airway protection in the emergency department, because the mucosal swelling resulted in upper airway compromise. After conservative treatment in the intensive care unit, he underwent tracheostomy because stenosis of the supraglottic and subglottic areas was not relieved. The tracheostomy tube was successfully removed after confirming recovery, and he was discharged 3 weeks after admission.

The Relationship between EEG Findings and Prognosis in Out-of-Hospital Cardiac Arrest Patients during Therapeutic Hypothermia

PURPOSE: Prediction of neurologic outcome in survivors after cardiac arrest is difficult. In particular, since therapeutic hypothermia has emerged as the standard treatment for post cardiac arrest syndrome, the prediction has been more difficult. Methods for prediction of neurologic prognosis include the general neurologic examination, SSEPs, EEG, serum biomarkers, and so on. Among these, EEG was recommended for detection of non-convulsive seizure since early phase of post cardiac arrest syndrome. However, the relationship between EEG finding and neurologic outcome is not yet clear. METHODS: We conducted a retrospective observational study using a prospectively collected hypothermia database. We collected EEG findings during hypothermia and other data from January 2010 to December 2012. The EEG findings were classified according to five patterns as extremely low voltage, continuous slow wave, burst suppression, status epilepticus, and other. We analyzed the relationship between EEG pattern and one-month CPC score after cardiac arrest. RESULTS: During the study period, 121 patients were enrolled in the hypothermia database. Among these patients, 84 patients underwent EEG during hypothermia and were enrolled. The EEG patterns of enrolled patients were 20 extremely low voltage, 39 generalized slow wave, 15 burst suppression, 8 status epilepticus, and 2 alpha coma. None of the periodic, status eplilepticus, and alpha coma pattern patients showed a good neurologic outcome (CPC 1 or 2). Two of 20 extremely low voltage and 28 of 39 continuous slow wave pattern patients recovered to good neurologic outcome. CONCLUSION: Burst suppression and status epilepticus EEG pattern during hypothermia treatment showed an association with poor neurologic outcome.

The Relationship between EEG Findings and Prognosis in Out-of-Hospital Cardiac Arrest Patients during Therapeutic Hypothermia

PURPOSE: Prediction of neurologic outcome in survivors after cardiac arrest is difficult. In particular, since therapeutic hypothermia has emerged as the standard treatment for post cardiac arrest syndrome, the prediction has been more difficult. Methods for prediction of neurologic prognosis include the general neurologic examination, SSEPs, EEG, serum biomarkers, and so on. Among these, EEG was recommended for detection of non-convulsive seizure since early phase of post cardiac arrest syndrome. However, the relationship between EEG finding and neurologic outcome is not yet clear. METHODS: We conducted a retrospective observational study using a prospectively collected hypothermia database. We collected EEG findings during hypothermia and other data from January 2010 to December 2012. The EEG findings were classified according to five patterns as extremely low voltage, continuous slow wave, burst suppression, status epilepticus, and other. We analyzed the relationship between EEG pattern and one-month CPC score after cardiac arrest. RESULTS: During the study period, 121 patients were enrolled in the hypothermia database. Among these patients, 84 patients underwent EEG during hypothermia and were enrolled. The EEG patterns of enrolled patients were 20 extremely low voltage, 39 generalized slow wave, 15 burst suppression, 8 status epilepticus, and 2 alpha coma. None of the periodic, status eplilepticus, and alpha coma pattern patients showed a good neurologic outcome (CPC 1 or 2). Two of 20 extremely low voltage and 28 of 39 continuous slow wave pattern patients recovered to good neurologic outcome. CONCLUSION: Burst suppression and status epilepticus EEG pattern during hypothermia treatment showed an association with poor neurologic outcome.

Survival and Neurologic Outcomes of Out-of-Hospital Cardiac Arrest Patients Who Were Transferred after Return of Spontaneous Circulation for Integrated Post-Cardiac Arrest Syndrome Care: The Another Feasibility of the Cardiac Arrest Center

It has been proven that safety and efficiency of out-of-hospital cardiac arrest (OHCA) patients is transported to specialized hospitals that have the capability of performing therapeutic hypothermia (TH). However, the outcome of the patients who have been transferred after return of spontaneous circulation (ROSC) has not been well evaluated. We conducted a retrospective observational study between January 2010 to March 2012. There were primary outcomes as good neurofunctional status at 1 month and the secondary outcomes as the survivals at 1 month between Samsung Medical Center (SMC) group and transferred group. A total of 91 patients were enrolled this study. There was no statistical difference between good neurologic outcomes between both groups (38% transferred group vs. 40.6% SMC group, P=0.908). There was no statistical difference in 1 month survival between the 2 groups (66% transferred group vs. 75.6% SMC group, P=0.318). In the univariate and multivariate models, the ROSC to induction time and the induction time had no association with good neurologic outcomes. The good neurologic outcome and survival at 1 month had no significant differences between the 2 groups. This finding suggests the possibility of integrated post-cardiac arrest care for OHCA patients who are transferred from other hospitals after ROSC in the cardiac arrest center.

The Relationship between the Postreturn of Spontaneous Circulation Electrocardiogram and Coronary Angiography Finding in out-of-Hospital Cardiac Arrest Patients

PURPOSE: Coronary artery disease is the most common cause of out-of-hospital cardiac arrest (OHCA). However, there are no definite indications of coronary angiography (CAG) followed by percutaneous coronary intervention (PCI) in patients with OHCA for diagnosis and treatment. The aim of this study was to determine correlation between ECG findings and results of CAG of patients with return of spontaneous circulation after OHCA. METHODS: We collected data from January 2010 until April 2014. CAG was performed in patients with ROSC after OHCA in whom ST-elevation or left bundle branch block (LBBB) was detected on ECG. If ECG showed another rhythm and no obvious non-cardiac cause of cardiac arrest, CAG was performed as an agreement between the emergency physician and cardiologist following by Samsung Medical Center OHCA protocol. RESULTS: CAG was performed in 75 patients among 131 patients who were successfully resuscitated from OHCA. We divided patients into two groups, ST-elevation or LBBB group and other group. Twenty nine patients in the ST-elevation or LBBB group had coronary lesion and nine patients in the other group had coronary lesion on CAG (p<0.01); 15 patients and five patients, respectively, had undergone PCI (p=0.02). CONCLUSION: ECG findings of ST-elevation or LBBB were highly associated with coronary lesions in successfully resuscitated patients from OHCA. However, these ECG findings were not an absolute indication for performing CAG because coronary artery lesions were also observed in patients in the other group.

Impact of Source of Infection on Outcome in Patients with Severe Sepsis and Septic Shock in the Emergency Department

PURPOSE: The purpose of this study was to investigate the effect of common sources of infection on outcome in patients with severe sepsis and septic shock in the emergency department (ED). METHODS: We conducted a retrospective observational study involving adult patients who were diagnosed with severe sepsis or septic shock in the ED of a tertiary care hospital during the period between August 2008 and March 2012. We categorized patients according to four groups based on source of infection (respiratory infection, intra-abdominal infection [IAI], urinary tract infection [UTI], and other sources [OS] group). The primary outcome was inhospital mortality. Multivariable logistic regression analysis was performed for adjustment of potential confounders, including age, gender, serum lactate concentrations, the Sequential Organ Failure Assessment score, timely antibiotic use, and achievements of early resuscitation targets. RESULTS: A total of 758 patients were included and overall in-hospital mortality was 16.6%. Significant differences in mortality were observed between four groups (27.5% for respiratory infection, 12.1% for IAI, 2.6% for UTI, and 20.0% for other sources, p<0.01). In patients with IAI, adjusted odds ratios (ORs) for mortality were 0.49 (95% confidence interval [CI], 0.27-0.92) compared with the OS group and 0.57 (95% CI, 0.35-0.93) compared with non-IAI. For UTI, adjusted ORs were 0.08 (95% CI, 0.02-0.32) compared with the OS group and 0.09 (95% CI, 0.03-0.35) compared with non-UTI. For respiratory infection, adjusted ORs were 1.33 (95% CI, 0.74-2.39) compared with the OS group and 2.56 (95% CI, 1.60-4.10) compared with non-respiratory infection. CONCLUSION: Results of our study showed that source of infection was independently associated with in-hospital mortality in patients with severe sepsis and septic shock in the ED. In particular, UTI and IAI showed significant association with in-hospital survival. Patients with respiratory infection showed significantly higher mortality, compared with non-respiratory infection patients.

Comparison of Wound Healing Process between Burn and Skin Defect in a Porcine Model

PURPOSE: The purpose of this study was to develop porcine full thickness skin wound healing model of thermal burn and skin defect and to compare wound healing process between them. METHODS: Twelve thermal burns and 12 skin defect wounds were created on the back of 3 domestic pigs. A round shaped heated electric iron was contacted for 30 seconds to develop full thickness burn. Appropriate dressings were applied for 30 days after wounding. Full thickness skin biopsies were obtained for histologic analysis by a pathologist. The amount of wound discharge, the surface area of each wound, and wound culture results were compared between skin defect and burn wound. RESULTS: Of 12 burn wound sections, 7 (58%) were identified to full thickness dermal injury. Complete wound reepithelialization was seen between postburn days 21 and 28 in both wounds. The initial wound area was smaller in burn than skin defect (P<0.001, 14.4+/-0.8 cm2 vs 22.8+/-3.4 cm2). The wound area of both burn and skin defect was slightly increased for 9 days after wounding and rapidly decreased after that time. The linear advancement length of wound edge was significantly slower in burn (P=0.009, 1.06+/-0.28 vs 1.48+/-0.42 cm). The amount of wound discharge was greater in skin defect than burn (P=0.002, 35.1+/-8.3 vs 49.5+/-11.2 g). CONCLUSION: We developed a porcine model of both thermal burn and skin defect. Time for complete reepithelialization was similar but the linear advancement length of wound edge was slower in burn than skin defect wound.

Body Mass Index and Outcomes in Patients with Severe Sepsis or Septic Shock / 대한구급학회지

BACKGROUND: The aim of this study was to investigate the association between body mass index (BMI) and survival in patients with severe sepsis or septic shock. METHODS: We analyzed the sepsis registry of patients presenting to the emergency department (ED) of a tertiary urban hospital and meeting the criteria for severe sepsis or septic shock from August 2008 to March 2012. We categorized patients into the underweight group (BMI or = 25 kg/m2). Then, we analyzed the registry to evaluate the relation between obesity and in-hospital mortality. RESULTS: A total of 770 adult patients with severe sepsis and septic shock were analyzed. In-hospital mortality rate of the underweight group (n = 86), the normal weight group (n = 489) and the obese group (n = 195) was 22.1%, 15.3% and 16.4%, respectively. In a multivariate regression analysis, the underweight group had a significant association with in-hospital mortality compared with the normal weight group (odds ratio [OR], 1.12; 95% confidence interval [CI], 0.68-1.87; p = 0.028). The obese group showed no significant difference in mortality (OR, 2.04; 95% CI, 1.08-3.86; p = 0.65). CONCLUSIONS: The underweight patients showed significantly higher mortality than the normal weight patients with severe sepsis and septic shock.

A Study on Attitudes Toward and Knowledge of Cardiopulmonary Resuscitation in Korean High School Students

PURPOSE: The instruction of cardiopulmonary resuscitation (CPR) to students has been advocated in many countries. To formulate an effective policy for high school students in Korea, data on attitudes toward CPR and the levels of knowledge in this technique for this population are needed. METHODS: A thirty-question questionnaire was given to Korean high school juniors to assess their attitudes toward and knowledge level of CPR. Two hundred seventy one of 341 students (79.5%) responded to the questionnaire and their male to female ratio was 1:2.2. RESULTS: Most students (n=262, 96.7%) had heard of CPR, mainly through television (n=193, 71.2%) or a school activity (160, 59.0%). Only 50(18.5%) and 15(5.5%) students responded that they would be willing to provide CPR to a "family or friend" and "stranger", respectively. One hundred twunty four students (45.8%) had received some form of education on CPR, but only 10(3.7%) had received an advanced education (although most were willing to be educated further on CPR). The most common reason for not receiving CPR training was a lack of knowledge for training resources (n=79, 53.7%). Only 88(32.4%) students understood the purpose of an automated external defibrillator. Although half of the students (147, 54.2%) correctly chose the location for CPR chest compression, only 19.2% and 16.6% correctly responded to questions on the appropriate compression speed and depth, respectively. CONCLUSION: Although students receive some exposure on the importance of CPR, their willingness to perform CPR and their knowledge level of AEDs and CPR is not adequate. A systemic approach for educating and training students in CPR is needed.

Effectiveness of a Cardiopulmonary Resuscitation Team with an Emergency Physician for In-Hospital Cardiac Arrest

PURPOSE: Emergency physicians are usually more experienced in emergency situations; therefore, a cardiopulmonary resuscitation team with an emergency physician as a leader would be operated effectively. The aim of this study is to evaluate the effectiveness of a cardiopulmonary resuscitation that includes an emergency physician. METHODS: A retrospective analysis for in-hospital arrests that occurred in the general ward was conducted based on the in-hospital cardiopulmonary resuscitation registry of a tertiary care university hospital in Korea from January 1, 2005 through December 31, 2010. We compared outcomes of cardiopulmonary resuscitation performed by a team that included an emergency physician with those by a cardiopulmonary resuscitation team that included a non-emergency physician. RESULTS: Survival rates at discharge were 29.6% for the emergency physician team and 17.7% for the non-emergency physician team. The good neurologic outcome rates at discharge were 20.6% and 10.6%, respectively. In multivariate analysis with adjustment for pre-arrest patient condition and arrest variables, survival rate did not differ significantly between the two groups. However, the good neurologic outcomes showed an association with the emergency physician team. CONCLUSION: For in-hospital cardiac arrest, outcomes for patients who were rescued by the emergency physician-directing CPR team might be comparable or better, compared with those by the non-emergency physician team.

Evaluating the Accuracy of Emergency Medicine Resident Interpretations of Abdominal CTs in Patients with Non-Traumatic Abdominal Pain

Abdominal computed tomography (CT) is widely used as a diagnostic tool in emergency medicine (EM) to accurately diagnose abdominal pain. EM residents must be able to offer preliminary interpretations of CT imaging. In this study, we evaluated the preliminary interpretation ability of a sample of emergency residents presented with adult abdominal CT images, and compared their results with those of radiology residents. We conducted a prospective observational study from November 16, 2008 to June 30, 2009. During this time, we gathered preliminary interpretations of consecutive abdominal CT made by emergency and radiology residents. We assessed the discrepancy rates of both samples by comparing their findings to the final reports from attending radiologists. A total of 884 cases were enrolled in the present study. The discrepancy rates of emergency and radiology residents were 16.7% and 12.2%, respectively. When female genital organs, peritoneum, adrenal glands, or the musculoskeletal system were abnormal, we found that emergency residents' preliminary interpretations of CT images were insufficient compared to those of radiology residents. Therefore more formal education is needed to emergency residents. If possible, the preliminary interpretations of radiology attending physicians are ideal until improving the ability of interpretations of emergency residents in abdomen CT.

Improving Survival Rate of Patients with In-Hospital Cardiac Arrest: Five Years of Experience in a Single Center in Korea

The aim of this study was to describe the cause of the recent improvement in the outcomes of patients who experienced in-hospital cardiac arrest. We retrospectively analyzed the in-hospital arrest registry of a tertiary care university hospital in Korea between 2005 and 2009. Major changes to the in-hospital resuscitation policies occurred during the study period, which included the requirement of extensive education of basic life support and advanced cardiac life support, the reformation of cardiopulmonary resuscitation (CPR) team with trained physicians, and the activation of a medical emergency team. A total of 958 patients with in-hospital cardiac arrest were enrolled. A significant annual trend in in-hospital survival improvement (odds ratio = 0.77, 95% confidence interval 0.65-0.90) was observed in a multivariate model. The adjusted trend analysis of the return of spontaneous circulation, six-month survival, and survival with minimal neurologic impairment upon discharge and six-months afterward revealed similar results to the original analysis. These trends in outcome improvement throughout the study were apparent in non-ICU (Intensive Care Unit) areas. We report that the in-hospital survival of cardiac arrest patients gradually improved. Multidisciplinary hospital-based efforts that reinforce the Chain of Survival concept may have contributed to this improvement.

Effect of Hydrogel Pad and Conventional Method on the Induction Time of Therapeutic Hypothermia in Patients with Out-of-Hospital Cardiac Arrest / 대한구급학회지

BACKGROUND: Therapeutic hypothermia has been recommended as a standard treatment of cardiac arrest patients after return of spontaneous circulation. There are various methods to drop patient's core body temperature below 33.5degrees C. We compared the cooling rate of the conventional cooling method using cold saline bladder irrigation with the commercial hydrogel pad in out-of-hospital cardiac arrest (OHCA) patients. METHODS: We collected data retrospectively from the Samsung Medical Center hypothermia database. The conventional method group was cooled with IV infusion of 2,000 ml of 4degrees C cold saline and cold saline bladder irrigation. Patients in the hydrogel pad group had their body temperature lowered with the Artic Sun(R) after receiving 2,000 ml of 4degrees C cold saline intravenously. The induction time was defined as time from cold saline infusion to the esophageal core temperature below 33.5degrees C. The esophageal temperature probe insertion to the target temperature time (ET to target BT time) was defined as the time from the esophageal probe insertion to the core temperature below 33.5degrees C. We compared these times and cooling rates between the two groups. RESULTS: Eighty one patients were enrolled. Fifty seven patients were included in the hydrogel pad group and 24 patients were in the conventional group. There were no statistical differences of baseline characteristics between the two groups. The induction time of the conventional group (138 min., IQR 98-295) was shorter than that of the hydrogel pad group (190 min., IQR 140-250). The ET to target BT time of the conventional group (106 min., IQR 68-249) was shorter than that of the hydrogel pad group (163 min., IQR 108-222). The cooling rate of the conventional group (0.93degrees C/hr., IQR 0.58-2.08) was lower than that of the hydrogel pad group (1.05degrees C/hr., IQR 0.74-1.96). However, there were no statistical differences in the induction time, the ET to target BT time and the cooling rate between the two groups. CONCLUSIONS: There was no significant statistical difference of the cooling rate of the hydrogel pad and conventional method on the induction time of therapeutic hypothermia in Patients with OHCA. The conventional cooling method can be used as an effective and efficient way to lower OHCA patient's core body temperature during the induction phase of therapeutic hypothermia.